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Tropical Storm Chris; August hurricane outlook, part II

By: Dr. Jeff Masters, 11:37 AM GMT on August 01, 2006

It's August in the tropics, the first of the peak months of hurricane season. Befitting the arrival of August comes the arrival of Tropical Storm Chris, which formed this morning just east of the Leeward Islands. The formation of Chris came in defiance of significant adversity--wind shear was 20-25 knots last night when the storm formed into a tropical depression, and is still a rather hefty 15-20 knots. Considerable dry air lies to Chris' north, and strong upper-level winds from the north are acting to push this dry air into Chris' core, keeping the storm from intensifying much. Radar out of Martinique shows a decent band of thunderstorm to the storm's southeast and east, but no thunderstorm activity on the northwest side where shear and dry air are impacting the storm. We don't have a recent QuikSCAT pass to gauge the winds, but two passes by a satellite equipped with a microwave sensor came up with an estimate of 40 mph surface winds. The Hurricane Hunters are scheduled to visit at 2pm EDT this afternoon, so we'll know more then.

This shear and dry air will continue to affect Chris over the next two days. The shear is forecast to gradually weaken, which may allow some slow intensification. Chris must tightrope walk a very narrow path between two upper-level cold lows in order to strengthen significantly. One of these cold lows is just north of the Bahamas, and the other is northeast of Chris. These lows are forecast to move slowly west-northwest in tandem with Chris, and if Chris can stay exactly between them, low enough wind shear exists to potentially allow some strengthening. Any deviation from this scenario will put Chris under hostile wind shear, which will act to limit intensification or even dissipate the storm.

Last night's computer model runs did not start out with a very good initial picture of the current strength of Chris, and dissipated the storm within 72 hours. We need to wait until the next set of model runs based on this morning's 8am EDT (12Z) data are available before taking much stock in both the track and intensity forecasts of the models. The NOAA jet is scheduled to fly the storm tonight, so the best model data for Chris will be available Wednesday morning.

Chris will bring heavy rains and high winds to the Leeward Islands today, primarily to those islands lying to the south of the storm's center, where dry and and wind shear are less of a problem. Puerto Rico should get a good soaking on Wednesday, and after that, the prognosis is very uncertain. Chris could become a hurricane late in the week, but I put the chances of this at 10%. Dissipation is a more likely scenario, since there is so much wind shear around. The most likely scenario of all is that Chris will remain a tropical storm over the next five days.

August hurricane outlook
As we've seen repeatedly, sea surface temperatures are important for hurricane formation and intensification, but nothing happens unless the wind shear is low. When we look at wind shear, the standard measure is the wind at the upper atmosphere (200 mb, usually around 40,000 feet in altitude) minus the wind just above the surface (850 mb, or about 5,000 feet altitude). This difference in wind speed is plotted in Figure 1 for July 2006. The key feature to look at is the anomalies in the bottom portion of the plot. The entire tropical Atlantic was under higher than normal wind shear during July, with wind shear up to 6-8 meters per second over the Caribbean (12-16 knots). The only region that experienced below normal wind shear was off the coast of North Carolina. Not coincidentally, this is where July's only named storm formed (Beryl).


Figure 1. Observed wind shear for July 2006. The top portion shows the difference in wind between 200 mb and 850 mb pressure levels, and the bottom image shows the departure from normal.Image credit: NOAA's Climate Prediction Center.

What, then can we expect for wind shear in August? The long range shear forecast from NOAA (Figure 2) shows near normal wind shear over the Atlantic for the remainder of hurricane season. The latest 2-week outlook from the GFS model agrees, calling for near normal wind shear during the first half of August. Since wind shear is expected to be near normal, and SSTs should be near normal, we should expect a near normal level of hurricane activity for August. "Normal" should be placed in context with the above-normal level of hurricane activity we've been seeing since 1995. In the ten years since 1995, not including the El Nino year of 1997, the Atlantic has averaged 4.4 named storms, 2 hurricanes, and one intense hurricane in August. My prediction for August follows a similar line: 4-5 named storms, two hurricanes, and one intense hurricane. All this assumes that El Nino doesn't rear its head; the recent warming of ocean waters in the Equatorial Pacific along the coast of South America could be the prelude to an El Nino event. These events create atmospheric circulation patterns that greatly increase the wind shear over the Atlantic, significantly cutting down on hurricane activity. However, the El Nino forecast models are predicting a continuation of the current neutral El Nino condition through August and September, and it is uncommon to have an El Nino event begin at this time of year. I doubt El Nino will be a factor in this year's hurricane season.


Figure 2. Forecast wind shear July August through October 2006. Image credit: NOAA's Climate Prediction Center.

What will be the steering pattern for August?
For much of June and July, the jet stream made a dip over the eastern U.S., creating a persistent trough of low pressure. In concert with the jet stream, the Bermuda High has stayed further east than it did in 2005. The resulting steering pattern has been taking tropical waves through the Bahamas, then north along the East Coast and out to sea. Tropical Storm Beryl took this path as well. The long range forecast from NOAA's Climate Prediction Center calls for not as strong a trough of low pressure for the remainder of hurricane season. Instead, we should expect a near normal steering pattern, with all regions of the Atlantic under their usual risk of hurricane strikes. However, the latest 2-week GFS model forecast is calling for a continuation of the June and July steering pattern, but with a somewhat weaker trough over the Eastern U.S. Thus, I am forecasting that the entire East Coast of the U.S. will have a higher than average risk of hurricane strikes in August, and the Gulf Coast will have a lower than average risk. The highest risk area of the East Coast will probably be North Carolina and South Carolina. As far as the actual percentage risks, I'll leave that up to Dr. Bill Gray's forecast team at Colorado State, who will be putting out their updated Atlantic hurricane season forecast on Thursday, August 3.

Jeff Masters

The views of the author are his/her own and do not necessarily represent the position of The Weather Company or its parent, IBM.

Reader Comments

What do the water temps look like for the area?
are u sure that is for chris??? It says beryl on top ??? I will show it here :
000
URNT12 KNHC 210851
VORTEX DATA MESSAGE
A. 21/08:35:10Z
B. 41 deg 40 min N
069 deg 42 min W
C. 850 mb 1400 m
D. NA kt
E. NA deg nm
F. 147 deg 050 kt
G. 053 deg 043 nm
H. 1001 mb
I. 12 C/ 1760 m
J. 16 C/ 1768 m
K. 15 C/ NA
L. NA
M. NA
N. 1345 / 8
O. 0.02 / 4 nm
P. AF300 0602A BERYL OB 16
MAX FL WIND 67 KT SE QUAD 07:02:30 Z
MAX FL TEMP 17 C 207 / 6 NM FROM FL CNTR


Yea i think this is for beryl

1005. katytex
I tend to agree with tornado7. Once the ULL backs away, the high should strengthen over the western atlantic. Also, it looks like there is a trough coming into the East coast later this week. Once that pulls out, the high builds in.

Feel free to correct me if I am wrong, I am far from an expert.
there will be a high pressure that sits in and will push it west once it gets close to fl and then will turn north once it gets close to la
1007. will40
Posted By: LRandyB at 1:49 PM CDT on August 01, 2006.
I lied.. sorry.. that was an old one
What are the chances of it hitting FL panhandle/AL?? You can send me a message so as to not use up all the space here.
hmmmm aron took a way overe 100 commet the # is back down to 805post
Hey JP.. goin back to work bro. does it look like chris will get into gulf? or turn n go up east coast??
2:15pm EDT - Convection starting to fire over the center, that might be causing the increase in winds....

if that high sits there its only about a 20% chance of it hiting al or the fl panhandle
Well, the gulf has LOTS of potential energy for any storm this year. If Chris does enter the gulf and decide to check out LA, it could be another devastating blow to the state.
The worst case scenario is if it strenthens considerably, up to Cat 2 or higher, and hits close to where Katrina hit. That could potentialy reflood much of devastated N.O, luckily there arent as much people there this time around.
During reconnaissance of tropical system CHRIS a maximum sustained wind speed of 53 mph at 974 feet, and a maximum wind gust of 54 mph at 974 feet, were found by the government plane.
1022. nash28
LOL Gulf!!!!!
jphurricane2006...You're just wasting your time with these people. Forget it.
thanks JP!! the track now looks scary for southeast Fla. who knows where it will go after 5 days?
Chris has at least 45 mph winds
1028. Melagoo
This could be a very significant storm! Cat 5 in the Gulf and I think Tornado7 may be right LA is f@#*! again. Up here in Southern Ontario we are getting extremely hot weather (120+ humidex) from the jet stream sucking everything up from the south and as the Storm approaches it will follow the path that doesn't seem to be changing any time soon.
1030. PCNole
tornado7: 20% is still fairly high odds. Is there a chance that the H could be farther east and pull it north sooner?
LRandyB~
We'll forgive ya!

Tue Aug 01 2006
1844 GMT
Latitude 17.4 N
Longitude 60.7 W
No turbulence
Currently flying in and out of clouds
Flight altitude 984 feet (300 meters)
Flight level winds 230 degrees at 38 knots (43 mph)
Temperature 23 C Dewpoint 23 C
Surface Pressure 1011 millibars
Surface winds 240 at 45 knots (51 mph)
Remarks: AF303 0103A CHRIS OB 09
(these are credit to WU)

Is it fun flying this low or what?

53 knots FL (42.4 knots at the surface)
Look Guys, many want to see a hurricane but if Chris makes it to the gulf, BIG TROUBLE...SST are HOT and wind shear is LOW....

So Lets Just pray Chris is a fish storm....how much more can Florida and the Gulf Coast take....



I am starting to get worried....... i see the potential for a Cat 2 in the bahamas around friday
looks to me the COC is now under the heavy convection near the center..... we could have a hurricane by 11pm....... if the current trends hold up..... and i see nothing to change them in the next 12-24 hrs..... cat1 is definately within reach! ;)
Thanks GulfScotsman. We dont sleep well in these FEMA trailer anyway so we will be watching closely thru the coming week.
1038. KRL
Got to keep in mind wind speeds can vary dramatically when you are hit straight on with one of these storms. I found that out last year.

The recorded publicized speed may say 50, 60 or whatever, but these frickin gusts can zoom way past the figures forecasters are talking about and really get intense.

Lesson being never go by just the numbers you see posted by all the major forecasts and assume a wide latitude of speed variance in both directions.
I heart u guys
tornado7, your forecast is reasonable. All I would add is that where the western edge of the ridge ends up is always up for grabs this far out. This does seems to be a fairly straightforward forecast in general. The hardest part will be the next few days and intensity.
I don't think chris will be all that signifigant in the Gulf... the ull will move there and prevent to much development.... but I definitly could see a cat 1 or cat.2 in the gulf...but it is still way to early to say
there is a chance it might but i dont think so there is nothing to push it out because the cold front will stay north thats all that will push it out
1043. rxse7en
Mid-level shear looks pretty mild for the immediate area around Chris. http://cimss.ssec.wisc.edu/tropic/real-time/atlantic/winds/wg8midshr.html

How's that ULL looking?

B
1045. 900MB
So looks like 45-50mph at the surface. This is pretty strong for something that is not terribly organized yet. If it gets better organized, it could become terribly strong. New few hours should be interesting. Looks like it could become an east coast threat...looking a little further North than dated models.
i am wrong.... a cat 2 is signifigant.... the gulf doesn't even need a tropical storm at this point.... but lets worry about puerto rico, antilles, bahamas and florida first
1047. Ldog74
I agree with 456, go out in a boat into the gulf and see what he means. Remember Dennis once it got off Cuba was a category 1 Hurricane, not really expected to strengthen that much, and guess what happened.
2:45pm EDT - Tropical Storm Chris is begining to tighten up convection near the center....
Chris is reorganizing again.......

Webcam from Antigua

Webcam from Saint Maarten
Webcam from Guadeloupe

Wind Shear Map
Dust Map


Pressure down to 1008mbar according to the NRL site.....

1049. 900MB
P.S....Off Topic, 98 degrees and counting here in the Big (Baked) Apple. Heat index 110 and counting, tomorrow will be worse. Good bet sea surface temps will be pretty toasty by the end of the week and they are already high up in these parts...I'm going for an iced tea...
The LCC is still on the north side of the convections. Lets don't declare this superstorm yet. It still as a LONG way to go to even be a hurricane. That being said it is looking better.
I still think my forecasting contest was agreat idea, just for these moments.
i got to go i will be back later
has the recon made it to the center yet?
1053. 900MB
I'll bet Dr. Jeff is writing up a blog update as we speak..
1054. nash28
I am sure Dr. Masters will update if there is a borderline hurricane come the 11pm adv.
FLweather , Yes, but i haven't seen the vortex report yet.
1056. katytex
I agree that there is a lot of ground to cover before this storm even thinks of making it to the gulf coast, but it is obvious that this isn't your standard recurve out to sea. I think that it is better that people are concerned and aware as opposed to the opposite.
Any update from the Lessers? They look to be in the firing line currently. Crossing fingers and toes hoping for dissapation here in Louisiana.
1059. Melagoo
I think Chris will be like Andrew in 92.
Jack, not really true, the worst case for New Orleans is a hit about 30 miles west where Katrina hit, which would put New Orleans on the east side of the storm, and bring much stronger winds to the city. Such a storm, even a slow moving category 3, would blow down almost half, or 100,000 of the 200,000 housing units that were flooded by Katrina, and probably reflood the city from breaches in the western side of the Industrial Canal (the Eastern side has been repaired by the ACof Engineers.) A strike a little farther to the west near Morgan City will flood the West Bank with its 700,000 people. This is from Von Heernden who is the expert at LSU......
1062. Ldog74
Well thats comforting Melagoo
Melagoo: I think Chris will be like Andrew in 92.

That's quite a claim there.
We havnt rain here in Saint Kitts since early this morning...It has been pretty hot for most of the day. Its a general calm mood here........
Well recon was interesting...just not real exciting. Maybe an increase to 45mph at 5pm advisory. Probably be about it.
URNT12 KNHC 011910
VORTEX DATA MESSAGE
A. 01/18:50:50Z
B. 17 deg 39 min N
060 deg 43 min W
C. NA mb NA m
D. 55 kt
E. 128 deg 010 nm
F. 179 deg 053 kt
G. 128 deg 010 nm
H. EXTRAP 1007 mb
I. 23 C/ 298 m
J. 25 C/ 301 m
K. 25 C/ NA
L. NA
M. NA
N. 12345/ 1
O. 0.02 / 2 nm
P. AF303 0103A CHRIS OB 10
MAX FL WIND 53 KT SE QUAD 18:47:40 Z
SLP EXTRAP FROM 1500 FT
1067. Patrap
...Corps of Engineers briefing this afternoon on progress & status of !7th St. Canal Floodgate., here in Orleans parish...timings everything..
jphurricane2006, Thank you, yap this confirms a 50 storm.
1070. Melagoo
I have that feeling - sorry :c(
so can tany one tell me what the winds are like now if there 53kts winds in mph is that arond 50mph?
i personally don't think it will hit new orleans...it will probably hit Texas... but i am not sure yet
1073. katytex
jphurricane, I agree with you, but considering some of the posts on this site I don't think I am too far off the subject.
A. 01/18:50:50Z
B. 17 deg 39 min N
060 deg 43 min W
C. NA mb NA m
D. 55 kt
E. 128 deg 010 nm
F. 179 deg 053 kt
G. 128 deg 010 nm
H. EXTRAP 1007 mb
I. 23 C/ 298 m
J. 25 C/ 301 m
K. 25 C/ NA
L. NA
M. NA
N. 12345/ 1
O. 0.02 / 2 nm
P. AF303 0103A CHRIS OB 10
MAX FL WIND 53 KT SE QUAD 18:47:40 Z
SLP EXTRAP FROM 1500 FT
I just saw your map a moment ago ...St Kitts is like this little tiny piece of property in the middle of the Atlantic. That storm could cover it up. Man...I bet it is paradise most of the time, but today, not so much. Hang in there...hate to see you guys get battered...then again, I am REALLY jealous that someone can make a living in a place that wonderful... Really though...hang in there - hopefully it will die down and just give you more rain.

53 knots = 60 mph...but at the surface it is around 50 mph
1078. nash28
Anyone notice there has been a bias from all of the major models that want to take Chris right over Hispanola and through the mountains which would weaken it? Even the latest 12z GFDL brings Chris's top wind speed to 91kts but then has it taking a nose dive both in strength and direction right into land mass. I am really not buying this solution as Chris will most likely remain north of the mountains and stay over water. Thoughts?
In the middle of a core flare up...
I'm glad that I scheduled our cruise to PR and the VI for November.

I just looked at the newest frame, the convection is really firing up now. As it gets closer to evening I think this things going to explode. I would wager it is a Cat1 by 5AM.
1081. Patrap
..thanxz the weather Gods that he was in Katrinas western eyewall.1 click west of Bucktown...
D. 55 kt is equivalent to 65 mph winds at the surface. Chris is damn near a hurricane.
wow ..so it is 50 mph..... i think it will have at least 65 mph by 11 pm advisory
is that vortex report at the surface????? No right??
Melagoo- what makes you think this will be like Andrew?
Hmmm, rapidintensify, funny your chiming in after yesterdays comments...I'd still have my head in the sand.
1088. katytex
Fair enough. Now lets talk about the next 12 hours. I don't see this ramping up to hurricane status that quick, but I do see a much stronger TS. How about you?
JP,here

1091. nash28
Yeah JP, I do chuckle when the LBAR has a higher batting average with this one thus far. I'm sure once the new data from the recon is plugged into the 18z runs, then maybe (we can hope) the models will get their collective acts together.
1092. Zaphod
It seems to me that the most significant issue that Chris will face is land interaction. While larger storms can cruise over Cuba without too much impact, a smaller storm like Chris will likely be impacted by each island. The current storm tracks have it approaching or hitting all the major islands -- Puerto Rico, Haiti, Cuba -- in a row.

I may be missing something major, but I don't see any reason for it to head north anytime soon. I think it will make it to the gulf, but I am not convinced it will be more than a strong TS or maybe Cat 1 in the next couple of days. I do not think it will dissipate, though.

But we will know soon enough......
Zap
Here we go again south florida....
hey well with these storms history usually tells us alot, look at hurricane debby from 2000, same path, same origin point and same point in the year and debby dove down into eastern tip of cuba when projected to go to south florida...jus a thought
1098. Fshhead
well, I guess the nervousness is starting for us Floridians, especially when we keep seeing the computer models pointing at us
When a storm - even the size of Chris - hits those islands, what happens, do you ever worry about surge to the point of putting you COMPLETELY under water. Do they try to evacuate the islands or just make you "hunker down". I would guess about right now would be the time to make those decisions.
If it doesn't hit puerto rico and dr/haiti .... then i think this will become a cat 2.... but it isn't supposed to go over these islands
A band of showers is begining to come throught, the sky is starting to look rainy....from the NE......
tampabayfish...your right, I was dead wrong yesterday, I've seen so many blobs this year I did not think any of them would develop. I won't quit my day job.

jp...isn't D. the strongest wind recorded at the surface?
Any new thoughts, please, on the safety of the US Virgin Islanders and residents of Puerto Rico given the latest info about winds, pressure, etc.? The "could have a hurricane by 11 pm" thought is a pretty disturbing bit of news for those of us who are only a few hundred miles ahead of the storm.
1104. nash28
Ok guys. Gonna head home from St. Pete now. Be back on in a bit.
1106. CaneKid
re: Nash28 - I also don't understand why almost all dynamical models are taking it 270/10 or even 250/10 after 72h but the official track is staying 285? It seems the expectation is for Chris to stay between the two lows. I do think that if it strengthens as quickly as it seems to be trying to - it'll hop north and begin getting sheared by the cold low. Comments?
Guys right now we have 53kts in the SE Quad and 1007 mbs.
I think Chris will become a much larger storm
1109. Melagoo
The conditions are near perfect for a significant storm - warm to hot water - jet stream holding back any front that could cause shearing
Crucian - I would prepare for the worst like Gulf said people along the panhandle do. Either way, you guys are going to get SOMETHING from this storm. Least of which I suppose is flooding and wind, worst of which ... we won't even think it.
I thought D was the maximum estimated winds at surface in kts
D. ESTIMATE OF MAXIMUM SURFACE WIND OBSERVED IN KNOTS. 65 kt means the highest estimated surface wind is 65 knots on this particular inbound leg. The flight meteorologist looks at the sea surface and can estimate how strong the winds are by what the sea looks like. At particular wind speeds, the sea begins to form white caps, then patches of foam, then some of the foam patches begin to appear green, etc. The key word here is "observed"; the meteorologist may not see the highest surface winds because of darkness, heavy rain or clouds, so often this number is lower than the maximum flight level wind. A "knot" is a nautical mile (nm) per hour. To convert to miles per hour, use 1.15 miles/nm; 65 nm/hr x 1.15 mi/nm = 75 miles per hour. To convert to meters per second, cut knots in half: 65 kt = 33 m/s. If not observed at all, this block is reported as NA (Not Applicable).
LOL no panic here (not let anyway). Just a deep gutted fear of deva vue. Thanks again for the useful posts. Stay safe everyone.
1114. Patrap
..sees Chris running parellel along the center of the forecast track in time..after that looks problamatic out 5 days.
THE ULL WILL MOVE TO THE WEST INTO THE GULF!!!!!!!!!!!!!!!!!!!!!!!!!!1
1116. Zaphod
BAMM has it just north of the islands. The track seems to be just N of the models, so maybe all will adjust northward.

If so, the chance of greater intensity is greater. Of course, the bigger it gets the more island interaction it will have tomorrow.

Seems like S. Florida and the keys should be heads-up soon.
Zap
hey jp hurricnae23 or weather456 dos this thing trying to get a eye yet


start watching the eye now day they are comeing more and more now that i noted the pin hole eye so if this thing gets a eye soon start looking out for that
This is a new update with Recon data included!





Click the image to go to hurricane warning.


Chris is strengthening. I have made a complete update on hurricane warning including all the latest data up to 7:45 AM EST aboout 99L. This includes, satellite, computer model, SAL, wind shear, and SST data. It is all wrapped into a very informative analysis of 99L. Feel free to discuss 99L on my blog.
3:15pm EDT- In just 15 minutes a massive out burst of convection near the center. Chris becoming stronger....

1120. Zaphod
JP,
Thanks. Just figured that out myself too!
Zap
AccuWeather reporting that the Hurricane Hunters found:

Maximum Sustained Wind: 50mph
Minimum Central Pressure: 1007mb
Current Position: 65 miles ENE of Antigua, Leeward Islands
Current Movement: NW @ 10mph
listen i dun kno cuz i have not been there but these islands go through more tropical disturbances or storms then we can ever imagine and i garuntee u that they are not overly worried about chris...a tropical storm is basically a severe storm that lasts for a few hours...now the potential is high for chris down the line but right now it is a 40 to 50 mph tropical storm...and take it only a small portion of these islands will actually receive these winds and the surge will only be a few feet above normal
Here is the definition of D from the NHC decoder ring:
D. ESTIMATE OF MAXIMUM SURFACE WIND OBSERVED IN KNOTS. 65 kt means the highest estimated surface wind is 65 knots on this particular inbound leg. The flight meteorologist looks at the sea surface and can estimate how strong the winds are by what the sea looks like. At particular wind speeds, the sea begins to form white caps, then patches of foam, then some of the foam patches begin to appear green, etc. The key word here is "observed"; the meteorologist may not see the highest surface winds because of darkness, heavy rain or clouds, so often this number is lower than the maximum flight level wind. A "knot" is a nautical mile (nm) per hour. To convert to miles per hour, use 1.15 miles/nm; 65 nm/hr x 1.15 mi/nm = 75 miles per hour. To convert to meters per second, cut knots in half: 65 kt = 33 m/s. If not observed at all, this block is reported as NA (Not Applicable).
I won't guess whether it will get weaker or stronger because this is one that has gone through some pretty rough stuff for development and it has still developed this far along. Just keep your eyes on it and be prepared for anything...Too early to tell where this storm will be beyond the next three days....still have a long way to go until November 30th...oh how I dread this time of the year. Andrew buzzed through 6 months after I had bought my house, Wilma allowed me to see the milky way for the first time from my front yard 2 months after I had just got my new roof put on.
CrucianCrip....Chris is still fairly shallow. Tops have started to cool off a bit in the SW quad a bit. Still not as cold as this AM. All NHC forecasts and track are the best and "official" information there is right now.
Posted By: hurricane23 at 12:31 PM PDT on August 01, 2006.
Guys right now we have 53kts in the SE Quad and 1007 mbs

what dos 53kts winds mean in mph? 55mph or 60 mph some in like that?
1127. JimJax
Where does one find the latest computer models for Chris??
Yea 456 iam seeing that convection continue to flare very close to the center or if not right over it.Getting better organized this afternoon.
Chris is definitely looking much better. The center has been completely covered by the exploding thunderstorms. Very interesting to see what happens this evening. People in puerto rico need to pay close attention to CHRIS!
I just saw a cool cumulonimbus cloud out on the ocean in a NE direction, perfect anvil shape, and I have no camera to take it with......bummer...
1131. Astinus
I noticed some people having some troubles converting Knots to MPH. Here's a trick for some of you who enjoy doing little mental math tricks.

For this example, I'll use 50 knots.

1) Move the decimal point one spot left. (50 becoems 5.0 - or just 5)
2) Add half of that to the number (5 + 2.5 = 7.5)
3) Add that number to the original (50 + 7.5 = 57.5)

For those who are quick about doing basic math in their head, this could be a lot quicker than even pulling out a calculator and typing x1.15.

When reading it, it may seem like a bit more work, but when put into practice it's quite easy.
surface winds are 65mph and will be for the next advisory unless the hunters find a greater wind before 5:00.
53 knots at flight level is, using .75, 39.75 knots, using .8 it is 42.4 knots...
jphurricane2006, could chris become a hurricane before tomorow?????
1136. Zaphod
JP,
So the exact timing of the ULL moving out and a high building in will thereby determine whether it hits Cuba or the straits of FL?
Zap
55 kt surface winds (see D. in vortex message) = 63.25 mph which is rounded to 65 mph.
Pascagoula, I think its just the reality of the start of the real hurricane season....
1139. Dan187
is the plane still out there?
Guys this is guess right now...But i think the NHC will go with a 50mph TS at 5:00 advisory.
Posted By: rapidintensify at 12:38 PM PDT on August 01, 2006.
surface winds are 65mph and will be for the next advisory unless the hunters find a greater wind before 5:00.


wow thanks 65 mph wow this went from a 40mph to a 65mph i think where going to see more then this a TS could i be right rapidintensify?
rapidintensity - do you suppose the vortex message has a typo? How could there be estimated 65 kt at surface with 53 actual at flight level?
hurricane23...They might only go to 45mph. They won't get too excited about this yet.
I think Chris is anywhere from 45-55 mph right now and strengthening pretty steadily. Convection cloud tops continue to cool around the COC and covection is becoming almost completely around the LLC, if not already completely. It is, in fact, definetely possible that Chris becomes a hurricane in less than 48 hours, and the AccuWeather Hurricane team of meteorologists agree w/ this possibility. In my opinion, there will be a minimum of 12 hours before Chris can reach hurricane strength, because it is still developing & re-organizing.
oops *rapidintensify and 55 kts at sfc
45-50 mph on advisory.
1148. SLU
THIS SYSTEM IS STRENGTHENING RAPIDLY NOW. THE RADAR SHOWS THAT AN INCOMPLETE EYEWALL-LIKE STRUCTURE IS TRYING TO FORM ABOUT 50 MILES EAST OF BARBUDA. SO IT MUST BE A PRETTY STRONG TROPICAL STORM....OF AT LEAST 50MPH
1149. Finnmet
Yes,I say this from 3 or 4 days.We will have a 90 or 100 knots storm and this is what right now it's happening.Who stay in Bahamas and S.Florida really...attention this will be a bad one.Not an Andrew,but close.
Randrewl... I think They will upgrade it to 50mph, then if it's still looking good or stronger, they will go up to 55 or 60. NHC doesn't do huge jumps unless there's indisputable data (like when Rita jumped 105 to 175 in 3 hours...)
This is a new update with Recon data included!





Click the image to go to hurricane warning.


Chris is strengthening. I have made a complete update on hurricane warning including all the latest data up to 7:45 AM EST aboout 99L. This includes, satellite, computer model, SAL, wind shear, and SST data. It is all wrapped into a very informative analysis of 99L. Feel free to discuss 99L on my blog.
eye wall? where you get that from

wow i was right this thing is a BOOM!
1153. IKE
I'm not sure if anyone posted this earlier...this from this afternoons Miami discussion...Discussion...main weather feature dictating the weather conditions
across South Florida will be...no, is not T.S. Chris...it will be
the upper low located near 25n 71w. This low is finally showing a
westward movement advertised by GFS. This low will be in the
vicinity of the northern Bahamas by Wednesday and over South
Florida by Thursday.
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MIAMI FL
244 PM EDT TUE AUG 1 2006


.DISCUSSION...MAIN WEATHER FEATURE DICTATING THE WX CONDITIONS
ACROSS SOUTH FLORIDA WILL BE...NO, IS NOT T.S. CHRIS...IT WILL BE
THE UPPER LOW LOCATED NEAR 25N 71W. THIS LOW IS FINALLY SHOWING A
WESTWARD MOVEMENT ADVERTISED BY GFS. THIS LOW WILL BE IN THE
VICINITY OF THE NORTHERN BAHAMAS BY WEDNESDAY AND OVER SOUTH
FLORIDA BY THURSDAY.
BEYOND, SATURDAY, THE FORECAST GETS MORE COMPLICATED. STILL LOTS
OF UNCERTAINTIES ASSOCIATED WITH FUTURE TRACK OF T.S. CHRIS. CHRIS
CURRENTLY JUST EAST OF ANTIGUA AND BARBUDA AND MOVING WEST-
NORTHWEST AT 10 MPH. CURRENTLY UNDERGOING NORTHERLY SHEAR AS
SUGGESTED BY SATELLITE IMAGES WITH MOST OF THE DEEP CONVECTION
SOUTH OF THE CENTER. ALMOST ALL THE MODELS MOVE THE SYSTEM WEST-
NORTHWEST AND KILL IT OVER THE CENTRAL BAHAMAS BY FRIDAY MORNING
KEEPING JUST AN OPEN WAVE AFTERWARDS. THE OFFICIAL FORECAST,
THOUGH, BRINGS THE CENTER TO JUST SOUTH OF ANDROS ISLAND BY SUNDAY
MORNING SLIGHTLY WEAKER THAN THE PREVIOUS FORECAST. GIVING THE
UNCERTAINTIES ASSOCIATED WITH THIS SYSTEM AND THE FACT THAT THE
GUIDANCE DO NOT LIKE THIS SYSTEM, WILL KEEP THE EXTENDED PORTION
OF THE FORECAST BASICALLY UNCHANGED AND CLOSER TO CLIMATOLOGICAL
VALUES. FURTHER MODEL RUNS MAY GIVE US A BETTER TREND IN THE
So here we are at 24hrs to hurricane when most were putting the odds at 10percent, even Dr Masters had it very low a few days ago, got to give Turtle in posting a warning very early on.
ok just checking in ( i am at work) whats the forcast for pr


there are some who still seem to think the center is "exposed"...... negative....

we have a strengthening TS, and the COC is underneath some very high cloud tops....
I do believe at this track and w/ no interferences (which may possibly occur), Chris has a chance of becoming our first major hurricane this season or close after 72 hours. FLORIDA PREPARE - it's always better to have preparations made and have nothing happen then to not prepare and to have a large hurricane hit.
based on geostationary satellite imagery...the overall organization
of the tropical cyclone has changed little over the past several
hours. Radar imagery from Guadeloupe show some fairly well-defined
spiral rain bands. Dvorak intensity estimates from
TAFB...SAB...and AFWA are 35 kt...35 kt...and 25 kt respectively.
Since there is no evidence of strengthening...the advisory
intensity remains at 35 kt. Chris is in a rather anticyclonic
lower-tropospheric environment as evidenced by high sea level
pressures over the islands of the northeastern Caribbean Sea. In
fact...the 850 mb environmental vorticity is a significant negative
predictor in the 12z SHIPS model intensity forecast for Chris.
Northerly shear is currently impacting the system and this is
inhibiting upper-level outflow over the northwest quadrant. As
noted in the previous discussion...Chris could become favorably
situated in a col region between two upper-level lows over the next
several days. This might lead to a low-shear environment that
would be favorable for strengthening. The official forecast is
very similar to the current SHIPS model output and is above the
intensity forecast consensus...icon. It should noted that the
GFS...U.K. Met...NOGAPS...and ECMWF global models essentially
dissipate Chris within 5 days.
Even with high-resolution visible images...the center is not
well-defined. However the advisory location is in reasonable
agreement with the Guadeloupe radar observations. Initial motion
is estimated at 295/9. Chris is currently situated to the south of
a mid-tropospheric high pressure area. A weakness in the
subtropical ridge...associated with a well-defined upper-level
low...is now in the vicinity of 70w longitude. This weakness is
forecast to shift westward while a ridge is maintained to the north
of Chris. This steering regime should maintain the
west-northwestward track for the next few days. The official track
forecast is very similar to the previous one...and a little to the
north of the dynamical consensus.
Air Force recon are scheduled to make an 1800 UTC fix on Chris. We
expect the aircraft data to provide US with a better handle on the
location...strength...and structure of the tropical cyclone later
today.

Forecast positions and Max winds

initial 01/1500z 17.3n 60.3w 35 kt
12hr VT 02/0000z 17.9n 61.9w 40 kt
24hr VT 02/1200z 18.8n 64.1w 45 kt
36hr VT 03/0000z 19.7n 66.3w 50 kt
48hr VT 03/1200z 20.4n 68.4w 50 kt
72hr VT 04/1200z 21.7n 72.0w 50 kt
96hr VT 05/1200z 23.0n 75.5w 50 kt
120hr VT 06/1200z 24.0n 78.5w 50 kt

Thanks, saddlegait. Our supplies and generator have been primed since late May, and the shutters are going up tonight (when the sun goes down).

miamihurricane12: Please remember that most Virgin Islanders weren't at all worried about Hugo until the storm was almost upon them. That was the cat 5 that wiped the island of St. Croix flat in 89. Folks are more cautious now, especially those who went through Hugo, Marilyn, etc. as well as the more recent transplants. We take all storms seriously and watch them from the time when they're just waves rolling off the African coast or popping up elsewhere.

Appreciate everyone's help in keeping those of us on the "Alley" as up to date as possible.
Randrewl these forecasts have been trying to kill 90L for days.....but its like the energizer keeps on coming.
Guys in this pic from the NAVY you can see the explosion of convection going on with chris.

Free Image Hosting at www.ImageShack.us
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MELBOURNE FL
230 PM EDT TUE AUG 1 2006


UPPER LOW SHOWN MOVING
VERY SLOWLY ACROSS THE SOUTHERN PENINSULA THU-FRI.
SAT-TUE...MODEL TREND IS FOR LOW LEVEL RIDGE AXIS TO NUDGE NORTHWARD
WITH MORE OF A SOUTHEAST WIND FLOW. THIS IS DUE TO THE MOVEMENT OF
CHRIS AROUND THE PERIPHERY OF THE RIDGE WITH LATEST NHC TRACK TAKING
THE SYSTEM NEAR SOUTH FLORIDA/KEYS SUN/MON. LATEST GFS ALSO SHOWS
ANOTHER TROPICAL WAVE MOVING THROUGH THE BAHAMAS/SOUTH FL MON NIGHT/
TUE. OF COURSE...MUCH CAN CHANGE BETWEEN NOW AND THEN AS THE LONGER
RANGE PORTION OF FORECASTS FOR DEVELOPING TROPICAL SYSTEMS TYPICALLY
HAVE GREAT UNCERTAINTY. WILL STAY WITH CLIMO SCATTERED POPS DURING
THIS PERIOD UNTIL THERE IS MORE CONFIDENCE IN STRENGTH/TIMING OF THE
TROPICAL SYSTEM(S).
Based on what the NHC has said, wind shear and wind shear forecast, dust values and visible, water vapor and infrared imagery,
I give Chris 25% chance of becoming Hurricane Chris, and less than 5% of becoming Major Hurricane Chris.....
1167. Zaphod
Aren't we approaching the diurnal minimum? Shouldn't we expect to see growing convection tonight?
Zap
hey sammy, whats up
nola70119....trying to kill 90L for days??
Hey - anyone who is having trouble converting wind speeds from knots to MPH, m/s, whatever, this is a great website and is easy to use if you want to convert fast. Hope you find it useful!
Wind Speed Converter
Remember this time yesterday? we were talking MAYBE a short lived depression.... now the talk is what category. There is too many dynamic variables associated with storm to trust these models outside of 24 to 36 hours..i.e. the ULLs, shear, H20 temp etc... That said, Chris is beginning to look very healthy with definite hurricane potential, we'll see if this current flare up persists...
Jp you are probably right, the blog has been out ahead of the NHC on this though....it certainly has been an eye opener.
1176. PBG00
Scorpion..see that new wave comin off Africa??How long is the cruise for?
so could the winds go from 40mph to 65mph or whats going on her
jphurricane2006...Uncertainty and the fact that the local NWS boys are not yet buying into Chris as a local Florida threat. That can and most likely will change....but I have a lot of admiration for the local boys. Let's see what evolves in the coming days.
Yeah, 99......sorry, typo.
thelmores, i know ir looks impressive, but Vis is more informative and MORE impressive. You can really see the blowup on vis. IR sometimes the circus cause false ideas.
This blog knew about TD 03, 2 hours before the NHC had it.....
1184. Finnmet
Wave in the EATL show signs of organization.Just keep an eye.There is a 1011 low and no more dust.
1187. PBG00
I was watchin the tropical update and Lyons did the whole bit without a mention of td status..then at the end was handed a piece of paper and called it..went to commecial and came back to dish.
: jphurricane2006 do this thing try to get a eye yet or not this yet but keep a vary watch full eye on that it may be a pin hole eye
you can see the blow up here...


Recon observed 55kt surface winds, but only encountered 53kt? That's weird. Still, Chris is strengthening fast, I think the shear has been horribly mis-analyzed.
CaneWatcher06, expect around 50mph on the next advisory. But with the convection over the center its begining to do what it needs to become a real player. Also the movement will stabilize now. Notice earlier that it would go wnw when it had th then turn more w when it didn't. Once it gets good th that willl keep it on the wnw.
1193. 900MB
Chris looking strong. Definite convection gains in the center and higher tops. The visible loop is most convincing here, over the past 3 hours it really has begun to spin and look much more like a hurricane. No doubt it will be one by tomorrow afternoon, as I previous predicted. Think it may be by 11 pm tonight at this rate. I still have it tracking North of guidance, somewher like Amelia Island Florida at this point, but way too early to tell.
I wonder when Cantore will land in south Florida? That's you sign that things could get bad or that they think it could get bad -
1195. Finnmet
yes jp is high for the next 24 hours but after is forecast to relax.
In the latest visible loop from Tropical Floater 1, looks like Chris' convection to the east is increasing and starting to fill in. If this convection builds up and coordinates with the recent burst of convection around the COC before the 5:00PM advisory, then NHC might just upgrade the winds from 50-65mph. Once again, Floridians start considering prepartion and supplies, as Chris looks to be coming towards you.

On another note - Dr. Lyons is on! Finally!
tx..... i try to look at all 4 image sources, vis, ir, wv, and radar. please don't believe that the only thing i look at is IR! LOL

bottom line, the COC is tucked underneath some intense tstorm activity, and all indications are we are undergoing "some" stregthening.....

How does a storm that size relax? I guess there are conditions that cause that, but what and where are they. It looks like all free and clear for it to just keep going.
txweather so if the wnw right now that could this could take it right in the the gulf that not good 2 eddys
Dr. Lyons says it is strengthening and we'll have a stronger storm at 5:00 PM.
hurricane23,good image thats the kind of picture I talked about.
Starting to get a little breezy here......
afternoon all how are we doing and how is our champ and where do we expect him to go i live in sw florida.
1205. ricderr
This blog knew about TD 03, 2 hours before the NHC had it....

Weather...correction This blog knew about TD 03, 2 hours before the NHC "reported it"..

NHC reports every 6 hours and updates every three when needed....funny..but one could get the impression here that they are the evil empire..more misinformation is passed on as fact here than they ever put out..but..this blog does make for better reading
Is 99L the one ne of the bahamas? if so, I would say it is going from extratropical to tropical very soon. looks as if the thunderstorm activity is getting closer to the COC.
1209. rxse7en
Has there ever been a case of Saharan dust knocking down a hurricane or a tropical storm for that matter?
i still say we will have hurr Chris by 11pm
1211. Patrap
...Nasa scrubbed this mornings attempt to roll -out Atlantis to 39B due to Local weather concerns of T-storms in the 6-7 hr rollout window...have rescheduled for o200am est Wed morn..Launch Sched for Aug 27th...
thelmores, no offense intended.

Canewathcher06, unknown as of now, butt hat seems plausable. The bad thing about convection over the lcc is that I can't track it anymore. But before, it went under it almost looked like due w.
3:45pm EDT-Convection continues to fire...Dr. Steve lyons said its strenghtening.....

I donot want to jump to conclusion, but someone tell if there is something forming under the recent convection....It looks pretty strange....



hello all, I live in Boca Raton and am watching this storm very closely, I just get this strange feeling about nasty storms and I am getting the same feeling I got when Francis, Jean and Wilma were approching. I hope I am wrong.
1217. WSI
"Where does one find the latest computer models for Chris??"

Hey Jim. WU has some model runs here under their tropical section.

I also have a list of links on the Tropical Breakdown page at weathercore.com.
456 Are you right under the edge now?
I dont believe it...but Chris might be on its way to become our first 'cane......
weather456 it could be a eye poping up but i dont no yet
saddle, yes...we have some very gusting winds now.....the sky is now almost completly cover.....it wont belong before we get some rain.....
is south fla more in trouble now than before since it is moving nw. the track will have to me moved north slightly and south fla might be in the middle of the cone, you agree?
I remember with Ivan, the sky literally spun - are you seeing that there 456?
Actually try a close up on the VIS. Right before the convection blew up yuo could almsot see the center get pulled into blob.

Also to help alittle some generalities on systems.

Td/early storm- burst of convection with just some organization

midstorm -ealyhurricane/strong storm-CDO, an area of strong convection forms near the center and persist with only alittle bandind.

Right now we are right at the border between these two and if the convection continue we will have a CDO.
South Fl people COULD go ahead and make their reservations - they could always cancel later on, but if they wait until the last minute, shelters will probably be their only option.
There won't be an eye for a while.
Well, it's been 18 hours since the first NHC discussion on TD3, and Chris has already intensified to twice what the wooses at the NHC predicted. At this rate of progression winds should be at about 1600 knots by the time it hits land, unless it goes into the GOM, then 4800 knots is possible. Unless of course it dissipates over Hispaniola or runs into unfavorable shear from the ULL's. We shall see.
So what's the consensus? How strong is it now?
SJ..
The mods have lifted the 2k limit on blog comments.

CosmicEvents..

Am I doing my math wrong or are you really saying the storm could generate 500 mph winds (4800 knots)????
saddle, you can say that....but what amazes me is how the place went from calm to gusty in minutes....Now the last time i was affected by a tropical system directly like Chris was Hurricane Lenny in 1999, so i forgot how it can be....
NEW BLOG
1234. Melagoo
This is an phenomenal weather website!

I have been to many and this site has it all.

Thank you Dr. Jeff Masters and the rest of the crew!
well, looks like i best put up the shutters for the season - I'm in Palm Beach,FL
ok you guys,
shall I prep, or what's this thing doing?
1990 - It's always better to be prepared than to get caught without any preparations. Watch until tomorrow evening then make your decision.
Just started watching this site a few days ago. Have to thank everyone for their input, good or bad. It is really helping me understand how hurricanes form. Also help me plan for the next location I will be going to. LOL
Again, keep up the good work and maybe no one will need my assistance.
you guys are awesome...............where'd you all go?
disasterworker - you an adjuster?
Disasterworker. Thxs for ur hard work, its really appreciated. BUT hope u dont have to come see us anytime real soon. LOL. Stay safe.
Guess I need to start looking at what we have in the way of water, batteries, gas, and spam .. LOL
DATA SUGGESTS WINDS ARE APPROACHING 100 KMH/60 MPH CANE STATUS POSSIBLE BY 8 PM EST TRACK WILL REMAIN EXTREME NORTH LEEWARDS WESTWARDS ALONG OR JUST OFFSHORE OF P.RICO EXPECT CAT 1 STATUS TILL EXIT FROM LEEWARDS THEN CAT 2 POSS.CAT 3 FROM P.RICO ONWARD TO CAT ISLAND SHEAR IS FAILING TO AFFECT THIS STORM HURRICANE WATCH SHOULD BE ISSUED FOR P. RICO HURRICANE WARNING FOR NORTHERN LEEWARDS.THIS IS GOING TO BE A COMPACT STORM WITH A VERY SMALL EYE WHICH ARE INDICATIONS OF A VERY POWERFUL STORM YET TO COME
not adjuster, new employee of (now don't get all excited) FEMA. At first deployment in PA now. Watching to see if i can go home a while or to FL, not passing GO or collecting $200.
Weather456

Chris is knocking on your door my friend, keep us up to date on how you are faring..
Winds have been upgraded to 60 MPH - so I'm giving Chris a 45% chance of becoming a hurricane in the next 6-12 hours. At the 10:30 PM, I believe that the winds will be 60-70 MPH.
WHERE IS EVERYBODY?!
Boynton get your clipboard and "Sunday's best ready ! You've got work !
Whats the last steering on this thing ?
Thanks Weather 456:

It is a hurricane in 24 hrs. !