Invest 96L: Organizing in the Gulf

By: Dr. Jeff Masters , 1:17 AM GMT on July 08, 2010

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Hi everybody, Dr. Rob Carver filling in for Jeff while he's on vacation.

Invest 96L appears to be in the process of developing into a tropical cyclone. The strength and extent of it's thunderstorms is much improved from yesterday (I used CIMMS tropical storm page for my analysis). It's under an upper-level anticyclone which promotes development because it efficiently removes "exhaust" from the thunderstorms. Shear is relatively low (~10 knots), and SST's are adequate for supporting a tropical cyclone (~28 deg. C). In the most recent Tropical Weather Outlook, NHC mentioned that research flights found that upper-level conditions were promising for storm development, so they assess the chances of 96L of becoming a tropical cyclone at 80%. My take is that 96L has an 80% chance of becoming TD #2, and about a 40% chance of being named Bonnie. My reasoning is that 96L has about 24 hours to intensify before interactions with land start interfering with intensification processes. Also, model intensity forecasts are not very supportive of 96L attaining tropical storm force winds. The model track forecast aids have 96L's center of circulation making landfall somewhere between Brownsville and Corpus Christi.

Impacts
The 12Z operational GFS, HWRF, NOGAPS, and 18Z NAM tell a similar story about the surface winds. Near tropical-storm force winds affect the Texas coast from Corpus Christi to Matagorda Bay. A broad area of 30+ mph winds also affects the Deepwater Horizon oil spill recovery efforts. The 12Z Canadian global model downplays the wind strengths, and the 12Z parallel GFS fails to develop any significant surface wind (> 20 mph). That said, I believe that 96L's greatest impact will be in the form of rain.

The Rio Grande from Del Rio to Laredo is either at major flood stage or is forecast to reach major flood stage in the next 24 hours. This is due to Alex and the moisture he brought to the high terrain of northern Mexico. Nearly all of the forecast models I've looked at forecast 2-3 inches of rain over the Rio Grande Valley in the next 5 days. That will only encourage more flooding. The main forecast problem is how much rain will fall along the Gulf Coast. The parallel GFS and HWRF suggest that 4.5 to 6.5 inches of rain will fall in the Galveston/Houston area in the next 5 days. In my opinion, people living in this area should be prepared for flooding.


Fig. 1. 120 hr accumulated precipitation (mm) for 12Z parallel GFS. Operational GFS


Fig. 2. 120 hr accumulated precipitation (mm) for 12Z HWRF.


Fig. 3. 120 hr accumulated precipitation (mm) for 12Z Canadian global model. NOGAPS

Emergency Preparations
People living along the Gulf coast from south of the Rio Grande to the Texas/Louisiana border should review their emergency preparations (hurricane preparations also make for good flood preparations). Jeff has put together a guide to hurricane preparedness with plenty of links for more information.

Next Update
If 96L becomes TD2 or Bonnie, I'll have an update tonight. Shaun Tanner may post something in the morning if that's when the naming occurs. Otherwise, I'll post a tropical update tomorrow afternoon.

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Member Since: Posts: Comments:
1190. tkeith
TD or weak TS the relevant issue to me is, it's rainfall amount. This______(insert opinion) needs to "giddy up"...
Member Since: Posts: Comments:
Quoting reedzone:
Sorry, this looks more like a disturbance then an actual Tropical Storm.


its the obs that count, not what it looks like.
i agree it is any ugly storm but it would have to be classified if it meets the criteria, regardless of what it looks like. Again, i am sure the NHC knows what they are doing.
Member Since: Posts: Comments:
I can see the rationale behind the upgrade last night. That made sense to me. A further upgrade this morning, IMO, is [at least so far] not worth it. But we shall see what we shall see...
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Here's JB's take on the Heatwave, TD2 and the ATL System this morning.

92.5??? WANNA BET IT'S AT LEAST A DEGREE HIGHER?

The GFS has stunk up the Eastern Seaboard during this heat wave... missing on six hour forecasts by an average of over 2 degrees at each of these duel cities (yesterday it had 98.5, it wound up at 101.5), and today should be another beating by at least 2 degrees over the sample cities. Big deal??? Actually it is, since it shows how bad the model is. Even Garrett remarked to me, why is it every day the forecast he sees on the automated forecast on the cable channel that has the weather is too low here? Yesterday, they had 92... again. Every day it keeps getting warmer. It's because the model is incapable of seeing anything that goes beyond the limits of it. It wants to adjust temperatures down to the climo, and the farther away from day one, the worse it is.

Now, when it rains, or it's cloudy, different story. The "hope" for a sub-90 day in D.C. is Saturday because of the threat of heavy rains the night before and lingering clouds on Saturday. The shadow of rain is a big deal, and certainly helps keep temperatures down as we see in parts of the Ohio Valley, which have failed to launch compared to where the drought is.

There is a very dangerous flight going into TD2 now. I hope the pilots don't fall asleep looking at this. It is what it is, which is what has been described here. Seas are running to 12 feet in Texas coastal waters, and there are some gusty winds. The but over 75 percent of the area under a tropical storm warning (what a joke south of the track) won't see much with this. And there will be stronger winds outside the warning area toward the upper Texas coast than where this crosses land. I marvel at how these things are issued. I pointed that out with Alex. The wind is liable to average under 7 knots today in the Mexican part of the warning area, and even into the lower Rio Grande Valley.

Now let's see if they wake up to what is going on off the East Coast. A 1010 mb low over 84-degree water, entraining heat from a tropical wave... though non-tropical now, won't be for long with the thunderstorms going off around it, though in the world of the hatched-egg threats, obviously it's not being acknowledged as such. This may acquire warm core characteristics east of the N.C. coast tomorrow, and then head off to the north-northeast.

Thanks for reading, ciao for now. ****


WEDNESDAY 11 PM

TPC CLASSIFIES... NO CHANGE TO MY IDEA.

I have no dog in the status fight here since for several days the idea that tropical storm conditions could reach Texas coastal waters with this makes it a moot point. It will be ashore by 3 p.m. tomorrow, named or not, and I guess the only difference might be is that it will be the second storm to impact the U.S. coastline with tropical storm conditions this year.

What's in a name... in this case, if it's named, nothing different than if it isn't.

Ciao for now. ****
Member Since: Posts: Comments:
Meanwhile, a bigger and more impressive system off the East Coast is forming into a Subtropical Cyclone. I expect this to be tagged later today as 97L. Structure has gotten worse on TD2 since it was upgraded.. I don't see how this is a TS, very ragged, some deep convection, but not impressive enough to name it in my opinion, they might just do it though.
Member Since: July 1, 2008 Posts: 13 Comments: 7340
Quoting beell:


Good gosh 'a mighty. Take a good look at this with some objectivity. This is not even a depression.

I understand the rain threat. The Mexican and US Weather Services can handle this one from here on out.
It meets the NHC criteria for a tropical depression. Say what ya' want, it's a tropical depression.
Member Since: September 2, 2009 Posts: 130 Comments: 21091
1184. beell
Quoting MiamiHurricanes09:
Several SFMR wind reading in excess of 40mph should take TD #2 to Bonnie at 11PM EDT.


Good gosh 'a mighty. Take a good look at this with some objectivity. This is not even a depression.

I understand the rain threat. The Mexican and US Weather Services can handle this one from here on out.
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Quoting calder:


copy and paste them?

Post 1181.
Member Since: September 2, 2009 Posts: 130 Comments: 21091
1182. calder
Quoting MiamiHurricanes09:
Recon has found several SFMR winds of more than 40mph. With those readings it would be kinda dumb not to upgrade it.


copy and paste them?

Member Since: Posts: Comments:
Quoting calder:


I can't see them! copy and paste?


07/8 11:30:00Z | 11 | 1006.9 | 40 kts | 34 kts
07/8 11:40:00Z | 12 | 1008.4 | 41 kts | 36 kts

There were a few other readings, but these were the ones with supportable flight level winds.
Member Since: July 8, 2005 Posts: 259 Comments: 23619
Sorry, this looks more like a disturbance then an actual Tropical Storm.
Member Since: July 1, 2008 Posts: 13 Comments: 7340
1179. Makoto1
Quoting reedzone:
Yet again, I am unimpressed with TD2, what a joke this was to call it a TD. Ball of convection? no, it didn't do what it should have done, time is running out and I give TD2 a 10% to become Bonnie.


From what they found last night I think they got it right when calling it a TD myself. Tropical depressions aren't usually impressive.
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Quoting reedzone:
Yet again, I am unimpressed with TD2, what a joke this was to call it a TD. Ball of convection? no, it didn't do what it should have done, time is running out and I give TD2 a 10% to become Bonnie.
Recon has found several SFMR winds of more than 40mph. With those readings it would be kinda dumb not to upgrade it.
Member Since: September 2, 2009 Posts: 130 Comments: 21091
Quoting IKE:
Anyone ever see any west winds on recon? I haven't.
Last night. Somebody posted here.
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Quoting Netflyer:
Good morning brilliant weather forecasters, can you help a newb and explain to me why the open Atlantic isn't of interest?

http://www.ssd.noaa.gov/goes/east/eaus/loop-wv.html


Possibly because it's not a tropical low and the models forecast it being swept out to sea by the frontal boundary moving across the US.
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1175. calder
right i have only seen one valid smfr wind of 39.1 mph. There are other readings from 12z onwards but if you look at the flight level winds then these are definately not valid.
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Quoting sailingallover:

Last night it looked organized but now it looks more like a low with gale force winds. I can't believe they will upgrade it even with the winds..


They would have too,it still is a some-what organized system with a closed CoC with deep convection around the center.If they find tropical-storm forced winds,they will most definatly upgrade it.
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1173. calder
Quoting CybrTeddy:


Not so, the one right above that ob was 41 knots and 36 knots.

2 valid TS winds.


I can't see them! copy and paste?
Member Since: Posts: Comments:
Yet again, I am unimpressed with TD2, what a joke this was to call it a TD. Ball of convection? no, it didn't do what it should have done, time is running out and I give TD2 a 10% to become Bonnie.
Member Since: July 1, 2008 Posts: 13 Comments: 7340
Guess they don't think its a TS yet. If Recon finds more valid winds I won't be surprised if they upgrade it.
Member Since: July 8, 2005 Posts: 259 Comments: 23619
Several SFMR wind reading in excess of 40mph should take TD #2 to Bonnie at 11AM* EDT.

Fixed the error, meant to say 11AM EDT.
Member Since: September 2, 2009 Posts: 130 Comments: 21091
1169. Makoto1
Quoting IKE:
Anyone ever see any west winds on recon? I haven't.


I haven't either but I have a feeling the actual center might be quite small and they may have missed it.
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1168. SLU
121

WHXX01 KWBC 081242

CHGHUR

TROPICAL CYCLONE GUIDANCE MESSAGE

NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL

1242 UTC THU JUL 8 2010



DISCLAIMER...NUMERICAL MODELS ARE SUBJECT TO LARGE ERRORS.

PLEASE REFER TO NHC OFFICIAL FORECASTS FOR TROPICAL CYCLONE

AND SUBTROPICAL CYCLONE INFORMATION.



ATLANTIC OBJECTIVE AIDS FOR



TROPICAL CYCLONE TWO (AL022010) 20100708 1200 UTC



...00 HRS... ...12 HRS... ...24 HRS. .. ...36 HRS...

100708 1200 100709 0000 100709 1200 100710 0000



LAT LON LAT LON LAT LON LAT LON

BAMS 25.4N 96.2W 26.7N 98.4W 27.8N 100.5W 28.7N 102.6W

BAMD 25.4N 96.2W 26.2N 98.3W 26.8N 100.4W 27.4N 102.5W

BAMM 25.4N 96.2W 26.5N 98.3W 27.4N 100.4W 28.3N 102.3W

LBAR 25.4N 96.2W 26.8N 98.5W 28.5N 100.6W 30.2N 102.3W

SHIP 30KTS 32KTS 35KTS 38KTS

DSHP 30KTS 27KTS 27KTS 27KTS



...48 HRS... ...72 HRS... ...96 HRS. .. ..120 HRS...

100710 1200 100711 1200 100712 1200 100713 1200



LAT LON LAT LON LAT LON LAT LON

BAMS 29.6N 104.5W 31.4N 106.8W 32.2N 106.1W 32.2N 106.0W

BAMD 28.0N 104.5W 29.5N 107.7W 30.7N 108.5W 30.9N 108.3W

BAMM 29.1N 104.2W 31.0N 106.9W 32.2N 106.7W 32.3N 105.7W

LBAR 31.8N 103.1W 34.3N 101.4W 35.0N 95.6W 36.4N 87.2W

SHIP 41KTS 49KTS 55KTS 55KTS

DSHP 27KTS 27KTS 27KTS 27KTS



...INITIAL CONDITIONS...

LATCUR = 25.4N LONCUR = 96.2W DIRCUR = 310DEG SPDCUR = 13KT

LATM12 = 23.6N LONM12 = 93.6W DIRM12 = 313DEG SPDM12 = 12KT

LATM24 = 22.1N LONM24 = 92.0W

WNDCUR = 30KT RMAXWD = 60NM WNDM12 = 30KT

CENPRS = 1006MB OUTPRS = 1009MB OUTRAD = 180NM SDEPTH = D

RD34NE = 0NM RD34SE = 0NM RD34SW = 0NM RD34NW = 0NM



$$

NNNN


Member Since: Posts: Comments:
Quoting sailingallover:

The ITCZ started out moving north very fast this season. Very active as well for most of late April- May.
Normally the ITCZ follows the Ocean waters heated by the sun. Since the waters are so warm already the relative low pressure belt is staying farther south. It has made the ITCZ broader and weaker. The Columbian Low is not there to give the ITCZ a boost in the west.
The Dust from the Large if not strong Azores high is also killing convection to the north keep the rising air farther south.
The trades which feed it have been weaker as well, all that rising air comes from the NE trades.
End result weak low latitude ITCZ


Thanks..............
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Quoting calder:


Got that one, the other barbs from 1205z onwards are false readings, look at the flight level winds


Not so, the one right above that ob was 41 knots and 36 knots.

2 valid TS winds.
Member Since: July 8, 2005 Posts: 259 Comments: 23619
Link

Sorry about the non-active link... this should work, like I said... newb...
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1163. IKE
Anyone ever see any west winds on recon? I haven't.
Member Since: June 9, 2005 Posts: 23 Comments: 37858
Quoting calder:


oh apologies, my google earth doesn't seem to be showing them


Not a problem! Lets see what they say when they issue vortex message. IMO, this appears to be TS Bonnie even though its disorganized.
Member Since: July 8, 2005 Posts: 259 Comments: 23619
Good morning brilliant weather forecasters, can you help a newb and explain to me why the open Atlantic isn't of interest?

http://www.ssd.noaa.gov/goes/east/eaus/loop-wv.html
Member Since: Posts: Comments:
1159. calder
Quoting CybrTeddy:
Flight level wind peak was 41 knots (46 mph) with the SFMR recording 34 knots (39 mph) on that same ob.


Got that one, the other barbs from 1205z onwards are false readings, look at the flight level winds
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1158. GCAT
Its light rain so far this morning, no training but is does feel like Cambodia outside. I expect at least 4 inches of rain in next 18h.
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1157. calder
Quoting CybrTeddy:


No, they were not.
Link

SFMR peak was 40 knots.


oh apologies, my google earth doesn't seem to be showing them
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Flight level wind peak was 41 knots (46 mph) with the SFMR recording 34 knots (39 mph) on that same ob.
Member Since: July 8, 2005 Posts: 259 Comments: 23619
Inre 1116, edited in the correction:
"TropicalDepressionTwo was^heading toward RioHondo,Texas..."
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thanx StormW
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1153. IKE
Quoting CybrTeddy:
Another TS reading.
34.0 knots (~ 39.1 mph)
Tropical Storm


120-150 miles south of Brownsville.
Member Since: June 9, 2005 Posts: 23 Comments: 37858
1152. calder
Quoting CybrTeddy:
Another TS reading.
34.0 knots (~ 39.1 mph)
Tropical Storm


Yeh i saw that SFMR reading, where are the others?
Member Since: Posts: Comments:
Dvorak Current Intensity Chart
Member Since: September 10, 2007 Posts: 0 Comments: 11003
Quoting calder:


They are all flight level winds


No, they were not.
Link

SFMR peak was 40 knots.
Member Since: July 8, 2005 Posts: 259 Comments: 23619
Confusing storms this year, their data and appearances don't match! Making it a challenge to learn.
Member Since: Posts: Comments:
If you look at the NASA GOES satellite images (which are more updated than the SSD ones), 02L appears better organized. But the central convective area is small.Link
Member Since: August 2, 2007 Posts: 19 Comments: 19234
Another TS reading.
34.0 knots (~ 39.1 mph)
Tropical Storm
Member Since: July 8, 2005 Posts: 259 Comments: 23619
That ULL off our coast ain't doing nothing but giving us a 20% chance of an afternoon shower.

VERY WARM TO HOT TEMPERATURES WILL CONTINUE TODAY...WITH SLIGHTLY
COOLER READINGS ALONG AND NEAR THE NORTH CAROLINA COAST...WHERE A
FEW SHOWERS OR THUNDERSTORMS COULD DEVELOP AS AN UPPER LOW OFFSHORE
APPROACHES.


Ocean is flat as a pancake and will continue to stay that way.

BUT BROAD SURFACE CIRCULATION OFFSHORE LINKED WITH UPPER LOW
WILL NOT CONTRIBUTE MUCH TO ADDITIONAL SHORE-WARD MOVING WAVE ENERGY
ASIDE FROM A BIT OF SHORT-WAVELENGTH ENERGY OF LOW AMPLITUDE NORTH
OF CAPE FEAR.


Now back to your regularly scheduled Gulf update.
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Quoting HurricaneSwirl:


Wow, raw T#'s just under hurricane status? lol


They went down a bit...now 55kts

----- Current Analysis -----
Date : 08 JUL 2010 Time : 114500 UTC
Lat : 25:08:14 N Lon : 95:39:29 W


CI# /Pressure/ Vmax
2.4 /1005.8mb/ 34.0kt


Final T# Adj T# Raw T#
2.4 2.7 3.5
Member Since: August 2, 2007 Posts: 19 Comments: 19234
1143. calder
Quoting CybrTeddy:
Found 4 readings of TS force winds from the Recon one was up to 40 knots.


They are all flight level winds
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1142. IKE
Brownsville, Texas (Airport)
Updated: 16 min 41 sec ago
Mostly Cloudy
81 °F
Mostly Cloudy
Humidity: 89%
Dew Point: 77 °F
Wind: 8 mph from the NNW
Pressure: 29.77 in (Rising)

Heat Index: 87 °F
Visibility: 10.0 miles
UV: 0 out of 16
Pollen: 3.80 out of 12
Pollen Forecast new!
Clouds:
Scattered Clouds 900 ft
Mostly Cloudy 2000 ft
Mostly Cloudy 2900 ft
(Above Ground Level)
Elevation: 20 ft
Member Since: June 9, 2005 Posts: 23 Comments: 37858
Quoting extreme236:


Raw T-numbers are objective numbers that the ADT measured the organization to be at on that cycle. These can often be much higher or lower than the Current Intensity (CI) number. But numerous higher raw T-numbers will increase that CI overtime if they persist.

Thank you very much for your explanation.
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Jeff co-founded the Weather Underground in 1995 while working on his Ph.D. He flew with the NOAA Hurricane Hunters from 1986-1990.