Igor spares Bermuda; Fanapi hits China; exceptionally quiet in the Pacific

By: Dr. Jeff Masters , 1:29 PM GMT on September 20, 2010

Share this Blog
2
+

The core of Category 1 Hurricane Igor passed approximately 40 miles west of Bermuda at 11 pm AST last night, bringing winds just below hurricane force to the island. Winds at the Bermuda Airport peaked at 68 mph, gusting to 93 mph, at 11:22 pm AST last night. Tropical storm force winds of 39 mph began at 10 am AST on Sunday, and were still present as of 9:38 am AST (44 mph, gusting to 53 mph.) Bermuda radar shows that the core of Igor is now well past Bermuda, with only a few spiral bands to the south that will bring occasional rain squalls to the island this morning. Pressures are rising rapidly, and the storm is almost over for Bermuda. No injuries or major damage has been reported from Bermuda thus far, though Igor's waves are being blamed for two deaths in the Caribbean, one on Puerto Rico and one on St. Croix.

Igor is headed northeastward, out to sea, but will pass close enough to southeast Newfoundland to bring tropical storm force winds there on Tuesday night. Rainfall amounts of 3 - 5 inches are possible for the capital of St. Johns.


Figure 1. The eye of Hurricane Igor as seen by the International Space Station at 9:56 am EDT September 14, 2010. At the time, Igor was a Category 4 hurricane with 135 mph winds. This image ranks as one of the top-five most spectacular hurricane images ever taken from space, in my mind. To see the full-size image, visit the NASA Earth Observatory web site.

94L
A tropical wave (Invest 94L) off the coast of Africa, a few hundred miles west of the Cape Verdes Islands, has developed a well-defined surface circulation and is threat to develop into a tropical depression. The wave is under a low 5 - 10 knots of wind shear, and is over warm 28°C waters. Dry air from the Sahara is interfering with development, and downdrafts created by mid-level dry air getting ingested into the storm are creating surface arc clouds on the west side of the storm, as seen in recent visible satellite loops. 94L only has a modest amount of heavy thunderstorm activity associated with it, and the amount of thunderstorm activity will have to increase in order for this system to be considered a tropical depression. Shear is expected to be low for the next four days, and most of the major forecast models develop 94L into a tropical depression 1 - 4 days from now. NHC is giving the wave a 80% of developing into a tropical depression by Wednesday.


Figure 2. Morning satellite image of Invest 94L.

Julia
Tropical Storm Julia is being ripped apart by wind shear from Igor, and will likely dissipate on Tuesday.

Typhoon Fanapi hits China
Typhoon Fanapi made landfall in mainland China about 150 miles east-northeast of Hong Kong this morning as a Category 1 storm with 75 mph winds. Fanapi was the strongest typhoon so far this season, peaking at Category 3 strength with 120 mph winds shortly before weakening to a Category 2 storm with 105 mph winds when it hit northern Taiwan early Sunday morning, local time. Fanapi killed three people on the island, and brought rains of up to 1400 mm (4.6 feet) to mountainous regions in the interior. Taipei 101, the second tallest building in the world with more than 100 stories, reportedly swayed some 15 cm in Fanapi's winds.

A remarkably quiet Western Pacific typhoon season and Eastern Pacific hurricane season
It has been an exceptionally quiet Western Pacific typhoon season. Before Fanapi, the strongest typhoon this season was Typhoon Kompasu, a low-end Category 3 storm with 115 mph winds that hit South Korea in early September. According to statistics forwarded to me by NOAA meteorologist Paul Stanko on Guam, by this point in an ordinary typhoon season, we should have had 17 named storms, 11 typhoons, and 2 super supertyphoons (winds of 150+ mph.) This year, we've had just 11 named storms, 5 typhoons, and no supertyphoons. The record low for a typhoon season was 18 named storms (set in 1998), 9 typhoons (set in 1998), and no supertyphoons (set in 1974.) We have a chance of beating all of these records this year. The peak date for the Western Pacific typhoon season is August 28, so we are well past the peak.

It's a similar story out in the Eastern Pacific, where a near-record quiet hurricane season is occurring. So far there have been 6 named storms, 3 hurricanes, and 2 intense hurricanes. Ordinarily, we should have had 12 named storms, 6 hurricanes, and 2 intense hurricane by this point in the season. Since reliable satellite records of Eastern Pacific hurricane activity began in 1970, the quietest season on record was 1977, when just 8 named storms occurred. The fewest hurricanes occurred in 2007 (four), and there have been two years with no intense hurricanes. The peak of Eastern Pacific hurricane season is around August 25, and on average we can expect just 3 more named storms this year. Thus, we could set records for the fewest named storms and hurricanes this year.


Figure 3. Typhoon Fanapi at landfall in China at 5:15 UTC on September 20, 2010. Image credit: NASA.

Elsewhere in the tropics
The NOGAPS, ECMWF, and GFS models have been predicting development of a strong tropical disturbance or tropical depression in the Central Caribbean 6 - 9 days from now. However, the timing, location, and track of the potential development have been inconsistent from run to run. We should merely take note of the fact that these models predict that the Caribbean will be ripe for tropical storm development late this week and early next week, and not put much faith in the specifics of these highly unreliable long-range forecasts.

I'll have a new post on Tuesday morning.

Jeff Masters

Reader Comments

Comments will take a few seconds to appear.

Post Your Comments

Please sign in to post comments.

or Join

Not only will you be able to leave comments on this blog, but you'll also have the ability to upload and share your photos in our Wunder Photos section.

Display: 0, 50, 100, 200 Sort: Newest First - Order Posted

Viewing: 2282 - 2232

Page: 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | 31 | 32 | 33 | 34 | 35 | 36 | 37 | 38 | 39 | 40 | 41 | 42 | 43 | 44 | 45 | 46 | 47 | 48 | 49 | 50 | 51 | 52Blog Index

2282. surfmom
Quoting FlyingScotsman:
Anyone still paying attention to Igor? Looks like he's ready to wreak some havoc in Newfoundland today. Winds at St. Pierre already up to 56 mph with gusts to 77. And offshore, significant wave heights are up to 32 ft.


WhOOOOOOOO - that's a whole lot of heavy water!!!!Hope photoman Incogkneetoe isn't out and about in those winds taking pictures --Igor's weather's a bit rowdy up there
Member Since: Posts: Comments:
Quoting DestinJeff:
GFS seems a bit confused in the long-range


same theme, slightly different story with each run

kind of like my son getting through college
Member Since: Posts: Comments:
2279. surfmom
GeorgefromLosCabos - concerns for flooding? Got the Surfboard waxed?
Member Since: Posts: Comments:
Good morning all. From the Lake Charles NWS, 5:30 am update:

FORECAST CONFIDENCE HAS INCREASED A LITTLE FOR THE WEEKEND INTO
EARLY NEXT WEEK...WITH THE GLOBAL MODELS COMING INTO BETTER
AGREEMENT WITH A DEEP TROF/CUT OFF LOW DIGGING INTO THE EASTERN
CONUS AS A RIDGE AMPLIFIES OVER THE CENTRAL/SOUTHERN PLAINS. THIS
TROF RESULTS IN AN INITIAL FRONT PASSING THROUGH THE AREA LATE
SATURDAY...WITH A SECONDARY FRONT COMING THROUGH LATE SUNDAY. THIS
SECONDARY FRONT IS PROGGED TO DRIVE SLIGHTLY COOLER BUT SIGNIFICANTLY
DRIER AIR INTO THE REGION SUNDAY NIGHT. IN FACT...RAW DEWPOINT FIELDS IN
THE GFS AND ECMWF DROP INTO THE 40S BY MONDAY AFTERNOON. I HAVE
NOT GONE QUITE THIS FAR YET...AS I SUSPECT NOTWITHSTANDING THE
FAIR AGREEMENT THIS MORNING THE MODELS WILL CONTINUE TO FLOP
AROUND A BIT WITH THE DEPTH/POSITION OF THE TROF...BUT DID LOWER
DEWPOINTS TO NEAR OR BELOW LATEST MEX GUIDANCE...AND FOLLOWED SUIT
WITH OVERNIGHT LOWS.

MODELS ALSO CONTINUE TO FORECAST TROPICAL CYCLONE DEVELOPMENT IN
THE CARIBBEAN SEA TOWARD THE END OF THE WEEK...WITH THE WAVE OF
INTEREST CURRENTLY NEAR THE LESSER ANTILLES. FOR WHAT IT IS
WORTH...MODEL CONSENSUS THIS MORNING IS THAT THE AFOREMENTIONED
EASTERN CONUS TROF WILL BE DEEP ENOUGH TO DEFLECT ANY SUCH SYSTEM
NORTH THROUGH THE EASTERN GULF OR EVEN ACROSS CUBA AND THROUGH THE
BAHAMAS. CERTAINLY NOTHING CARVED IN STONE THIS FAR IN ADVANCE...SO
WILL CONTINUE TO MONITOR TRENDS.


Member Since: Posts: Comments:
2276. scott39
Didnt Karl start out where the new AOI is?
Member Since: Posts: Comments:
Anyone still paying attention to Igor? Looks like he's ready to wreak some havoc in Newfoundland today. Winds at St. Pierre already up to 56 mph with gusts to 77. And offshore, significant wave heights are up to 32 ft.
Member Since: Posts: Comments:
2274. scott39
Quoting IKE:
Here's the extended discussion from Birmingham,AL....

"THURSDAY AND FRIDAY LOOK WARM AND DRY. AS MENTIONED
EARLIER...GUIDANCE IS NOW IN BETTER AGREEMENT THAT RELIEF FROM THE
HEAT IS ON THE WAY. A COLD FRONT IS FORECAST TO MOVE INTO CENTRAL
ALABAMA LATE SATURDAY...PUSHING SOUTH OF THE AREA ON SUNDAY. THERE
WILL NOT BE A TON OF MOISTURE IN PLACE AHEAD OF THIS SYSTEM...BUT
WE SHOULD SEE AT LEAST SCATTERED SHOWERS AND/OR THUNDERSTORMS
SATURDAY AFTERNOON AND OVERNIGHT. A DRY AND COOLER AIRMASS WILL
BUILD IN BEHIND THE FRONT SUNDAY AFTERNOON INTO EARLY NEXT
WEEK...AND WE MAY GET OUR FIRST REAL TASTE OF FALL EARLY NEXT
WEEK. HANG IN THERE."


Come on trough, push it back to Africa!
Member Since: Posts: Comments:
Well, Invest96 is getting closer to Los Cabos here in Mexico. It just rained 1.8inches in 12hours. Lets see what happen in a few hours more.
Live from Cabo

Link
Member Since: Posts: Comments:
2272. surfmom
Is it a Good Morning? - I think so -
scanning....scanning
Lisa - no worries
the carib/gomex
ahhhhh there's the map & the gulp
and yes,as Neapolitan says, we got a whole lotta heat here
that's had no where to go
(same could be said for local surfers this summer)

we have the ingredients... what going to strike the match? still too early to trust the models - they don't have the catwalk down just yet
Member Since: Posts: Comments:
2271. scott39
I hate the waiting game when an AOI has the potential to be a land threat.
Member Since: Posts: Comments:
2270. lhwhelk
The 50% chance of rain for Lake Jackson today (50 miles south of Houston) has turned into 2 1/2" since 3 a.m. Whatever that left-over piece of Karl actually is, it sure is persistent.
Member Since: Posts: Comments:
Quoting IKE:
Another thing I notice on the long range GFS...fall 2010 will be getting here in the SE USA in the next couple of weeks...IF it verifies.

@ 384 hours....


Well, nothing unusual about that, right? I guess it depends on how "fall" is defined. All I know is we've never had the first real cold front come through SWFL before about October 25th or later than about November 5th, so we've lots of time left here...
Member Since: Posts: Comments:
2268. IKE
Here's the extended discussion from Birmingham,AL....

"THURSDAY AND FRIDAY LOOK WARM AND DRY. AS MENTIONED
EARLIER...GUIDANCE IS NOW IN BETTER AGREEMENT THAT RELIEF FROM THE
HEAT IS ON THE WAY. A COLD FRONT IS FORECAST TO MOVE INTO CENTRAL
ALABAMA LATE SATURDAY...PUSHING SOUTH OF THE AREA ON SUNDAY. THERE
WILL NOT BE A TON OF MOISTURE IN PLACE AHEAD OF THIS SYSTEM...BUT
WE SHOULD SEE AT LEAST SCATTERED SHOWERS AND/OR THUNDERSTORMS
SATURDAY AFTERNOON AND OVERNIGHT. A DRY AND COOLER AIRMASS WILL
BUILD IN BEHIND THE FRONT SUNDAY AFTERNOON INTO EARLY NEXT
WEEK...AND WE MAY GET OUR FIRST REAL TASTE OF FALL EARLY NEXT
WEEK. HANG IN THERE."


Member Since: Posts: Comments:
2267. MahFL
Quoting BioChemist:


yeah but even a cat 3 or two can be nasty in florida. especially if it gets a large windfield.

so we should know a little more by the weekend huh? meaning, what and how strong it will get



Cat3 ?, strong Tropical Storms will knock power out pretty much anywhere.....
Member Since: Posts: Comments:
Quoting IKE:
Another thing I notice on the long range GFS...fall 2010 will be getting here in the SE USA in the next couple of weeks...IF it verifies.


It has to be a strong front to make through Florida.
I am ready for Fall. It's still in the 90's everyday. Usually by now we are getting some high 80's, but that appears to be holding off. The ridge has been protecting us all season so far. I have to admit to a fondness for the ridge.
Member Since: Posts: Comments:
2264. scott39
Quoting IKE:


I hope it's wrong. See what the 12Z ECMWF shows.

I know a cold front is going to make it through the northern gulf coast this weekend. I would hope that would turn anything away from here.
I hope so too Ike. The guy from Crown Weather seems to think the trough is overdone with the GFS turning it too soon. I read this on another site yesterday as well. Lets hope it doesnt get bad for anybodys sake. Wind shear is up in the GOM right now.
Member Since: Posts: Comments:
2262. IKE
Another thing I notice on the long range GFS...fall 2010 will be getting here in the SE USA in the next couple of weeks...IF it verifies.

@ 384 hours....

Member Since: Posts: Comments:
2260. IKE
Quoting rmbjoe1954:
Wha does 12Zecmwf show?


It won't be coming out until 1 pm CDST today.
Member Since: Posts: Comments:
What does 12Zecmwf show?
2257. IKE
Quoting scott39:
What do you think about the current ECMWF run?


I hope it's wrong. See what the 12Z ECMWF shows.

I know a cold front is going to make it through the northern gulf coast this weekend. I would hope that would turn anything away from here.
Member Since: Posts: Comments:
Quoting IKE:
240 hour 6Z GFS....



wow Ike- still looks like it's all over Florida then he SE coast
Morning guys.

I see Lisa is here. And looks like she's not going to continue the run of majors.

It'll be almost odd to see the Atlantic without a hurricane later today.
Member Since: August 23, 2008 Posts: 7 Comments: 5300
2253. scott39
Quoting IKE:
240 hour 6Z GFS....

What do you think about the current ECMWF run?
Member Since: Posts: Comments:
2252. IKE
240 hour 6Z GFS....

Member Since: Posts: Comments:
2251. IKE
SYNOPSIS FOR THE GULF OF MEXICO
430 AM CDT TUE SEP 21 2010

.SYNOPSIS...A RIDGE WILL EXTEND EASTWARD ALONG THE NORTHERN GULF
COAST THROUGH THE PERIOD. A NW TO SE ORIENTED TROUGH WILL PERSIST
OVER THE FAR SW GULF WATERS THROUGH SAT. A TROPICAL WAVE WILL
APPROACH THE YUCATAN PENINSULA FROM THE NW CARIBBEAN SEA LATE
SAT.
.............................................

SYNOPSIS FOR CARIBBEAN SEA AND TROPICAL N ATLC FROM 07N TO 22N
BETWEEN 55W AND 65W
530 AM EDT TUE SEP 21 2010

.SYNOPSIS...EASTERLY TRADES WILL BECOME ESTABLISHED ACROSS THE
REGION THROUGH THE PERIOD. A TROPICAL WAVE OVER THE LESSER
ANTILLES WILL MOVE W ACROSS THE E CARIBBEAN TODAY THROUGH WED
THEN WILL MOVE THROUGH THE CENTRAL CARIBBEAN THU...REACHING THE
W CARIBBEAN FRI THROUGH SAT.
Member Since: Posts: Comments:
2250. scott39
Except for the close proximity to land, conditions look good for developement, concerning the new AOI intrest in the SE Carribean.
Member Since: Posts: Comments:
Quoting KoritheMan:


Correct. No need to be overly concerned right now. They're just long-range model prognostications, which are subject to change.

Right now, what we know is that it's a very good chance something will coalesce into a tropical cyclone in the central or southwest Caribbean over the next 4-5 days, emanating from the tropical wave over the Windward Islands.


Models had TD 5 a cat 3 when it crossed Miami so chillax for now
Member Since: Posts: Comments:
2248. tkeith
Quoting btwntx08:

lol hate them but anyways if they keep barely winning they will find ways to lose this season will find out who is the better team on thanksgiving :)
tisk,tisk,tisk...08. I know you didn't mean that :)

Member Since: Posts: Comments:
I actually though tomorrow I'll see Lisa with 40mph winds and 1005mb I'm excited I'm right but it was just a guess, I was wrong about the circles.
Member Since: Posts: Comments:
2246. scott39
Goodmorning, Looks like we are getting closer to the reality of possibly having a major hurricane in the GOM. This is due to the consistancy of the Global Models. Most forecasters that I have heard or seen, thinks the trough is overdone with the GFS pulling it N too quick. Lets hope some shear comes in and rips this AOI up!
Member Since: Posts: Comments:
Looks like models are hinting on a SW-NE moving caribbean system in early october. Remember 2008 Omar, that's bot impossible at all.
Member Since: Posts: Comments:
Good morning, everyone. I see we do have Lisa this morning.
Member Since: Posts: Comments:
Quoting markot:
did i see nhc discussion turns lisa to the west, in a few days.....


In the midst of strong vertical shear.
Member Since: Posts: Comments:
I think Lisa will repeat her 2004 self. Wiki says Karl's damage is at 3.9 billion that can't be right
Member Since: Posts: Comments:
2241. bird72
Quoting markot:
some people were saying on here earlier tonite the season was over.......


Maybe they were talking about some team or something, remember, some people here like to mix weather and balls.
Member Since: Posts: Comments:
2239. bird72
Quoting Neapolitan:
With Lisa, we now have seen--of course--six September storms (and there's a likely-busy ten days left in the month). That means this year has seen more September action than any years since the current "active" period began in 1995 except for '98 and '00, which both birthed seven, and '02 and '07, which both saw eight.

However...while it may not happen this year, it's interesting to note that of those four years that produced 30 named September storms among them, their attendant Octobers managed to only come up with six altogether. Even more interesting: the two years with eight-storm Septembers managed to only come up with one single paltry October storm between them. IOW, there seems to be--at least on the surface of things--an inverse relationship going: the more September storms a season has, the fewer October storms that follow. But again, with things as they are this year--particularly the as-yet untapped heat in the Caribbean--one senses that October probably won't be a similar bust this year.

As always: guess we'll have to wait and see...

Hey sir, great analysis.
Member Since: Posts: Comments:
Quoting Neapolitan:
With Lisa, we now have seen--of course--six September storms (and there's a likely-busy ten days left in the month). That means this year has seen more September action than any years since the current "active" period began in 1995 except for '98 and '00, which both birthed seven, and '02 and '07, which both saw eight.

However...while it may not happen this year, it's interesting to note that of those four years that produced 30 named September storms among them, their attendant Octobers managed to only come up with six altogether. Even more interesting: the two years with eight-storm Septembers managed to only come up with one single paltry October storm between them. IOW, there seems to be--at least on the surface of things--an inverse relationship going: the more September storms a season has, the fewer October storms that follow. But again, with things as they are this year--particularly the as-yet untapped heat in the Caribbean--one senses that October probably won't be a similar bust this year.

As always: guess we'll have to wait and see...


Interesting. Thanks. :)
Member Since: Posts: Comments:
Well, we are having some strong rain from the Invest96, probably tropical storm georgette. Will make landfall in Cabo San Lucas later today.

http://www.wunderground.com/swf/Rapid_Fire.swf?units=metric&station=IBAJACAL4
Member Since: Posts: Comments:
With Lisa, we now have seen--of course--six September storms (and there's a likely-busy ten days left in the month). That means this year has seen more September action than any years since the current "active" period began in 1995 except for '98 and '00, which both birthed seven, and '02 and '07, which both saw eight.

However...while it may not happen this year, it's interesting to note that of those four years that produced 30 named September storms among them, their attendant Octobers managed to only come up with six altogether. Even more interesting: the two years with eight-storm Septembers managed to only come up with one single paltry October storm between them. IOW, there seems to be--at least on the surface of things--an inverse relationship going: the more September storms a season has, the fewer October storms that follow. But again, with things as they are this year--particularly the as-yet untapped heat in the Caribbean--one senses that October probably won't be a similar bust this year.

As always: guess we'll have to wait and see...
Member Since: Posts: Comments:
2235. markot
did i see nhc discussion turns lisa to the west, in a few days.....
Member Since: Posts: Comments:
HurricaneIgor's heading had turned eastward to (4.2degrees east of) NorthEast
from its previous heading of (1.2degrees north of) NorthEast
H.Igor's average speed moving between its last 2 reported positions was ~53.7mph(~86.4km/h)

20Sep 09amGMT - - 34.2n64.4w - - 75mph - - 957mb - - #49
20Sep 12pmGMT - - 35.2n64.0w - - 75mph - - 957mb - - #49A
20Sep 03pmGMT - - 36.1n63.3w - - 75mph - - 960mb - - #50
20Sep 03pmGMT - - 37.1n62.5w - - 75mph - - 965mb - - NHC.Adv.#50A
20Sep 09pmGMT - - 38.2n61.5w - - 75mph - - 968mb - - #51
21Sep 12amGMT - - 39.0n60.5w - - 75mph - - 968mb - - #51A
21Sep 03amGMT - - 39.9n59.3w - - 75mph - - 968mb - - #52
21Sep 06amGMT - - 41.3n57.5w - - 75mph - - 968mb - - #52A
21Sep 09amGMT - - 42.8n55.1w - - 75mph - - 966mb - - #53

Copy&paste 34.2n64.4w, 35.2n64.0w, 36.1n63.3w, 37.1n62.5w, 38.2n61.5w-39.0n60.5w, 39.0n60.5w-39.9n59.3w, 39.9n59.3w-41.3n57.5w, 41.3n57.5w-42.8n55.1w, pwm, yyt into the GreatCircleMapper for a look at the last 12hours.
Member Since: August 21, 2007 Posts: 0 Comments: 4860
000
WTNT41 KNHC 210855
TCDAT1
HURRICANE IGOR DISCUSSION NUMBER 53
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL112010
500 AM AST TUE SEP 21 2010

IGOR CONTINUES TO LOSE TROPICAL CYCLONE CHARACTERISTICS AS IT
BECOMES MORE INVOLVED WITH A BAROCLINIC ZONE. HOWEVER...A SMALL
AREA OF CONVECTION HAS DEVELOPED NORTH OF THE CENTER...AND THE
CYCLONE HAS NOT YET DEVELOPED A WELL-DEFINED FRONTAL BOUNDARY SOUTH
OF THE CENTER. THUS...IGOR IS AGAIN MAINTAINED AS A TROPICAL
CYCLONE. EXTRATROPICAL TRANSITION IS LIKELY TO BE COMPLETE LATER
TODAY...WITH SOME BAROCLINICALLY-INDUCED STRENGTHENING EXPECTED.
LATE IN THE FORECAST PERIOD...THE SYSTEM WILL BE MERGING WITH
ANOTHER EXTRATROPICAL LOW OVER HIGH LATITUDES.

THE INITIAL MOTION IS 045/36. IGOR...OR THE EXTRATROPICAL LOW IT IS
FORECAST TO BECOME...IS LIKELY TO BE STEERED AROUND A LARGE
MID-LEVEL CYCLONIC GYRE OVER NORTHEASTERN NORTH AMERICA OVER THE
NEXT FEW DAYS. THE NEW FORECAST TRACK IS SIMILAR TO THE PREVIOUS
FORECAST THROUGH 48 HR...THEN ADJUSTED SOMEWHAT TO THE SOUTH
THEREAFTER DURING THE FORECAST NORTHWESTWARD MOTION AT 72-96 HR.

EVEN THOUGH IGOR IS FORECAST TO BE EXTRATROPICAL AS IT PASSES
NEWFOUNDLAND...TROPICAL-STORM AND POSSIBLY HURRICANE-FORCE WINDS
COULD REACH THE COAST OF NEWFOUNDLAND BEFORE THE TRANSITION IS
COMPLETE. ENVIRONMENT CANADA HAS ISSUED A HURRICANE WATCH AND
EXTENDED THE TROPICAL STORM WARNING FOR THE EASTERN PART OF THAT
PROVINCE.

FORECAST POSITIONS AND MAX WINDS

INITIAL 21/0900Z 42.8N 55.1W 65 KT
12HR VT 21/1800Z 46.7N 51.3W 70 KT...POST-TROP/EXTRATROP
24HR VT 22/0600Z 52.3N 48.4W 75 KT...POST-TROP/EXTRATROP
36HR VT 22/1800Z 56.7N 48.3W 65 KT...POST-TROP/EXTRATROP
48HR VT 23/0600Z 60.5N 52.5W 65 KT...POST-TROP/EXTRATROP
72HR VT 24/0600Z 62.5N 59.0W 45 KT...POST-TROP/EXTRATROP
96HR VT 25/0600Z 64.0N 61.0W 35 KT...POST-TROP/EXTRATROP
120HR VT 26/0600Z...DISSIPATED

$$
FORECASTER BEVEN
Member Since: Posts: Comments:
000
WTNT44 KNHC 210855
TCDAT4
TROPICAL STORM LISA DISCUSSION NUMBER 2
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL142010
500 AM EDT TUE SEP 21 2010

ENHANCED INFRARED AND SHORTWAVE IMAGERY...ALONG WITH AN AMSU
OVERPASS..INDICATE THAT THE TROPICAL CYCLONE HAS BECOME BETTER
ORGANIZED. BURSTS OF DEEP CONVECTION ARE FORMING NEAR THE
CIRCULATION CENTER...AND CLOUD TOPS ASSOCIATED WITH A BANDING
FEATURE OVER THE EAST SEMICIRCLE HAVE COOLED TO -70 CELSIUS.
DVORAK SATELLITE INTENSITY ESTIMATES ARE T2.5...35 KT...FROM BOTH
TAFB AND SAB. THESE ESTIMATES ALONG WITH AN ADT ESTIMATE OF 39 KT
SUPPORT AN UPGRADE OF THE DEPRESSION TO A 35 KT TROPICAL STORM.

THE SHEAR IS LOW...AND ENVIRONMENTAL CONDITIONS ARE EXPECTED TO
REMAIN CONDUCIVE FOR FURTHER STRENGTHENING DURING THE NEXT 36
HOURS. THROUGH THE REMAINING PERIOD...THE LARGE-SCALE MODELS SHOW
AN UPPER ANTICYCLONE LOCATED OVER THE CENTRAL ATLANTIC OCEAN
RETROGRADING SOUTHWESTWARD TOWARD THE GREATER ANTILLES...AND A MID-
TO UPPER-LEVEL TROUGH TO THE NORTH OF LISA FILLING AND MOVING
NORTHEASTWARD. THIS CHANGE IN THE SYNOPTIC PATTERN IS EXPECTED TO
INCREASE THE WESTERLY SHEAR ALONG THE FORECAST TRACK. THE
INTENSITY FORECAST IS BASED ON THE AFOREMENTIONED SCENARIO AND IS A
COMPROMISE OF THE SHIPS MODEL AND THE LGEM.

THE INITIAL MOTION ESTIMATE IS 360/4...WITHIN THE WEAK STEERING
CURRENT ASSOCIATED WITH A BREAK IN THE SUBTROPICAL RIDGE OVER THE
EASTERN ATLANTIC. THE GLOBAL MODELS...AS WELL AS THE ECMWF AND GFS
ENSEMBLES...SUGGEST A RATHER SLOW NORTHWARD MOTION DURING THE NEXT
36 HOURS. BY DAY 2...A GRADUAL TURN TOWARD THE WEST-NORTHWEST IS
INDICATED AS THE TROUGH LIFTS NORTHEASTWARD AND THE SUBTROPICAL
RIDGE BUILDS IN TO THE NORTH OF THE CYCLONE. THE NHC OFFICIAL
TRACK FORECAST REFLECTS A BLEND OF THE GLOBAL AND ENSEMBLE
MODELS...AND IS SHIFTED TO THE LEFT OF THE PREVIOUS ADVISORY.


FORECAST POSITIONS AND MAX WINDS

INITIAL 21/0900Z 17.7N 31.8W 35 KT
12HR VT 21/1800Z 18.0N 31.7W 45 KT
24HR VT 22/0600Z 18.4N 31.7W 50 KT
36HR VT 22/1800Z 18.7N 31.9W 55 KT
48HR VT 23/0600Z 19.0N 32.6W 55 KT
72HR VT 24/0600Z 19.8N 34.3W 55 KT
96HR VT 25/0600Z 20.5N 35.5W 50 KT
120HR VT 26/0600Z 21.5N 37.0W 45 KT

$$
FORECASTER ROBERTS/BEVEN
Member Since: Posts: Comments:

Viewing: 2282 - 2232

Page: 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | 31 | 32 | 33 | 34 | 35 | 36 | 37 | 38 | 39 | 40 | 41 | 42 | 43 | 44 | 45 | 46 | 47 | 48 | 49 | 50 | 51 | 52Blog Index

Top of Page

About

Jeff co-founded the Weather Underground in 1995 while working on his Ph.D. He flew with the NOAA Hurricane Hunters from 1986-1990.