Tropical Depression Isaac:

[srainhoutx]

12Z Tracks & Intensity:

[MontgomeryCoWx]

Those are not good paths for us.

Churning through the North to NW part of the Caribbean and then bam, IKE/RITA/KATRINA style all up in here.

[srainhoutx]

RECON Missions for 94L have been increased:

Code: Select all

WEATHER RECONNAISSANCE FLIGHTS
CARCAH, NATIONAL HURRICANE CENTER, MIAMI, FL.
1045 AM EDT MON 20 AUGUST 2012
SUBJECT: TROPICAL CYCLONE PLAN OF THE DAY (TCPOD)
         VALID 21/1100Z TO 22/1100Z AUGUST 2012
         TCPOD NUMBER.....12-093

I.  ATLANTIC REQUIREMENTS 
    1. SUSPECT AREA (GULF OF MEXICO)
       FLIGHT ONE --TEAL 70--
       A. 21/1600Z
       B. AFXXX 02BBA INVEST
       C. 21/1315Z
       D. 24.5N 97.0W
       E. 21/1530Z TO 21/1900Z
       F. SFC TO 10,000FT

    2. SUSPECT AREA (APPROACHING LESSER ANTILLES)
       FLIGHT ONE --TEAL 71--        FLIGHT TWO --TEAL 72--
       A. 21/1800Z                   A. 22/0600Z, 1200Z
       B. AFXXX 01DDA INVEST         B. AFXXX 0209A CYCLONE
       C. 21/1530Z                   C. 22/0400Z
       D. 16.2N 54.5W                D. 16.4N 58.3W
       E. 21/1730Z TO 21/2200Z       E. 22/0530 TO 22/1200Z
       F. SFC TO 10,000 FT           F. SFC TO 10,000 FT

    3. SUCCEEDING DAY OUTLOOK:
       A. NEGATIVE IN THE GULF OF MEXICO.
       B. CONTINUE 6-HRLY FIXES ON SYSTEM ENTERING CARIBBEAN.

[srainhoutx]

HPC:

FINAL...

ADDED A TROPICAL LOW NEAR SOUTHERN FLORIDA DAY 7 AS PER
COORDINATION WITH THE NATIONAL HURRICANE CENTER...THOUGH AT THIS
POINT...THE SYMBOL MOSTLY REPRESENTS A POSSIBLE TRACK OF AL94
AMIDST A SEA OF MODEL SPREAD. OTHERWISE...NOTHING IN THE 12Z/20
CYCLE WAS NOTED THAT COMPELLED A SIGNIFICANT CHANGE IN THE MASS
FIELD PREFERENCES EXPRESSED IN THE UPDATE PACKAGE.

[srainhoutx]

The overnight guidance continues to raise an eyebrow with 94L which is organizing a bit further S than previously expected. Microwave and IR imagery suggests we may well see a TD or TS at any time. RECON is scheduled to investigate today and Watches/Warnings may be hoisted for portions of the Caribbean Islands later today. The overnight operational guidance has trended a bit further W in the Caribbean which would tend to favor a Gulf of Mexico threat potential. Stay Tuned. The Euro is suggesting a powerful Hurricane in the Eastern Gulf in the longer range. There does appear to be enough ridging to the N to favor a W to WNW track toward the NW Caribbean. We will see.

[srainhoutx]

BEGIN
NHC_ATCF
invest_RENUMBER_al942012_al092012.ren
FSTDA
R
U
040
010
0000
201208210753
NONE
NOTIFY=ATRP
END

[srainhoutx]

A WELL-DEFINED LOW PRESSURE PRESSURE IS LOCATED ABOUT 725 MILES
EAST OF THE LESSER ANTILLES. THUNDERSTORM ACTIVITY HAS INCREASED
AND BECOME BETTER ORGANIZED NEAR THE CENTER DURING THE PAST SEVERAL
HOURS. IF THIS RECENT DEVELOPMENT TREND CONTINUES...THEN A TROPICAL
DEPRESSION COULD FORM LATER THIS MORNING. THIS SYSTEM HAS A HIGH
CHANCE...NEAR 100 PERCENT...OF BECOMING A TROPICAL CYCLONE DURING
THE NEXT 48 HOURS AS IT MOVES WESTWARD AT 20 TO 25 MPH. THIS LARGE
DISTURBANCE COULD REACH THE LESSER ANTILLES BY WEDNESDAY...AND
INTERESTS IN THAT AREA SHOULD CLOSELY MONITOR THE PROGRESS OF THIS
SYSTEM SINCE TROPICAL STORM WATCHES COULD SOON BE REQUIRED FOR
PORTIONS OF THOSE ISLANDS.

[srainhoutx]

BULLETIN
TROPICAL DEPRESSION NINE ADVISORY NUMBER 1
NWS NATIONAL HURRICANE CENTER MIAMI FL AL092012
500 AM AST TUE AUG 21 2012

...NINTH DEPRESSION OF THE SEASON FORMS EAST OF THE LESSER
ANTILLES...TROPICAL STORM WARNINGS AND WATCHES ISSUED...


SUMMARY OF 500 AM AST...0900 UTC...INFORMATION
----------------------------------------------
LOCATION...15.2N 51.2W
ABOUT 715 MI...1150 KM E OF THE LEEWARD ISLANDS
MAXIMUM SUSTAINED WINDS...35 MPH...55 KM/H
PRESENT MOVEMENT...W OR 270 DEGREES AT 20 MPH...32 KM/H
MINIMUM CENTRAL PRESSURE...1007 MB...29.74 INCHES


WATCHES AND WARNINGS
--------------------
CHANGES WITH THIS ADVISORY...

THE METEOROLOGICAL SERVICE OF BARBADOS HAS ISSUED A TROPICAL STORM
WARNING FOR DOMINICA.

THE GOVERNMENT OF FRANCE HAS ISSUED A TROPICAL STORM WARNING FOR
GUADELOUPE...DESIRADE...LES SAINTES...MARIE GALANTE...AND ST.
MARTIN.

THE GOVERNMENT OF ANTIGUA HAS ISSUED A TROPICAL STORM WARNING FOR
ST. KITTS...NEVIS...ANTIGUA...MONTSERRAT...AND BARBUDA.

THE GOVERNMENT OF CURACAO HAS ISSUED A TROPICAL STORM WATCH FOR
SABA...ST. EUSTATIUS...AND ST. MAARTEN.

THE GOVERNMENT OF ANTIGUA HAS ISSUED A TROPICAL STORM WATCH FOR THE
BRITISH VIRGIN ISLANDS.

A TROPICAL STORM WATCH HAS BEEN ISSUED FOR PUERTO RICO...VIEQUES...
CULEBRA...AND THE U.S. VIRGIN ISLANDS.

SUMMARY OF WATCHES AND WARNINGS IN EFFECT...

A TROPICAL STORM WARNING IS IN EFFECT FOR...
* DOMINICA
*GUADELOUPE...DESIRADE...LES SAINTES...MARIE GALANTE...AND ST.
MARTIN
* ST. KITTS...NEVIS...ANTIGUA...MONTSERRAT...AND BARBUDA

A TROPICAL STORM WATCH IS IN EFFECT FOR...
* SABA...ST. EUSTATIUS...AND ST. MAARTEN
* BRITISH VIRGIN ISLANDS
* PUERTO RICO...VIEQUES...CULEBRA...AND THE U.S. VIRGIN ISLANDS

A TROPICAL STORM WARNING MEANS THAT TROPICAL STORM CONDITIONS ARE
EXPECTED SOMEWHERE WITHIN THE WARNING AREA WITHIN 36 HOURS.

A TROPICAL STORM WATCH MEANS THAT TROPICAL STORM CONDITIONS ARE
POSSIBLE WITHIN THE WATCH AREA...GENERALLY WITHIN 48 HOURS.

FOR STORM INFORMATION SPECIFIC TO YOUR AREA...PLEASE MONITOR
PRODUCTS ISSUED BY YOUR NATIONAL METEOROLOGICAL SERVICE.


DISCUSSION AND 48-HOUR OUTLOOK
------------------------------
AT 500 AM AST...0900 UTC...THE CENTER OF TROPICAL DEPRESSION NINE
WAS LOCATED NEAR LATITUDE 15.2 NORTH...LONGITUDE 51.2 WEST. THE
DEPRESSION IS MOVING TOWARD THE WEST NEAR 20 MPH...32 KM/H...AND
THIS GENERAL MOTION IS EXPECTED TO CONTINUE FOR THE NEXT COUPLE OF
DAYS. ON THE FORECAST TRACK...THE CYCLONE SHOULD MOVE THROUGH THE
SOUTHERN LEEWARD ISLANDS AND NORTHERN WINDWARD ISLANDS WEDNESDAY
AFTERNOON...AND EMERGE OVER THE EASTERN CARIBBEAN SEA BY THURSDAY
MORNING.

MAXIMUM SUSTAINED WINDS ARE NEAR 35 MPH...55 KM/H...WITH HIGHER
GUSTS. STRENGTHENING IS FORECAST DURING THE NEXT 48 HOURS...AND
THE DEPRESSION IS EXPECTED TO BECOME A TROPICAL STORM LATER TODAY.

ESTIMATED MINIMUM CENTRAL PRESSURE IS 1007 MB...29.74 INCHES.


HAZARDS AFFECTING LAND
----------------------
WIND...TROPICAL STORM CONDITIONS ARE EXPECTED TO REACH THE WARNING
AREA BY WEDNESDAY AFTERNOON...MAKING OUTSIDE PREPARATIONS DIFFICULT
OR DANGEROUS.

RAINFALL...TOTAL RAIN ACCUMULATIONS OF 4 TO 8 INCHES ARE POSSIBLE
OVER THE NORTHERN WINDWARD ISLANDS AND THE LEEWARD ISLANDS.

SURF...DANGEROUS SURF AND RIP CURRENT CONDITIONS WILL AFFECT THE
WINDWARD ISLANDS AND THE LEEWARD ISLANDS DURING THE NEXT COUPLE OF
DAYS. PLEASE CONSULT PRODUCTS FROM YOUR LOCAL WEATHER OFFICE FOR
MORE INFORMATION.


NEXT ADVISORY
-------------
NEXT INTERMEDIATE ADVISORY...800 AM AST.
NEXT COMPLETE ADVISORY...1100 AM AST.

$$
FORECASTER STEWART

TROPICAL DEPRESSION NINE TROPICAL CYCLONE UPDATE
NWS NATIONAL HURRICANE CENTER MIAMI FL AL092012
510 AM AST TUE AUG 21 2012


...TROPICAL STORM WARNING ISSUED FOR ANGUILLA...

THE GOVERNMENT OF ANTIGUA HAS ISSUED A TROPICAL STORM WARNING FOR
ANGUILLA.

$$
FORECASTER STEWART

[srainhoutx]

TROPICAL DEPRESSION NINE DISCUSSION NUMBER 1
NWS NATIONAL HURRICANE CENTER MIAMI FL AL092012
500 AM AST TUE AUG 21 2012

THE LARGE LOW PRESSURE SYSTEM THAT HAS BEEN TRAVERSING THE CENTRAL
TROPICAL ATLANTIC FOR THE PAST FEW DAYS HAS ACQUIRED ENOUGH
ORGANIZED DEEP CONVECTION NEAR THE CENTER TO BE CLASSIFIED AS A
TROPICAL DEPRESSION. THE INITIAL INTENSITY OF 30 KT IS BASED ON A
SATELLITE INTENSITY ESTIMATE OF T2.0/30 KT FROM TAFB AND T1.5/25 KT
FROM SAB. SINCE THE 0600 UTC SATELLITE CLASSIFICATIONS...
CONVECTION HAS CONTINUED TO INCREASE WITH SOME CLOUD TOP
TEMPERATURES COLDER THAN -80C NOTED JUST SOUTHWEST OF THE LOW-LEVEL
CENTER.

THE INITIAL MOTION ESTIMATE IS 270/17 KT. THE DEPRESSION IS LOCATED
SOUTH OF A DEEP-LAYER SUBTROPICAL RIDGE THAT IS FORECAST TO REMAIN
INTACT FOR THE NEXT FOUR DAYS...WHICH SHOULD KEEP THE CYCLONE
MOVING IN A WESTWARD TO WEST-NORTHWESTWARD DIRECTION THROUGH 96
HOURS. BY DAY 5...HOWEVER...THE GLOBAL MODELS ARE FORECASTING A
SHORTWAVE TROUGH TO DIG SOUTHWARD OVER THE SOUTHEASTERN U.S. AND
THE GULF OF MEXICO...WHICH IS EXPECTED TO WEAKEN THE RIDGE ACROSS
FLORIDA AND THE BAHAMAS. THIS SHOULD ALLOW THE CYCLONE TO TURN
NORTHWESTWARD AND SLOW DOWN ACROSS THE NORTH-CENTRAL CARIBBEAN SEA.
THE OFFICIAL FORECAST TRACK IS CLOSE TO THE MULTI-MODEL CONSENSUS
TVCA...WHICH IS A COMPROMISE OF THE FASTER GFS MODEL AND SLOWER
ECMWF MODEL.

OTHER THAN SOME MODEST NORTHEASTERLY VERTICAL WIND SHEAR FOR THE
NEXT 24 HOURS OR SO...ENVIRONMENTAL CONDITIONS ARE EXPECTED TO BE
QUITE FAVORABLE FOR INTENSIFICATION TO OCCUR. DURING DAYS 2-3...THE
VERTICAL SHEAR IS FORECAST TO BE THE WEAKEST AND WATER TEMPERATURES
THE WARMEST...AND THAT IS WHEN THE MOST SIGNIFICANT STRENGTHENING
SHOULD OCCUR. AT DAYS 4 AND 5...POSSIBLE INTERACTION WITH LAND
MASSES OF HAITI AND CUBA...RESPECTIVELY...IS THE PRIMARY REASON
FOR THE LEVELING OFF IN THE INTENSITY. THE OFFICIAL INTENSITY
FORECAST CLOSELY FOLLOWS THE TREND OF...BUT IS LOWER THAN...THE
SHIPS AND LGEM INTENSITY MODELS...ESPECIALLY AT DAYS 3 AND 4.

AN AIR FORCE RESERVE RECONNAISSANCE AIRCRAFT WILL INVESTIGATE THE
CYCLONE THIS AFTERNOON.

FORECAST POSITIONS AND MAX WINDS

INIT 21/0900Z 15.2N 51.2W 30 KT 35 MPH
12H 21/1800Z 15.3N 53.8W 35 KT 40 MPH
24H 22/0600Z 15.7N 57.2W 40 KT 45 MPH
36H 22/1800Z 16.0N 60.5W 50 KT 60 MPH
48H 23/0600Z 16.3N 63.6W 65 KT 75 MPH
72H 24/0600Z 16.9N 69.3W 80 KT 90 MPH
96H 25/0600Z 18.0N 74.0W 95 KT 110 MPH
120H 26/0600Z 20.0N 77.3W 95 KT 110 MPH

$$
FORECASTER STEWART

[srainhoutx]

PRELIMINARY EXTENDED FORECAST DISCUSSION
NWS HYDROMETEOROLOGICAL PREDICTION CENTER COLLEGE PARK MD
342 AM EDT TUE AUG 21 2012

VALID 12Z SAT AUG 25 2012 - 12Z TUE AUG 28 2012

MODELS ARE IN FAIRLY GOOD LONGWAVE AGREEMENT THIS
CYCLE...PERPETUATING A MEAN TROUGH OVER THE NORTHWEST THROUGH A
SERIES OF QUICK MOVING SHORTWAVE TROUGHS...AND A BROAD SOMEWHAT
COMPLICATED TROUGH ALONG THE EAST COAST THAT BECOMES MORE OF JUST
A WEAKNESS IN AN UPPER HIGH OVER THE GULF OF MEXICO. THE
SHORTWAVE PATTERN AGREEMENT IS NOT QUITE AS GOOD HOWEVER...WITH
THE INCREASING SOLUTION SPREAD AND POOR RUN-TO-RUN CONTINUITY
JUSTIFYING BELOW AVERAGE CONFIDENCE IN THE SPECIFICS FROM DAY
5/SUN ONWARD. REGARDING REGIONAL DIFFERENCES AND
PREFERENCES...STARTING WITH DAY 5 THE 00Z GFS MOVES TOWARD THE
SLOW EDGE OF THE GUIDANCE WITH A SIGNIFICANT UPPER LOW MOVING INTO
THE PACIFIC NORTHWEST...AND THUS IS LESS PREFERRED COMPARED TO THE
00Z ECMWF WHICH HAS THE BULK OF DETERMINISTIC AND ENSEMBLE MEMBER
SUPPORT. ADDITIONALLY...THE GFS BECOMES QUESTIONABLY FAST WITH A
SHORTWAVE TROUGH CROSSING THE PLAINS ON DAY 5 AND THUS IS NOT
PREFERRED COMPARED TO THE BETTER SUPPORTED ECMWF SOLUTION. FOR
DAYS 6-7/MON-TUE...GENERALLY PREFER THE ECMWF ENSEMBLE MEAN
BLENDED SLIGHTLY WITH THE OPERATIONAL ECMWF FOR AMPLITUDE. THIS
APPROACH IS ALSO USED FOR THE TRACK OF TD NINE CURRENTLY NEARING
THE CARIBBEAN SEA...WHICH WAS COORDINATED WITH THE NHC YESTERDAY
AFTERNOON TO REACH SOUTHERN FLORIDA BY DAY 6/MON

00Z Euro Ensembles:

[srainhoutx]

Morning e-mail from Jeff:

New tropical depression forms in the Atlantic Ocean 645 miles East of the Leeward Islands.

Tropical Storm Warnings are issued for the Leeward Islands

Tropical Storm Watches are issued for the US/British Virgin Islands and Puerto Rico.

Discussion:
The well defined low pressure system that has been crossing the Atlantic for the past several days has developed enough deep convection overnight to be classified as at TD. The system clearly has a large circulation envelop on visible images with deep convection on its SW side this morning. The system appears to be undergoing a bit of northeasterly wind shear which is keeping thunderstorms removed to the SW side of the circulation. Additionally dry air is lurking to the NE and W of the system, but its large circulation should help to protect the developing inner core from much dry air penetration.

Track:
The depression is located south of a deep layer ridge of high pressure over the central Atlantic Ocean and this will result in a W to WNW track for the next 72 to 96 hours. This will bring the system across the Leeward and Windward Islands on Wednesday and then south of Puerto Rico and Hispaniola late this week. After 72 hours the system will begin to reach the western edge of the sub-tropical ridge over the Atlantic and a fairly decent short wave trough is forecast to dig SE from the Midwest into the central Gulf coast. This should induce a more WNW or NW motion in the days 4-5 time period toward Cuba. Model guidance is actually in very good agreement with the GFS, GFDL, and HWRF fairly close on track through 96 hours. The ECMWF is slower and more westward while the CMC is far to the right in the longer range. The GFS has been consistent over the past 24 hours with this general track reasoning. The current NHC track is a little to the west of the multi model consensus at 120 hours.

Intensity:
Except for the current shear and potential for dry air intrusion, conditions appear favorable for intensification. Most of the models bring this to a tropical storm in the next 12 -24 hours, if it is already not one currently. Suspect the large circulation will take a little bit of time to consolidate and build an inner core so will follow a slow but steady intensification in the next 48 hours and then more rapid increases beyond. One big caveat to the intensity is the potential for land interaction in the 72-120 hour time period with the islands of Hispaniola and Cuba. Any slight deviation of the forecast track could bring the system deeper across these islands which would slow intensification and likely result in some weakening. The current track brings the system just south of these islands and continues over warm waters…so it makes sense currently to follow the stronger intensity guidance at the longer range (the LGEM and SHIPS). Both make the system a major hurricane, while the GFDL, HWRF, GFS, and ECMWF do not show anywhere near as much intensification, but this is likely due to the models indicating more land interaction. Current NHC forecast brings the system to just below major hurricane status at 96 and 120 hours. Forecast intensity in the longer range is fairly low confidence.

96L:
Another area of well defined low pressure has developed about 450 miles SW of the Cape Verde Islands. Thunderstorms activity has increased with this system overnight and conditions appear favorable for development into a tropical cyclone in the next 48 hours. NHC currently gives the system at 60% chance of formation in the next 48 hours.

Forecast Track Guidance:

[kellybell4770]

I know it is way too soon to predict too far out however, are they thinking that this storm will continue back out into the Atlantic after it crosses Florida or do they think it could swing around into the Gulf?

[srainhoutx]

I know it is way too soon to predict too far out however, are they thinking that this storm will continue back out into the Atlantic after it crosses Florida or do they think it could swing around into the Gulf?

The general thinking is anywhere from Upper Texas Coast to the Bahamas as of this time. It's way too soon to know with any certainty exactly where a future Isaac may head.

[srainhoutx]

HPC Update:

PRELIMINARY UPDATE...

USED THE 00Z/21 ECENS MEAN TO UPDATE THE PRELIMINARY FRONTS AND
PRESSURES FOR DAYS 3 THROUGH 7. THE ECENS MEAN SHARED MORE IN
COMMON WITH THE VARIOUS GLOBAL DETERMINISTIC MODELS THAN THE GEFS
MEAN...THE SAID DETERMINISTIC GUIDANCE SHOWING ENOUGH SPREAD
THROUGH THE PERIOD TO NOT TRUST THEIR DETAILS. EXTRAPOLATED THE
09Z/21 NATIONAL HURRICANE CENTER FORECAST FOR THE DEPICTION OF
TROPICAL DEPRESSION NINE...WHICH WOULD TAKE THE SYSTEM TOWARD THE
FLORIDA PENINSULA DAYS 6 AND 7. WILL REFINE THE TRACK OF THIS
POTENTIAL HURRICANE DURING THE MIDDAY COORDINATION CALL.

[JackCruz]

I don't think this will be a threat to our area. This is Florida's. But anything can happen....

[unome]

look at day 7 in the loop (other images are not updated as of yet) http://www.hpc.ncep.noaa.gov/basicwx/day0-7loop.html

I'll bet Tampa's getting nervous...

HPC Update:

PRELIMINARY UPDATE...

USED THE 00Z/21 ECENS MEAN TO UPDATE THE PRELIMINARY FRONTS AND
PRESSURES FOR DAYS 3 THROUGH 7. THE ECENS MEAN SHARED MORE IN
COMMON WITH THE VARIOUS GLOBAL DETERMINISTIC MODELS THAN THE GEFS
MEAN...THE SAID DETERMINISTIC GUIDANCE SHOWING ENOUGH SPREAD
THROUGH THE PERIOD TO NOT TRUST THEIR DETAILS. EXTRAPOLATED THE
09Z/21 NATIONAL HURRICANE CENTER FORECAST FOR THE DEPICTION OF
TROPICAL DEPRESSION NINE...WHICH WOULD TAKE THE SYSTEM TOWARD THE
FLORIDA PENINSULA DAYS 6 AND 7. WILL REFINE THE TRACK OF THIS
POTENTIAL HURRICANE DURING THE MIDDAY COORDINATION CALL.

[srainhoutx]

look at day 7 in the loop (other images are not updated as of yet) http://www.hpc.ncep.noaa.gov/basicwx/day0-7loop.html

I'll bet Tampa's getting nervous...

9 days out I'm not so sure that anyone other than those folks in the Caribbean Islands need to be 'nevrous' about this potential threat. As we saw with Ike, things will change as time goes on...

http://www.nhc.noaa.gov/archive/2008/gr ... p_5W.shtml

[djmike]

It still amazes me that this far out, people continue to think they know where landfall will occur just by whichever way the 5 day track is pointing....I can remember several storms that had tracks (and the models) pointing towards the entire Gulf coast states before final landfall was determined. Take IKE for example.... Everyone in FL needs to chill for the time being and just keep an eye on the storm.

[Belmer]

One thing is for sure, TD9 is already a huge storm. If it misses a lot of the major islands, this could and will be a dangerous storm wherever it hits.

[srainhoutx]

BULLETIN
TROPICAL DEPRESSION NINE ADVISORY NUMBER 2
NWS NATIONAL HURRICANE CENTER MIAMI FL AL092012
1100 AM AST TUE AUG 21 2012

...TROPICAL DEPRESSION MOVING QUICKLY WESTWARD TOWARD THE LESSER
ANTILLES...NEW WARNINGS ISSUED...


SUMMARY OF 1100 AM AST...1500 UTC...INFORMATION
-----------------------------------------------
LOCATION...15.1N 52.8W
ABOUT 580 MI...930 KM E OF GUADELOUPE
MAXIMUM SUSTAINED WINDS...35 MPH...55 KM/H
PRESENT MOVEMENT...W OR 270 DEGREES AT 20 MPH...32 KM/H
MINIMUM CENTRAL PRESSURE...1008 MB...29.77 INCHES


WATCHES AND WARNINGS
--------------------
CHANGES WITH THIS ADVISORY...

THE GOVERNMENT OF CURACAO HAS ISSUED A TROPICAL STORM WARNING FOR
SABA...ST. EUSTATIUS...AND ST. MAARTEN.

THE GOVERNMENT OF FRANCE HAS ISSUED A TROPICAL STORM WARNING FOR
MARTINIQUE.

SUMMARY OF WATCHES AND WARNINGS IN EFFECT...

A TROPICAL STORM WARNING IS IN EFFECT FOR...
* MARTINIQUE
* DOMINICA
* GUADELOUPE AND THE SURROUNDING ISLANDS...AND ST. MARTIN
* ST. KITTS...NEVIS...ANTIGUA...MONTSERRAT...ANGUILLA...AND BARBUDA
* SABA...ST. EUSTATIUS...AND ST. MAARTEN

A TROPICAL STORM WATCH IS IN EFFECT FOR...
* BRITISH VIRGIN ISLANDS
* PUERTO RICO...VIEQUES...CULEBRA...AND THE U.S. VIRGIN ISLANDS

A TROPICAL STORM WARNING MEANS THAT TROPICAL STORM CONDITIONS ARE
EXPECTED SOMEWHERE WITHIN THE WARNING AREA WITHIN 36 HOURS.

A TROPICAL STORM WATCH MEANS THAT TROPICAL STORM CONDITIONS ARE
POSSIBLE WITHIN THE WATCH AREA...GENERALLY WITHIN 48 HOURS.

FOR STORM INFORMATION SPECIFIC TO YOUR AREA IN THE UNITED
STATES...INCLUDING POSSIBLE INLAND WATCHES AND WARNINGS...PLEASE
MONITOR PRODUCTS ISSUED BY YOUR LOCAL NATIONAL WEATHER SERVICE
FORECAST OFFICE. FOR STORM INFORMATION SPECIFIC TO YOUR AREA OUTSIDE
THE UNITED STATES...PLEASE MONITOR PRODUCTS ISSUED BY YOUR NATIONAL
METEOROLOGICAL SERVICE.


DISCUSSION AND 48-HOUR OUTLOOK
------------------------------
AT 1100 AM AST...1500 UTC...THE CENTER OF TROPICAL DEPRESSION NINE
WAS LOCATED NEAR LATITUDE 15.1 NORTH...LONGITUDE 52.8 WEST. THE
DEPRESSION IS MOVING TOWARD THE WEST NEAR 20 MPH...32 KM/H...AND
THIS GENERAL MOTION IS EXPECTED TO CONTINUE FOR THE NEXT 48 HOURS.
ON THE FORECAST TRACK...THE CYCLONE SHOULD MOVE THROUGH THE
CENTRAL LESSER ANTILLES WEDNESDAY AFTERNOON OR EVENING...AND EMERGE
OVER THE EASTERN CARIBBEAN SEA BY THURSDAY MORNING.

MAXIMUM SUSTAINED WINDS ARE NEAR 35 MPH...55 KM/H...WITH HIGHER
GUSTS. STRENGTHENING IS FORECAST DURING THE NEXT 48 HOURS...AND
THE DEPRESSION IS EXPECTED TO BECOME A TROPICAL STORM LATER TODAY.
AN AIR FORCE RESERVE HURRICANE HUNTER AIRCRAFT IS SCHEDULED TO
INVESTIGATE THE DEPRESSION THIS AFTERNOON.

ESTIMATED MINIMUM CENTRAL PRESSURE IS 1008 MB...29.77 INCHES.


HAZARDS AFFECTING LAND
----------------------
WIND...TROPICAL STORM CONDITIONS ARE EXPECTED TO REACH THE WARNING
AREA BY WEDNESDAY AFTERNOON...MAKING OUTSIDE PREPARATIONS DIFFICULT
OR DANGEROUS.

RAINFALL...TOTAL RAIN ACCUMULATIONS OF 4 TO 8 INCHES ARE POSSIBLE
OVER THE NORTHERN WINDWARD ISLANDS AND THE LEEWARD ISLANDS. TOTAL
RAIN ACCUMULATIONS OF 1 TO 3 INCHES WITH MAXIMUM AMOUNTS OF 6
INCHES ARE POSSIBLE OVER PUERTO RICO AND THE VIRGIN ISLANDS.

STORM SURGE...A STORM SURGE WILL RAISE WATER LEVELS BY AS MUCH AS 1
TO 3 FEET ABOVE NORMAL TIDE LEVELS IN THE NORTHERN LEEWARD ISLANDS.
NEAR THE COAST...THE SURGE WILL BE ACCOMPANIED BY DANGEROUS WAVES.

SURF...DANGEROUS SURF AND RIP CURRENT CONDITIONS WILL AFFECT THE
WINDWARD AND LEEWARD ISLANDS DURING THE NEXT COUPLE OF DAYS. PLEASE
CONSULT PRODUCTS FROM YOUR LOCAL WEATHER OFFICE FOR MORE
INFORMATION.


NEXT ADVISORY
-------------
NEXT INTERMEDIATE ADVISORY...200 PM AST.
NEXT COMPLETE ADVISORY...500 PM AST.

$$
FORECASTER BEVEN

TROPICAL DEPRESSION NINE DISCUSSION NUMBER 2
NWS NATIONAL HURRICANE CENTER MIAMI FL AL092012
1100 AM AST TUE AUG 21 2012

A BURST OF CONVECTION CONTINUES JUST SOUTH OR SOUTHWEST OF THE
CENTER OF TROPICAL DEPRESSION NINE...ALTHOUGH THE OVERALL COVERAGE
HAS DECREASED DURING THE PAST FEW HOURS. SATELLITE INTENSITY
ESTIMATES ARE 35 KT FROM TAFB AND 30 KT FROM SAB. BASED ON THESE
DATA AND THE RELATIVELY HIGH PRESSURE OF 1010 MB AT NOAA BUOY
41040...THE INITIAL INTENSITY REMAINS 30 KT. AN AIR FORCE RESERVE
HURRICANE HUNTER AIRCRAFT IS SCHEDULED TO INVESTIGATE THE
DEPRESSION THIS AFTERNOON.

THE INITIAL MOTION REMAINS 270/17. THE DEPRESSION IS LOCATED SOUTH
OF A DEEP-LAYER SUBTROPICAL RIDGE THAT IS FORECAST TO REMAIN INTACT
FOR THE NEXT 72 HR...WHICH SHOULD KEEP THE CYCLONE MOVING GENERALLY
WESTWARD AS SHOWN BY THE TIGHTLY CLUSTERED TRACK MODEL GUIDANCE.
AFTER THAT...THE GLOBAL MODELS ARE FORECASTING A SHORTWAVE TROUGH
TO DIG SOUTHWARD OVER THE SOUTHEASTERN U.S. AND THE GULF OF
MEXICO...WHICH IS EXPECTED TO WEAKEN THE RIDGE ACROSS FLORIDA AND
THE BAHAMAS. THIS SHOULD ALLOW THE CYCLONE TO TURN WEST-
NORTHWESTWARD AND SLOW DOWN ACROSS THE NORTH-CENTRAL CARIBBEAN SEA.
THE GUIDANCE SHOWS MORE SPREAD DURING THIS PERIOD...WITH THE UKMET
ON THE RIGHT EDGE SHOWING THE CYCLONE MOVING ALONG THE NORTHERN
COAST OF HISPANIOLA...AND THE ECMWF AND GFS ON THE LEFT EDGE
SHOWING THE SYSTEM PASSING SOUTH OF HISPANIOLA. THE NEW FORECAST
TRACK IS SIMILAR TO THE PREVIOUS TRACK THROUGH 72 HR...THEN IS A
LITTLE TO THE RIGHT OF THE PREVIOUS TRACK AFTER THAT. THE TRACK IS
IN BEST AGREEMENT WITH A BLEND OF THE GFS AND ECMWF MODELS.

THE DEPRESSION IS CURRENTLY EXPERIENCING LIGHT/MODERATE
NORTHEASTERLY VERTICAL WIND SHEAR. THIS SHOULD DIMINISH DURING THE
NEXT 24 HR OR SO...LEAVING THE CYCLONE IN A FAVORABLE ENVIRONMENT
FOR DEVELOPMENT. THE NEW INTENSITY FORECAST IS THE SAME AS THE
PREVIOUS FORECAST THROUGH 72 HR...SHOWING THE SYSTEM BECOMING A
TROPICAL STORM IN 12 HR AND A HURRICANE IN 48 HR. AFTER 72
HR...THE FORECAST TRACK BRINGS THE SYSTEM CLOSER TO HISPANIOLA AND
CUBA THAN THE PREVIOUS TRACK. BASED ON THIS...THE INTENSITY
FORECAST DURING THAT TIME HAS BEEN LOWERED BY 5-10 KT.


FORECAST POSITIONS AND MAX WINDS

INIT 21/1500Z 15.1N 52.8W 30 KT 35 MPH
12H 22/0000Z 15.2N 55.3W 35 KT 40 MPH
24H 22/1200Z 15.5N 58.4W 40 KT 45 MPH
36H 23/0000Z 15.9N 61.5W 50 KT 60 MPH
48H 23/1200Z 16.2N 64.6W 65 KT 75 MPH
72H 24/1200Z 17.0N 70.0W 80 KT 90 MPH
96H 25/1200Z 18.5N 74.0W 90 KT 105 MPH...INLAND
120H 26/1200Z 20.5N 77.5W 85 KT 100 MPH...OVER WATER

$$
FORECASTER BEVEN