Tropical Depression Isaac:

[rnmm]

I know things in the tropics change from day to day, model run to model run, etc....but this storm is gonna be a fun one to track no matter how strong it gets, no matter where it heads...what gets me I guess is how the models have changed so much as far as intensity and track....I know I know its the tropics

[srainhoutx]

The NHC has a lot of interest in 94L RECON has been tasked as well as a high altitude G-IV mission scheduled. That data will be very valuable for future model data and will provide for a better forecast of this potential storm.

WEATHER RECONNAISSANCE FLIGHTS
CARCAH, NATIONAL HURRICANE CENTER, MIAMI, FL.
1115 AM EDT SUN 19 AUGUST 2012
SUBJECT: TROPICAL CYCLONE PLAN OF THE DAY (TCPOD)
VALID 20/1100Z TO 21/1100Z AUGUST 2012
TCPOD NUMBER.....12-092

I. ATLANTIC REQUIREMENTS
SUSPECT AREA EAST OF ISLANDS.
1. NEGATIVE RECONNAISSANCE REQUIREMENTS.
2. OUTLOOK FOR SUCCEEDING DAY: LOW LEVEL INVEST FOR
21/1800Z NEAR 15.5N AND 53.0W IF SYSTEM DEVELOPS.
3. REMARKS: ADDITIONAL DAY OUTLOOK: BEGIN 6 HRLY FIXES
22/0600Z. A NOAA GIV FLIGHT FOR 22/0000Z.

[srainhoutx]

While we are days away and many things will change throughout the time period as RECON data is ingested into the model output, the GFS does raise an eyebrow and suggests a well developed tropical cyclone in the Gulf of Mexico. We will see.

[texoz]

Oooh, things are going to get very interesting this week as we watch 94L.

[cisa]

Are y'all thinking about 10 days out on this one?

[srainhoutx]

The 12Z Euro suggests a Yucatan threat...

[Ptarmigan]

Oooh, things are going to get very interesting this week as we watch 94L.

http://raleighwx.americanwx.com/models/ ... cal288.gif

Looks like a major hurricane over Texas. Don't want that on our door step.

[djjordan]

Oooh, things are going to get very interesting this week as we watch 94L.

http://raleighwx.americanwx.com/models/ ... cal288.gif

That's one way to usher in September. I'd rather not though!!!!!

[Alvin Girl]

Oooh, things are going to get very interesting this week as we watch 94L.

http://raleighwx.americanwx.com/models/ ... cal288.gif

That's one way to usher in September. I'd rather not though!!!!!

Indeed - wouldn't that be something to have another "I" storm pay us a visit (Ike 2008 and Issac, if this storm gets that name)

[sambucol]

A nickname for Isaac is IKE!

[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: