T.S. Isaac Discussion #27

000
WTNT44 KNHC 272058
TCDAT4

TROPICAL STORM ISAAC DISCUSSION NUMBER  27
NWS NATIONAL HURRICANE CENTER MIAMI FL  AL092012
400 PM CDT MON AUG 27 2012

THE MUCH ANTICIPATED INTENSIFICATION 
PROCESS APPEARS TO HAVE FINALLY 
STARTED BASED ON REPORTS FROM AN AIR 
FORCE RESERVE RECONNAISSANCE 
AIRCRAFT AND FROM NEARBY NOAA BUOY 
42003. THE CENTRAL PRESSURE HAS 
DECREASED BY AT LEAST 7 MB SINCE THE 
PREVIOUS ADVISORY. THE HIGHEST FLIGHT-
LEVEL WINDS OBSERVED HAVE BEEN 74 KT 
IN THE SOUTHWEST QUADRANT AND THE 
HIGHEST BIAS-ADJUSTED SFMR WINDS ARE 
NEAR 58 KT. THESE DATA SUPPORT AN 
INTENSITY OF 60 KT.

ISAAC WOBBLED WESTWARD THIS 
AFTERNOON...BUT A REPRESENTATIVE 
INITIAL MOTION ESTIMATE IS 305/10. THE 
LATEST 12Z NHC MODEL GUIDANCE IS IN 
BETTER AGREEMENT ON A WEST-
NORTHWEST TO NORTHWEST MOTION 
TOWARD THE SOUTHEAST LOUISIANA AND 
MISSISSIPPI COASTAL AREAS OVER THE 
NEXT 36-48 HOURS. AFTER 48 
HOURS...HOWEVER...THE MODEL GUIDANCE 
REMAINS DIVERGENT ON THE HANDLING OF 
A SHORTWAVE TROUGH FORECAST TO DIG 
SOUTHEASTWARD FROM THE UPPER 
MIDWEST AND INTO THE MID-ATLANTIC 
REGION...FOLLOWED BY A RIDGE BUILDING 
IN BEHIND THE TROUGH. THE GFS AND 
ECMWF...OUR MOST RELIABLE MODELS... 
NOW HAVE VERY SIMILAR SOLUTIONS 
THROUGH DAY 5...AND THE OFFICIAL 
FORECAST TRACK IS BETWEEN THOSE TWO 
MODELS.

SATELLITE DATA INDICATE ISAAC HAS 
BECOME BETTER ORGANIZED OVER THE 
PAST 6 HOURS WITH THE DEVELOPMENT OF 
A CENTRAL DENSE OVERCAST CLOUD 
PATTERN OVER THE CENTER ALONG WITH A 
DEVELOPING EYE IN RECON DATA. 
SATELLITE DATA T-NUMBERS HAVE 
INCREASED TO T4.5/77 KT FROM TAFB AND 
SAB. RECON WIND DATA INDICATE THE 
RADIUS OF MAXIMUM WINDS HAS ALSO 
PULLED INWARD TO ABOUT 30 N MI. 
ALTHOUGH ADDITIONAL CONVECTION HAS 
BEEN DEVELOPING IN THE NORTHEASTERN 
QUADRANT...DRY MID-LEVEL AIR STILL 
LURKS JUST TO THE EAST AND SOUTHEAST 
OF THE CDO FEATURE... WHICH COULD BE 
ENTRAINED INTO THE INNER CORE AT ANY 
TIME AND DISRUPT THE DEVELOPMENT 
PROCESS. DUE TO THE PROXIMITY OF DRY 
AIR...THE INTENSITY FORECAST INDICATES 
ONLY MODEST DEVELOPMENT FOR THE 
NEXT 24 HOURS. 

HOWEVER...STRENGTHENING IS EXPECTED 
TO CONTINUE  RIGHT UP UNTIL LANDFALL 
OCCURS DUE TO THE VERY WARM WATERS 
THE CYCLONE WILL BE PASSING OVER AND 
THE VERY FAVORABLE UPPER-LEVEL 
OUTFLOW REGIME THAT ISAAC IS 
FORECAST TO DEVELOP BY 24 HOURS. THE 
INTENSITY FORECAST IS JUST SLIGHTLY 
HIGHER THAN THE MODEL GUIDANCE.

BECAUSE SIGNIFICANT HAZARDS EXTEND 
WELL AWAY FROM THE CENTER...IT IS 
IMPORTANT NOT TO FOCUS ON THE EXACT 
FORECAST TRACK. THE SLOW FORWARD 
SPED OF AROUND 5 KT AFTER LANDFALL 
WILL RESULT IN A HEAVY RAIN AND FLOOD 
SITUATION FOR PORTIONS OF THE CENTRAL 
GULF COAST AND LOWER MISSISSIPPI 
VALLEY REGIONS.

FORECAST POSITIONS AND MAX WINDS

INIT  27/2100Z 26.4N  86.2W   60 KT  70 MPH
 12H  28/0600Z 27.4N  87.5W   70 KT  80 MPH
 24H  28/1800Z 28.6N  89.0W   80 KT  90 MPH
 36H  29/0600Z 29.5N  90.0W   85 KT 100 MPH...NEAR THE COAST
 48H  29/1800Z 30.3N  90.7W   75 KT  85 MPH...INLAND
 72H  30/1800Z 32.2N  91.8W   35 KT  40 MPH...INLAND
 96H  31/1800Z 35.9N  92.1W   25 KT  30 MPH...INLAND
120H  01/1800Z 38.7N  89.3W   20 KT  25 MPH...INLAND

$$
FORECASTER STEWART

T.S. Isaac Discussion #23

000
WTNT44 KNHC 262102
TCDAT4

TROPICAL STORM ISAAC DISCUSSION NUMBER  23
NWS NATIONAL HURRICANE CENTER MIAMI FL  AL092012
500 PM EDT SUN AUG 26 2012

ALTHOUGH SATELLITE AND RADAR IMAGES 
HAVE SUGGESTED THAT THE TROPICAL
CYCLONE WAS BECOMING A LITTLE BETTER 
ORGANIZED...AN AIR FORCE HURRICANE 
HUNTER AIRCRAFT INVESTIGATING ISAAC 
THIS AFTERNOON HAVE FOUND THAT THERE 
HAS BEEN NO STRENGTHENING OF THE STORM. 
FLIGHT-LEVEL AND SFMR-OBSERVED WINDS 
SUPPORT AN INTENSITY OF 50 KT. THERE IS 
STILL A WELL-ESTABLISHED UPPER-LEVEL 
OUTFLOW PATTERN OVER THE SYSTEM...
AND VERTICAL SHEAR SHOULD REMAIN 
FAIRLY LIGHT FOR THE NEXT COUPLE OF 
DAYS.  INTENSIFICATION STILL SEEMS LIKELY
AS ISAAC MOVES OVER THE EASTERN GULF...
AND  POSSIBLY OVER THE HIGHER HEAT
CONTENT OF THE LOOP CURRENT.  THE 
OFFICIAL INTENSITY FOREAST IS CLOSE TO 
THE LATEST LGEM GUIDANCE...AND NOT 
MUCH DIFFERENT FROM THE PREVIOUS 
NHC FORECAST.    

ISAAC HAS MOVED A LITTLE TO THE LEFT 
OF PREVIOUS PROJECTIONS AND CENTER 
FIXES YIELD A 6- TO 12-HOUR AVERAGED 
MOTION OF 295/15.   THE TRACK FORECAST 
CONTINUES TO BE CHALLENGING.  THE 
DYNAMICAL MODELS SHOW THE TROPICAL 
STORM/HURRICANE GRADUALLY TURNING 
TO THE RIGHT AND HEADING FOR A BREAK 
IN THE SUBTROPICAL RIDGE.  HOWEVER...
THERE ARE SUBSTANTIAL DIFFERENCES 
AMONG THE MOST RELIABLE MODELS AS 
TO WHERE ISAAC MIGHT CROSS THE
NORTHERN GULF COAST.  THE U.K. MET. 
OFFICE AND ECMWF MODELS ARE ABOUT 
300 N MI TO THE EAST OF THE GFS AT 
LANDFALL.  IT SHOULD BE NOTED THAT 
NEARLY ALL OF THE GFS ENSMEBLE  
MEMBERS ARE EAST OF THE GFS CONTROL
TRACK.  BECAUSE OF THE WIDE MODEL
SPREAD...THERE CONTINUES TO BE 
GREATER THAN USUAL TRACK FORECAST 
UNCERTAINTY.  

THROUGHOUT THE PERIOD...IT IS 
IMPORTANT NOT TO FOCUS ON THE EXACT
FORECAST TRACK DUE TO FORECAST 
UNCERTAINTIES AND THE FACT THAT
SIGNIFICANT HAZARDS EXTEND WELL 
AWAY FROM THE CENTER.

THE OFFICIAL FORECAST TRACK AND 
WIND RADII NECESSITATE THE ISSUANCE
OF A HURRICANE WARNING FOR THE 
NORTHERN GULF COAST AT THIS TIME. 

FORECAST POSITIONS AND MAX WINDS

INIT  26/2100Z 24.2N  82.3W   50 KT  60 MPH
 12H  27/0600Z 25.1N  83.9W   55 KT  65 MPH
 24H  27/1800Z 26.3N  85.9W   60 KT  70 MPH
 36H  28/0600Z 27.7N  87.6W   70 KT  80 MPH
 48H  28/1800Z 28.9N  88.5W   80 KT  90 MPH
 72H  29/1800Z 30.7N  89.5W   85 KT 100 MPH...INLAND
 96H  30/1800Z 32.5N  90.0W   30 KT  35 MPH...INLAND
120H  31/1800Z 34.5N  90.0W   20 KT  25 MPH...INLAND

$$
FORECASTER PASCH

Tropical Storm Bonnie Advisory Number 3

Bonnie is now a tropical storm. Models show a gradual curve which would take the center very close to the oil spill area. The effect will depend on how organized a currently rather disorganized tropical storm becomes.

The oil spill efforts are largely halted, and hurrevac procedures have begun. Check the usual frequencies, plus US Coast Guard simplex.

--------------------

000
WTNT33 KNHC 230242
TCPAT3
BULLETIN
TROPICAL STORM BONNIE ADVISORY NUMBER 3
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL032010
1100 PM EDT THU JUL 22 2010

...CENTER OF BONNIE APPROACHING THE NORTHWESTERN BAHAMAS...NEW TROPICAL STORM WARNINGS FOR SOUTHERN FLORIDA...


SUMMARY OF 1100 PM EDT...0300 UTC...INFORMATION
-----------------------------------------------
LOCATION...23.4N 76.5W
ABOUT 125 MI...200 KM SSE OF NASSAU
ABOUT 285 MI...460 KM SE OF MIAMI FLORIDA
MAXIMUM SUSTAINED WINDS...40 MPH...65 KM/HR
PRESENT MOVEMENT...NW OR 305 DEGREES AT 14 MPH...22 KM/HR
MINIMUM CENTRAL PRESSURE...1007 MB...29.74 INCHES


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

A TROPICAL STORM WARNING HAS BEEN ISSUED FOR THE EAST COAST OF FLORIDA NORTH OF GOLDEN BEACH TO DEERFIELD BEACH.

A TROPICAL STORM WARNING HAS BEEN ISSUED FOR THE WEST COAST OF FLORIDA NORTH OF BONITA BEACH TO ENGLEWOOD.

SUMMARY OF WATCHES AND WARNINGS IN EFFECT...

A TROPICAL STORM WARNING IS IN EFFECT FOR...
* CENTRAL AND NORTHWESTERN BAHAMAS
* FOR THE FLORIDA EAST COAST FROM DEERFIELD BEACH SOUTHWARD INCLUDING THE ENTIRE FLORIDA KEYS AND FLORIDA BAY...AND ALONG THE WEST COAST OF FLORIDA NORTHWARD TO ENGLEWOOD

A TROPICAL STORM WATCH IN IN EFFECT FOR...
* THE EAST COAST OF FLORIDA NORTH OF DEERFIELD BEACH TO JUPITER INLET INCLUDING LAKE OKEECHOBEE

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.

INTEREST ALONG THE NORTHERN GULF COAST SHOULD MONITOR THE PROGRESS OF BONNIE. WATCHES MAY BE REQUIRED FOR PORTIONS OF THE NORTHERN GULF COAST ON FRIDAY.

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 UNITED STATES...PLEASE MONITOR PRODUCTS ISSUED BY YOUR NATIONAL METEOROLOGICAL SERVICE.


DISCUSSION AND 48-HOUR OUTLOOK
------------------------------
AT 1100 PM EDT...0300 UTC...THE CENTER OF TROPICAL STORM BONNIE WAS LOCATED NEAR LATITUDE 23.4 NORTH...LONGITUDE 76.5 WEST. BONNIE IS MOVING TOWARD THE NORTHWEST NEAR 14 MPH...22 KM/HR. A TURN TOWARD THE WEST-NORTHWEST AND A FASTER FORWARD SPEED ARE FORECAST ON FRIDAY. ON THE FORECAST TRACK...THE CENTER OF BONNIE IS EXPECTED TO PASS NEAR OR OVER THE FLORIDA KEYS AND THE SOUTHERN FLORIDA PENINSULA ON FRIDAY...AND MOVE INTO THE EASTERN GULF OF MEXICO FRIDAY NIGHT AND SATURDAY.

MAXIMUM SUSTAINED WINDS ARE NEAR 40 MPH...65 KM/HR...WITH HIGHER GUSTS. SLOW STRENGTHENING IS POSSIBLE DURING THE NEXT 48 HOURS.

TROPICAL STORM FORCE WINDS EXTEND OUTWARD UP TO 45 MILES...75 KM MAINLY TO THE NORTHEAST OF THE CENTER.

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


HAZARDS AFFECTING LAND
----------------------
WIND...TROPICAL STORM CONDITIONS WILL SPREAD OVER THE CENTRAL AND NORTHWESTERN BAHAMAS TONIGHT AND FRIDAY. WEATHER CONDITIONS WILL BEGIN TO DETERIORATE ON THE FLORIDA COAST AND FLORIDA KEYS WITHIN THE WARNING AREA EARLY FRIDAY MORNING.

RAINFALL...BONNIE IS EXPECTED TO PRODUCE TOTAL RAIN ACCUMULATIONS OF 2 TO 4 INCHES OVER SOUTH FLORIDA...WITH POSSIBLE ISOLATED MAXIMUM AMOUNTS OF 6 INCHES. RAINFALL AMOUNTS OF 3 TO 5 INCHES ARE EXPECTED OVER THE CENTRAL AND NORTHWEST BAHAMAS...WITH POSSIBLE ISOLATED AMOUNTS OF 5 TO 7 INCHES.

STORM SURGE...STORM SURGE WILL RAISE WATER LEVELS BY AS MUCH AS 1 TO 2 FEET ABOVE GROUND LEVEL OVER PORTIONS OF THE BAHAMAS...THE FLORIDA KEYS...AND THE SOUTHERN FLORIDA PENINSULA.


NEXT ADVISORY
-------------
NEXT INTERMEDIATE ADVISORY...200 AM EDT.
NEXT COMPLETE ADVISORY...500 AM EDT.

$$
FORECASTER BEVEN