Tropical Depression Isaac:

[srainhoutx]

TROPICAL STORM ISAAC DISCUSSION NUMBER 14
NWS NATIONAL HURRICANE CENTER MIAMI FL AL092012
1100 AM EDT FRI AUG 24 2012

RECONNAISSANCE AIRCRAFT DATA AND SATELLITE IMAGERY INDICATE THAT
ISAAC HAS BECOME BETTER ORGANIZED DURING THE PAST SEVERAL HOURS.
WHILE THE CIRCULATION CENTER REMAINS ELONGATED EAST-TO-WEST WITH
MULTIPLE EMBEDDED VORTICITY MAXIMA...THE LARGE CENTRAL AREA OF
LIGHT WINDS HAS SHRUNK AS THE STRONGEST WINDS MOVE CLOSER TO THE
CENTER. AN AIR FORCE RESERVE HURRICANE HUNTER AIRCRAFT REPORTED
66 KT FLIGHT-LEVEL WINDS AT 850 MB NORTHEAST OF THE CENTER...ALONG
WITH SFMR BIAS-CORRECTED WIND ESTIMATES NEAR 50 KT. BASED ON THESE
DATA...THE INITIAL INTENSITY IS INCREASED TO 50 KT.

THE 12Z POSITION USED A MEAN CENTER...WHICH RESULTED IN A SOUTHWARD
ADJUSTMENT. SINCE THEN...ISAAC APPEARS TO HAVE ACQUIRED A STRONGER
NORTHWARD COMPONENT OF MOTION...AND THE INITIAL MOTION IS A
SOMEWHAT UNCERTAIN 295/12. THE TRACK MODEL GUIDANCE IS IN GOOD
AGREEMENT THAT ISAAC SHOULD MOVED NORTHWESTWARD FOR THE NEXT 72
HR...STEERED BY THE SUBTROPICAL RIDGE OVER THE WESTERN ATLANTIC
TOWARD A WEAKNESS IN THE RIDGE OVER THE SOUTHEASTERN UNITED STATES.
THIS PART OF THE NEW FORECAST TRACK IS SHIFTED A LITTLE TO THE LEFT
OF THE PREVIOUS TRACK BASED ON THE INITIAL POSITION...AND LIES NEAR
THE CONSENSUS MODELS. AFTER 72 HR...THE SPREAD OF THE TRACK
GUIDANCE INCREASES DUE TO MODEL DISAGREEMENT ON THE EVOLUTION OF A
TROUGH OVER THE EASTERN UNITED STATES. THE ECMWF KEEPS MORE RIDGE
BETWEEN ISAAC AND THE TROUGH...WHICH RESULTS IN A NORTHWESTWARD
MOTION THROUGH DAY 5. THE GFS HAS A STRONGER TROUGH...WHICH
RESULTS IN A MORE NORTHWARD MOTION. THE GUIDANCE ENVELOPE HAS
SHIFTED A LITTLE EASTWARD AFTER 72 HR...AND THUS THE LATTER PORTION
OF THE NEW FORECAST TRACK IS ALSO ADJUSTED EASTWARD.

WHILE THE ORGANIZATION HAS IMPROVED...THE STRUCTURE OF ISAAC STILL
DOES NOT FAVOR RAPID INTENSIFICATION DESPITE A VERY FAVORABLE
UPPER-LEVEL WIND PATTERN. THE EARLY PART OF THE INTENSITY FORECAST
SHOWS A LITTLE MORE STRENGTHENING THAN EARLIER...AND IT IS POSSIBLE
THAT ISAAC COULD BE NEAR HURRICANE STRENGTH WHEN IT REACHES
HISPANIOLA. LAND INTERACTION WILL LIMIT THE INTENSITY FROM 24-48
HR...AND THIS PART OF THE FORECAST MAY NEED SOME ADJUSTMENT AFTER
IT IS SEEN WHAT STRUCTURE ISAAC HAS AFTER CROSSING HISPANIOLA.
ISAAC SHOULD STRENGTHEN OVER THE GULF OF MEXICO...WITH THE FORECAST
SHOWING THE CYCLONE BECOMING A HURRICANE BEFORE REACHING THE
NORTHERN GULF COAST.

IT IS IMPORTANT NOT TO FOCUS ON THE EXACT TRACK DUE TO THE
UNCERTAINTIES IN THE FORECAST AND THE FACT THAT ISAAC HAS A LARGE
AREA OF TROPICAL STORM FORCE WINDS ASSOCIATED WITH IT.


FORECAST POSITIONS AND MAX WINDS

INIT 24/1500Z 16.3N 70.8W 50 KT 60 MPH
12H 25/0000Z 17.4N 72.6W 55 KT 65 MPH
24H 25/1200Z 19.2N 75.1W 55 KT 65 MPH
36H 26/0000Z 20.9N 77.6W 50 KT 60 MPH...INLAND
48H 26/1200Z 22.3N 79.5W 45 KT 50 MPH...INLAND
72H 27/1200Z 25.0N 83.0W 55 KT 65 MPH...OVER WATER
96H 28/1200Z 28.0N 85.5W 65 KT 75 MPH
120H 29/1200Z 31.0N 86.5W 70 KT 80 MPH...INLAND

$$
FORECASTER BEVEN

[unome]

in case you missed it, weatherbell has some pages available to the general public (non-paying ppl), not sure how long it will last, but definitely worth a browse while it's free

[wxman57]

Current visual shows absolutely no northerly component in movement. I suppose a wnw movement might be difficult to detect without a grid, but I do not buy a NW trajectory. Going to need the NHC to establish position and movement a couple more times.

I'd think the same thing if I hadn't watched a 24hr water vapor loop that clearly shows a trof digging southward through the FL straits. This trof could induce a northward movement of Isaac for the next 24-36 hours, taking it close to the southern tip of Florida before the ridge builds back to its north and turns it WNW again and into the eastern Gulf. Not far from the GFS' 12Z track, though a bit west of that.

[jasons2k]

Great images, all thanks!!

My $.02 over lunch break:

Thought the G-IV data would bring more clarity today, but now there's more confusion than ever, except the western path (LA or Even TX) look close to impossible at this point.

Florida impacts are a giant question mark at this time. Florida will get impacted, but exactly where and how strong Issac will be are very big question marks at this time.

[unome]

yes, thank you wxman - really appreciate your input & all the other pros

here's a flash link from Univ of AZ I like for 500mb http://www.atmo.arizona.edu/products/wx ... 0mbwv.html

you can pick enhancement, I like "convection", really shows dry air well

Isaac isn't in view on this yet, but it won't be long...

they have many other great products also http://www.atmo.arizona.edu/products

[wxman57]

G-IV should be taking off soon to drop 36 dropsondes in the path of Isaac:
http://noaahrd.files.wordpress.com/2012 ... 9track.gif

[unome]

as Isaac gets closer to FL, NWS Melourne has awesome "local analysis" & "local model" info

http://www.srh.noaa.gov/mlb/

[srainhoutx]

HiRes Rapid scan VIS imagery suggests a WNW motion is continuing. Latest Visible images:

[srainhoutx]

MODEL DIAGNOSTIC DISCUSSION
NWS HYDROMETEOROLOGICAL PREDICTION CENTER COLLEGE PARK MD
142 PM EDT FRI AUG 24 2012

VALID AUG 24/1200 UTC THRU AUG 28/0000 UTC


...SEE NOUS42 KWNO (ADMNFD) FOR THE STATUS OF THE UPPER AIR
INGEST...

12Z MODEL EVALUATION INCLUDING THE UKMET AND CANADIAN

INITIALIZATION ERRORS DO NOT APPEAR TO SIGNIFICANTLY IMPACT THE
LARGE SCALE FORECAST.


...TROPICAL STORM ISAAC...

THE TRACK OF ISAAC IN THE 12Z NAM NOW MORE CLOSELY RESEMBLES THE
MAJORITY OF GUIDANCE...WHEREAS EARLIER NAM RUNS HAD BEEN FAR TO
THE RIGHT. IN THIS RUN...HOWEVER...THE STRUCTURE IS MUCH
DIFFERENT. MOST OF THE MODELS INDICATE A BROAD AREA OF SURFACE LOW
PRESSURE...AND PERHAPS A SECOND LOCAL PRESSURE MINIMUM SOUTHWEST
OF THE TRACK CENTER-LINE. THE NAM NOW SHOWS THE MORE SOUTHWESTERN
MINIMUM BECOMING EQUAL TO THE ORIGINAL CENTER...AND THEN BECOMING
DOMINANT AS THE SYSTEM CROSSES CUBA. THIS NOTION IS NOT REFLECTED
IN THE OTHER MODELS...BUT AT LEAST BEARS WATCHING GIVEN THAT THE
SYSTEM IS BROAD...HAS BEEN SLOW TO ORGANIZE...AND WILL BE
INTERACTING WITH THE LARGER ISLANDS AT THE WESTERN END OF THE
ANTILLES.

THE 12Z GFS CAME IN WITH A TRACK SIMILAR TO THE OFFICIAL
TRACK...BUT IS ABOUT 90 NM TO THE RIGHT BY DAY 3. THE
CANADIAN...INCLUDING ITS 12Z RUN...WAS SIMILAR...BEGINNING TO
DRIFT RIGHT OF THE OFFICIAL TRACK AFTER 26/00Z. STILL...THESE
SOLUTIONS FALL TO THE RIGHT OF CONSENSUS...AND WE NOTE THAT THE
12Z UKMET DEPICTS A TRACK THAT IS VERY CLOSE TO THE ECMWF AND THE
OFFICIAL TRACK. PLEASE REFER TO THE NATIONAL HURRICANE CENTER FOR
UPDATES ON THE OFFICIAL FORECAST TRACK/STRENGTH AND FOR ADDITIONAL
INFORMATION.

[srainhoutx]

BULLETIN
TROPICAL STORM ISAAC INTERMEDIATE ADVISORY NUMBER 14A
NWS NATIONAL HURRICANE CENTER MIAMI FL AL092012
200 PM EDT FRI AUG 24 2012

...ISAAC TURNS NORTHWESTWARD...CENTER APPROACHING THE SOUTHERN COAST
OF HISPANIOLA...


SUMMARY OF 200 PM EDT...1800 UTC...INFORMATION
----------------------------------------------
LOCATION...16.8N 71.4W
ABOUT 135 MI...215 KM SSE OF PORT AU PRINCE HAITI
ABOUT 160 MI...255 KM SW OF SANTO DOMINGO DOMINICAN REPUBLIC
MAXIMUM SUSTAINED WINDS...60 MPH...95 KM/H
PRESENT MOVEMENT...NW OR 305 DEGREES AT 14 MPH...22 KM/H
MINIMUM CENTRAL PRESSURE...997 MB...29.44 INCHES


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

NONE.

SUMMARY OF WATCHES AND WARNINGS IN EFFECT...

A HURRICANE WATCH IS IN EFFECT FOR...
* HAITI

A TROPICAL STORM WARNING IS IN EFFECT FOR...
* DOMINICAN REPUBLIC
* HAITI
* CUBAN PROVINCES OF CIEGO DE AVILA...SANCTI SPIRITUS...VILLA
CLARA...CAMAGUEY...LAS TUNAS...GRANMA...HOLGUIN...SANTIAGO DE
CUBA...AND GUANTANAMO
* THE CENTRAL BAHAMAS INCLUDING CAT ISLAND...THE EXUMAS...LONG
ISLAND...RUM CAY...AND SAN SALVADOR
* SOUTHEASTERN BAHAMAS INCLUDING THE ACKLINS...CROOKED ISLAND...LONG
CAY...THE INAGUAS...MAYAGUANA...AND THE RAGGED ISLANDS
* TURKS AND CAICOS ISLANDS

A TROPICAL STORM WATCH IS IN EFFECT FOR...
* CUBAN PROVINCES OF MATANZAS AND CIENFUEGOS
* ANDROS ISLAND
* JAMAICA

A HURRICANE WATCH MEANS THAT HURRICANE CONDITIONS ARE POSSIBLE
WITHIN THE WATCH AREA...IN THIS CASE WITHIN THE NEXT 24 TO 36 HOURS.

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.

INTERESTS THE REMAINDER OF CUBA...THE REMAINDER OF THE BAHAMAS...
SOUTH FLORIDA...AND THE FLORIDA KEYS SHOULD MONITOR THE PROGRESS OF
ISAAC. WATCHES WILL LIKELY BE REQUIRED FOR PORTIONS OF THE FLORIDA
KEYS LATER TODAY AND ARE ALSO POSSIBLE FOR PORTIONS OF THE SOUTHERN
FLORIDA PENINSULA.

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


DISCUSSION AND 48-HOUR OUTLOOK
------------------------------
AT 200 PM EDT...1800 UTC...THE CENTER OF TROPICAL STORM ISAAC WAS
LOCATED NEAR LATITUDE 16.8 NORTH...LONGITUDE 71.4 WEST. ISAAC IS NOW
MOVING TOWARD THE NORTHWEST NEAR 14 MPH...22 KM/H..AND THIS GENERAL
MOTION IS EXPECTED TO CONTINUE FOR THE NEXT COUPLE OF DAYS. ON THE
FORECAST TRACK...THE CENTER OF ISAAC WILL APPROACH THE SOUTHERN
COAST OF HISPANIOLA THIS AFTERNOON...PASS NEAR OR OVER HAITI
TONIGHT...AND MOVE NEAR OR OVER EASTERN AND CENTRAL CUBA SATURDAY
AND SUNDAY.

MAXIMUM SUSTAINED WINDS ARE NEAR 60 MPH...95 KM/H...WITH HIGHER
GUSTS. SOME STRENGTHENING IS POSSIBLE BEFORE THE CENTER REACHES THE
COAST OF HISPANIOLA TONIGHT...AND ISAAC COULD BE NEAR HURRICANE
STRENGTH AT LANDFALL.

TROPICAL STORM FORCE WINDS EXTEND OUTWARD UP TO 185 MILES...295 KM
FROM THE CENTER.

THE ESTIMATED MINIMUM CENTRAL PRESSURE BASED ON A SHIP REPORT IS 997
MB...29.44 INCHES.


HAZARDS AFFECTING LAND
----------------------
RAINFALL...TOTAL RAINFALL ACCUMULATIONS OF 8 TO 12 INCHES...WITH
MAXIMUM AMOUNTS OF 20 INCHES...ARE POSSIBLE OVER HISPANIOLA. THESE
RAINS COULD CAUSE LIFE-THREATENING FLASH FLOODS AND MUD SLIDES.
TOTAL RAIN ACCUMULATIONS OF 4 TO 8 INCHES...WITH MAXIMUM AMOUNTS OF
12 INCHES...ARE POSSIBLE ACROSS EASTERN CUBA AND JAMAICA. TOTAL
RAIN ACCUMULATIONS OF 2 TO 4 INCHES...WITH MAXIMUM AMOUNTS OF 6
INCHES ARE EXPECTED OVER PUERTO RICO AND THE VIRGIN ISLANDS. TOTAL
RAIN ACCUMULATIONS OF 2 TO 4 INCHES ARE POSSIBLE OVER THE
SOUTHEASTERN BAHAMAS.

WIND...TROPICAL STORM CONDITIONS ARE EXPECTED OVER PORTIONS OF THE
DOMINICAN REPUBLIC AND HAITI THIS AFTERNOON...WITH HURRICANE
CONDITIONS POSSIBLE. TROPICAL STORM CONDITIONS ARE EXPECTED OVER
THE SOUTHEASTERN BAHAMAS AND THE TURKS AND CAICOS ISLANDS LATER
TODAY AND TONIGHT...AND ARE EXPECTED OVER THE CENTRAL BAHAMAS BY
SATURDAY OR SATURDAY NIGHT. TROPICAL STORM CONDITIONS ARE EXPECTED
OVER EASTERN CUBA BY TONIGHT AND OVER CENTRAL CUBA BY SATURDAY OR
SATURDAY NIGHT. TROPICAL STORM CONDITIONS COULD REACH NORTHWESTERN
CUBA AND ANDROS ISLAND BY SATURDAY NIGHT.

STORM SURGE...A STORM SURGE WILL RAISE WATER LEVELS BY AS MUCH AS 1
TO 3 FEET ABOVE NORMAL TIDE LEVELS IN AREAS OF ONSHORE WINDS IN THE
TROPICAL STORM WARNING AREA. NEAR THE COAST...THE SURGE WILL BE
ACCOMPANIED BY DANGEROUS WAVES.

SURF...DANGEROUS SURF AND RIP CURRENT CONDITIONS WILL AFFECT THE
VIRGIN ISLANDS...PUERTO RICO...HISPANIOLA...THE SOUTHEASTERN AND
CENTRAL BAHAMAS...THE TURKS AND CAICOS...AND EASTERN AND CENTRAL
CUBA DURING THE NEXT COUPLE OF DAYS. PLEASE CONSULT PRODUCTS FROM
YOUR LOCAL WEATHER OFFICE FOR MORE INFORMATION.


NEXT ADVISORY
-------------
NEXT COMPLETE ADVISORY...500 PM EDT.

$$
FORECASTER BEVEN

[srainhoutx]

12Z HWRF and GFDL are into the Florida Panhandle near Pensacola/Panama City. It is noteworthy that this is the first time the GFDL has been W inline with other Hurricane Guidance..

[wxman57]

12Z HWRF and GFDL are into the Florida Panhandle near Pensacola/Panama City. It is noteworthy that this is the first time the GFDL has been W inline with other Hurricane Guidance..

And it's the first time I've actually liked a GFDL run all year.

[srainhoutx]

12Z Euro suggests a quick pass over Haiti/Western Cuba near Key West and W of Ft Myers by hour 72:

The attachment 08242012 12Z Euro NATL_GRD_850mb_072.gif is no longer available

Hour 96: South of Pensacola:

Hour 120: Near MS/AL and a close brush with SE LA:

[srainhoutx]

EXTENDED FORECAST DISCUSSION
NWS HYDROMETEOROLOGICAL PREDICTION CENTER COLLEGE PARK MD
229 PM EDT FRI AUG 24 2012

VALID 12Z MON AUG 27 2012 - 12Z FRI AUG 31 2012

...ISAAC EXPECTED TO MOVE INTO THE MID-SOUTH BY NEXT FRIDAY...

THE WESTERLIES ACROSS THE NORTHERN PACIFIC ARE NORTH OF WHAT IS
NORMAL FOR LATE AUGUST. THIS FORCES ENERGY TO POOL DOWNSTREAM,
ACROSS THE PACIFIC NORTHWEST, WITH DOWNSTREAM TROUGHING EXPECTED
ACROSS THE NORTHEAST AND A WARM CORE RIDGE EXPECTED TO WAVER IN
POSITION AND STRENGTH BETWEEN THE CENTRAL ROCKIES AND CENTRAL
PLAINS. THE DETERMINISTIC AND ENSEMBLE MEAN GUIDANCE IS IN GOOD
AGREEMENT ON THESE GENERAL IDEAS. THE MODEL CHOICE THIS PERIOD
WAS PARTIALLY CONSTRAINED BY THE LATEST NATIONAL HURRICANE CENTER
(NHC) FORECAST FOR ISAAC, WHICH RESEMBLED THE 12Z UKMET THROUGH
THURSDAY MORNING. A 00Z GFS/00Z ECMWF COMPROMISE WAS USED
THEREAFTER, WITH INPUT RECEIVED FROM NHC REGARDING TROPICAL
SYSTEMS AT 17Z. THE 06Z/12Z GFS AND 12Z CANADIAN SOLUTIONS HAD TO
BE THROWN OUT BY DEFAULT. THIS LED TO REASONABLE CONTINUITY WITH
THE MID-MORNING PRESSURES.

TROPICAL CYCLONE ISAAC
======================
THE 06Z/12Z GFS AND 12Z CANADIAN RECURVE THE SYSTEM QUICKER
THROUGH THE MID-ATLANTIC STATES THAN THE OTHER GUIDANCE, WHILE THE
00Z/12Z ECMWF AND ITS ENSEMBLE MEAN SHOW STRONGER RIDGING ACROSS
THE PLAINS/MIDWEST WHICH KEEPS THE SYSTEM ON A SLOWER AND MORE
WESTERLY TRAJECTORY. THE QUICKER SOLUTION CANNOT BE RULED OUT AS
THE PREFERRED MODEL BLEND DROPS ENERGY FROM THE WESTERLIES AROUND
THE NORTHWEST SIDE OF ISAAC, CLOSING OFF A MID TO UPPER LEVEL LOW
ACROSS TEXAS BY NEXT THURSDAY AND FRIDAY. THIS DEVELOPMENT WOULD
EFFECTIVELY SHIFT THE COL IN THE STEERING PATTERN SO FAR SOUTH
THAT ISAAC WOULD HAVE LITTLE CHOICE BUT TO RECURVE AROUND THE
PERIPHERY OF THE SUBTROPICAL RIDGE, INITIALLY LURED BY A BREAK IN
THE RIDGE ACROSS THE UPPER OHIO VALLEY TUESDAY (SIMILAR TO DEBBY
IN LATE JUNE BUT FARTHER TO THE WEST). HEAVY CORE RAINFALL WITH
AREAL AVERAGE AMOUNTS OF 8-9 INCHES ARE EXPECTED ACROSS SOUTHERN
FLORIDA/THE FLORIDA KEYS/THE FLORIDA PANHANDLE WITH THE SYSTEM
THROUGH WEDNESDAY MORNING PER THE 15Z NHC TRACK, WITH LESSER
AMOUNTS OF 3-5 INCHES POSSIBLE ACROSS THE SOUTHEAST AND MID-SOUTH
BY NEXT FRIDAY NEAR ITS TRACK, ITS DRAPING FRONTAL BOUNDARY ACROSS
THE SOUTHEAST, AND WITHIN ITS MAIN INFLOW BAND FROM THE GULF OF
MEXICO ON ITS EASTERN SIDE. LOCAL AMOUNTS OF 12-16 INCHES ARE
POSSIBLE BOTH WITHIN ITS CENTRAL DENSE OVERCAST (CDO) AND WHERE
ITS MAIN INFLOW BAND SETS UP AND PIVOTS, WHICH COULD BE AS FAR
EAST AS GEORGIA. THE CURRENT SIZE AND FORECAST TRACK FOR ISAAC
RESEMBLE HURRICANE DENNIS OF 2005, THOUGH SOMEWHAT TO THE EAST
AFTER LANDFALL. CENTRAL GEORGIA REMAINS IN AN EXCEPTIONAL,
LONG-DURATION DROUGHT SO THEY COULD USE THE RAINFALL. NORTHEAST
FLORIDA AND SOUTHERN GEORGIA WERE SATURATED FROM BERYL AND DEBBY
AS WELL AS SYNOPTICALLY-DRIVEN RAINFALL EVENTS DURING THE PAST
SEVERAL DAYS, SO THE RAIN WOULD BE PROBLEMATIC IN THAT AREA.

[srainhoutx]

Product: Air Force Vortex Message (URNT12 KNHC)
Transmitted: 24th day of the month at 19:05Z
Aircraft: Air Force Aircraft (Last 3 digits of the tail number are 300)
Storm Number & Year: 09L in 2012
Storm Name: Isaac (flight in the North Atlantic basin)
Mission Number: 12
Observation Number: 02
A. Time of Center Fix: 24th day of the month at 18:43:50Z
B. Center Fix Coordinates: 16°48'N 71°31'W (16.8N 71.5167W)
B. Center Fix Location: 132 miles (212 km) to the SSE (156°) from Port-au-Prince, Haiti.
C. Minimum Height at Standard Level: 1,381m (4,531ft) at 850mb
D. Estimated (by SFMR or visually) Maximum Surface Wind: 55kts (~ 63.3mph)
E. Location of the Estimated Maximum Surface Wind: 49 nautical miles (56 statute miles) to the ENE/E (79°) of center fix
F. Maximum Flight Level Wind Inbound: From 155° at 70kts (From the SSE at ~ 80.6mph)
G. Location of Maximum Flight Level Wind Inbound: 68 nautical miles (78 statute miles) to the ENE (75°) of center fix
H. Minimum Sea Level Pressure: 995mb (29.38 inHg)
I. Maximum Flight Level Temp & Pressure Altitude Outside Eye: 14°C (57°F) at a pressure alt. of 1,524m (5,000ft)
J. Maximum Flight Level Temp & Pressure Altitude Inside Eye: 18°C (64°F) at a pressure alt. of 1,525m (5,003ft)
K. Dewpoint Temp (collected at same location as temp inside eye): 16°C (61°F)
K. Sea Surface Temp (collected at same location as temp inside eye): Not Available
L. Eye Character: Not Available
M. Eye Shape: Not Available
N. Fix Determined By: Penetration, Wind, Pressure and Temperature
N. Fix Levels (sfc and flt lvl centers are within 5nm of each other): Surface and 850mb
O. Navigation Fix Accuracy: 0.02 nautical miles
O. Meteorological Accuracy: 4 nautical miles
Remarks Section:
Maximum Flight Level Wind: 70kts (~ 80.6mph) in the east quadrant at 18:21:30Z

[srainhoutx]

Product: Air Force Vortex Message (URNT12 KNHC)
Transmitted: 24th day of the month at 20:03Z
Aircraft: Air Force Aircraft (Last 3 digits of the tail number are 300)
Storm Number & Year: 09L in 2012
Storm Name: Isaac (flight in the North Atlantic basin)
Mission Number: 12
Observation Number: 06
A. Time of Center Fix: 24th day of the month at 19:54:50Z
B. Center Fix Coordinates: 16°54'N 71°42'W (16.9N 71.7W) (View map)
B. Center Fix Location: 121 miles (195 km) to the SSE (160°) from Port-au-Prince, Haiti.
C. Minimum Height at Standard Level: 1,378m (4,521ft) at 850mb
D. Estimated (by SFMR or visually) Maximum Surface Wind: 31kts (~ 35.7mph)
E. Location of the Estimated Maximum Surface Wind: 27 nautical miles (31 statute miles) to the SE (139°) of center fix
F. Maximum Flight Level Wind Inbound: From 237° at 34kts (From the WSW at ~ 39.1mph)
G. Location of Maximum Flight Level Wind Inbound: 34 nautical miles (39 statute miles) to the SE (140°) of center fix
H. Minimum Sea Level Pressure: 994mb (29.35 inHg)
I. Maximum Flight Level Temp & Pressure Altitude Outside Eye: 17°C (63°F) at a pressure alt. of 1,525m (5,003ft)
J. Maximum Flight Level Temp & Pressure Altitude Inside Eye: 18°C (64°F) at a pressure alt. of 1,524m (5,000ft)
K. Dewpoint Temp (collected at same location as temp inside eye): 18°C (64°F)
K. Sea Surface Temp (collected at same location as temp inside eye): Not Available
L. Eye Character: Not Available
M. Eye Shape: Not Available
N. Fix Determined By: Penetration, Wind, Pressure and Temperature
N. Fix Levels (sfc and flt lvl centers are within 5nm of each other): Surface and 850mb
O. Navigation Fix Accuracy: 0.02 nautical miles
O. Meteorological Accuracy: 2 nautical miles
Remarks Section:
Maximum Flight Level Wind: 70kts (~ 80.6mph) in the east quadrant at 18:21:30Z

[srainhoutx]

BULLETIN
TROPICAL STORM ISAAC ADVISORY NUMBER 15
NWS NATIONAL HURRICANE CENTER MIAMI FL AL092012
500 PM EDT FRI AUG 24 2012

...ISAAC STRENGTHENS A LITTLE MORE...CENTER TO MAKE LANDFALL IN
HAITI TONIGHT...


SUMMARY OF 500 PM EDT...2100 UTC...INFORMATION
----------------------------------------------
LOCATION...17.2N 71.9W
ABOUT 100 MI...160 KM SSE OF PORT AU PRINCE HAITI
ABOUT 300 MI...480 KM SE OF GUANTANAMO CUBA
MAXIMUM SUSTAINED WINDS...65 MPH...100 KM/H
PRESENT MOVEMENT...NW OR 315 DEGREES AT 16 MPH...26 KM/H
MINIMUM CENTRAL PRESSURE...994 MB...29.35 INCHES


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

THE GOVERNMENT OF THE BAHAMAS HAS ISSUED A TROPICAL STORM WARNING
FOR ANDROS ISLAND.

THE GOVERNMENT OF THE BAHAMAS HAS ISSUED A TROPICAL STORM WATCH FOR
THE NORTHWESTERN BAHAMAS...INCLUDING THE ABACOS...BERRY ISLANDS...
BIMINI...ELEUTHERA...GRAND BAHAMA ISLAND...AND NEW PROVIDENCE.

A TROPICAL STORM WATCH HAS BEEN ISSUED FOR ALL OF THE FLORIDA
KEYS INCLUDING THE DRY TORTUGAS...THE FLORIDA EAST COAST SOUTH OF
JUPITER INLET...THE FLORIDA WEST COAST SOUTH OF BONITA
BEACH...FLORIDA BAY...AND LAKE OKEECHOBEE.

SUMMARY OF WATCHES AND WARNINGS IN EFFECT...

A HURRICANE WATCH IS IN EFFECT FOR...
* HAITI

A TROPICAL STORM WARNING IS IN EFFECT FOR...
* DOMINICAN REPUBLIC
* HAITI
* CUBAN PROVINCES OF CIEGO DE AVILA...SANCTI SPIRITUS...VILLA
CLARA...CAMAGUEY...LAS TUNAS...GRANMA...HOLGUIN...SANTIAGO DE
CUBA...AND GUANTANAMO
* ANDROS ISLAND
* THE CENTRAL BAHAMAS INCLUDING CAT ISLAND...THE EXUMAS...LONG
ISLAND...RUM CAY...AND SAN SALVADOR
* SOUTHEASTERN BAHAMAS INCLUDING THE ACKLINS...CROOKED ISLAND...LONG
CAY...THE INAGUAS...MAYAGUANA...AND THE RAGGED ISLANDS
* TURKS AND CAICOS ISLANDS

A TROPICAL STORM WATCH IS IN EFFECT FOR...
* CUBAN PROVINCES OF MATANZAS AND CIENFUEGOS
* JAMAICA
* THE NORTHWESTERN BAHAMAS...INCLUDING THE ABACOS...BERRY ISLANDS...
BIMINI...ELEUTHERA...GRAND BAHAMA ISLAND...AND NEW PROVIDENCE.
* THE FLORIDA KEYS INCLUDING THE DRY TORTUGAS
* THE FLORIDA EAST COAST SOUTH OF JUPITER INLET
* THE FLORIDA WEST COAST SOUTH OF BONITA BEACH
* FLORIDA BAY AND LAKE OKEECHOBEE

A HURRICANE WATCH MEANS THAT HURRICANE CONDITIONS ARE POSSIBLE
WITHIN THE WATCH AREA...IN THIS CASE WITHIN THE NEXT 24 TO 36 HOURS.

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.

INTERESTS IN THE REMAINDER OF CUBA AND THE REMAINDER OF THE FLORIDA
PENINSULA SHOULD MONITOR THE PROGRESS OF ISAAC.

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 500 PM EDT...2100 UTC...THE CENTER OF TROPICAL STORM ISAAC WAS
LOCATED NEAR LATITUDE 17.2 NORTH...LONGITUDE 71.9 WEST. ISAAC IS
MOVING TOWARD THE NORTHWEST NEAR 16 MPH...26 KM/H...AND THIS MOTION
IS EXPECTED TO CONTINUE FOR THE NEXT COUPLE OF DAYS. ON THE
FORECAST TRACK...THE CENTER OF ISAAC SHOULD MAKE LANDFALL IN HAITI
THIS EVENING...MOVE NEAR OR OVER SOUTHEASTERN CUBA ON SATURDAY...
MOVE NEAR OR OVER CENTRAL CUBA SATURDAY NIGHT...AND APPROACH THE
FLORIDA KEYS ON SUNDAY.

REPORTS FROM AN AIR FORCE RESERVE HURRICANE HUNTER AIRCRAFT INDICATE
THAT MAXIMUM SUSTAINED WINDS HAVE INCREASED TO NEAR 65 MPH...100
KM/H...WITH HIGHER GUSTS. LITTLE CHANGE IN STRENGTH IS LIKELY
BEFORE LANDFALL...FOLLOWED BY SOME WEAKENING AS THE CENTER CROSSES
HAITI AND SOUTHEASTERN CUBA.

TROPICAL STORM FORCE WINDS EXTEND OUTWARD UP TO 185 MILES...295 KM
FROM THE CENTER.

THE MINIMUM CENTRAL PRESSURE REPORTED BY THE HURRICANE HUNTER
AIRCRAFT IS 994 MB...29.35 INCHES.


HAZARDS AFFECTING LAND
----------------------
RAINFALL...TOTAL RAINFALL ACCUMULATIONS OF 8 TO 12 INCHES...WITH
MAXIMUM AMOUNTS OF 20 INCHES...ARE POSSIBLE OVER HISPANIOLA. THESE
RAINS COULD CAUSE LIFE-THREATENING FLASH FLOODS AND MUD SLIDES.
TOTAL RAIN ACCUMULATIONS OF 4 TO 8 INCHES...WITH MAXIMUM AMOUNTS OF
12 INCHES...ARE POSSIBLE ACROSS CENTRAL AND EASTERN CUBA...AS WELL
AS JAMAICA. TOTAL RAIN ACCUMULATIONS OF 2 TO 4 INCHES...WITH
MAXIMUM AMOUNTS OF 6 INCHES ARE EXPECTED OVER PUERTO RICO. TOTAL
RAIN ACCUMULATIONS OF 2 TO 4 INCHES ARE POSSIBLE OVER THE
SOUTHEASTERN AND CENTRAL BAHAMAS. RAIN ACCUMULATIONS OF 4 TO 8
INCHES...WITH MAXIMUM AMOUNTS OF 12 INCHES...ARE POSSIBLE OVER THE
FLORIDA KEYS AND THE SOUTHERN FLORIDA PENINSULA.

WIND...TROPICAL STORM CONDITIONS ARE SPREADING OVER PORTIONS OF THE
DOMINICAN REPUBLIC AND HAITI...WITH HURRICANE CONDITIONS POSSIBLE.
TROPICAL STORM CONDITIONS ARE EXPECTED OVER THE SOUTHEASTERN
BAHAMAS AND THE TURKS AND CAICOS ISLANDS LATER TODAY AND
TONIGHT...ARE EXPECTED OVER THE CENTRAL BAHAMAS BY SATURDAY OR
SATURDAY NIGHT...AND ARE EXPECTED OVER ANDROS ISLAND BY SUNDAY.
TROPICAL STORM CONDITIONS ARE EXPECTED OVER EASTERN CUBA BY TONIGHT
AND OVER CENTRAL CUBA BY SATURDAY OR SATURDAY NIGHT. TROPICAL STORM
CONDITIONS COULD REACH NORTHWESTERN CUBA AND THE NORTHWESTERN
BAHAMAS BY SATURDAY NIGHT OR SUNDAY...AND SOUTH FLORIDA AND THE
FLORIDA KEYS ON SUNDAY.

STORM SURGE...A STORM SURGE WILL RAISE WATER LEVELS BY AS MUCH AS 1
TO 3 FEET ABOVE NORMAL TIDE LEVELS IN AREAS OF ONSHORE WINDS IN THE
TROPICAL STORM WARNING AREAS. NEAR THE COAST...THE SURGE WILL BE
ACCOMPANIED BY DANGEROUS WAVES.

SURF...DANGEROUS SURF AND RIP CURRENT CONDITIONS WILL AFFECT PUERTO
RICO...HISPANIOLA...THE SOUTHEASTERN AND CENTRAL BAHAMAS...THE
TURKS AND CAICOS...AND EASTERN AND CENTRAL CUBA DURING THE NEXT
COUPLE OF DAYS. PLEASE CONSULT PRODUCTS FROM YOUR LOCAL WEATHER
OFFICE FOR MORE INFORMATION.


NEXT ADVISORY
-------------
NEXT INTERMEDIATE ADVISORY...800 PM EDT.
NEXT COMPLETE ADVISORY...1100 PM EDT.

$$
FORECASTER BEVEN




TROPICAL STORM ISAAC DISCUSSION NUMBER 15
NWS NATIONAL HURRICANE CENTER MIAMI FL AL092012
500 PM EDT FRI AUG 24 2012

RECONNAISSANCE AIRCRAFT DATA INDICATE THAT THE CIRCULATION OF ISAAC
HAS BECOME BETTER ORGANIZED THIS AFTERNOON...WITH A WELL-DEFINED
AND MORE CIRCULAR INNER CIRCULATION. THE MAXIMUM 850 MB
FLIGHT-LEVEL WINDS HAVE BEEN 70 KT...THE MAXIMUM RELIABLE SFMR
SURFACE WIND ESTIMATE HAS BEEN 55 KT...AND THE MINIMUM REPORTED
PRESSURE HAS BEEN 994 MB. BASED ON THESE DATA...THE INITIAL
INTENSITY IS INCREASED TO 55 KT. ONE SIGN OF ONGOING ORGANIZATION
ISSUES...HOWEVER...IS THE LACK OF PERSISTENCE OF THE INNER CORE
CONVECTION...WHICH HAS WANED OVER THE PAST FEW HOURS.

ISAAC HAS MADE ITS EXPECTED TURN TOWARD THE NORTHWEST AND THE
INITIAL MOTION IS NOW 315/14. DURING THE FIRST 48-60 HR...THE
TRACK GUIDANCE MADE AN EASTWARD SHIFT SINCE THE LAST ADVISORY.
THIS WAS LED BY THE GFS...WHICH CHANGED TO A TRACK INTO THE
SOUTHEASTERN GULF OF MEXICO TO LANDFALL IN SOUTHEASTERN FLORIDA.
THE ECMWF AND UKMET ARE NOW ON THE LEFT EDGE OF THE GUIDANCE...
SHOWING A TRACK ALONG THE NORTH COAST OF CUBA. THIS PART OF
THE FORECAST TRACK IS SHIFTED EASTWARD BUT STILL LIES A LITTLE TO
THE LEFT OF THE CENTER OF THE GUIDANCE ENVELOPE AND THE CONSENSUS
MODELS. THERE REMAINS A SPREAD IN THE MODEL GUIDANCE AFTER 48
HR. THE GFS-BASED GUIDANCE SHOWS A NORTHEASTWARD MOTION AFTER
LANDFALL ON THE NORTHERN GULF COAST...WHILE THE UKMET AND ECMWF
SHOW A NORTHWARD MOTION. THE LATTER PART OF THE FORECAST TRACK IS
SHIFTED EASTWARD CLOSE TO THE CONSENSUS MODELS.

THE MAIN CONVECTIVE BAND AND STRONGEST WINDS NORTHEAST OF THE CENTER
ARE MOVING INLAND AT THIS TIME. BASED ON THIS AND THE CURRENT LACK
OF CONVECTION NEAR THE CENTER...LITTLE CHANGE IN STRENGTH IS
EXPECTED BEFORE LANDFALL. THE INTENSITY FROM 12-48 HR WILL BE
DETERMINED BY THE AMOUNT OF LAND INTERACTION. THE CURRENT FORECAST
IS BASED ON THE PREMISE THAT ISAAC WILL REMAIN OVER LAND LONG
ENOUGH TO ALLOW GRADUAL WEAKENING. HOWEVER...ANY CHANGE IN THE
TRACK THAT ALLOWS IT TO REMAIN OVER WATER FOR A LONGER TIME COULD
ALLOW IT TO BE STRONGER THAN FORECAST. AFTER 48 HR...THE
ENVIRONMENTAL CONDITIONS APPEAR GENERALLY FAVORABLE FOR ISAAC TO
STRENGTHEN INTO A HURRICANE OVER THE GULF OF MEXICO...AND THE
INTENSITY FORECAST REFLECTS THIS. CONVERSELY...A LONGER TRACK OVER
LAND MAY DISRUPT ISAAC ENOUGH TO BE UNABLE TO TAKE ADVANTAGE OF
THESE FAVORABLE CONDITIONS.

IT IS IMPORTANT NOT TO FOCUS ON THE EXACT TRACK DUE TO THE
UNCERTAINTIES IN THE FORECAST AND THE FACT THAT ISAAC HAS A LARGE
AREA OF TROPICAL STORM FORCE WINDS ASSOCIATED WITH IT. THE TROPICAL
STORM WATCH FOR SOUTH FLORIDA AND THE FLORIDA KEYS MAY HAVE TO BE
UPGRADED TO A HURRICANE WATCH IF THE INTENSITY FORECAST IS REVISED
UPWARD.

FORECAST POSITIONS AND MAX WINDS

INIT 24/2100Z 17.2N 71.9W 55 KT 65 MPH
12H 25/0600Z 18.7N 73.6W 50 KT 60 MPH
24H 25/1800Z 20.7N 76.2W 50 KT 60 MPH...INLAND
36H 26/0600Z 22.4N 78.6W 45 KT 50 MPH...NEAR COAST OF CUBA
48H 26/1800Z 23.9N 80.7W 55 KT 65 MPH...OVER WATER
72H 27/1800Z 26.5N 84.0W 65 KT 75 MPH
96H 28/1800Z 29.5N 86.0W 75 KT 85 MPH
120H 29/1800Z 32.0N 86.0W 45 KT 50 MPH...INLAND

$$
FORECASTER BEVEN

[srainhoutx]

Afternoon update from Jeff:

At 400pm Tropical Strom Watches are issued for all of the Florida Keys, the FL east coast south of Jupiter Inlet, the FL west coast south of Bonita Beach including Florida Bay and Lake Okeechobee.

Isaac has become better organized this afternoon with one center finally become dominant. The central pressure has fallen to 998mb and the winds have increased to 60mph. While some of the 12Z guidance has shifted to the west today again, the shift has been much less than yesterday and there remains a good model consensus on Isaac crossing the FL Keys and then curving NNW then N into the Fl panhandle. Most guidance is now suggesting a fairly sharp NE to ENE motion after landfall suggesting the east coast trough captures the system. The most likely landfall location on the US Gulf coast in narrowing in between the MS/AL state line and the FL panhandle.

Isaac has turned to the NW and on this track will cross over SW Haiti tonight and eastern Cuba on Saturday. It remains to be seen what affect this passage over the landmasses has on the system and in what shape Isaac enters the warm waters of the FL Straits. While conditions will be favorable for intensification as the system crosses the FL Keys and the eastern Gulf of Mexico most of the guidance shows on modest strengthening to a category 1 hurricane. This may be in part to Isaac’s large size.

Isaac is a larger than normal tropical cyclone and its effects will be far reaching. Much of the state of FL will feel the effects of this system and even with the current forecast track there could be some decent storm surge on the FL west coast with hours on onshore flow. The current track also supports a significant storm surge event into Apalachicola Bay as a long period of S winds on the east side of Isaac with trap sea water in this concave shaped bay…similar to Hurricane Dennis in 2005.

[srainhoutx]

Product: Air Force Vortex Message (URNT12 KNHC)
Transmitted: 24th day of the month at 21:40Z
Aircraft: Air Force Aircraft (Last 3 digits of the tail number are 300)
Storm Number & Year: 09L in 2012
Storm Name: Isaac (flight in the North Atlantic basin)
Mission Number: 12
Observation Number: 10
A. Time of Center Fix: 24th day of the month at 21:15:10Z
B. Center Fix Coordinates: 17°06'N 71°46'W (17.1N 71.7667W)
B. Center Fix Location: 106 miles (171 km) to the SSE (159°) from Port-au-Prince, Haiti.
C. Minimum Height at Standard Level: 1,374m (4,508ft) at 850mb
D. Estimated (by SFMR or visually) Maximum Surface Wind: 50kts (~ 57.5mph)
E. Location of the Estimated Maximum Surface Wind: 44 nautical miles (51 statute miles) to the E (90°) of center fix
F. Maximum Flight Level Wind Inbound: From 1° at 43kts (From the N at ~ 49.5mph)
G. Location of Maximum Flight Level Wind Inbound: 62 nautical miles (71 statute miles) to the WSW (253°) of center fix
H. Minimum Sea Level Pressure: 994mb (29.35 inHg)
I. Maximum Flight Level Temp & Pressure Altitude Outside Eye: 17°C (63°F) at a pressure alt. of 1,524m (5,000ft)
J. Maximum Flight Level Temp & Pressure Altitude Inside Eye: 18°C (64°F) at a pressure alt. of 1,525m (5,003ft)
K. Dewpoint Temp (collected at same location as temp inside eye): 17°C (63°F)
K. Sea Surface Temp (collected at same location as temp inside eye): Not Available
L. Eye Character: Open in the west (center has 50% or more, but less than 100%, of eyewall coverage)
M. Eye Shape & Diameter: Circular with a diameter of 16 nautical miles (18 statute miles)
N. Fix Determined By: Penetration, Radar, Wind, Pressure and Temperature
N. Fix Level: 850mb
O. Navigation Fix Accuracy: 0.02 nautical miles
O. Meteorological Accuracy: 3 nautical miles
Remarks Section - Remarks That Were Decoded...
Maximum Flight Level Wind: 70kts (~ 80.6mph) in the east quadrant at 18:21:30Z
Maximum Flight Level Temp: 18°C (64°F) which was observed 19 nautical miles (22 statute miles) to the WSW (251°) from the flight level center
Remarks Section - Additional Remarks...
RAGGED EYE PRESENTATION ON RADAR

[Rip76]

Wow,
Mike Seidel reporting out of Havana, Cuba.