Wx Infinity Forums

TexasBreeze wrote:Well with that I wouldn't expect too much of a change in track, unless they put much more stock in gfs.

It definitely poses an extremely challenging forecast for the NHC especially considering the evac time needed for NO in a worse case scenario. HPC still seems to favor the Euro in their discos and their updated one may come out about an hour before the next full advisory.

The Euro and GFS pose such different tracks/patterns..

I'd guess we will see another shift to the W and operations in NO to begin heating up to stay on the safe side.

Boy, this sure got interesting in a hurry, didn't it. With two or three more days to watch the models maybe head west, I'm feeling a little worried. Mainly for New Orleans at the moment.

New advisory nudges it west. TX not yet included. Hurricane Watches issued for the northern gulf. Winds 65 mph, moving NW at 18 mph. Sorry, don't know how to attach the path on here.

This is a touch concerning....

THE INITIAL MOTION ESTIMATE IS 305/16...A LITTLE FASTER THAN BEFORE.
AS THE UPPER-LOW TO THE WEST OF ISAAC RETREATS WESTWARD AND THE
CLOSED LOW OVER THE MID-ATLANTIC STATES LIFTS NORTHWARD...ISAAC
WILL MOVE GENERALLY WEST-NORTHWESTWARD OR NORTHWESTWARD AROUND THE
WESTERN PERIPHERY OF THE ATLANTIC SUBTROPICAL RIDGE FOR THE NEXT 48
HOURS. BEYOND THAT TIME...THERE IS CONSIDERABLE SPREAD IN THE MODEL
GUIDANCE. MOST OF THE MODELS...WITH THE EXCEPTION OF THE UKMET...NO
LONGER SHOW ISAAC RECURVING AHEAD OF A SHORTWAVE TROUGH MOVING
EASTWARD ACROSS THE EASTERN UNITED STATES. ONE CAMP OF GUIDANCE...
INCLUDING THE GFS...HWRF...AND GFS ENSEMBLE MEAN SHOW A
NORTHWESTWARD TRACK TOWARD THE CENTRAL GULF COAST AS THE SHORTWAVE
BYPASSES ISAAC COMPLETELY. THE ECMWF AND GFDL SHOW HAVE MORE OF A
WEAKNESS IN THE RIDGE AND SHOW ISAAC TURNING NORTHWARD TOWARD THE
EASTERN GULF COAST. THE NEW NHC FORECAST IS FASTER THAN THE
PREVIOUS ONE THROUGH MUCH OF THE PERIOD...BUT IS ALONG THE PREVIOUS
TRACK THROUGH 36 HOURS. AFTER THAT TIME...A SIGNIFICANT WESTWARD
ADJUSTMENT WAS MADE...AND THE NEW NHC TRACK IS CLOSE TO THE TVCA
MULTI-MODEL CONSENSUS AND THE ECMWF...SHOWING A NORTH-NORTHWESTWARD
AND NORTHWARD TURN AT DAYS 3 THROUGH 5. GIVEN THE LARGE SPREAD IN
THE GUIDANCE...CONFIDENCE IN THE LONG-RANGE TRACK FORECAST IS QUITE
LOW...AND IT IS TOO EARLY TO DETERMINE EXACTLY WHERE AND WHEN ISAAC
WILL MAKE LANDFALL ALONG THE GULF COAST. FURTHER ADJUSTMENTS TO THE
TRACK MAY BE NECESSARY LATER TODAY.

THROUGHOUT THE PERIOD...IT IS IMPORTANT NOT TO FOCUS ON THE EXACT
FORECAST TRACK SINCE SIGNIFICANT HAZARDS EXTEND WELL AWAY FROM THE
CENTER.

GIVEN THE NEW NHC FORECAST...A HURRICANE WATCH HAS BEEN ISSUED FOR A
PORTION OF THE NORTHERN GULF COAST.

It's Mobile Bay 90 kt (105 mph)

BULLETIN
TROPICAL STORM ISAAC ADVISORY NUMBER 21
NWS NATIONAL HURRICANE CENTER MIAMI FL AL092012
500 AM EDT SUN AUG 26 2012

...ISAAC A LITTLE STRONGER...EXPECTED TO APPROACH THE FLORIDA KEYS
LATER TODAY...HURRICANE WATCH ISSUED FOR PART OF THE NORTHERN GULF
COAST...


SUMMARY OF 500 AM EDT...0900 UTC...INFORMATION
----------------------------------------------
LOCATION...23.1N 79.0W
ABOUT 205 MI...330 KM ESE OF KEY WEST FLORIDA
ABOUT 215 MI...350 KM E OF HAVANA CUBA
MAXIMUM SUSTAINED WINDS...65 MPH...100 KM/H
PRESENT MOVEMENT...NW OR 305 DEGREES AT 18 MPH...30 KM/H
MINIMUM CENTRAL PRESSURE...995 MB...29.38 INCHES


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

A HURRICANE WATCH HAS BEEN ISSUED FROM THE MOUTH OF THE MISSISSIPPI
RIVER EASTWARD TO INDIAN PASS FLORIDA...NOT INCLUDING METROPOLITAN
NEW ORLEANS.

THE TROPICAL STORM WARNING HAS BEEN EXTENDED NORTHWARD AND WESTWARD
ALONG THE FLORIDA WEST COAST AND THE FLORIDA PANHANDLE TO INDIAN
PASS.

THE GOVERNMENT OF THE BAHAMAS HAS DISCONTINUED THE TROPICAL STORM
WARNING FOR THE TURKS AND CAICOS ISLANDS.

SUMMARY OF WATCHES AND WARNINGS IN EFFECT...

A HURRICANE WARNING IS IN EFFECT FOR...
* THE FLORIDA KEYS INCLUDING THE DRY TORTUGAS
* THE WEST COAST OF FLORIDA FROM BONITA BEACH SOUTHWARD TO OCEAN
REEF
* FLORIDA BAY
* ANDROS ISLAND IN THE BAHAMAS

A HURRICANE WATCH IS IN EFFECT FOR...
* THE FLORIDA EAST COAST FROM GOLDEN BEACH SOUTHWARD TO OCEAN REEF
* THE MOUTH OF THE MISSISSIPPI RIVER TO INDIAN PASS FLORIDA...NOT
INCLUDING METROPOLITAN NEW ORLEANS

A TROPICAL STORM WARNING IS IN EFFECT FOR...
* CUBAN PROVINCES OF CIEGO DE AVILA...SANCTI SPIRITUS...VILLA
CLARA...CAMAGUEY...LAS TUNAS...GRANMA...HOLGUIN...SANTIAGO DE
CUBA...AND GUANTANAMO
* THE BAHAMAS EXCLUDING ANDROS ISLAND
* THE FLORIDA EAST COAST FROM SEBASTIAN INLET SOUTHWARD TO OCEAN
REEF
* LAKE OKEECHOBEE
* THE FLORIDA WEST COAST AND THE FLORIDA PANHANDLE FROM NORTH OF
BONITA BEACH TO INDIAN PASS...INCLUDING TAMPA BAY

A TROPICAL STORM WATCH IS IN EFFECT FOR...
* CUBAN PROVINCES OF MATANZAS AND CIENFUEGOS
* THE FLORIDA EAST COAST NORTH OF SEBASTIAN INLET TO FLAGLER BEACH

A HURRICANE WARNING MEANS THAT HURRICANE CONDITIONS ARE EXPECTED
SOMEWHERE WITHIN THE WARNING AREA...IN THIS CASE WITHIN THE NEXT 24
HOURS. PREPARATIONS TO PROTECT LIFE AND PROPERTY SHOULD BE RUSHED
TO COMPLETION.

A HURRICANE WATCH MEANS THAT HURRICANE CONDITIONS ARE POSSIBLE
WITHIN THE WATCH AREA. A WATCH IS TYPICALLY ISSUED 48 HOURS
BEFORE THE ANTICIPATED FIRST OCCURRENCE OF TROPICAL-STORM-FORCE
WINDS...CONDITIONS THAT MAKE OUTSIDE PREPARATIONS DIFFICULT OR
DANGEROUS.

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...THE REMAINDER OF FLORIDA...AND
THE REMAINDER OF THE NORTHERN GULF COAST 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 AM EDT...0900 UTC...THE CENTER OF TROPICAL STORM ISAAC WAS
LOCATED NEAR LATITUDE 23.1 NORTH...LONGITUDE 79.0 WEST. ISAAC IS
MOVING TOWARD THE NORTHWEST NEAR 18 MPH...30 KM/H. A WEST-
NORTHWESTWARD TO NORTHWESTWARD MOTION IS EXPECTED DURING THE NEXT
48 HOURS WITH A GRADUAL DECREASE IN FORWARD SPEED. ON THE FORECAST
TRACK...THE CENTER OF ISAAC IS EXPECTED TO MOVE JUST NORTH OF THE
NORTH COAST OF CUBA THIS MORNING...MOVE NEAR OR OVER THE FLORIDA
KEYS LATER TODAY AND TONIGHT...AND MOVE INTO THE EASTERN GULF OF
MEXICO ON MONDAY.

DATA 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. SOME ADDITIONAL STRENGTHENING IS FORECAST
DURING THE NEXT 48 HOURS...AND ISAAC IS EXPECTED TO BE AT OR NEAR
HURRICANE STRENGTH WHEN IT REACHES THE FLORIDA KEYS.

TROPICAL-STORM-FORCE WINDS EXTEND OUTWARD UP TO 205 MILES...335 KM
FROM THE CENTER.

THE LATEST MINIMUM CENTRAL PRESSURE REPORTED BY THE AIRCRAFT WAS 995
MB...29.38 INCHES.


HAZARDS AFFECTING LAND
----------------------
RAINFALL...TOTAL RAINFALL ACCUMULATIONS OF 4 TO 8 INCHES...WITH
MAXIMUM AMOUNTS OF 12 INCHES...ARE POSSIBLE ACROSS THE FLORIDA
KEYS...THE SOUTHERN PENINSULA OF FLORIDA AND PORTIONS OF CENTRAL AND
EASTERN CUBA. TOTAL RAIN ACCUMULATIONS OF 3 TO 6 INCHES ARE
POSSIBLE OVER THE CENTRAL AND SOUTHERN BAHAMAS.

WIND...TROPICAL STORM CONDITIONS ARE OCCURRING OVER PORTIONS OF
EASTERN AND CENTRAL CUBA AND THE BAHAMAS AND THE TURKS AND CAICOS
ISLANDS. HURRICANE CONDITIONS ARE EXPECTED ON ANDROS ISLAND ON
SUNDAY. TROPICAL STORM CONDITIONS ARE POSSIBLE IN PORTIONS OF
NORTHWESTERN CUBA BY LATE SUNDAY.

HURRICANE CONDITIONS ARE EXPECTED IN THE HURRICANE WARNING AREA IN
SOUTHWEST FLORIDA AND THE FLORIDA KEYS TODAY...WITH TROPICAL
STORM CONDITIONS EXPECTED LATER THIS MORNING. HURRICANE CONDITIONS
ARE POSSIBLE IN THE HURRICANE WATCH AREA IN SOUTHEAST FLORIDA
TODAY...WITH TROPICAL STORM CONDITIONS EXPECTED IN THE TROPICAL
STORM WARNING AREA ALONG THE FLORIDA EAST COAST BY THIS MORNING.
TROPICAL STORM CONDITIONS ARE EXPECTED TO SPREAD NORTHWARD ALONG
THE WEST COAST OF FLORIDA AND INTO THE EASTERN FLORIDA PANHANDLE IN
THE TROPICAL STORM WARNING AREA TONIGHT AND MONDAY.

HURRICANE CONDITIONS ARE POSSIBLE IN THE HURRICANE WATCH AREA ALONG
THE NORTHERN GULF COAST ON TUESDAY...WITH TROPICAL STORM CONDITIONS
POSSIBLE BY MONDAY NIGHT.

STORM SURGE...THE COMBINATION OF A STORM SURGE AND THE TIDE WILL
CAUSE NORMALLY DRY AREAS NEAR THE COAST TO BE FLOODED BY RISING
WATERS. THE WATER COULD REACH THE FOLLOWING DEPTHS ABOVE GROUND IF
THE PEAK SURGE OCCURS AT THE TIME OF HIGH TIDE...

* CRYSTAL RIVER THROUGH THE BIG BEND OF FLORIDA...4 TO 7 FT
* SOUTHWEST FLORIDA COAST WITHIN HURRICANE WARNING AREA...4 TO 6 FT
* FLORIDA WEST COAST FROM BONITA BEACH TO SOUTH OF CRYSTAL RIVER
INCLUDING TAMPA BAY...3 TO 5 FT
* SOUTHEAST FLORIDA COAST AND THE FLORIDA KEYS...1 TO 3 FT
* CENTRAL AND EASTERN CUBA...1 TO 3 FT
* THE BAHAMAS...1 TO 3 FT

THE DEEPEST WATER WILL OCCUR ALONG THE IMMEDIATE COAST IN AREAS OF
ONSHORE FLOW. SURGE-RELATED FLOODING DEPENDS ON THE RELATIVE TIMING
OF THE SURGE AND THE TIDAL CYCLE...AND CAN VARY GREATLY OVER SHORT
DISTANCES. FOR INFORMATION SPECIFIC TO YOUR AREA...PLEASE SEE
PRODUCTS ISSUED BY YOUR LOCAL WEATHER SERVICE OFFICE. NEAR THE
COAST...THE SURGE WILL BE ACCOMPANIED BY DANGEROUS WAVES.

TORNADOES...ISOLATED TORNADOES ARE POSSIBLE OVER PORTIONS OF CENTRAL
AND SOUTHERN FLORIDA AND THE FLORIDA KEYS ON SUNDAY.

SURF...DANGEROUS SURF AND RIP CURRENT CONDITIONS WILL CONTINUE TO
AFFECT THE BAHAMAS...THE TURKS AND CAICOS...EASTERN AND CENTRAL
CUBA...THE FLORIDA PENINSULA AND THE FLORIDA KEYS DURING THE NEXT
COUPLE OF DAYS. PLEASE CONSULT PRODUCTS FROM YOUR LOCAL WEATHER
OFFICE FOR MORE INFORMATION.


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

$$
FORECASTER BRENNAN

6z GFS is generally an extension of the 0z.

Moves Isaac right at the Mississippi mouth and then smacks up against the ridge and starts moving almost due W across the coast before finally moving WNW/NW near the border. Still close to a hurricane and impacts would be felt by our Beaumont/Pt Arthur area neighbors.

Again this is just another model run. Grain of salt required.

This could be very bad for MS and possibly even into New Orleans, as a large volume of water may be directed toward SE LA. Landfall on the 29th, the 7th anniversary of Katrina.

Three runs in a row the GFS looks a lot like Thursdays 12oz Euro run.

Scott747 wrote:6z GFS is generally an extension of the 0z.

Moves Isaac right at the Mississippi mouth and then smacks up against the ridge and starts moving almost due W across the coast before finally moving WNW/NW near the border. Still close to a hurricane and impacts would be felt by our Beaumont/Pt Arthur area neighbors.

Again this is just another model run. Grain of salt required.

I know its uncertain at this point, but how likely is this scenario to play out (pulling up almost to coast near NOLA and head west skirting the coast)? I'm not so concerned for our area, we would probably get a lot of rain, maybe some wind. But thus would be really bad for our cajun friends to the east.

nuby3 wrote:Boy, this sure got interesting in a hurry, didn't it. With two or three more days to watch the models maybe head west, I'm feeling a little worried. Mainly for New Orleans at the moment.

Scott747 wrote:6z GFS is generally an extension of the 0z.

Moves Isaac right at the Mississippi mouth and then smacks up against the ridge and starts moving almost due W across the coast before finally moving WNW/NW near the border. Still close to a hurricane and impacts would be felt by our Beaumont/Pt Arthur area neighbors.

Again this is just another model run. Grain of salt required.

I get the caution,but 3 runs.If the 12oz GFS shows the same tract then what.

If this thing comes in around the mouth of the Mississippi River would we get some rain off of it? When is the next full model run.

Karen wrote:If this thing comes in around the mouth of the Mississippi River would we get some rain off of it? When is the next full model run.

The GFS will run in a couple of hours,the Euro around 1 oclock.

12Z Tracks & Intensity:

Key West Radar:

Looks like it's moving due west right now

Am I wrong seeing a west movement? I don't like this one bit!

Alvin Girl wrote:

Scott747 wrote:6z GFS is generally an extension of the 0z.

Moves Isaac right at the Mississippi mouth and then smacks up against the ridge and starts moving almost due W across the coast before finally moving WNW/NW near the border. Still close to a hurricane and impacts would be felt by our Beaumont/Pt Arthur area neighbors.

Again this is just another model run. Grain of salt required.

I know its uncertain at this point, but how likely is this scenario to play out (pulling up almost to coast near NOLA and head west skirting the coast)? I'm not so concerned for our area, we would probably get a lot of rain, maybe some wind. But thus would be really bad for our cajun friends to the east.

It's honestly hard to say. Isaac could easily be influenced by a weakness to the N and head towards the panhandle of Florida thus only having a small impact on Louisiana. These model runs that we post and share opinions/thoughts on are only small tools that the NHC uses to create and put out a forecast.

I wonder if somewhere in the ether, the spirit of Isaac Cline is saying "you can't name a storm after me and think I'd go to Florida, do you?!"

OK, that is my one lame attempt this morning to lighten the mood. Back to discussing the weather. These upcoming 12z runs obviously will be huge for a lot of us.