Tropical Storm Isaac Forecast Thoughts… Saturday Night Update – 10pm

 

Good Saturday night! As of 10pm, new model data is out and the latest National Hurricane Center forecast track. The track above has shifted west a tad, and pulls the storm inland Tuesday night about 30 miles west of Destin and moves north to hit the Montgomery area after sunset on Wednesday. The NHC forecasts the storm winds of 105 mph at landfall, weakening to a strong tropical storm over south central Alabama Wednesday evening. Here’s the deal, there’s a good chance it will be much stronger at landfall sometime Tuesday night. Some of our forecast data ramps this thing up to a category 3 or 4 storm before landfall, which would be very problematic.

Remember, the track is going to change some over the next 12 to 36 hours, as the center becomes well established and pulls away from Cuba. Model data is having a tough time because the circulation center has weakened over Cuba and Haiti. The center has now moved off the northern coast of Cuba, but it’s still interacting with land. Big thunderstorms have recently developed near the center, so strengthening may be occurring now. As the storm moves away from Cuba and into the Gulf of Mexico, rapid strengthening is possible. This will likely occur late Sunday, on Monday and Tuesday.

Here’s the new 0z model data. As we noted, model data has shifted west, but there’s a larger spread of possible landfall points. Each line represents a computer model forecast path of Isaac. There’s no doubt that significant impacts are possible along the Alabama Gulf Coast and maybe well into central and west Alabama. The exact landfall point will determined who gets flooding, damaging winds and tornadoes. There are just too many questions right now to give an exact answer.

I would say there is a fair chance of widespread heavy rain, strong winds and tornadoes across all of west and central Alabama sometime Tuesday evening through Wednesday night. Again, there could be some major changes to our forecast, so stay tuned for updates.

Send us your weather pictures! Send them to weather@wvuatv.com. Also, look us up on facebook and twitter. Like us on facebook by searching facebook.com/wvuaweather or WVUA-TV Weather. You can find us on twitter by searching weather@wvuatv.comor WVUA-TV Weather. Great way to get weather updates! Plus, facebook is a great way to send us weather pictures. Simply tag us!

Join us live on WVUA-TV weekdays at 4, 5, 6 and 10 pm and weekends at 10pm for the very latest on your news, weather and sports.

Richard Scott

WVUA Chief Meteorologist

rscott@wvuatv.com

Tropical Storm Isaac Update – Saturday 10 p.m.

TROPICAL STORM ISAAC ADVISORY NUMBER  20
NWS NATIONAL HURRICANE CENTER MIAMI FL       AL092012
1100 PM EDT SAT AUG 25 2012

…ISAAC HEADING TOWARD THE STRAITS OF FLORIDA…EXPECTED TO STRENGTHEN…

SUMMARY OF 1100 PM EDT…0300 UTC…INFORMATION
———————————————–
LOCATION…22.1N 77.2W
ABOUT 65 MI…105 KM NE OF CAMAGUEY CUBA
ABOUT 340 MI…545 KM ESE OF KEY WEST FLORIDA
MAXIMUM SUSTAINED WINDS…60 MPH…95 KM/H
PRESENT MOVEMENT…NW OR 305 DEGREES AT 17 MPH…28 KM/H
MINIMUM CENTRAL PRESSURE…997 MB…29.44 INCHES

WATCHES AND WARNINGS
——————–
CHANGES WITH THIS ADVISORY…

THE TROPICAL STORM WATCH ALONG THE WEST COAST OF FLORIDA FROM BONITA BEACH TO TARPON SPRINGS HAS BEEN REPLACED WITH A TROPICAL STORM WARNING.

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

THE TROPICAL STORM WARNING HAS BEEN DISCONTINUED FOR HAITI.

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

A HURRICANE WATCH IS IN EFFECT FOR…
* THE FLORIDA EAST COAST FROM GOLDEN BEACH SOUTHWARD TO OCEAN REEF
* ANDROS ISLAND IN THE BAHAMAS

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
* TURKS AND CAICOS ISLANDS
* THE FLORIDA EAST COAST FROM SEBASTIAN INLET SOUTHWARD TO OCEAN REEF
* LAKE OKEECHOBEE
* THE FLORIDA WEST COAST FROM NORTH OF BONITA BEACH TO TARPON SPRINGS…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
* THE FLORIDA WEST COAST AND THE FLORIDA PANHANDLE NORTH OF TARPON SPRINGS TO INDIAN PASS

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…IN THIS CASE WITHIN THE NEXT 24 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…THE REMAINDER OF FLORIDA…AND ELSEWHERE ALONG THE NORTHERN GULF COAST SHOULD MONITOR THE PROGRESS OF ISAAC.  A HURRICANE WATCH MAY BE REQUIRED FOR A PORTION OF THE NORTHERN GULF COAST ON SUNDAY MORNING.

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 PM EDT…0300 UTC…THE CENTER OF TROPICAL STORM ISAAC WAS LOCATED NEAR LATITUDE 22.1 NORTH…LONGITUDE 77.2 WEST. ISAAC IS MOVING TOWARD THE NORTHWEST NEAR 17 MPH…28 KM/H…AND THIS
GENERAL MOTION IS EXPECTED TO CONTINUE DURING THE NEXT 48 HOURS. ON THE FORECAST TRACK…THE CENTER OF ISAAC SHOULD MOVE JUST NORTH OF THE CENTRAL COAST OF CUBA TONIGHT…AND MOVE NEAR OR OVER THE FLORIDA KEYS SUNDAY OR SUNDAY NIGHT.  ISAAC IS FORECAST TO MOVE OVER THE SOUTHEASTERN GULF OF MEXICO BY EARLY MONDAY.

MAXIMUM SUSTAINED WINDS ARE NEAR 60 MPH…95 KM/H…WITH HIGHER GUSTS.  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.

ESTIMATED MINIMUM CENTRAL PRESSURE 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 JAMAICA…THE CENTRAL AND EASTERN PORTIONS OF CUBA…THE FLORIDA KEYS AND THE SOUTHERN PENINSULA OF FLORIDA. TOTAL RAIN ACCUMULATIONS OF 3 TO 5 INCHES ARE POSSIBLE OVER THE CENTRAL AND SOUTHERN BAHAMAS.

WIND…TROPICAL STORM CONDITIONS ARE OCCURRING OVER PORTIONS OF EASTERN CUBA…THE BAHAMAS AND THE TURKS AND CAICOS ISLANDS. HURRICANE CONDITIONS ARE POSSIBLE ON ANDROS ISLAND ON SUNDAY. TROPICAL STORM CONDITIONS ARE EXPECTED OVER CENTRAL CUBA TONIGHT AND 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 ON SUNDAY…WITH TROPICAL STORM CONDITIONS EXPECTED BY EARLY SUNDAY. HURRICANE CONDITIONS ARE POSSIBLE IN THE HURRICANE WATCH AREA IN SOUTHEAST FLORIDA ON SUNDAY…WITH TROPICAL STORM CONDITIONS EXPECTED IN THE TROPICAL STORM WARNING AREA IN FLORIDA BY EARLY SUNDAY.  TROPICAL STORM CONDITIONS ARE EXPECTED TO SPREAD NORTHWARD ALONG THE WEST COAST OF FLORIDA IN THE WARNING AREA BY EARLY MONDAY.  TROPICAL STORM CONDITIONS ARE POSSIBLE ALONG THE WEST COAST OF FLORIDA AND THE EASTERN FLORIDA PANHANDLE BY LATE MONDAY IN THE TROPICAL STORM
WATCH AREA.

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…

* SOUTHWEST FLORIDA COAST WITHIN HURRICANE WARNING AREA…5 TO 7 FT
* FLORIDA WEST COAST IN THE TROPICAL STORM WARNING AREA 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 AND TURKS AND CAICOS…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 AFFECT HISPANIOLA…THE BAHAMAS…THE TURKS AND CAICOS…EASTERN AND CENTRAL CUBA…AND 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…200 AM EDT.
NEXT COMPLETE ADVISORY…500 AM EDT.

Daniel Sparkman
dsparkman@wvuatv.com
WVUA Weather

Saturday Evening Forecast Discussion – 9:35 p.m.

We are still watching things in the Gulf closely. The forecast changes on an hourly basis, but we are very confident that Alabama will feel the effects of Isaac Tuesday through Thursday, how intense it is, is still yet to be determined. The latest update from the National Hurricane Center is due out at 10 p.m.

As for the rest of the weekend, don’t expect much, if any, rain coverage on Sunday as a ridge axis builds across the lower Mississippi River Valley and toward West Alabama. This ridge combined with the effects of Tropical Storm Isaac will suppress activity through Monday. Highs Sunday and Monday will run in the low 90s with generally only high clouds across the area.

Attention turns toward Isaac for the forecast beyond Monday. Current NHC forecast track brings Isaac ashore near Destin and tracks north-northwestward into southeast Central Alabama by Wednesday morning. Outer rain bands could begin affecting far southeast Central Alabama Monday night, with rain chances increasing dramatically Tuesday and Tuesday night. Greatest rain chances, wind gust threat, and any isolated tornado threat will be across the southeast and then east central portions of the area. You should continue to watch the latest forecasts over the next couple of days as shifts in the forecast track and intensity of Isaac will play a significant role in conditions across Central Alabama. There remains a high level of uncertainty with this storm as models continue to shift their tracks and even a small shift or change in speed could be significant.

Daniel Sparkman
dsparkman@wvuatv.com
WVUA Weather

Damaging Central Gulf Coast Hurricane Likely… My Latest Thoughts… Saturday Update 4:40pm

 

Good Saturday afternoon to you! I’ve been on vacation for the past few days, but I’m back in town. Going through the data this afternoon, we’re looking at a dangerous situation for the northern and central Gulf Coast States, as Tropical Storm Isaac moves in this general direction. This storm is having a tough time right now due to the interaction of land over Cuba this afternoon, but that will change tonight, as the storm pulls away from the Cuba coast.

Above is our spaghetti plot of tropical models, ran at 18z today. This new set came out at 3pm today. There are some models that take it across Florida, but they are strictly climatology models and have little to no importance. The models you should be concerned with are the ones that take it inland anywhere from New Orleans to Panama City. These show landfall times sometime Tuesday evening through Wednesday early afternoon. If the storm tracks across the Gulf, well away from Florida, it could grow into a powerful system. The water temperatures are in the 85 to 90 degree range all across the central, eastern and northern Gulf of Mexico. This is a prime source of fuel for Isaac. Wind shear is forecasted to die out over the next 12 hours, and the environment is going to grow very favorable for development between tomorrow morning and Tuesday night.

Above is a run of a reliable  12z run of the GFS. It shows a powerful hurricane, making landfall near the Alabama, Mississippi line sometime Tuesday night. The storm then tracks along the state line inland. If you take this one model as being the correct solution, we would experience damaging winds across much of west and central Alabama, flooding rains and tornadoes late Tuesday through Thursday. It’s hard to say what model will be correct at this point, but confidence is increasing that a significant hurricane will cause big problems along the central Gulf Coast and well inland near the center. I say near the center, but the effects will likely be felt very far from the center due to it’s large size. In terms of a large swath of winds, the storm compares to the size of Ivan or Katrina. Will this storm be as damaging as Ivan or Katrina? It’s still a little early in the game to know. It all depends on what happens as the storm pulls away from Cuba. If it moves far enough away from Florida and begins a rapid development, then major issues will become likely. If the storm has a tough time getting organized for a day or so, then it will probably not reach major hurricane status. I want to warn you that there is a real chance this storm could grow to category 3 or 4 status before reaching landfall. This is a real threat and you need to pay very close attention to the forecasting trends.

Here’s the 5pm track from the National Hurricane Center. Again, I want to warn you, this will change over the next couple of days. The NHC forecasts Isaac to move inland near Destin, then move north into east central Alabama on Wednesday. The forecast this storm as a category 2 at landfall, with 100 mph winds. One, this storm is huge and will impact a large area, so the exact landfall point isn’t important. Two, many of our reliable models bring this thing inland along the Alabama or Mississippi Gulf Coast, so the track could easily shift west and include a damaging storm surge along our Alabama beaches. The most damaging portion of the storm will occur along and east of the center. If you take the exact forecast track as being dead on, the dangerous part of Isaac would occur around and east of Montgomery. I think there’s a good chance all of central and west Alabama could deal with flooding rain, damaging wind and tornadoes. It’s just going to take another 12 hours before we know… I’ll continue to update you as more information comes in.

Worst case scenario for our area, west and central Alabama could deal with a similar storm to hurricane Ivan back in 2004. Best case scenario for our area, the storm tracks to our east and we stay on the west side of the center. That would keep the damaging wind threat, flooding and tornadoes east of our area. Again, this is a real threat for our area and needs to be paid a close attention over the next few days. Again, more updates to come…

Send us your weather pictures! Send them to weather@wvuatv.com. Also, look us up on facebook and twitter. Like us on facebook by searching facebook.com/wvuaweather or WVUA-TV Weather. You can find us on twitter by searching weather@wvuatv.comor WVUA-TV Weather. Great way to get weather updates! Plus, facebook is a great way to send us weather pictures. Simply tag us!

Join us live on WVUA-TV weekdays at 4, 5, 6 and 10 pm and weekends at 10pm for the very latest on your news, weather and sports.

Richard Scott

WVUA Chief Meteorologist

rscott@wvuatv.com

 

Tropical Storm Isaac Update – Saturday 4 p.m.

TROPICAL STORM ISAAC ADVISORY NUMBER  19
NWS NATIONAL HURRICANE CENTER MIAMI FL       AL092012
500 PM EDT SAT AUG 25 2012

…CENTER OF ISAAC MOVING ALONG THE NORTHERN COAST OF EASTERN CUBA WITH LITTLE CHANGE IN STRENGTH…
SUMMARY OF 500 PM EDT…2100 UTC…INFORMATION
———————————————-

LOCATION…21.3N 76.0W
ABOUT 120 MI…195 KM E OF CAMAGUEY CUBA
ABOUT 270 MI…435 KM SSE OF NASSAU
MAXIMUM SUSTAINED WINDS…60 MPH…95 KM/H
PRESENT MOVEMENT…NW OR 310 DEGREES AT 21 MPH…33 KM/H
MINIMUM CENTRAL PRESSURE…997 MB…29.44 INCHES
WATCHES AND WARNINGS
——————–

CHANGES WITH THIS ADVISORY…

A TROPICAL STORM WATCH HAS BEEN ISSUED FOR THE FLORIDA WEST COAST NORTH OF TARPON SPRINGS TO SUWANNEE RIVER. THE GOVERNMENT OF THE DOMINICAN REPUBLIC HAS DISCONTINUED THE TROPICAL STORM WARNING FOR THE DOMINICAN REPUBLIC.

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

A HURRICANE WATCH IS IN EFFECT FOR…
* THE FLORIDA EAST COAST FROM GOLDEN BEACH SOUTHWARD TO OCEAN REEF
* ANDROS ISLAND IN THE BAHAMAS

A TROPICAL STORM WARNING IS IN EFFECT FOR…
* HAITI
* CUBAN PROVINCES OF CIEGO DE AVILA…SANCTI SPIRITUS…VILLA CLARA…CAMAGUEY…LAS TUNAS…GRANMA…HOLGUIN…SANTIAGO DE CUBA…AND GUANTANAMO
* THE BAHAMAS
* TURKS AND CAICOS ISLANDS
* THE FLORIDA EAST COAST FROM SEBASTIAN INLET SOUTHWARD TO OCEAN REEF
* LAKE OKEECHOBEE

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
* THE FLORIDA WEST COAST NORTH OF BONITA BEACH TO SUWANNEE RIVER

A HURRICANE WARNING MEANS THAT HURRICANE CONDITIONS ARE EXPECTED SOMEWHERE WITHIN THE WARNING AREA. A WARNING IS TYPICALLY ISSUED 36 HOURS BEFORE THE ANTICIPATED FIRST OCCURRENCE OF TROPICAL STORM FORCE WINDS…CONDITIONS THAT MAKE OUTSIDE PREPARATIONS DIFFICULT OR DANGEROUS. PREPARATIONS TO PROTECT LIFE AND PROPERTY SHOULD BE RUSHED TO COMPLETION.

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…THE REMAINDER OF FLORIDA…AND ELSEWHERE ALONG 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 PM EDT…2100 UTC…THE CENTER OF TROPICAL STORM ISAAC WAS LOCATED NEAR LATITUDE 21.3 NORTH…LONGITUDE 76.0 WEST. ISAAC IS MOVING TOWARD THE NORTHWEST NEAR 21 MPH…33 KM/H…AND THIS GENERAL MOTION IS EXPECTED TO CONTINUE DURING THE NEXT 48 HOURS. ON THE FORECAST TRACK…THE CENTER OF ISAAC SHOULD MOVE NEAR OR OVER EASTERN CUBA THIS EVENING…NEAR OR OVER CENTRAL CUBA TONIGHT…AND MOVE NEAR OR OVER THE FLORIDA KEYS AND THE SOUTHERN FLORIDA PENINSULA SUNDAY OR SUNDAY NIGHT.

MAXIMUM SUSTAINED WINDS ARE NEAR 60 MPH…95 KM/H…WITH HIGHER GUSTS.  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 MAINLY TO THE NORTH OF THE CENTER.

THE ESTIMATED MINIMUM CENTRAL PRESSURE BASED ON HURRICANE HUNTER AIRCRAFT AND CUBAN SURFACE OBSERVATIONS 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 JAMAICA…THE CENTRAL AND EASTERN PORTIONS OF CUBA…THE FLORIDA KEYS AND THE SOUTHERN PENINSULA OF FLORIDA. TOTAL RAIN ACCUMULATIONS OF 3 TO 5 INCHES ARE POSSIBLE OVER THE CENTRAL AND SOUTHERN BAHAMAS.

WIND…TROPICAL STORM CONDITIONS ARE OCCURRING OVER PORTIONS OF THE HAITI…EASTERN CUBA…THE CENTRAL AND SOUTHEASTERN BAHAMAS AND THE TURKS AND CAICOS ISLANDS. TROPICAL STORM CONDITIONS ARE EXPECTED OVER THE NORTHWESTERN BAHAMAS BY SUNDAY MORNING. HURRICANE CONDITIONS ARE POSSIBLE ON ANDROS ISLAND ON SUNDAY. TROPICAL STORM CONDITIONS ARE EXPECTED OVER CENTRAL CUBA TONIGHT. TROPICAL STORM CONDITIONS ARE EXPECTED TO REACH NORTHWESTERN CUBA ON SUNDAY.

HURRICANE CONDITIONS ARE EXPECTED IN THE HURRICANE WARNING AREA IN SOUTHWEST FLORIDA AND THE FLORIDA KEYS ON SUNDAY…WITH TROPICAL STORM CONDITIONS EXPECTED BY EARLY SUNDAY. HURRICANE CONDITIONS ARE POSSIBLE IN THE HURRICANE WATCH AREA IN SOUTHEAST FLORIDA ON SUNDAY…WITH TROPICAL STORM CONDITIONS EXPECTED IN THE TROPICAL STORM WARNING AREA IN FLORIDA BY EARLY SUNDAY.  TROPICAL STORM CONDITIONS COULD SPREAD NORTHWARD ALONG THE WEST COAST OF FLORIDA IN THE WATCH AREA BY EARLY MONDAY.

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…

* SOUTHWEST FLORIDA COAST WITHIN HURRICANE WARNING AREA…5 TO 7 FT
* FLA WEST COAST WITHIN WATCH AREA INCLUDING TAMPA BAY…3 TO 5 FT
* SOUTHEAST FLORIDA COAST AND THE FLORIDA KEYS…1 TO 3 FT
* HISPANIOLA AND EASTERN CUBA…1 TO 3 FT
* THE BAHAMAS AND TURKS AND CAICOS…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.

SURF…DANGEROUS SURF AND RIP CURRENT CONDITIONS WILL AFFECT HISPANIOLA…THE BAHAMAS…THE TURKS AND CAICOS…EASTERN AND CENTRAL CUBA…AND THE EAST COAST OF FLORIDA 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 PM EDT.
NEXT COMPLETE ADVISORY…1100 PM EDT.

Daniel Sparkman
dsparkman@wvuatv.com
WVUA Weather

Tropical Storm Isaac Forecast Discussion – Saturday 4:15 a.m.

TROPICAL STORM ISAAC DISCUSSION NUMBER  17
NWS NATIONAL HURRICANE CENTER MIAMI FL       AL092012
500 AM EDT SAT AUG 25 2012

THE CIRCULATION OF ISAAC HAS REMAINED RELATIVELY INTACT AFTER MOVING ACROSS THE SOUTHWESTERN PENINSULA OF HAITI OVERNIGHT. BEFORE THE CENTER MOVED INLAND…HURRICANE HUNTER AIRCRAFT DATA SUGGESTED THAT THE CYCLONE HAD PEAK WINDS OF ABOUT 55 KT. ASSUMING THE CYCLONE WEAKENED A LITTLE AFTER ENCOUNTERING THE HIGH TERRAIN…THE INITIAL INTENSITY IS LOWERED TO 50 KT FOR THIS ADVISORY.

THE INITIAL MOTION ESTIMATE IS 320/12. AS A MID-LEVEL TROUGH LIFTS OUT OF THE SOUTHEASTERN UNITED STATES…ISAAC WILL MOVE GENERALLY WEST-NORTHWESTWARD AROUND THE WEST SIDE OF THE SUBTROPICAL RIDGE FOR THE NEXT THREE DAYS OR SO…AND THEN TURN NORTHWARD LATE IN THE PERIOD AS A SHORTWAVE TROUGH AMPLIFIES OVER THE EASTERN UNITED STATES. THERE HAS BEEN LITTLE CHANGE TO THE NHC FORECAST THIS CYCLE…AND THE NEW TRACK FORECAST IS CLOSE TO THE MIDDLE OF THE GUIDANCE ENVELOPE AND LIES CLOSE TO THE GFS AND THE TVCA MULTI-MODEL CONSENSUS THROUGH 96 HOURS. BY DAY 5 THERE IS SOME DISAGREEMENT AS TO WHETHER ISAAC WILL TURN NORTHEASTWARD AHEAD OF THE SHORTWAVE TROUGH AS SHOWN BY THE GFS…UKMET…AND THE GFDL OR BE LEFT BEHIND AS SHOWN BY THE ECMWF AND HWRF. THE NHC DAY 5 POINT IS BETWEEN THE TWO CAMPS SHOWING A SLOW NORTHWARD MOTION.

GIVEN THAT THE CYCLONE HAS FARED RATHER WELL AFTER MOVING ACROSS HAITI…AND THAT THE TRACK FORECAST HAS ONLY MINIMAL INTERACTION WITH CUBA…THE INTENSITY FORECAST AFTER 12 HOURS HAS BEEN ADJUSTED UPWARD FOLLOWING THE TREND OF THE LATEST INTENSITY GUIDANCE. ISAAC IS EXPECTED TO BECOME A HURRICANE IN ABOUT 36 HOURS…WITH ADDITIONAL INTENSIFICATION EXPECTED AS THE CYCLONE MOVES INTO THE EASTERN GULF OF MEXICO IN A FAVORABLE ENVIRONMENT. THE NEW NHC INTENSITY FORECAST IS CLOSE TO THE INTENSITY CONSENSUS AIDS THROUGH 72 HOURS AND FOLLOWS A BLEND OF THE DECAY SHIPS AND LGEM AFTERWARD.

THE NEW NHC FORECAST NECESSITATES THE ISSUANCE OF A HURRICANE WARNING FOR THE FLORIDA KEYS AND A PORTION OF THE SOUTHWEST COAST OF FLORIDA AT THIS TIME.

IT IS IMPORTANT NOT TO FOCUS ON THE EXACT TRACK OF ISAAC 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  25/0900Z 19.0N  73.3W   50 KT  60 MPH
12H  25/1800Z 20.4N  75.0W   50 KT  60 MPH…INLAND
24H  26/0600Z 22.2N  77.6W   55 KT  65 MPH…OVER WATER
36H  26/1800Z 23.8N  80.0W   65 KT  75 MPH
48H  27/0600Z 25.0N  81.8W   70 KT  80 MPH
72H  28/0600Z 27.7N  84.9W   80 KT  90 MPH
96H  29/0600Z 30.5N  86.0W   70 KT  80 MPH…INLAND
120H  30/0600Z 32.5N  86.0W   35 KT  40 MPH…INLAND

Daniel Sparkman
dsparkman@wvuatv.com
WVUA Weather

Tropical Storm Isaac Update – Saturday 4 a.m.

TROPICAL STORM ISAAC ADVISORY NUMBER  17
NWS NATIONAL HURRICANE CENTER MIAMI FL       AL092012
500 AM EDT SAT AUG 25 2012

…ISAAC EMERGING FROM THE COAST OF HAITI…NEW WATCHES AND WARNINGS ISSUED FOR SOUTH FLORIDA AND THE KEYS…

SUMMARY OF 500 AM EDT…0900 UTC…INFORMATION
———————————————-

LOCATION…19.0N 73.3W
ABOUT 145 MI…235 KM S OF GREAT INAGUA ISLAND
ABOUT 150 MI…240 KM SE OF GUANTANAMO CUBA
MAXIMUM SUSTAINED WINDS…60 MPH…95 KM/H
PRESENT MOVEMENT…NW OR 320 DEGREES AT 14 MPH…22 KM/H
MINIMUM CENTRAL PRESSURE…992 MB…29.29 INCHES

WATCHES AND WARNINGS
——————–

CHANGES WITH THIS ADVISORY…

A HURRICANE WARNING HAS BEEN ISSUED FOR THE FLORIDA KEYS INCLUDING THE DRY TORTUGAS…THE WEST COAST OF FLORIDA FROM BONITA BEACH SOUTHWARD…AND FLORIDA BAY.

A HURRICANE WATCH HAS BEEN ISSUED FOR THE FLORIDA EAST COAST FROM GOLDEN BEACH SOUTHWARD.

THE GOVERNMENT OF THE BAHAMAS HAS ISSUED A HURRICANE WATCH FOR ANDROS ISLAND.

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
* FLORIDA BAY

A HURRICANE WATCH IS IN EFFECT FOR…
* HAITI
* THE FLORIDA EAST COAST FROM GOLDEN BEACH SOUTHWARD
* ANDROS ISLAND IN THE BAHAMAS

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 BAHAMAS
* TURKS AND CAICOS ISLANDS
* THE FLORIDA EAST COAST FROM JUPITER INLET SOUTHWARD
* LAKE OKEECHOBEE

A TROPICAL STORM WATCH IS IN EFFECT FOR…
* CUBAN PROVINCES OF MATANZAS AND CIENFUEGOS
* JAMAICA
* THE FLORIDA EAST COAST NORTH OF JUPITER INLET TO SEBASTIAN INLET

A HURRICANE WARNING MEANS THAT HURRICANE CONDITIONS ARE EXPECTED SOMEWHERE WITHIN THE WARNING AREA. A WARNING IS TYPICALLY ISSUED 36 HOURS BEFORE THE ANTICIPATED FIRST OCCURRENCE OF TROPICAL STORM FORCE WINDS…CONDITIONS THAT MAKE OUTSIDE PREPARATIONS DIFFICULT OR DANGEROUS. PREPARATIONS TO PROTECT LIFE AND PROPERTY SHOULD BE RUSHED TO COMPLETION.

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 AM EDT…0900 UTC…THE CENTER OF TROPICAL STORM ISAAC WAS LOCATED NEAR LATITUDE 19.0 NORTH…LONGITUDE 73.3 WEST. ISAAC IS MOVING TOWARD THE NORTHWEST NEAR 14 MPH…22 KM/H…AND A WEST-NORTHWEST TO NORTHWEST MOTION IS EXPECTED TO CONTINUE FOR THE NEXT COUPLE OF DAYS WITH SOME INCREASE IN FORWARD SPEED. ON THE FORECAST TRACK…THE CENTER OF ISAAC WILL MOVE NEAR OR OVER EASTERN CUBA TODAY…AND MOVE NEAR THE NORTH COAST OF CUBA TONIGHT AND APPROACH THE FLORIDA KEYS ON SUNDAY.

MAXIMUM SUSTAINED WINDS ARE NEAR 60 MPH…95 KM/H…WITH HIGHER GUSTS. SOME STRENGTHENING IS FORECAST AFTER ISAAC MOVES OVER EASTERN CUBA LATER TODAY…AND ISAAC IS EXPECTED TO BECOME A HURRICANE ON SUNDAY. TROPICAL STORM FORCE WINDS EXTEND OUTWARD UP TO 230 MILES…370 KM FROM THE CENTER. THE ESTIMATED MINIMUM CENTRAL PRESSURE IS 992 MB…29.29 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 JAMAICA…THE CENTRAL AND EASTERN PORTIONS OF CUBA…THE FLORIDA KEYS AND THE SOUTHERN PENINSULA OF FLORIDA. TOTAL RAIN ACCUMULATIONS OF 2 TO 4 INCHES ARE POSSIBLE OVER THE CENTRAL AND SOUTHEASTERN BAHAMAS.

WIND…TROPICAL STORM CONDITIONS ARE OCCURRING OVER PORTIONS OF THE DOMINICAN REPUBLIC AND HAITI…EASTERN CUBA…THE SOUTHEASTERN BAHAMAS AND THE TURKS AND CAICOS ISLANDS. TROPICAL STORM CONDITIONS ARE EXPECTED OVER THE CENTRAL BAHAMAS LATER TODAY AND TONIGHT…AND OVER THE NORTHWESTERN BAHAMAS BY SUNDAY MORNING. HURRICANE CONDITIONS ARE POSSIBLE ON ANDROS ISLAND ON SUNDAY. TROPICAL STORM CONDITIONS ARE EXPECTED OVER CENTRAL CUBA BY LATER TODAY AND TONIGHT. TROPICAL STORM CONDITIONS ARE EXPECTED TO REACH NORTHWESTERN CUBA AND THE NORTHWESTERN BAHAMAS BY TONIGHT OR SUNDAY.

HURRICANE CONDITIONS ARE EXPECTED IN THE HURRICANE WARNING AREA IN SOUTHWEST FLORIDA AND THE FLORIDA KEYS ON SUNDAY…WITH TROPICAL STORM CONDITIONS EXPECTED BY EARLY SUNDAY. HURRICANE CONDITIONS ARE POSSIBLE IN THE HURRICANE WATCH AREA IN SOUTHEAST FLORIDA ON SUNDAY…WITH TROPICAL STORM CONDITIONS EXPECTED IN THE TROPICAL STORM WARNING AREA IN FLORIDA BY EARLY SUNDAY.

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…

SOUTHWEST FLORIDA COAST…3 TO 5 FT
SOUTHEAST FLORIDA COAST AND THE FLORIDA KEYS…1 TO 3 FT
HISPANIOLA AND EASTERN CUBA…1 TO 3 FT
THE BAHAMAS AND TURKS AND CAICOS…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.

SURF…DANGEROUS SURF AND RIP CURRENT CONDITIONS WILL AFFECT PUERTO RICO…HISPANIOLA…THE BAHAMAS…THE TURKS AND CAICOS…EASTERN AND CENTRAL CUBA…AND THE EAST COAST OF FLORIDA 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.

Daniel Sparkman
dsparkman@wvuatv.com
WVUA Weather