Tropical Storm Hanna

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Tropical Storm Hanna

• 1400L 03 Sept 2008
• LT Paul Kemp, NOAA Corps
• NOAA Desk Officer

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(No Transcript)
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Current Satellite Image
Center TS Hanna
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5 Day Total RainfallEnding Sunday Evening, Sept.
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HANNA BEGINNING TO MOVE NORTH-NORTHWESTWARD

• AT 200 PM AST, THE CENTER OF TROPICAL STORM
  HANNA WAS LOCATED JUST SOUTH OF THE CAICOS
  ISLANDS. HANNA IS MOVING TOWARD THE
  NORTH-NORTHWEST NEAR 10 MPH. A TURN TO THE
  NORTHWEST WITH AN INCREASE IN FORWARD SPEED IS
  EXPECTED OVER THE NEXT 24 HOURS.
• ON THE FORECAST TRACK, THE CENTER OF HANNA SHOULD
  BE MOVING THROUGH OR JUST EAST OF THE CENTRAL AND
  NORTHWESTERN BAHAMAS OVER THE NEXT COUPLE OF
  DAYS. MAXIMUM SUSTAINED WINDS ARE NEAR 60 MPH
  WITH HIGHER GUSTS.
• LITTLE CHANGE IN STRENGTH IS FORECAST TODAY, BUT
  HANNA COULD REGAIN HURRICANE STRENGTH TOMORROW OR
  ON FRIDAY. HANNA IS A LARGE TROPICAL CYCLONE.
  TROPICAL STORM FORCE WINDS EXTEND OUTWARD UP TO
  290 MILES MAINLY TO THE NORTH OF THE CENTER.
• THE LATEST MINIMUM CENTRAL PRESSURE REPORTED BY
  RECONNAISSANCE AIRCRAFT WAS 994 MB...29.35
  INCHES.

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Watches and Warnings

• A HURRICANE WATCH IS IN EFFECT FOR THE
  NORTHWESTERN BAHAMAS... INCLUDING THE
  ABACOS...ANDROS ISLAND...BERRY ISLANDS...BIMINI...
  ELEUTHERA...GRAND BAHAMA ISLAND...AND NEW
  PROVIDENCE.
• A HURRICANE WARNING REMAINS IN EFFECT FOR THE
  CENTRAL BAHAMAS...THE SOUTHEASTERN BAHAMAS...AND
  THE TURKS AND CAICOS ISLANDS.
• A TROPICAL STORM WARNING REMAINS IN EFFECT FOR
  THE NORTHERN COAST OF THE DOMINICAN REPUBLIC FROM
  PUERTO PLATA WESTWARD TO BAHIA DE MANZANILLO.
• A TROPICAL STORM WARNING IS ALSO IN EFFECT FOR
  HAITI FROM THE NORTHERN BORDER WITH THE DOMINICAN
  REPUBLIC TO PORT-AU-PRINCE.
• INTERESTS IN THE SOUTHEASTERN UNITED STATES
  SHOULD MONITOR THE PROGRESS OF HANNA.

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Rainfall and Ocean Swells

• HANNA IS EXPECTED TO PRODUCE RAINFALL TOTALS OF 4
  TO 8 INCHES... WITH MAXIMUM ISOLATED AMOUNTS OF
  12 INCHES...OVER THE SOUTHEASTERN BAHAMAS...THE
  TURKS AND CAICOS ISLANDS...AND EASTERN CUBA.
  RAINFALL TOTALS OF 6 TO 10 INCHES...WITH ISOLATED
  MAXIMUM AMOUNTS OF UP TO 15 INCHES...ARE POSSIBLE
  OVER HISPANIOLA
• THESE RAINS COULD CAUSE LIFE-THREATENING MUD
  SLIDES AND FLASH FLOODING.
• COASTAL STORM SURGE FLOODING OF 1 TO 3 FEET ABOVE
  NORMAL TIDE LEVELS...ALONG WITH LARGE AND
  DANGEROUS BATTERING WAVES...CAN BE EXPECTED IN
  AREAS OF ONSHORE FLOW WITHIN THE HURRICANE
  WARNING AREA.
• MODERATE TO LOCALLY HEAVY RAINFALL IS POSSIBLE
  ALONG THE EAST COAST OF FLORIDA BY FRIDAY
  MORNING.
• SWELLS FROM HANNA ARE EXPECTED TO INCREASE THE
  RISK OF DANGEROUS RIP CURRENTS ALONG PORTIONS OF
  THE SOUTHEASTERN UNITED STATES COAST DURING THE
  NEXT COUPLE OF DAYS.

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Technical Discussion

• THERE HAVE BEEN SOME STRUCTURAL CHANGES WITH
  HANNA TODAY AS IT INTERACTS WITH THE UPPER-LEVEL
  LOW MOVING THROUGH THE NORTHWESTERN BAHAMAS. THE
  WIND FIELD HAS EXPANDED IN THE NORTHERN
  SEMICIRCLE AND THE LOW-LEVEL CIRCULATION CENTER
  HAS BECOME LESS WELL DEFINED. VISIBLE IMAGERY
  SUGGESTS MULTIPLE LOW-LEVEL SWIRLS COMING OUT OF
  THE DEEP CONVECTION TO THE NORTH OF A MEAN
  CENTER...AND THE SYSTEM'S CONVECTIVE BANDS ARE
  WELL REMOVED FROM THE CORE.
• THE STEERING FLOW SHOULD BECOME BETTER DEFINED
  OVER THE NEXT 24-48 HOURS AS THE UPPER LOW MOVES
  WEST-SOUTHWESTWARD AND MID-LEVEL RIDGING BUILDS
  IN BEHIND THE LARGE DEEP-LAYER LOW OFF THE UPPER
  U.S. EAST COAST.
• WESTERLY SHEAR AND DRY AIR ASSOCIATED WITH THE
  UPPER LOW WILL INHIBIT DEVELOPMENT IN THE SHORT
  TERM BUT SHOULD DIMINISH OVER THE NEXT COUPLE OF
  DAYS...TO BE REPLACED WITH MODERATE SOUTHEASTERLY
  SHEAR. THIS PATTERN WOULD PERMIT SOME
  RE-INTENSIFICATION...BUT HANNA WILL NEED TO
  RECREATE AN INNER CORE IN ORDER TO INTENSIFY
  SUBSTANTIALLY.