[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 250048 AAA
TWDAT

TROPICAL WEATHER DISCUSSION...AMENDED
NWS NATIONAL HURRICANE CENTER MIAMI FL
805 PM EDT THU MAY 24 2012

AMENDED SPECIAL FEATURES SECTION FOR UPDATED TROPICAL WEATHER
OUTLOOK UPDATE

TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL
AMERICA...GULF OF MEXICO...CARIBBEAN SEA...NORTHERN SECTIONS OF
SOUTH AMERICA...AND ATLANTIC OCEAN TO THE AFRICAN COAST FROM THE
EQUATOR TO 32N. THE FOLLOWING INFORMATION IS BASED ON SATELLITE
IMAGERY...WEATHER OBSERVATIONS...RADAR...AND METEOROLOGICAL
ANALYSIS.

BASED ON 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
2315 UTC.

...SPECIAL FEATURES...

A 1008 MB LOW PRESSURE CENTERED OVER THE UPPER FLORIDA KEYS NEAR
25N80W CONTINUES TO MOVE NORTHEAST THIS EVENING AS AN UPPER
LEVEL TROUGH WITH AXIS OVER THE EASTERN GULF OF MEXICO LIFTS
EAST-NORTHEASTWARD. SURFACE TROUGHING EXTENDS TO 31N77W NE OF
THE LOW AND TO 20N84W SW OF THE LOW. PLENTY OF MIDDLE TO UPPER
LEVEL MOISTURE ADVECTION IS NOTED ON WATER VAPOR IMAGERY OVER
THE AREA 540 NM EAST OF THE SURFACE TROUGH AXIS WITH SCATTERED
SHOWERS AND ISOLATED TSTMS OCCURRING WITHIN TWO AREAS...ONE FROM
20N-24N BETWEEN 76W-81W...INCLUDING PORTIONS OF CENTRAL CUBA...
AND THE OTHER FROM 25N-32N BETWEEN 71W-79W OVER THE SW NORTH
ATLC...INCLUDING THE NW BAHAMAS. SIGNIFICANT RAINFALL IS
EXPECTED WITH THIS CONVECTION OVER LAND AREAS THROUGH THE
OVERNIGHT HOURS AND AN INCREASED THREAT FOR FLOODING AND
POSSIBLE MUDSLIDES WILL PERSIST ACROSS PORTIONS OF CUBA. WHILE
UPPER LEVEL CONDITIONS ARE NOT CURRENTLY CONDUCIVE FOR FURTHER
DEVELOPMENT DUE TO STRONG WIND SHEAR...THE WIND SHEAR IS
EXPECTED TO LESSEN OVER THE WEEKEND AS THE LOW MEANDERS OFF THE
SOUTH CAROLINA AND GEORGIA COAST BY SUNDAY. THERE IS A HIGH
CHANCE OF THIS SYSTEM DEVELOPING INTO A TROPICAL OR SUBTROPICAL
CYCLONE OVER THE NEXT 48 HOURS.

...TROPICAL WAVES...

TROPICAL WAVE EXTENDS FROM 04N40W TO 11N37W MOVING W AT 15-20
KT. THE WAVE REMAINS ON THE LEADING EDGE OF A SURGE OF DEEP
LAYER MOISTURE NOTED IN TOTAL PRECIPITABLE WATER IMAGERY BETWEEN
25W-39W. THERE IS A LACK OF DEEP CONVECTION IN THE VICINITY OF
THE WAVE LIKELY DUE TO SAHARAN DUST SURROUNDING THE WAVE AXIS.

TROPICAL WAVE EXTENDS FROM 08N61W TO 14N60W MOVING W AT 10-15
KT. THE WAVE CONTINUES TO BE EMBEDDED WITHIN AN AREA OF DEEP
LAYER MOISTURE IMPACTING THE SE CARIBBEAN SEA S OF 15N BETWEEN
56W-67W. WIDELY SCATTERED SHOWERS AND ISOLATED MODERATE
CONVECTION ARE OCCURRING S OF 14N BETWEEN 56W-66W...INCLUDING NE
VENEZUELA...THE WINDWARD ISLANDS...AND ADJACENT COASTAL WATERS
IN THE SE CARIBBEAN SEA.

...ITCZ/MONSOON TROUGH...

THE MONSOON TROUGH EXTENDS FROM THE AFRICAN COAST NEAR 09N13W TO
02N22W. THE INTERTROPICAL CONVERGENCE ZONE AXIS EXTENDS FROM
02N22W TO 05N32W TO 05N40W TO 02N50W. WIDELY SCATTERED MODERATE
CONVECTION IS FROM 01N-08N BETWEEN THE PRIME MERIDIAN AND
18W...AND FROM 08N-12N BETWEEN 12W-16W. ISOLATED MODERATE
CONVECTION IS FROM 01N-07N BETWEEN 23W-29W.

...DISCUSSION...

GULF OF MEXICO...
AN UPPER LEVEL TROUGH AXIS EXTENDS FROM THE SE CONUS NEAR 34N83W
OVER THE NORTHEASTERN GULF WATERS TO A BASE NEAR 24N90W. WATER
VAPOR IMAGERY INDICATES THAT DRY AIR AND SUBSIDENCE COVERS THE
BASIN AND THIS DRYNESS ALOFT EXTENDS EASTWARD ACROSS THE FLORIDA
PENINSULA. AS A RESULT OF THE OVERALL SUBSIDENT ATMOSPHERE...A
SURFACE RIDGE AXIS EXTENDS FROM THE NE GULF TO THE FAR SW GULF
IN THE BAY OF CAMPECHE. SKIES REMAIN CLEAR THROUGHOUT WITH LIGHT
NE TO E WINDS E OF 90W AND E TO SE WINDS IN THE RANGE OF 15 TO
25 KT W OF 92W. THE RIDGE IS FORECAST TO SLIDE WESTWARD AND
WEAKEN THROUGH SUNDAY AS THE SPECIAL FEATURES LOW PRESSURE
SYSTEM DRIFTS WESTWARD FROM THE SW NORTH ATLC WATERS INLAND
ACROSS NE FLORIDA AND SOUTHERN GEORGIA LATE SUNDAY THROUGH THE
EARLY PART OF NEXT WEEK. GENTLE TO MODERATE BREEZE WILL DOMINATE
THE GULF OVER THE WEEKEND THROUGH TUESDAY.

CARIBBEAN SEA...
SOUTHWESTERLY UPPER LEVEL FLOW DOMINATES OVER THE NW CARIBBEAN
BETWEEN AN UPPER LEVEL TROUGH ACROSS THE EASTERN GULF OF MEXICO
AND AN UPPER LEVEL ANTICYCLONIC CIRCULATION CENTERED NORTH OF
HISPANIOLA NEAR 21N72W. MIDDLE TO UPPER LEVEL MOISTURE CONTINUES
TO ADVECT NORTHEASTWARD N OF 16N ACROSS CUBA AND INTO THE SW
NORTH ATLC IN ASSOCIATION WITH THE SPECIAL FEATURES LOW CENTERED
OVER THE UPPER FLORIDA KEYS. WIDELY SCATTERED SHOWERS AND
ISOLATED TSTMS ARE OCCURRING N OF 17N BETWEEN 74W-82W...
INCLUDING PORTIONS OF CENTRAL AND EASTERN CUBA. ANOTHER AREA OF
ACTIVE CONVECTION THIS EVENING IN THE FORM OF SCATTERED SHOWERS
AND TSTMS IS ACROSS INLAND CENTRAL AMERICA...NAMELY NORTHERN
COSTA RICA...NICARAGUA...HONDURAS...AND EL SALVADOR. FARTHER
EAST...THE UPPER LEVEL ANTICYCLONE NORTH OF THE BASIN IS
PROVIDING MOSTLY EASTERLY FLOW S OF 20N BETWEEN 60W-80W. WATER
VAPOR IMAGERY INDICATES MOSTLY DRY AIR...HOWEVER WITH THE
APPROACH OF A TROPICAL WAVE ALONG 60W...INCREASED DEEP LAYERED
MOISTURE IS ACROSS THE SW CARIBBEAN AND WINDWARD ISLANDS. WIDELY
SCATTERED SHOWERS AND ISOLATED TSTMS ARE OCCURRING S OF 14N
BETWEEN 56W-66W...INCLUDING NE VENEZUELA...THE WINDWARD
ISLANDS...AND ADJACENT COASTAL WATERS IN THE SE CARIBBEAN SEA.

ATLANTIC OCEAN...
DIFFLUENCE ALOFT BETWEEN AN UPPER LEVEL TROUGH OVER THE EASTERN
CONUS AND AN UPPER LEVEL RIDGE WITH AXIS ALONG 21N72W TO BEYOND
32N66W IS SUPPORTING A BROAD AREA OF SCATTERED SHOWERS AND
ISOLATED TSTMS ACROSS CENTRAL AND EASTERN CUBA STRETCHING NE
ACROSS MUCH OF THE SW NORTH ATLC W OF 70W. MORE DETAILS ON THIS
SYSTEM ARE LOCATED IN THE SPECIAL FEATURES SECTION ABOVE. THE
UPPER LEVEL RIDGE CIRCULATION SUPPORTS BROAD SURFACE RIDGING
ANCHORED BY A PAIR OF 1027 MB HIGHS CENTERED NEAR 34N45W AND
35N37W THAT COVERS THE REMAINDER OF THE CENTRAL AND EASTERN ATLC
E OF 70W.

FOR ADDITIONAL INFORMATION PLEASE VISIT
HTTP://WWW.HURRICANES.GOV/MARINE

$$
HUFFMAN





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