[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 301743
TWDAT

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
105 PM EST WED DEC 30 2015

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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
1715 UTC.

...SPECIAL FEATURES...
A STRONG PRESSURE GRADIENT BETWEEN HIGH PRESSURE ANCHORED ACROSS
THE SW NORTH ATLC AND LOWER PRESSURE ANALYZED ACROSS NW SOUTH
AMERICA IS PRODUCING NEAR GALE TO GALE FORCE WINDS ACROSS
PORTIONS OF THE SW AND SOUTH-CENTRAL CARIBBEAN SEA. THESE
CONDITIONS ARE EXPECTED TO PERSIST THROUGH FRIDAY. SEE THE
LATEST NWS HIGH SEAS FORECAST UNDER AWIPS/WMO HEADER MIAHSFAT2/
FZNT02 KNHC FOR MORE DETAILS.

...ITCZ/MONSOON TROUGH...
THE MONSOON TROUGH EXTENDS FROM THE AFRICAN COAST NEAR 08N13W
INTO A 1015 MB LOW NEAR 10N15W TO 06N20W. THE INTERTROPICAL
CONVERGENCE ZONE AXIS EXTENDS FROM 06N20W TO 03N26W TO 02N40W TO
THE EQUATOR NEAR 48W. ISOLATED MODERATE CONVECTION IS FROM 02N-
05N BETWEEN 18W-27W.

...DISCUSSION...

GULF OF MEXICO...
BROAD LONGWAVE TROUGHING IS NOTED ON WATER VAPOR IMAGERY OVER
THE CENTRAL CONUS WITH MID-LEVEL SHORTWAVE ENERGY STRETCHING
FROM OVER THE NW GULF SOUTHWESTWARD TO OVER CENTRAL MEXICO. THIS
SHORTWAVE SUPPORTS A STATIONARY FRONT EXTENDING FROM NEAR MOBILE
BAY SW TO OFFSHORE OF BROWNSVILLE TEXAS THEN SOUTHWARD AS A
SURFACE TROUGH TO 20N96W. GIVEN THAT THE SUPPORTING MID-LEVEL
DYNAMICS ARE OVER THE NW GULF WATERS... SCATTERED SHOWERS AND
TSTMS ARE OCCURRING ACROSS THE NORTH-CENTRAL GULF N OF 27N
BETWEEN 86W-92W...INCLUDING INLAND PORTIONS OF NORTHERN
GEORGIA...ALABAMA...AND SOUTHERN MISSISSIPPI. ISOLATED SHOWERS
ARE ALSO WITHIN 90 NM EITHER SIDE OF THE FRONT W OF 92W.
OTHERWISE...GENTLE TO MODERATE SOUTHEASTERLY FLOW INFLUENCES THE
GULF SE OF THE FRONTAL BOUNDARY UNDER MOSTLY CLEAR SKIES WITHIN
THE SOUTHWESTERN PERIPHERY OF A RIDGE ANCHORED ACROSS THE SW
NORTH ATLC. NORTH AND WEST OF THE FRONT...FRESH TO OCCASIONAL
STRONG N TO NE WINDS PREVAIL THAT ARE EXPECTED TO PERSIST AND
EVENTUALLY BEGIN SPREADING EASTWARD BY LATE FRIDAY AS THE FRONT
TRANSITIONS TO COLD AND IS ENERGIZED BY MIDDLE TO UPPER LEVEL
ENERGY AND A STRONG SURFACE RIDGE BUILDING IN FROM THE CENTRAL
PLAINS.

CARIBBEAN SEA...
DRY AIR AND OVERALL STABLE CONDITIONS ALOFT CONTINUE TO SUPPORT
RATHER TRANQUIL CONDITIONS ACROSS THE CARIBBEAN BASIN THIS
AFTERNOON. ASIDE FROM A FEW PASSING LOW-TOPPED ISOLATED
SHOWERS...THE PRIMARY MARINE CONCERN REMAINS STRONG TO NEAR GALE
TRADES WITH THE INCLUSION OF THE SPECIAL FEATURES GALE FORCE
WINDS OCCURRING WITHIN CLOSE PROXIMITY TO THE COAST OF COLOMBIA.
THE OVERALL PRESSURE GRADIENT ACROSS THE BASIN IS EXPECTED TO
PERSIST THROUGH LATE FRIDAY WITH THE SURFACE RIDGE ANCHORED
ACROSS THE SW NORTH ATLC EVENTUALLY WEAKENING AND SLIDING
EASTWARD BY SATURDAY RESULTING IN A SLIGHT DECREASE IN THE TRADE
WIND REGIME.

...HISPANIOLA...
DRY AIR ALOFT IS PROMOTING FAIR SKIES FOR THE ISLAND THIS
AFTERNOON. A FEW PASSING ISOLATED SHOWERS ARE POSSIBLE HOWEVER
DUE TO PEAK DAYTIME HEATING AND OROGRAPHIC LIFT.

ATLANTIC OCEAN...
SURFACE HIGH PRESSURE ALONG WITH A MIDDLE TO UPPER LEVEL RIDGE
IS PROMOTING OVERALL FAIR CONDITIONS AND MOSTLY CLEAR SKIES
ACROSS THE SW NORTH ATLC WATERS THIS AFTERNOON. THE SURFACE
RIDGE IS EXPECTED TO PERSIST THROUGH LATE THURSDAY WHEN IT
BEGINS TO RETREAT EASTWARD AS A FRONT EMERGES OFF THE SE CONUS
COAST. FARTHER EAST...RELATIVELY ZONAL FLOW IS NOTED ON WATER
VAPOR IMAGERY N OF 30N E OF 50W WITH ONLY A WEAK COLD FRONT
ENTERING THE DISCUSSION AREA NEAR 32N26W EXTENDING W-SW TO
30N34W THEN BECOMING STATIONARY TO 30N46W. ISOLATED SHOWERS ARE
WITHIN 60 NM EITHER SIDE OF THE FRONT. OTHERWISE...EASTERLY FLOW
INFLUENCES MUCH OF THE CENTRAL AND EASTERN ATLC ON THE SOUTHERN
PERIPHERY OF A SURFACE RIDGE ANCHORED BY A 1034 MB HIGH CENTERED
NEAR 34N40W.

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

$$
HUFFMAN
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