[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 251138
TWDAT

TROPICAL WEATHER DISCUSSION...CORRECTED
NWS NATIONAL HURRICANE CENTER MIAMI FL
705 AM EST THU DEC 25 2014

CORRECTED TO INCLUDE SPECIAL FEATURES...

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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
1045 UTC.

...SPECIAL FEATURES...

FRESH TO STRONG TRADE WINDS WILL PREVAIL OVER THE CENTRAL
CARIBBEAN THROUGH MON NIGHT...REACHING MINIMAL GALE FORCE NEAR
THE COAST OF COLOMBIA TONIGHT INTO FRI MORNING. A GALE WARNING
HAS BEEN ISSUED.

...THE ITCZ/THE MONSOON TROUGH...

THE MONSOON TROUGH CROSSES THE COAST OF AFRICA NEAR 8N13W AND
CONTINUES OVER THE E ATLC WATERS TO NEAR 05N23W. THE ITCZ BEGINS
NEAR 05N23W AND CONTINUES ALONG 06N34W TO 05N40W TO 06N48W TO
THE COAST OF SOUTH AMERICA AT 5N52W. SCATTERED MODERATE
CONVECTION IS FROM 3N-6N BETWEEN 10W-20W.

...DISCUSSION...

GULF OF MEXICO...

AS OF 0900 UTC...A STRONG COLD FRONT EXTENDS FROM SOUTH FLORIDA
OVER WESTERN CUBA INTO THE FAR NW CARIBBEAN. THE FRONT WILL EXIT
THE GULF REGION THIS AFTERNOON AS HIGH PRESSURE BUILD IN ITS
WAKE. WINDS ARE DIMINISHING ACROSS THE AREA AND CURRENTLY THE
STRONGEST WINDS OF 20-25 KT ARE OBSERVED PER SCATTEROMETER AND
SURFACE DATA OVER THE SW GULF S OF 21N E OF 95W...INCLUDING THE
BAY OF CAMPECHE AND WITHIN AROUND 150 NM NW OF THE FRONT OVER
THE EASTERN GULF. WINDS AND SEAS WILL CONTINUE TO DIMINISH
THROUGH TONIGHT. DOPPLER RADAR REVEALS A PRE-FRONTAL BAND OF
SHOWERS WITH ISOLATED TSTMS AFFECTING SE FLORIDA AND THE FLORIDA
KEYS AS WELL AS HAVANA CUBA. AT UPPER LEVELS...WATER VAPOR
IMAGERY SHOWED PLENTY OF MOISTURE STREAMING NORTHEAST ACROSS THE
GULF REGION FROM SE MEXICO AND THE YUCATAN PENINSULA TO THE SE
CONUS IN A SOUTHWESTERLY FLOW ALOFT. THE NEXT COLD FRONT WILL
APPROACH THE TEXAS COAST SAT AFTERNOON...SLOWLY MOVING INTO THE
NW GULF THROUGH EARLY NEXT WEEK.

CARIBBEAN SEA...

FRESH TO STRONG TRADEWINDS PREVAIL ACROSS THE EAST AND CENTRAL
CARIBBEAN WITH THE STRONGEST WINDS OF 25-30 KT NEAR THE COAST OF
COLOMBIA. SCATTEROMETER PASSES CONFIRMED THE PRESENCE OF THESE
WIND SPEEDS. GENTLE TO MODERATE WINDS ARE BLOWING ACROSS THE NW
CARIBBEAN AHEAD OF A COLD FRONT THAT HAS JUST MOVED INTO THE FAR
NW CARIBBEAN. ISOLATED SHOWERS ARE NOTED AHEAD OF THE FRONT.
SHALLOW MOISTURE EMBEDDED IN THE TRADE WIND FLOW CONTINUES TO
MOVE ACROSS THE REGION PRODUCING ISOLATED TO SCATTERED PASSING
SHOWERS. SOME OF THEM ARE AFFECTING THE LESSER ANTILLES. PASSING
SHOWERS ARE ALSO SEEN OVER PUERTO RICO AND THE VIRGIN ISLANDS
ACCORDING TO THE SAN JUAN DOPPLER RADAR. FRESH TO STRONG TRADE
WINDS WILL PREVAIL OVER THE CENTRAL CARIBBEAN THROUGH MON NIGHT.
SEE SPECIAL FEATURES FOR DETAILS.  THE  COLD FRONT WILL STALL
FROM WESTERN CUBA TO THE GULF OF HONDURAS THIS AFTERNOON AND
GRADUALLY DISSIPATE THROUGH FRI. FRESH NORTHERLY WINDS ARE
EXPECTED IN THE WAKE OF THE FRONT. AT UPPER LEVELS...A RIDGE
WITH AXIS ACROSS NORTHERN SOUTH AMERICA AND THE CENTRAL
CARIBBEAN...THEN ACROSS EASTERN CUBA AND THE BAHAMAS DOMINATES
THE BASIN PRODUCING STRONG SUBSIDENCE. SOUTHERLY WINDS ARE
ADVECTING MID TO UPPER LEVEL MOISTURE ACROSS CENTRAL AMERICA.
COMPUTER MODELS SUGGESTS THAT A WEAKENING FRONTAL BOUNDARY WILL
REACH THE GREATER ANTILLES ON SUN WITH A BAND OF MOISTURE
EXTENDING ACROSS PUERTO RICO...HISPANIOLA AND EASTERN CUBA.

HISPANIOLA...

A GENERALLY DRY AIR MASS CONTINUES ACROSS THE ISLAND SUPPORTING
MOSTLY FAIR WEATHER. ISOLATED PASSING SHOWERS ARE EXPECTED. A
WEAKENING FRONTAL BOUNDARY WILL BRING SOME INCREASE IN MOISTURE
AND THE RISK OF SOME SHOWER ACTIVITY BY SUN.

ATLANTIC OCEAN...

THE STRONG COLD FRONT THAT WAS MOVING ACROSS THE GULF OF MEXICO
HAS ENTERED THE SW N ATLC. AS OF 0900 UTC...THE FRONT EXTENDS
FROM 31N78W TO SOUTH FLORIDA. A BAND OF SHOWERS WITH EMBEDDED
TSTMS IS AHEAD OF THE FRONT AND NOW IS APPROACHING THE NW
BAHAMAS. THE FRONT WILL WEAKEN AS IT REACHES FROM NEAR 31N70W TO
WESTERN CUBA THIS EVENING. THE SOUTHERN PART OF THE BOUNDARY
WILL STALL AND LIFT NORTHWARD FRI AS THE NORTHERN PART OF THE
BOUNDARY SHIFTS EASTWARD. BY FRI NIGHT...THE FRONTAL BOUNDARY
WILL EXTEND FROM NEAR 25N65W TO CENTRAL FLORIDA. THE FRONT WILL
CONTINUE SINKING SLOWLY SOUTH WHILE WEAKENING REACHING THE SE
BAHAMAS AND TURKS AND CAICOS ISLANDS BY SAT NIGHT AND LIKELY THE
GREATER ANTILLES...AS PREVIOUSLY MENTIONED...BY SUN. FARTHER
EAST...A 1022 MB SURFACE HIGH PRESSURE LOCATED NEAR 28N65W
EXTENDS A RIDGE ACROSS THE CENTRAL AND WESTERN ATLANTIC COVERING
ALSO THE NORTHERN PORTION OF THE CARIBBEAN SEA. MODERATE TO
LOCALLY FRESH EASTERLY WINDS ARE NOTED ACROSS THE SOUTHERN
PERIPHERY OF THE RIDGE. PATCHES OF LOW LEVEL MOISTURE ARE ALSO
NOTED UNDER THE INFLUENCE OF THIS SYSTEM. A COLD FRONT
ASSOCIATED WITH A STRONG LOW PRES CENTER LOCATED N OF AREA
ENTERS THE FORECAST REGION NEAR 31N28W THE EXTENDS SW TO 24N34W
TO 20N44W. SCATTERED MODERATE CONVECTION IS AHEAD OF THE FRONT
WITHIN AROUND 150 NM N OF 25N AND WITHIN 60 NM S OF 25N. COLD
AIR STRATOCUMULUS CLOUDS WITH EMBEDDED SHOWERS ARE ROTATING
AROUND THE LOW PRES SYSTEM AND COVERS THE ATLANTIC WATERS N OF
24N W OF FRONT TO ABOUT 46W. PRES GRADIENT BETWEEN THE LOW PRES
AND THE RIDGE TO THE W IS RESULTING IN AN AREA OF FRESH TO
STRONG NORTHERLY WINDS OVER THE CENTRAL ATLANTIC...ESPECIALLY N
OF 26N BETWEEN 40W AND 47W. FRESH SOUTHERLY WINDS ARE NOTED
AHEAD OF THE FRONT N OF 24N. A RIDGE DOMINATES THE REMAINDER OF
ATLANTIC FORECAST AREA. ALOFT...A RIDGE/TROUGH/RIDGE PATTERN IS
OBSERVED ACROSS THE REGION.

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

$$
GR


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