Tropical Weather Discussion
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000
AXNT20 KNHC 242356
TWDAT

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
705 PM EST WED DEC 24 2014

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
2345 UTC.

...SPECIAL FEATURES...

A STRONG COLD FRONT IS MOVING ACROSS THE GULF WATERS FOLLOWED BY
GALE FORCE WINDS. AS OF 1800 UTC...THE FRONT EXTENDS FROM
FLORIDA PANHANDLE TO 25N86W TO THE N CENTRAL YUCATAN PENINSULA.
A RECENT ASCAT PASS DATA AS WELL AS BUOY REPORTS SHOW GALE FORCE
WINDS W OF THE FRONT S OF 23N...WITH FRESH TO NEAR GALE FORCE
WINDS ELSEWHERE W OF THE FRONT. SEAS ARE REPORTED TO BE IN THE
10-15 KT RANGE. SCATTEROMETER DATA ALSO SHOWS OBSERVATIONS OF
FRESH TO STRONG SOUTHERLY WINDS AHEAD OF THE FRONT DUE TO THE
TIGHT PRES GRADIENT BETWEEN THE ATLANTIC RIDGE AND LOWER PRES
ACROSS THE EAST AND CENTRAL GULF. THE GALE FORCE WINDS AND SEAS
WILL GRADUALLY DIMINISH THROUGH THE EVENING HOURS. CURRENT MODEL
GUIDANCE SHOW THE FRONT REACHING THE TAMPA BAY AREA TO THE NE
YUCATAN PENINSULA EARLY TONIGHT...THEN FROM NEAR NAPLES TO THE
NW CARIBBEAN SEA LATE TONIGHT...AND TO E THE GULF BY THURSDAY.

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

THE MONSOON TROUGH CROSSES THE COAST OF AFRICA NEAR 08N13W AND
CONTINUES OVER THE E ATLC WATERS TO NEAR 06N19W. THE ITCZ BEGINS
NEAR 06N19W AND CONTINUES ALONG 04N30W TO 05N38W TO 04N48W.
ISOLATED MODERATE CONVECTION IS WITHIN 140 NM N OF THE ITCZ AXIS
BETWEEN 20W-30W.

...DISCUSSION...

GULF OF MEXICO...

AN UPPER-LEVEL TROUGH EXTENDING FROM CENTRAL TEXAS TO NORTHERN
MEXICO IS SUPPORTING A STRONG COLD FRONT THAT IS MOVING ACROSS
THE GULF REGION PRODUCING GALE FORCE WINDS AND ROUGH SEAS. SEE
THE SPECIAL FEATURES FOR MORE DETAILS. MOSAIC DOPPLER RADAR
IMAGERY SHOWS BANDS MODERATE TO STRONG CONVECTION AHEAD OF THE
FRONTAL BOUNDARY AFFECTING NW FLORIDA AND THE E GULF MAINLY E OF
89W. AT UPPER LEVELS...WATER VAPOR IMAGERY SHOWED PLENTY OF
MOISTURE STREAMING NORTHEAST ACROSS THE GULF REGION FROM SE
MEXICO TO THE SE CONUS. OVER THE NEXT 24-48 HOURS...EXPECT
INCREASING SOUTHERLY WINDS ACROSS THE WESTERN GULF AHEAD OF THE
NEXT COLD FRONT THAT IS FORECAST TO ENTER THE NW PORTION OF THE
BASIN BY SAT.

CARIBBEAN SEA...

A 1032 MB SURFACE HIGH IS LOCATED ACROSS THE NW ATLANTIC AND
EXTENDING ACROSS THE NORTHERN CARIBBEAN. A MODERATE TO FRESH
BREEZE PREVAILS ACROSS THE W CARIBBEAN INCLUDING THE YUCATAN
PENINSULA. FRESH TO STRONG TRADEWINDS PREVAIL ACROSS THE CENTRAL
CARIBBEAN WITH THE STRONGEST WINDS OF 25-30 KT S OF 14N BETWEEN
70W-76W NEAR THE COAST OF COLOMBIA AND THE GULF OF VENEZUELA. A
GENTLE BREEZE IS OBSERVED ACROSS THE E CARIBBEAN MAINLY E OF
70W. A COLD FRONT OVER THE NORTHERN FLORIDA AREA IS ENHANCING
CONVECTION ACROSS THE WHOLE PENINSULA EVEN REACHING WESTERN CUBA
AND THE NW CARIBBEAN. SCATTERED MODERATE CONVECTION IS N OF
18N...W OF 80W. SHALLOW MOISTURE EMBEDDED IN THE TRADE WIND FLOW
CONTINUES TO MOVE ACROSS THE REGION PRODUCING ISOLATED TO
SCATTERED SHOWERS MAINLY ACROSS THE EASTERN HALF OF THE
BASIN...AS NOTED ON DOPPLER RADAR IMAGERY OF THE PUERTO RICO
AREA. OVER THE NEXT 24-48 HOURS...THE COLD FRONT WILL CONTINUE
MOVING E ACROSS THE GULF REACHING THE YUCATAN CHANNEL AND THE NW
CARIBBEAN TONIGHT. THE FRONT IS FORECAST TO STALL AND GRADUALLY
WEAKEN ACROSS THE FLORIDA STRAITS BY FRIDAY.

HISPANIOLA...

A VERY STABLE ENVIRONMENT CONTINUES ACROSS THE ISLAND SUPPORTING
FAIR WEATHER. SIMILAR CONDITIONS ARE EXPECTED OVER THE NEXT 24
HOURS WITH LOW-TOPPED TRADE WIND SHOWERS MOVING MAINLY ACROSS
THE CARIBBEAN WATERS.

ATLANTIC OCEAN...

A 1032 MB SURFACE HIGH PRESSURE LOCATED NEAR 47N52W EXTENDS A
RIDGE ACROSS THE WESTERN ATLANTIC. WITH THIS...THE PRESSURE
GRADIENT BETWEEN THIS HIGH PRESSURE AND THE LOWER PRESSURE OVER
THE E GULF OF MEXICO IS PRODUCING AN INCREASE IN WIND SPEEDS
ACROSS THE FLORIDA PENINSULA AND W ATLANTIC. MODERATE S-SW WINDS
ARE NOTED ACROSS THE ATLANTIC WATERS E OF THE FLORIDA PENINSULA
AND SE US COAST AS THE COLD FRONT OVER THE E GULF OF MEXICO
APPROACHES. ISOLATED CONVECTION IS NOTED W OF 76W. TO THE E...A
988 MB SURFACE LOW IS CENTERED NEAR 39N40W AND EXTENDS ITS COLD
FRONT FROM 43N37W TO 23N40W. SCATTERED MODERATE CONVECTION IS
PRESENT E OF THIS FRONT N OF 21N BETWEEN 25W-39W. THE PRESSURE
GRADIENT GENERATED BY THIS LOW AND THE SURFACE HIGH DESCRIBED
ABOVE IS PRODUCING NEAR GALE FORCE WINDS N OF 30N BETWEEN 41W-
52W. LOOKING AHEAD OVER THE NEXT 24-48 HOURS...EXPECT FOR THE
COLD FRONT THAT IS MOVING ACROSS THE E GULF OF MEXICO TO ENTER
THE W ATLANTIC TONIGHT. THE FRONT WILL THEN STALL AND WEAKEN AS
IT QUICKLY REACHES THE FLORIDA STRAITS ON THURSDAY. FRESH TO
LOCALLY STRONG NW WINDS AND BUILDING SEAS ARE EXPECTED BEHIND
THE FRONT WEDNESDAY NIGHT AND THURSDAY. HIGH PRESSURE WILL BUILD
IN THE WAKE OF THE FRONT.

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

$$
ERA


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