000
AXNT20 KNHC 011738
TWDAT 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL  
105 PM EST FRI JAN 01 2010

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...METEOROLOGICAL ANALYSIS...WEATHER 
OBSERVATIONS...AND RADAR.

BASED ON 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
1715 UTC.

...THE ITCZ...
THE ITCZ AXIS IS CENTERED ALONG 7N9W 5N14W 7N22W 1N44W 1N52W. 
SCATTERED MODERATE CONVECTION IS WITHIN 60 NM OF 4N FROM 
14W-20W. DENSE MULTILAYERED CLOUDS WITH CLUSTERS OF ISOLATED 
MODERATE CONVECTION COVER THE AREA S OF 5N W OF 36W TO INLAND 
OVER SOUTH AMERICA. 

...DISCUSSION...

GULF OF MEXICO...
AS OF 1500 UTC...A 1014 MB LOW IS INLAND OVER FLORIDA NEAR 
ORLANDO WITH COLD FRONT EXTENDING INTO THE GULF ALONG 25N87W 
21N93W TO THE COAST OF S MEXICO NEAR COATZACOALCOS AND A 
PREFRONTAL SURFACE TROUGH THAT EXTENDS FROM FLORIDA BAY NEAR 
26N82W TO 24N86W. SCATTERED/HEAVY SHOWERS AND ISOLATED 
THUNDERSTORMS ARE BETWEEN THE TROUGH AND THE COLD FRONT E OF 88W 
WITH SCATTERED SHOWERS WITHIN 60 NM EITHER SIDE OF THE REMAINDER 
OF THE FRONT. THE UPPER LEVEL TROUGH SUPPORTING THIS FRONT 
COVERS MUCH OF THE E US AND GULF OF MEXICO N OF 25N. A MODERATE 
TO STRONG UPPER LEVEL JET REMAINS ACROSS THE N GULF N OF A LINE 
FROM JUST S OF MATAMOROS MEXICO TO THE FLORIDA KEYS WITH WINDS 
ESTIMATED TO BE BETWEEN 90 TO 160 KT. A STRONG SURFACE RIDGE IS 
BUILDING BEHIND THE FRONT ANCHORED BY A 1034 MB HIGH CENTRAL 
TEXAS. THIS FAST MOVING COLD FRONT IS EXPECTED TO BE SE OF AREA 
TONIGHT WITH GALE FORCE WINDS FOLLOWING FRONT THROUGH TONIGHT. A 
SECOND COLD FRONT WILL MOVE INTO NE GULF LATE SUN AND SWEEP 
THROUGH GULF TUE MORNING. 

CARIBBEAN SEA...
A SURFACE TROUGH...REMNANTS OF A FRONTAL BOUNDARY...ENTERS THE 
CARIBBEAN OVER THE LEEWARD ISLANDS NEAR SAINT LUCIA ISLAND 
CONTINUING NW ALONG 16N66W TO 17N72W WITH SCATTERED SHOWERS 
WITHIN 75 NM EITHER SIDE OF THE SURFACE TROUGH. BROAD UPPER 
RIDGE REMAINS OVER THE CARIBBEAN ANCHORED INLAND OVER VENEZUELA 
WITH STRONG SUBSIDENCE AND MOSTLY DRY STABLE OVER THE AREA E OF 
83W SUPPRESSING ANY DEEP CONVECTION. MOIST AIR HAS MOVED OVER 
THE FAR NW CARIBBEAN WITH THE APPROACH OF THE FRONT IN THE GULF 
OF MEXICO GENERATING SCATTERED SHOWERS MAINLY S OF 20N W OF 85W. 
THE SURFACE RIDGE ANCHORED OVER THE W ATLC CONTINUES TO PRODUCE 
A STRONG PRESSURE GRADIENT OVER THE CARIBBEAN S OF 16N AND 
GENERATING FRESH TO STRONG EASTERLY TRADE WINDS THAT WILL BEGIN 
TO DIMINISH TODAY AS THE COLD FRONT PUSHES INTO NW CARIBBEAN 
REACHING E CUBA TO BELIZE TONIGHT THEN STALL FROM SW HAITI TO E 
HONDURAS LATE SAT. 

ATLANTIC OCEAN...
AS OF 1500 UTC...A COLD FRONT ENTERS THE FAR W ATLC NEAR 32N75W 
EXTENDING OVER FLORIDA NEAR FLAGLER BEACH TO A 1014 MB LOW 
INLAND OVER FLORIDA NEAR ORLANDO CONTINUING INTO THE GULF OF 
MEXICO GENERATING SCATTERED/HEAVY SHOWERS AND ISOLATED 
THUNDERSTORMS N OF A LINE FROM NEAR BERMUDA TO NEAR VERA BEACH 
FLORIDA. THE UPPER LEVEL SUPPORT IS JUST MOVING OFF THE E US N 
OF THE REGION. A SURFACE RIDGE DOMINATES THE REMAINDER OF THE W 
ATLC INTO THE CENTRAL ATLC ANCHORED BY A 1025 MB HIGH NEAR 
31N58W. A COLD FRONT ENTERS THE E ATLC NEAR 32N30W EXTENDING 
ACROSS THE CENTRAL ATLC ALONG 24N35W TO 18N54W WHERE IT BECOMES 
STATIONARY TO 15N55W CONTINUING AS A SURFACE TROUGH ACROSS THE 
LEEWARD ISLANDS NEAR SAINT LUCIA AND INTO THE CARIBBEAN. THE 
UPPER TROUGH SUPPORTING THE FRONT COVERS THE AREA N OF 17N 
BETWEEN 26W-50W. SCATTERED SHOWERS AND POSSIBLE ISOLATED 
THUNDERSTORMS ARE WITHIN 150 NM E OF THE FRONT N OF 20N WITH 
SCATTERED SHOWERS WITHIN 90 NM EITHER SIDE OF THE REMAINDER OF 
THE FRONT AND SURFACE TROUGH. A SECOND BUT WEAKER SURFACE RIDGE 
COVERS THE REMAINDER OF THE E ATLC ANCHORED BY A 1022 MB HIGH NE 
OF THE CANARY ISLANDS. 

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

$$
WALLACE