000
AXNT20 KNHC 231739
TWDAT 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL  
105 PM EST WED DEC 23 2009

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 THE 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY 
THROUGH 1730 UTC.

...ITCZ...

THE ITCZ AXIS IS CENTERED ALONG 7N13W 5N21W 3N32W 4N40W 2N50W. 
WEAK TO MODERATE CONVECTION IS ALONG THE ITCZ BETWEEN 30W AND 
35W...AND ALSO BETWEEN 18W-28W. . 

...DISCUSSION...

GULF OF MEXICO...
SURFACE OBSERVATIONS SHOW SSE 15-25 KT WINDS OVER THE WESTERN 
GULF...WHILE THE EASTERN GULF HAS EASTERLY WINDS OF THE SAME 
MAGNITUDE. THE REGION IS MOSTLY UNDER MULTI-LAYER 
CLOUDS...INFLUENCED BY AN UPPER LEVEL TROUGH MOVING OVER THE 
REGION. THIS TROUGH WILL MOVE A COOLER AIRMASS TO THE WESTERN 
BASIN OVER THE NEXT 24 HOURS...BRINGING A COLD FRONT ALONG THE 
TEXAS COAST WITH PREFRONTAL CONVECTION EXTENDING OVER THE NNW 
GULF.  

CARIBBEAN SEA...
HEAVY RAINFALL EXPECTED OVER HISPANIOLA DURING THE NEXT 24 
HOURS. A SURFACE LOW MEASURING 1007 MB IS CENTERED NEAR 17N18W. 
THIS IS 80 NM SOUTH OF THE SOUTHERN COAST OF HAITI. A STATIONARY 
FRONT EXTENDS ACROSS HAITI FROM 19N72W TO THE LOW CENTER. A 
SURFACE TROUGH EXTENDS SSW FROM THE LOW CENTER TO CENTRAL 
PANAMA. STRONG CONVECTION IS HEADING TO CENTRAL HISPANIOLA OVER 
THE NEXT 12 HOURS. THIS LOW PRESSURE SYSTEM IS DEEPENING AS IT 
MOVES NNE AT ABOUT 20 KT. SIGNIFICANT UPPER LEVEL MOISTURE IS 
FEEDING THIS SYSTEM. HEAVY RAINFALL MAY INCREASE THE FLOODING 
POTENTIAL OVER THIS REGION...ESPECIALLY EAST AND CENTRAL 
HAITI...AND CENTRAL DOMINICAN REPUBLIC. SHIP AND BUOY 
OBSERVATIONS SHOW STRONG TO NEAR GALE WINDS AROUND THE LOW 
CENTER. THE WESTERN BASIN IS INFLUENCED BY STRONG SUBSIDENCE OF 
AIR BEHIND THE MAIN SYSTEM. MODERATE TRADEWINDS ARE OVER THIS 
REGION. EXPECT OVER THE NEXT 24 HOURS FOR THE SURFACE LOW TO 
CONTINUE TO MOVE NE TO NEAR THE TURKS AND CAICOS ISLANDS WITH A 
TROUGH EXTENDING S TO N COLOMBIA.

ATLANTIC OCEAN...
A WEAK COLD FRONT EXTENDS FROM THE EASTERN ATLANTIC NEAR 32N12W 
TO THE CENTRAL ATLANTIC AT 20N52W. GALE FORCE WINDS REMAIN 
BEHIND THE WEAKENING FRONT. MODERATE CONVECTION AHEAD OF THE 
FRONT IS OVER THE EASTERN ATLANTIC NEAR THE CANARY ISLANDS FROM 
27N-32N BETWEEN 10W-18W. SCATTERED SHOWERS ARE WITHIN 60 NM OF 
THE REMAINDER OF THE FRONT. EXPECT OVER THE NEXT 24 HOURS FOR 
THE COLD FRONT TO DISSIPATE AS ANOTHER FRONTAL SYSTEM ENTERS THE 
REGION ALONG THE 30N LINE. A STATIONARY FRONT LINKED TO THE LOW 
PRESSURE SYSTEM OVER THE NORTH-CENTRAL CARIBBEAN IS ANALYZED 
ALONG THE 22N LINE BETWEEN 53W AND 70W. WEAK CONVECTION IS 
WITHIN 40 NM OF THIS STATIONARY FRONT. MODELS INDICATE THAT AS 
THE LOW MOVES NE INTO THE ATLANTIC...WARM AIR SOUTH OF THE 
STATIONARY FRONT WILL PUSH THE FRONT NORTHWARD DURING THE NEXT 
24 HOURS...TRANSFORMING IT INTO A WARM FRONT. OTHERWISE...MOST 
OF THE CENTRAL ATLANTIC REMAINS UNDER THE INFLUENCE OF AN UPPER 
LEVEL RIDGE BRINGING STRONG SUBSIDENCE TO THIS REGION. A 1018 MB 
HIGH IS ANALYZED NEAR 16N36W. 

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

$$

GARCIA