000
AXNT20 KNHC 070000
TWDAT 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL  
705 PM EST WED JAN 06 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 THE 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY 
THROUGH 2345 UTC.

...ITCZ...

THE ITCZ AXIS IS ANALYZED FROM THE WEST AFRICA NEAR THE SOUTHERN 
COAST OF SIERRA LEONE AT 7N12W CONTINUING WESTWARD ALONG 5N20W 
2N30W 1.5N40W TO NORTHEAST BRAZIL NEAR THE CITY OF MACAPA AT 
EQ51. ISOLATED WEAK TO MODERATE CONVECTION IS OCCURRING FROM 2N 
TO 4N BETWEEN 24 AND 27W...AND ALONG THE ITCZ FROM BETWEEN 38W 
AND 42W.

...DISCUSSION...

GULF OF MEXICO...
A 1024 MB SURFACE HIGH OVER THE NORTHERN GULF CONTINUES TO 
DOMINATE THE WEATHER ACROSS THE BASIN...BRINGING FAIR CONDITIONS 
TO THE WHOLE REGION. SURFACE OBSERVATIONS SHOW ANTI-CYCLONIC AIR 
FLOW OVER THE ENTIRE BASIN RANGING FROM 5 TO 15 KT. WEATHER 
MODELS INDICATE THIS HIGH PRESSURE SYSTEM WILL GRADUALLY SHIFT 
EASTWARD AS A STRONGER HIGH PRESSURE DIGS DOWN TO SOUTH CENTRAL 
UNITED STATES...SUPPORTING A COLD FRONT THAT WILL ENTER THE 
WESTERN GULF BY THURSDAY OVERNIGHT...BRINGING A SECOND ROUND OF 
CONTINENTAL POLAR AIRMASS TO THE REGION. AS THIS COLD FRONT 
ENTERS THE WESTERN REGION OF THE GULF...WINDS ARE EXPECTED TO 
INCREASE TO NEAR 30 KT OVER THE WESTERN AND NORTH CENTRAL BASIN 
BY FRIDAY MORNING.

CARIBBEAN SEA...
IN THE UPPER LEVELS OF THE ATMOSPHERE ACROSS THE CARIBBEAN...DRY 
AND SUBSIDENT AIR ALOFT IS SUPPRESSING DEEP CONVECTION FROM 
HAPPENING IN THIS REGION. HOWEVER...A STATIONARY FRONT ENTERS 
THE NORTH CENTRAL BASIN THROUGH THE WINDWARD PASSAGE NEAR 20N74W 
CONTINUING THROUGH WESTERN JAMAICA TO NEAR 15N80W. SATELLITE 
IMAGERY SHOWS WEAK CONVECTION WITHIN 90 NM ON EITHER SIDE OF THE 
FRONT. FURTHERMORE...A SHEAR LINE IS ANALYZED FROM SOUTHEAST 
DOMINICAN REPUBLIC NEAR 18N69W CONTINUING SW ALONG 16N73W 15N78W 
12N80W TO 10N83W. CONVERGENT WINDS ALONG THE SHEAR LINE ARE 
PRODUCING SCATTERED SHOWERS WITHIN 70 NM OF THIS FEATURE. A 
TROUGH IS ANALYZED OVER THE SOUTH CENTRAL BASIN ALONG THE 70W 
LINE FROM 10N TO 16N. DOPPLER RADAR SHOWS A LINE OF WEAK TO 
MODERATE SHOWERS ASSOCIATED WITH THIS TROUGH IMPACTING THE 
WESTERN ISLAND OF PUERTO RICO. ELSEWHERE...FAIR WEATHER WILL 
CONTINUE ACROSS THE EASTERN CARIBBEAN OVER THE NEXT 24 HOURS 
WITH MODERATE TO FRESH TRADE WINDS.

ATLANTIC OCEAN...
A COLD AND DRY AIRMASS IS OVER THE WESTERN ATLANTIC...WEST OF A 
COLD FRONT ENTERING THE DISCUSSION AREA NEAR 32N54W EXTENDING 
SOUTHWEST ALONG 27N60W 22N65W TO THE WINDWARD PASSAGE NEAR 
20N73W. A PRE-FRONTAL SURFACE TROUGH IS ANALYZED 120 NM AHEAD OF 
THIS FRONT...ALONG 25N58W 23N61W...TO A WEAK SURFACE LOW NEAR 
20N67W. SATELLITE IMAGERY SHOWS WEAK TO MODERATE CONVECTION 
WITHIN 150 NM EAST OF THE COLD FRONT...AND WITHIN 100 NM ON 
EITHER SIDE OF THE TROUGH. THIS ACTIVITY CONTINUES TO BE 
ENHANCED BY DIFFLUENT FLOW ALOFT. FARTHER EAST ACROSS THE 
REMAINDER OF THE SOUTH CENTRAL AND EASTERN ATLANTIC...A SURFACE 
HIGH MEASURING 1023 MB IS BRINGING GENERALLY FAIR WEATHER TO 
THIS REGION. OVER THE NEXT 24 HOURS EXPECT THE COLD FRONT TO 
CONTINUE TO SLOWLY MOVE EASTWARD WITH CONVECTION AHEAD OF IT.

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

$$

GARCIA