000
AXNT20 KNHC 130029 CCA
TWDAT 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL  
705 PM EST TUE JAN 12 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY
THROUGH 2330 UTC.

...THE ITCZ...

THE ITCZ AXIS IS ANALYZED FROM WEST AFRICA NEAR THE NORTHERN 
COAST OF SIERRA LEONE AT 8N13W CONTINUING WESTWARD ALONG 5N20W 
2N30W EQ40W TO NORTHEAST BRAZIL NEAR 1S45W. WEAK CONVECTION IS 
FOUND ALONG THE ITCZ BETWEEN 30W AND 33W.

...DISCUSSION...

THE GULF OF MEXICO...
A WEAK SURFACE PRESSURE GRADIENT IS ANALYZED ACROSS THE GULF OF 
MEXICO...AS HIGH PRESSURE MOVES OVER THE NORTHWEST 
BASIN...BRINGING A COLD AND DRY AIRMASS TO THE REGION. SHIP AND 
OIL PLATFORM OBSERVATIONS SHOW 5 TO 15 KT ANTI-CYCLONIC FLOW 
OVER THE ENTIRE BASIN. SATELLITE VISIBLE IMAGERY AND DOPPLER 
RADAR DATA SHOW A WEAK LINE OF SHOWERS ALONG THE NORTHERN MEXICO 
COAST FROM 24N TO 26N. SATELLITE WATER VAPOR IMAGERY SHOWS UPPER 
LEVEL MOISTURE COVERING ALMOST THE ENTIRE GULF. THIS UPPER LEVEL 
MOISTURE IS BEEN TRANSFERRED FROM THE EAST TROPICAL PACIFIC INTO 
THE BASIN. THE WEATHER ACROSS THE GULF WILL CONTINUE TO BE 
DOMINATED BY THE HIGH PRESSURE SYSTEM OVER THE NEXT 24 HOURS. 
THEREFORE...NO SIGNIFICANT CHANGES ARE EXPECTED DURING THIS TIME 
PERIOD.

THE CARIBBEAN SEA...
A COLD FRONT ENTERS THE CARIBBEAN SEA FROM THE ATLANTIC THROUGH 
THE MONA PASSAGE...WHERE IT BECOMES STATIONARY AND CONTINUES 
WEST-SOUTHWEST ALONG 17N70W 15N75W 11N80W TO THE SOUTHWEST BASIN 
INTO NORTHERN PANAMA NEAR 9N82W. INFRA-RED SATELLITE IMAGERY 
SHOWS WEAK CONVECTION WITHIN 60 NM ON EITHER SIDE OF THE 
STATIONARY FRONT. TO THE WEST OF THE FRONTAL BOUNDARY...SHIP AND 
BUOY OBSERVATIONS SHOW NORTH-NORTHEAST WINDS 10 TO 20 KT OVER 
THE WEST AND NORTHWEST BASIN. ELSEWHERE EAST OF THE FRONTAL 
BOUNDARY...FAIR WEATHER CONTINUES WITH MODERATE TO FRESH TRADE 
WINDS...AS AN UPPER LEVEL RIDGE OF HIGH PRESSURE PROVIDES STRONG 
SUBSIDENCE AND DRY AIR TO THE MID AND UPPER LEVELS ACROSS THIS 
REGION. 

THE ATLANTIC OCEAN...
A SURFACE LOW PRESSURE SYSTEM IS OVER THE CENTRAL ATLANTIC NEAR 
39N36W. A COLD FRONT EXTENDS SOUTH-SOUTHWEST FROM THE LOW CENTER 
AND ENTERS THE DISCUSSION AREA NEAR 32N44W...AND CONTINUES ALONG 
26N50W 20N60W ENTERING THE CARIBBEAN SEA THROUGH THE MONA 
PASSAGE. THIS FRONT IS MOVING ALONG WITH AN UPPER LEVEL TROUGH 
THAT IS SUPPORTING THE LOW PRESSURE SYSTEM. LITTLE TO NO 
PRECIPITATION IS EVIDENT WITH THIS FRONT OVER OUR AREA OF 
DISCUSSION. HOWEVER...INFRA-RED SATELLITE IMAGERY SHOWS WEAK TO 
MODERATE CONVECTION 120 NM EAST OF THE FRONT NORTH OF 32N. THE 
REMAINDER OF THE ATLANTIC OCEAN IS DOMINATED BY A STRONG UPPER 
LEVEL RIDGE OF HIGH PRESSURE...BRINGING GENERALLY FAIR WEATHER 
CONDITIONS ACROSS THE REMAINDER OF THE ATLANTIC. OVER THE NEXT 
24 HOURS...THE COLD FRONT WILL CONTINUE TO EXPAND ACROSS THE 
CENTRAL ATLANTIC WITH CONVECTION WITHIN AND AHEAD OF IT.

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

$$

GARCIA