000
AXNT20 KNHC 120554
TWDAT 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL  
105 AM 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0515 UTC.

...ITCZ...

THE ITCZ AXIS IS CENTERED ALONG 6N11W 5N25W 2N40W AND TO THE 
EQUATOR NEAR 50W. SCATTERED SHOWERS AND ISOLATED MODERATE 
CONVECTION IS FROM THE EQUATOR TO 10N BETWEEN 11W-20W. ISOLATED 
MODERATE CONVECTION IS FROM 2N-4N BETWEEN 24W-35W.

...DISCUSSION...

GULF OF MEXICO...
A SURFACE RIDGE ENCOMPASSES THE ENTIRE GULF BASIN ANCHORED ON A 
1031 MB HIGH CENTERED OVER THE NORTH CENTRAL GULF WATERS SOUTH 
OF NEW ORLEANS LOUISIANA NEAR 29N90W. THIS SURFACE FEATURE IS 
PRODUCING PRIMARILY LIGHT NE TO E WINDS UP TO 15 KT ACROSS THE 
GULF THIS EVENING. ALOFT...ZONAL WESTERLY UPPER LEVEL FLOW IS 
OVER MUCH OF THE GULF EAST OF THE NEXT UPPER LEVEL SHORTWAVE 
TROUGH TO IMPACT THE WESTERN GULF BY LATE THURSDAY. THE SURFACE 
RIDGE IS FORECAST TO REMAIN IN PLACE ACROSS THE NE GULF THROUGH 
WEDNESDAY AS SE RETURN FLOW DEVELOPS OVER THE WESTERN GULF AHEAD 
OF THE NEXT LOW PRESSURE AREA AND ASSOCIATED COLD FRONT FORECAST 
TO EMERGE OFF THE EASTERN MEXICO COAST BY EARLY FRIDAY.

CARIBBEAN SEA...
A DISSIPATING STATIONARY FRONT ENTERS THE CARIBBEAN SEA THROUGH 
THE MONA PASSAGE AND TRAILS SW ALONG 17N70W 14N80W TO THE COAST 
OF SOUTHERN COSTA RICA NEAR 9N83W. THIS FRONT IS SUPPORTED ALOFT 
BY MOIST SWLY UPPER LEVEL FLOW AND WEAK UPPER LEVEL TROUGHING 
EXTENDING SOUTHWESTWARD FROM THE W ATLC INTO THE WESTERN 
CARIBBEAN. ISOLATED SHOWERS ARE PRIMARILY WITHIN 250 NM NW OF 
THE FRONTAL BOUNDARY ACROSS THE NW CARIBBEAN...JAMAICA...CUBA... 
HISPANIOLA...AND PORTIONS OF CENTRAL AMERICA. SE OF THE FRONT 
AND ACROSS THE EASTERN CARIBBEAN...NE TO E TRADEWINDS UP TO 25 
KT CONTINUE AS NOTED BY A RECENT 12/0220 ASCAT PASS. ALOFT...AN 
UPPER LEVEL ANTICYCLONIC CIRCULATION CENTERED OVER NORTHERN 
VENEZUELA NEAR 10N66W CONTINUES TO INFLUENCE THE EASTERN 
CARIBBEAN E OF 75W WITH RELATIVELY STRONG SUBSIDENCE AND STABLE 
CONDITIONS PROVIDING FOR GENERALLY CLEAR SKIES...HOWEVER A FEW 
ISOLATED LOW-LEVEL SHOWERS ARE MOVING OVER THE LESSER ANTILLES 
REMAINING E OF 64W.

ATLANTIC OCEAN...
AN UPPER LEVEL TROUGH AXIS IS OVER THE W ATLC AND EXTENDS FROM 
32N59W TO THE SE BAHAMAS NEAR 22N73W. THIS UPPER LEVEL FEATURE 
SUPPORTS A 1006 MB LOW CENTERED NEAR 34N56W AND AN ASSOCIATED 
COLD FRONT FROM THE LOW TO 25N60W TO THE MONA PASSAGE. LOW-LEVEL 
CONVERGENCE NEAR THE COLD FRONT AND AN AREA OF UPPER LEVEL 
DIFFLUENCE NEAR THE UPPER LEVEL TROUGH IS GENERATING SCATTERED 
SHOWERS WITHIN 300 NM EITHER SIDE OF THE FRONT. THE REMAINDER OF 
THE W ATLC IS UNDER THE INFLUENCE OF A SURFACE RIDGE EXTENDING 
FROM A 1031 MB HIGH CENTERED IN THE NORTH CENTRAL GULF OF 
MEXICO. EAST OF THE LOW...A STATIONARY FRONT EXTENDS ALONG 33N 
TO 42W. SWLY SURFACE WINDS AND A DIFFLUENT ENVIRONMENT ALOFT 
NORTH OF THE DISCUSSION AREA IS PROVIDING FOR POSSIBLE ISOLATED 
SHOWERS N OF 30N BETWEEN 42W-56W. ELSEWHERE THE REMAINDER OF THE 
CENTRAL AND EASTERN ATLC ARE UNDER THE INFLUENCE OF A SURFACE 
RIDGE ANCHORED BY A 1027 MB HIGH CENTERED NEAR 29N20W AND IS 
PROVIDING GENERALLY FAIR WEATHER WITH THE RIDGE AXIS EXTENDING 
WSW FROM THE HIGH ALONG 25N40W TO NE OF THE LEEWARD ISLANDS NEAR 
20N58W.

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

$$
HUFFMAN