000
AXNT20 KNHC 130552
TWDAT 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL  
105 AM EST WED JAN 13 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 3N40W 1N50W. NO 
SIGNIFICANT DEEP CONVECTION NOTED ALONG THE ITCZ AXIS.

...DISCUSSION...

GULF OF MEXICO...
A SURFACE RIDGE ENCOMPASSES THE ENTIRE GULF BASIN ANCHORED BY A 
1034 MB HIGH CENTERED OVER SE ARKANSAS NEAR 34N91W. THIS SURFACE 
FEATURE IS PRODUCING PRIMARILY LIGHT NORTHERLY WINDS UP TO 15 KT 
ACROSS THE EASTERN GULF AND FLORIDA PENINSULA WHILE LIGHT NE TO 
E WINDS ARE OCCURRING ACROSS THE WESTERN GULF. ALOFT...MOIST 
SWLY UPPER LEVEL FLOW DOMINATES AND CONTINUES TO ADVECT AMPLE 
MIDDLE TO UPPER LEVEL MOISTURE ACROSS SOUTHERN MEXICO AND THE 
GULF W OF 88W. THIS UPPER LEVEL PATTERN PRECEDES THE NEXT UPPER 
LEVEL SHORTWAVE TROUGH CURRENTLY ACROSS NORTH-CENTRAL MEXICO 
THAT IS EXPECTED TO IMPACT THE WESTERN GULF BY LATE THURSDAY. 
THE SURFACE RIDGE IS FORECAST TO REMAIN IN PLACE ACROSS THE NE 
GULF THROUGH EARLY THURSDAY GIVING WAY TO INCREASED 
SOUTHEASTERLY RETURN FLOW OVER THE WESTERN GULF AHEAD OF THE 
NEXT LOW PRESSURE AREA AND ASSOCIATED COLD FRONT FORECAST TO 
EMERGE OFF THE EASTERN MEXICO COAST EARLY FRIDAY.

CARIBBEAN SEA...
THE MAIN SURFACE FEATURE IN THE CARIBBEAN SEA IS A SHEAR LINE 
THAT IS ANALYZED ENTERING THE NORTH CENTRAL CARIBBEAN SOUTH OF 
HISPANIOLA NEAR 18N70W AND EXTENDS SW ALONG 15N79W TO THE COAST 
OF WESTERN PANAMA NEAR 9N82W. CONVERGENT NORTHERLY WINDS ACROSS 
THE NW CARIBBEAN AND NE TO E TRADES ACROSS THE CENTRAL CARIBBEAN 
ARE PRODUCING ISOLATED SHOWERS PRIMARILY WITHIN 200 NM EITHER 
SIDE OF THE SHEAR LINE. OTHER POSSIBLE ISOLATED SHOWERS ARE 
NOTED ON SATELLITE IMAGERY ACROSS THE NW CARIBBEAN AND PORTIONS 
OF CENTRAL AMERICA. FARTHER EAST...A SURFACE TROUGH ENTERS THE 
NE CARIBBEAN FROM THE TROPICAL NORTH ATLC THROUGH THE ANEGADA 
PASSAGE NEAR 19N64W AND EXTENDS SW TO NEAR 14N67W. ISOLATED 
SHOWERS ARE FOCUSED NEAR THE SOUTHERN EXTENT OF THIS BOUNDARY 
ACROSS THE SE CARIBBEAN FROM 11N-16N BETWEEN 64W-69W. ALOFT...A 
BROAD UPPER LEVEL ANTICYCLONIC CIRCULATION CENTERED OVER THE SE 
CARIBBEAN NEAR 13N66W CONTINUES TO INFLUENCE THE EASTERN 
CARIBBEAN E OF 74W WITH RELATIVELY STRONG SUBSIDENCE AND STABLE 
CONDITIONS PROVIDING FOR GENERALLY CLEAR SKIES...EXCEPT HOWEVER 
FOR THE PREVIOUSLY MENTIONED AREAS OF ISOLATED SHOWERS.

ATLANTIC OCEAN...
AN UPPER LEVEL SHORTWAVE TROUGH AXIS IS OVER THE W ATLC AND 
SUPPORTS A COLD FRONT THAT EXTENDS FROM NORTH OF THE DISCUSSION 
AREA TO NEAR 31N75W. MOST ISOLATED SHOWER ACTIVITY IS REMAINING 
N OF 30N AND WITHIN 120 NM E OF THE COLD FRONT. THE REMAINDER OF 
THE W ATLC IS UNDER THE INFLUENCE OF A SURFACE RIDGE THAT 
EXTENDS FROM THE CENTRAL FLORIDA PENINSULA TO NEAR 27N57W. SOUTH 
OF THIS RIDGE A SHEAR LINE EXTENDS ACROSS EASTERN HISPANIOLA 
NEAR 18N70W INTO THE TROPICAL SW NORTH ATLC TO 23N62W. POSSIBLE 
ISOLATED SHOWERS COVER AN AREA 300 NM NW OF THE BOUNDARY... 
INCLUDING HISPANIOLA AND THE TURKS AND CAICOS ISLANDS. FARTHER 
EAST...A COLD FRONT ENTERS THE DISCUSSION AREA NEAR 32N40W AND 
EXTENDS SW TO NEAR 22N56W WHERE IT CONTINUES TO THE ANEGADA 
PASSAGE AS A SURFACE TROUGH. ISOLATED SHOWERS ARE WITHIN 90 NW 
EITHER SIDE OF THE COLD FRONT AND SURFACE TROUGH. THIS FRONT IS 
SUPPORTED ALOFT BY AN UPPER LEVEL TROUGH AXIS THAT EXTENDS FROM 
29N49W TO BEYOND 32N43W. ELSEWHERE THE EASTERN ATLC IS DOMINATED 
BY A SURFACE RIDGE ANCHORED ON A 1026 MB HIGH CENTERED W OF THE 
CANARY ISLANDS NEAR 28N19W. GENERALLY FAIR WEATHER IS NOTED WITH 
A RIDGE AXIS EXTENDING FROM THE HIGH CENTER TO 24N45W.

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

$$
HUFFMAN