000
AXNT20 KNHC 270555
TWDAT 

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL  
105 AM EST SUN NOV 27 2011 

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...WEATHER OBSERVATIONS...RADAR...AND METEOROLOGICAL 
ANALYSIS.

BASED ON 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0515 UTC.

...ITCZ/MONSOON TROUGH...

THE MONSOON TROUGH EXTENDS FROM THE AFRICAN COAST NEAR 11N15W TO 
06N21W. THE INTERTROPICAL CONVERGENCE ZONE AXIS EXTENDS FROM 
06N21W TO 05N34W TO 03N51W. SCATTERED MODERATE CONVECTION IS 
FROM 04N-09N BETWEEN 19W-28W...AND FROM 02N-06N BETWEEN 28W-41W.

...DISCUSSION...

GULF OF MEXICO...
AN UPPER LEVEL RIDGE INFLUENCES THE GULF BASIN WITH AXIS 
EXTENDING FROM THE NW CARIBBEAN SEA NORTHWARD ALONG 84W AND 
INLAND OVER THE SE CONUS TO THE MID-ATLC COAST. THIS UPPER LEVEL 
RIDGE CONTINUES TO BE LOCATED BETWEEN TWO UPPER LEVEL TROUGHS... 
ONE LOCATED OVER THE SW NORTH ATLC BETWEEN 55W-75W...AND THE 
OTHER APPROACHING THE GULF FROM THE WEST CURRENTLY NOTED ON 
WATER VAPOR IMAGERY ACROSS THE SOUTHERN PLAINS AND NORTHERN 
MEXICO. WHILE THE UPPER LEVEL RIDGE SHIFTS GRADUALLY EASTWARD 
OVER THE NEXT 24 HOURS...IT CONTINUES TO SUPPORT SURFACE RIDGING 
OVER THE EASTERN GULF AND FLORIDA PENINSULA E OF 87W ANCHORED BY 
A 1027 MB HIGH CENTERED OFF THE CAROLINA COAST NEAR 34N74W. OVER 
THE WESTERN GULF...THE UPPER LEVEL TROUGHING SUPPORTS A COLD 
FRONT EXTENDING FROM PORT ARTHUR TEXAS TO S OF BROWNSVILLE NEAR 
25N97W. STRONG N-NW GALE FORCE WINDS ARE OCCURRING BEHIND THE 
FRONT WITH SCATTERED SHOWERS AND A FEW ISOLATED TSTMS OCCURRING 
IN THE VICINITY OF THE FRONT NW OF A LINE FROM 29N91W TO 19N96W. 
AN AREA OF WIDELY SCATTERED SHOWERS IS ALSO LOCATED EAST OF THE 
FRONT EMBEDDED WITHIN STRONG S-SE FLOW OCCURRING N OF 15N 
BETWEEN 86W-92W. THE COLD FRONT IS FORECAST TO MOVE EASTWARD 
THROUGH THE REMAINDER OF THE WEEKEND AND BEGIN TO IMPACT THE 
FLORIDA PENINSULA BY MONDAY.

CARIBBEAN SEA...
WATER VAPOR IMAGERY INDICATES DRY AND STABLE CONDITIONS UNDER 
W-SW FLOW ALOFT IS OVER THE NW CARIBBEAN N OF 15N W OF 76W. THIS 
AREA OVER THE NW CARIBBEAN IS LOCATED ON THE SOUTHWESTERN 
PERIPHERY OF A SW NORTH ATLC HIGH PRESSURE WITH NE TO E WINDS IN 
THE RANGE OF 10 TO 20 KT. LOW-LEVEL CONVERGENCE IS MAXIMIZED IN 
THE GULF OF HONDURAS WITH ISOLATED SHOWERS OCCURRING S OF 19N W 
OF 84W. FARTHER EAST...AN SW NORTH ATLC UPPER LEVEL TROUGH DIPS 
SOUTHWARD TO A BASE NEAR 20N74W AND CONTINUES TO PROVIDE THE 
REMAINDER OF THE BASIN WITH MOIST SOUTHWESTERLY FLOW ALOFT. 
SCATTERED SHOWERS AND TSTMS ARE OCCURRING OVER THE SW CARIBBEAN 
IN THE VICINITY OF THE MONSOON TROUGH ANALYZED ALONG 11N S OF 
14N BETWEEN 69W-80W. ELSEWHERE E OF 76W...WIDELY SCATTERED 
SHOWERS AND ISOLATED TSTMS ARE OCCURRING UNDER WEAK UPPER LEVEL 
DIFFLUENCE AND LOW-LEVEL CONVERGENCE DUE TO A SURFACE TROUGH 
ANALYZED OVER THE EASTERN CARIBBEAN FROM 11N66W TO 18N63W. THIS 
EVENING THE MOST INTENSE ACTIVITY IN THE VICINITY OF THE SURFACE 
TROUGH FEATURE IS N OF 14N BETWEEN 61W-66W.

ATLANTIC OCEAN...
AN UPPER LEVEL TROUGH IS NOTED ON WATER VAPOR IMAGERY ACROSS THE 
W ATLC WITH AXIS FROM 34N56W TO 28N70W TO A BASE NEAR 20N74W. 
THE TROUGHING SUPPORTS A DISSIPATING STATIONARY FRONT EXTENDING 
FROM 32N55W SW TO 23N63W. WITH UPPER LEVEL DIFFLUENCE EAST OF 
THE TROUGH AXIS AND LOW-LEVEL CONVERGENCE IN THE VICINITY OF THE 
FRONT...WIDELY SCATTERED SHOWERS ARE OCCURRING MAINLY EAST OF 
THE FRONT WITHIN 210 NM EITHER SIDE OF A LINE FROM 19N63W TO 
32N50W. THE REMAINDER OF THE SW NORTH ATLC IS UNDER THE 
INFLUENCE OF A SURFACE RIDGE ANCHORED BY A 1027 MB HIGH CENTERED 
OFF THE CAROLINA COAST NEAR 34N74W. NE TO E WINDS IN THE RANGE 
OF 15 TO 20 KT ARE EXPECTED TO PERSIST THROUGH LATE SUNDAY INTO 
MONDAY AS A COLD FRONT APPROACHES FROM THE WEST ACROSS THE GULF 
OF MEXICO BY MONDAY AFTERNOON. FARTHER EAST...AN UPPER LEVEL LOW 
IS CENTERED NEAR 27N26W. THE SURFACE LOW HAS DRIFTED WEST OF THE 
UPPER LEVEL FEATURE AND CONTINUES TO WEAK AS A 1016 MB LOW 
CENTERED NEAR 31N37W. A SURFACE TROUGH BOUNDARY REMAINS ANALYZED 
FROM 24N32W TO 30N32W WITH ISOLATED SHOWERS OCCURRING WITHIN 150 
NM EITHER SIDE OF THE BOUNDARY.

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

$$
HUFFMAN