000
AXNT20 KNHC 121146
TWDAT 

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
705 AM EST THU JAN 12 2012

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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
1115 UTC.

...ITCZ/MONSOON TROUGH...

THE MONSOON TROUGH EXTENDS FROM THE AFRICAN COAST NEAR 07N11W TO 
07N18W. THE INTERTROPICAL CONVERGENCE ZONE AXIS EXTENDS FROM 
07N18W TO THE EQUATOR NEAR 41W THEN TO 01S46W. ISOLATED MODERATE 
CONVECTION IS FROM THE EQUATOR TO 04N BETWEEN 33W-40W.

...DISCUSSION...

GULF OF MEXICO...
AN UPPER LEVEL TROUGH IS LOCATED OVER THE EASTERN GULF THIS 
MORNING WITH ONE SHORTWAVE WELL NORTH OF THE REGION OVER THE 
MID-ATLC STATES AND ANOTHER SHORTWAVE LOCATED OVER THE EASTERN 
GULF NEAR 27N84W. BOTH OF THESE SHORTWAVES ARE SUPPORTING A COLD 
FRONT ANALYZED ACROSS THE SOUTHERN FLORIDA PENINSULA AND INTO 
THE SE GULF NEAR 26N81W THEN SW TO WESTERN CUBA NEAR 22N85W. THE 
FRONT CONTINUES TO WEAKEN WITH ISOLATED SHOWERS OCCURRING EAST 
OF THE FRONT OVER PORTIONS OF THE FLORIDA STRAITS. THE REMAINDER 
OF THE GULF IS UNDER THE INFLUENCE OF A WEAK SURFACE RIDGE 
ANCHORED BY A 1014 MB HIGH CENTERED NEAR 22N88W WITH GENERALLY 
CLEAR SKIES NOTED ON SATELLITE IMAGERY. HOWEVER...THE NEXT UPPER 
LEVEL SHORTWAVE CONTINUES TO PROGRESS ACROSS THE SOUTHERN PLAINS 
AND AS OF 12/0900 UTC SUPPORTS A STRONGER COLD FRONT WHICH IS 
ANALYZED OVER THE EXTREME NW GULF FROM 30N93W TO THE TEXAS COAST 
NEAR 27N97W. THE FRONT HAS INTRODUCED STRONG NORTHERLY WINDS AND 
IS FORECAST TO SWEEP ACROSS THE ENTIRE GULF BY FRIDAY MORNING. 
THEREAFTER...HIGH PRESSURE IS THEN EXPECTED TO DOMINATE THROUGH 
THE UPCOMING WEEKEND.

CARIBBEAN SEA...
AN UPPER LEVEL RIDGE AXIS EXTENDS FROM THE TROPICAL NORTH ATLC 
NEAR 08N56W NW TO OVER HISPANIOLA NEAR 20N72W. WATER VAPOR 
IMAGERY INDICATES MOSTLY DRY AIR AND SUBSIDENCE IS LOCATED N OF 
10N AND IS PROVIDING AN OVERALL STABLE ATMOSPHERE ACROSS THE 
CARIBBEAN THIS MORNING. SHORTWAVE INFRARED SATELLITE IMAGERY 
SHOWS TRANQUIL CONDITIONS PERSIST WITH E-NE TRADES IN THE RANGE 
OF 10 TO 20 KT...WITH HIGHER WINDS EXPECTED IN THE VICINITY OF 
THE COAST OF COLOMBIA. THE ONLY EXCEPTION TO THE FAIR WEATHER 
BASIN WIDE IS LOCATED OVER THE EXTREME NW PORTION. A DISSIPATING 
STATIONARY FRONT EXTENDS FROM WESTERN CUBA NEAR 22N85W TO THE 
YUCATAN PENINSULA COAST NEAR 20N87W. SATELLITE IMAGERY INDICATES 
THAT ANY POSSIBLE ISOLATED SHOWER ACTIVITY IS OCCURRING NORTH OF 
THE YUCATAN CHANNEL WITHIN THE SE GULF OF MEXICO WATERS.

ATLANTIC OCEAN...
AN UPPER LEVEL RIDGE IS LOCATED OVER THE SW NORTH ATLC WITH 
RIDGE AXIS EXTENDING FROM OVER HISPANIOLA NEAR 20N70W TO BEYOND 
32N64W. ON THE WESTERN PERIPHERY OF THE RIDGE...MOIST 
SOUTHWESTERLY UPPER LEVEL FLOW IS NOTED BETWEEN THE RIDGE AND 
TROUGHING ACROSS THE SE CONUS AND EASTERN SEABOARD. THIS TROUGH 
SUPPORTS A COLD FRONT ANALYZED FROM COASTAL NORTH CAROLINA NEAR 
35N76W TO 32N76W THEN SW TO THE FLORIDA COAST NEAR 27N80W. 
SCATTERED SHOWERS AND ISOLATED TSTMS ARE OCCURRING WITHIN 90 NM 
EITHER SIDE OF A LINE FROM 32N73W TO 25N78W. FARTHER EAST...THE 
UPPER LEVEL RIDGING SUPPORTS A 1022 MB HIGH CENTERED NEAR 
32N58W. HOWEVER...A NORTH-CENTRAL ATLC UPPER LEVEL TROUGH 
SUPPORTS A COLD FRONT DRAPED INTO THE DISCUSSION AREA THAT 
PENETRATES THE SOUTHEASTERN PERIPHERY OF THE SURFACE RIDGE. THE 
COLD FRONT IS ANALYZED FROM 32N44W TO 27N58W. A PRE-FRONTAL 
TROUGH IS ALSO SE OF THE FRONT FROM 29N47W TO 24N52W WITH 
ISOLATED SHOWERS OCCURRING WITHIN 150 NM EAST OF THE SURFACE 
TROUGH AND COLD FRONT N OF 28N. THE LAST SURFACE FEATURE OF 
IMPORTANCE THIS MORNING IS A SURFACE TROUGH EXTENDING INTO THE 
DISCUSSION AREA NEAR 32N36W TO 21N38W. WATER VAPOR IMAGERY SHOWS 
THAT AN UPPER LEVEL TROUGH IS IN PLACE OVER THE SURFACE TROUGH 
WITH AXIS ALONG 34W. ISOLATED SHOWERS ARE OCCURRING EAST OF THE 
SURFACE TROUGH OVER THE AREA FROM 26N-32N BETWEEN 26W-33W AND IS 
LIKELY ENHANCED DUE TO UPPER LEVEL DIFFLUENCE EAST OF THE UPPER 
LEVEL TROUGH AXIS.

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

$$
HUFFMAN