000
AXNT20 KNHC 260545
TWDAT 

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
105 AM EST MON DEC 26 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 
0530 UTC.

...ITCZ/MONSOON TROUGH...

THE MONSOON TROUGH REMAINS INLAND OVER AFRICA. THE ITCZ AXIS 
EXTENDS WSW FROM THE COAST OF GUINEA NEAR 10N14W ALONG 5N25W 
2N37W TO EQ50W. SCATTERED MODERATE CONVECTION IS FROM 3N-8N 
BETWEEN 26W-35W.

...DISCUSSION...

GULF OF MEXICO...
SW FLOW ALOFT COVERS THE ENTIRE GULF THIS EVENING. THIS UPPER 
LEVEL FLOW PATTERN IS MOVING MIDDLE TO UPPER LEVEL MOISTURE 
NORTHEASTWARD ACROSS THE NRN AND ERN HALF OF THE GULF. WITHIN 
THIS REGION OF MOISTURE ALOFT...A STATIONARY FRONTAL BOUNDARY  
IS ANALYZED FROM 29N85W TO 28N92W THEN SOUTH TO THE COAST OF 
MEXICO NEAR 18N93W. VISIBLE NIGHT CHANNEL AND IR WINDOW SHOW A 
BROAD LAYER OF LOW LEVEL STRATOCUMULUS CLOUDS W OF THE FRONT TO 
THE MEXICO AND TEXAS COAST W OF 92W WITH A FEW ISOLATED SHOWERS 
OCCURRING WITHIN 90 NM EITHER SIDE OF THE FRONT S OF 28N92W. 
MOSAIC DOPPLER RADAR INDICATES SCATTERED SHOWERS AND ISOLATED 
THUNDERSTORMS N OF THE FRONT BETWEEN 84W-90W AFFECTING THE 
COASTAL WATERS OF MISSISSIPPI...ALABAMA...AND THE FLORIDA 
PANHANDLE. SURFACE RIDGING WILL RETURN TO THE WRN GULF OVER THE 
NEXT FEW DAYS.

CARIBBEAN SEA...
VERY DRY AIR ALOFT AND STRONG SUBSIDENCE COVERS MOST OF THE 
CARIBBEAN WATERS THIS EVENING. THIS AIRMASS IS SUPPRESSING DEEP 
CONVECTION ACROSS THE DISCUSSION AREA. FRESH TO STRONG TRADE 
WIND FLOW CONTINUES ACROSS MUCH OF THE BASIN...ESPECIALLY 
BETWEEN 68W-80W...WITH A FEW SMALL CLUSTERS OF LOW-TOP WEAK 
SHOWERS EMBEDDED IN THE FLOW. THESE CONDITIONS ARE EXPECTED TO 
PERSIST THROUGH TUESDAY MORNING.

ATLANTIC OCEAN...
AN UPPER LEVEL RIDGE IS ACROSS MUCH OF THE WESTERN ATLC W OF 45W 
WITH VERY DRY AIR ALOFT NOTICED ON WATER VAPOR IMAGERY. THIS 
FEATURE SUPPORTS A 1024 MB HIGH CENTERED NEAR 30N70W. SLICING 
THROUGH THE SURFACE RIDGE IS A WEAK COLD FRONT ANALYZED FROM 
32N50W TO 27N57W TO 26N64W WHERE LOW-LEVEL MOISTURE BECOMES MORE 
DIFFUSE AND A DISSIPATING COLD FRONT EXTENDS TO 27N70W. THIS 
FRONT IS GENERATING POSSIBLE ISOLATED SHOWERS WITHIN 30 NM 
EITHER SIDE OF IT. TO THE EAST OF THE FRONT...AN EARLIER ASCAT 
PASS REVEALED AN AREA OF LOW LEVEL CONFLUENCE OF LIGHT WINDS 
ANALYZED AS A WEAK SURFACE TROUGH FROM 32N44W TO 23N47W WITHOUT 
ANY ACTIVITY ASSOCIATED. A SIMILAR SURFACE TROUGH IS ALSO 
ANALYZED FROM 21N43W TO 10N49W. FARTHER EAST...AN UPPER LEVEL 
LOW IS CENTERED NEAR 21N40W. THIS SYSTEM IS GENERATING A BROAD 
AREA OF DIFFLUENCE FLOW ALOFT THAT COVERS THE ERN ATLC S OF 25N 
E OF 38W. SCATTERED SHOWERS AND POSSIBLE ISOLATED THUNDERSTORMS 
ARE IN THIS REGION...WITH NE WINDS UP TO 25 KT.

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

$$

GARCIA