000
AXNT20 KNHC 281158
TWDAT 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL  
705 AM EST TUE DEC 28 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
1115 UTC.

...THE ITCZ...

ITCZ AXIS IS ANALYZED ALONG 8N11W 4N18W 4N35W 1N51W. CLUSTERS OF 
SCATTERED MODERATE CONVECTION ARE FROM 1N-6N BETWEEN 8W-35W.   

...DISCUSSION...

GULF OF MEXICO...
SURFACE RIDGE REMAINS IN CONTROL OF THE GULF AGAIN THIS MORNING 
ANCHORED BY A 1029 MB HIGH OVER E/CENTRAL MISSISSIPPI. THE BROAD 
UPPER TROUGH ASSOCIATED WITH THE FRONT IN THE W/CENTRAL ATLC HAS 
MOVED OUT OF THE AREA GIVING THE GULF ZONAL WESTERLY FLOW ALOFT 
WITH MODERATE/STRONG SUBSIDENCE AND MOSTLY DRY STABLE AIR. THE 
RETURN FLOW CONTINUES TO BANK LOW CLOUDS WITH POSSIBLE ISOLATED 
SHOWERS OVER THE W GULF WITHIN 90 NM ALONG THE COAST TO ALONG 
THE E SLOPES OF THE SIERRA MADRE MOUNTAINS OF MEXICO N OF 
MINATITLAN MEXICO AND INLAND OVER E TEXAS AND N LOUISIANA. THIS 
IS MODERATING TEMPERATURES OVER THAT AREA WHILE THE TEMPERATURES 
OVER THE REMAINDER OF THE GULF COAST ARE HOVERING NEAR OR BELOW 
FREEZING. BROKEN TO OVERCAST COLD AIR STRATOCUMULUS CLOUDS COVER 
A PORTION OF THE GULF WITHIN 175 NM OF LINE FROM 25N96W 25N88W 
TO OVER W CUBA AND THE YUCATAN CHANNEL NEAR 22N85W. EXPECT THE 
SURFACE RIDGE TO REMAIN IN CONTROL OF THE GULF OVER THE NEXT 24 
HOURS AS IT SHIFTS SLOWLY EASTWARD.  

CARIBBEAN SEA...
A COLD FRONT EXTENDS FROM THE W ATLC ACROSS W PUERTO RICO ALONG 
15N74W TO THE COAST OF COLOMBIA NEAR BARRANQUILLA WITH BROKEN TO 
OVERCAST COLD AIR STRATOCUMULUS CLOUDS W OF A LINE FROM THE 
WINDWARD PASSAGE TO THE PANAMA CANAL. THE ENTIRE CARIBBEAN IS 
UNDER SW TO W FLOW ALOFT IN RESPONSE TO AN UPPER RIDGE ANCHORED 
IN THE TROPICS. DIFFLUENCE ALOFT OVER THE CENTRAL CARIBBEAN 
COMBINED WITH THE STRONG N TO NE SURFACE WINDS ARE GENERATING AN 
AREA OF BROKEN TO OVERCAST MULTILAYERED CLOUDS WITH SCATTERED 
SHOWERS/ISOLATED THUNDERSTORMS WITHIN 200/250 NM OF LINE FROM 
ACROSS PUERTO RICO AND HISPANIOLA NEAR 18N70W TO 11N76W. THIS IS 
LEAVING THE FAR SE CARIBBEAN UNDER MOSTLY CLEAR SKIES THIS 
MORNING. 

ATLANTIC OCEAN...
BROAD UPPER TROUGH COVERS THE W ATLC N OF 22N W OF 56W TO OVER 
THE FLORIDA PENINSULA SUPPORTING A COLD FRONT THAT ENTERS THE 
W/CENTRAL ATLC NEAR 32N55W ALONG 24N60W ACROSS W PUERTO RICO 
INTO THE CARIBBEAN WITH SCATTERED SHOWERS/ISOLATED THUNDERSTORMS 
WITHIN 120 NM E OF THE FRONT N OF 23N. BROKEN TO OVERCAST COLD 
AIR STRATOCUMULUS CLOUDS COVER THE W ATLC W OF THE FRONT. AN 
UPPER RIDGE AXIS IS JUST TO THE E EXTENDING FROM THE TROPICS 
NEAR 10N57W TO BEYOND 32N46W ENHANCING THE ACTIVITY ASSOCIATED 
WITH THE FRONT. A SURFACE RIDGE COVERS THE REMAINDER OF THE 
CENTRAL ATLC INTO THE E ATLC ANCHORED BY A 1021 MB HIGH NEAR 
29N42W. AN UPPER LEVEL TROUGH REMAINS IN THE E ATLC N OF 10N E 
OF 37W TO THE COAST OF W AFRICA SUPPORTING A DISSIPATING COLD 
FRONT THAT ENTERS THE E ATLC NEAR 32N18W EXTENDING TO 24N28W 
WITH ISOLATED SHOWERS POSSIBLE WITHIN 60 NM E OF THE FRONT. 
A SURFACE RIDGE IS E OF THE FRONT COVERING AFRICA ANCHORED BY A 
1027 MB HIGH OVER ALGERIA NEAR 30N5W. 

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

$$
PAW