Atlantic Tropical Weather Discussion

000
AXNT20 KNHC 281741
TWDAT 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL  
105 PM EST SAT NOV 28 2009

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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
1715 UTC.

...ITCZ...

THE ITCZ AXIS IS CENTERED ALONG 9N13W 5N30W 3N51W. WIDELY 
SCATTERED MODERATE CONVECTION IS FROM 3N-7N BETWEEN 9W-21W. 
SCATTERED MODERATE CONVECTION IS FROM 1N-7N BETWEEN 25W-38W.

...DISCUSSION...

GULF OF MEXICO...
A 1022 MB SURFACE HIGH PRESSURE CENTERED OVER THE WESTERN 
FLORIDA PANHANDLE CONTINUES TO STRETCH A RIDGE ACROSS THE 
FLORIDA PENINSULA AND NW BAHAMAS TO THE SE AND ANOTHER RIDGE 
S-SW TO SOUTHERN MEXICO AND THE BAY OF CAMPECHE. THE HIGH 
PRESSURE AREAS ARE BRINGING GENERALLY FAIR WEATHER ACROSS MUCH 
OF THE BASIN. HOWEVER...MOIST SWLY AND MID-LEVEL DIFFLUENT FLOW 
ALOFT BETWEEN AN UPPER LEVEL SHORTWAVE TROUGH OVER EASTERN TEXAS 
AND AN UPPER LEVEL RIDGE EXTENDING FROM THE WESTERN CARIBBEAN 
ACROSS THE SE GULF ARE GENERATING A FEW ISOLATED SHOWERS ACROSS 
LOUISIANA AND THE NW GULF N OF A LINE FROM NEW ORLEANS TO TUXPAN 
MEXICO. AS THE SURFACE HIGH SHIFTS GRADUALLY EASTWARD INTO THE W 
ATLC...SOUTHERLY RETURN FLOW IS FORECAST TO INCREASE ACROSS THE 
WESTERN GULF WATERS THROUGH SUNDAY AHEAD OF THE NEXT COLD FRONT 
TO ENTER THE NW GULF EARLY MONDAY.

CARIBBEAN SEA...
AS OF 1500 UTC...A STATIONARY FRONT EXTENDS FROM THE TURKS AND 
CAICOS ISLANDS IN THE W ATLC ACROSS EASTERN CUBA AND INTO THE NW 
CARIBBEAN NEAR 20N78W TO 18N84W. SCATTERED SHOWERS ARE OCCURRING 
WITHIN 120 NM EITHER SIDE OF THE FRONT. THIS SHOWER ACTIVITY 
LINGERS SW FROM THE TAIL END OF THE FRONT INTO THE GULF OF 
HONDURAS AND ACROSS PORTIONS OF CENTRAL AMERICA INCLUDING... 
HONDURAS...BELIZE...AND GUATEMALA. E-NE TRADE WINDS UP TO 25 KT 
ARE OBSERVED E OF THE FRONTAL BOUNDARY WITH SURFACE CONVERGENCE 
AND CLOSE PROXIMITY OF THE E PACIFIC ITCZ AXIS ALONG 7N 
GENERATING SCATTERED SHOWERS AND ISOLATED TSTMS OVER THE SW 
CARIBBEAN S OF 10N AND PORTIONS OF PANAMA AND COSTA RICA. 
FURTHER ENHANCING THIS CONVECTION IS THE PRESENCE OF AN UPPER 
LEVEL RIDGE AND DIFFLUENT FLOW ALOFT OVER COLOMBIA AND THE SW 
CARIBBEAN. THE REMAINDER OF THE CARIBBEAN IS EXPERIENCING 
GENERALLY FAIR WEATHER AND CLEAR SKIES UNDER THE INFLUENCE OF 
DRY AND SUBSIDENT AIR ALOFT ASSOCIATED WITH THE AFOREMENTIONED 
UPPER LEVEL ANTICYCLONIC FLOW COVERING THE ENTIRE BASIN. 

ATLANTIC OCEAN...
A COLD FRONT EXTENDS ACROSS THE W ATLC ENTERING THE DISCUSSION 
AREA NEAR 32N57W CONTINUING SW ALONG 25N65W TO THE TURKS AND 
CAICOS ISLANDS NEAR 22N71W THEN STATIONARY TO EASTERN CUBA AND 
INTO THE NW CARIBBEAN. A PRE-FRONTAL SURFACE TROUGH IS ANALYZED 
E OF THE FRONT FROM 25N64W TO 20N69W. SCATTERED SHOWERS ARE 
WITHIN 200 NM OF THE COLD FRONT N OF 25N AND WITHIN 60 NM EITHER 
SIDE OF THE FRONT AND SURFACE TROUGH S OF 25N. THE FRONT IS 
SUPPORTED ALOFT BY AN UPPER LEVEL TROUGH OVER THE WESTERN NORTH 
ATLC WITH AXIS EXTENDING FROM AN UPPER LEVEL LOW OVER NOVA 
SCOTIA TO NEAR 30N60W. UPPER LEVEL DIFFLUENT FLOW BETWEEN THIS 
UPPER LEVEL TROUGH AND AN UPPER LEVEL RIDGE EXTENDING FROM THE 
EASTERN CARIBBEAN TO NEAR 33N51W IS SUPPORTING THE CONVECTION. 
FARTHER EAST ACROSS THE CENTRAL ATLC...A NARROW UPPER LEVEL 
TROUGH WITH AXIS ALONG 48W IS SUPPORTING SCATTERED SHOWERS AND 
TSTMS FROM 18N-28N BETWEEN 43W-48W. A SURFACE TROUGH IS ANALYZED 
E OF THE LESSER ANTILLES EXTENDING FROM 11N56W TO 18N54W. 
POSSIBLE SCATTERED SHOWERS ARE OCCURRING WITHIN 120 NM EITHER 
SIDE OF THE SURFACE TROUGH. THE REMAINDER OF THE E ATLC IS 
DOMINATED BY A BROAD SURFACE RIDGE ANCHORED BY A 1029 MB HIGH 
CENTERED N OF THE DISCUSSION AREA NEAR 37N31W. HOWEVER...AN 
UPPER LEVEL SHORTWAVE TROUGH IS NEAR THE MADEIRA ISLANDS AND 
SUPPORTS A COLD FRONT THAT CLIPS THE FAR NE PORTION OF THE ATLC 
EXTENDING ALONG 31N BETWEEN 15W-22W. ISOLATED SHOWERS ARE WITHIN 
30 NM OF THE COLD FRONT. 

$$
HUFFMAN