000
AXNT20 KNHC 022355
TWDAT 

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
705 PM EST SUN DEC 02 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
2315 UTC.

...ITCZ/MONSOON TROUGH...

THE MONSOON TROUGH EXTENDS ACROSS WEST AFRICA TO THE SOUTHERN 
COAST OF GUINEA AT 9N13W TO 9N15W. THE ITCZ BEGINS AT 9N15W AND 
CONTINUES ALONG 5N26W 8N34W WHERE IT BREAKS DUE A SURFACE TROUGH 
ALONG 13N33W TO 7N36W. THE ITCZ RESUMES ALONG 7N37W 9N44W 10N49W 
WHERE IT BREAKS AGAIN DUE TO A SECOND SURFACE TROUGH ALONG 
13N46W TO 8N52W. A SMALL PORTION OF ITCZ CONTINUES WEST OF THIS 
TROUGH ALONG 8N53W TO 8N60W. ISOLATED MODERATE CONVECTION IS 
FROM 4N-9N BETWEEN 20W-33W. SCATTERED MODERATE/ISOLATED STRONG 
CONVECTION IS FROM 8N-11N BETWEEN 56W-61W.   

...DISCUSSION...

GULF OF MEXICO...
THE GULF OF MEXICO IS UNDER PLEASANT CONDITIONS DUE TO A DRY 
AIRMASS COVERING THE BASIN. MAINLY WEST TO NORTHWEST FLOW COVERS 
THE AREA AROUND A BROAD UPPER RIDGE MOVING THROUGH THE CENTRAL 
CONUS. AT THE SURFACE...SURFACE RIDGING EXTENDS ACROSS THE AREA 
FROM THE SE CONUS TOWARDS THE SW GULF. EAST TO SOUTHEAST FLOW IS 
AROUND THE RIDGE WITH LIGHT SPEEDS ACROSS THE NE GULF NEAREST 
THE HIGH CENTER...AND REACHING 15-20 KT ACROSS THE SOUTHERN GULF 
AND INTO THE NW GULF. ONLY A SMALL AREA OF SHOWERS IS MOVING 
NORTHWEST THROUGH THE BASIN FROM 23N-29N BETWEEN 92W-95W. EXPECT 
LITTLE CHANGE OVER THE NEXT 24 HOURS. 

CARIBBEAN SEA...
MAINLY SOUTHWEST TO WEST FLOW COVERS THE CARIBBEAN AROUND A 
BROAD UPPER LEVEL RIDGE COVERING THE AREA AND CONTINUING INTO 
THE CENTRAL ATLC. AT THE SURFACE...NE FLOW DOMINATES WITH LIGHT 
5-10 KT WINDS ACROSS THE EASTERN AND CENTRAL CARIBBEAN AND 
STRONGER WINDS OF 20-25 KT ACROSS THE NW CARIBBEAN. ISOLATED 
SHOWERS ARE EMBEDDED WITHIN THE NE FLOW AND ARE MOST 
CONCENTRATED NEAR PUERTO RICO...EAST OF BELIZE...AND OFFSHORE OF 
COSTA RICA. LITTLE CHANGE IS EXPECTED OVER THE NEXT 24 HOURS. 

ATLANTIC OCEAN...
A SHORTWAVE UPPER LEVEL TROUGH EXTENDS OVER THE SW NORTH ATLC 
ALONG 34N60W TO 24N71W. MOSTLY FAIR CONDITIONS ARE SEEN AT THE 
SURFACE WEST OF THE UPPER TROUGH. HOWEVER...TO THE EAST...MOIST 
SWLY FLOW ALOFT IS HELPING SCATTERED SHOWERS/POSSIBLE 
THUNDERSTORMS FROM 20N-28N BETWEEN 54W-65W. THE UPPER TROUGH 
ALSO SUPPORTS A SURFACE TROUGH ALONG 26N65W TO 19N66W. A BROAD 
UPPER RIDGE COVERS THE CENTRAL ATLC...BUT ANOTHER SHORTWAVE 
TROUGH TO THE EAST NEAR 40W IS CAUSING ANOTHER AREA OF DISTURBED 
WEATHER. THE UPPER TROUGH SUPPORTS A 1006 MB SURFACE LOW NEAR 
31N44W. A SURFACE TROUGH EXTENDS SOUTH FROM THE LOW CENTER TO 
NEAR 20N45W. SCATTERED SHOWERS/POSSIBLE THUNDERSTORMS ARE EAST 
OF THE TROUGH NORTH OF 20N BETWEEN 34W-39W. THE LOW IS EXPECTED 
TO MOVE NORTHEAST OUT OF THE DISCUSSION AREA IN THE NEXT 24 
HOURS. ACROSS THE FAR EAST ATLC...SURFACE RIDGING DOMINATES 
EXTENDING FROM A 1032 MB HIGH EAST OF THE AZORES ISLANDS. THE 
RIDGE IS SUPPORTED BY AN UPPER LEVEL RIDGE ALONG 31W. 

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

$$
WALTON