000 AXNT20 KNHC 201729 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 105 PM EST TUE NOV 20 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1715 UTC. ...THE ITCZ/THE MONSOON TROUGH... THE MONSOON TROUGH PASSES THROUGH COASTAL GUINEA-BISSAU NEAR 12N16W TO 9N17W. THE ITCZ CONTINUES FROM 9N17W TO 7N20W 6N35W TO 10N45W TO THE COAST OF GUYANA NEAR 8N59W. WIDELY SCATTERED MODERATE CONVECTION IS FROM 4N-7N BETWEEN 17W-24W...AND FROM 4N-10N BETWEEN 30W-38W. ...DISCUSSION... THE GULF OF MEXICO... A 1023 MB HIGH IS OVER MISSISSIPPI NEAR 33N89W. SURFACE RIDGING EXTENDS OVER THE NORTHERN GULF OF MEXICO N OF 26N. A SURFACE TROUGH IS OVER THE SW GULF OF MEXICO FROM 25N93W TO 19N91W. OVERCAST LOW CLOUDS WITH SCATTERED SHOWERS ARE S OF 24N BETWEEN 87W-95W. ELSEWHERE...BROKEN TO OVERCAST LOW CLOUDS ARE OVER S FLORIDA AND THE E GULF E OF 85W. 10-20 KT NE TO E WINDS ARE OVER THE GULF WITH THE STRONGEST WINDS N OF THE YUCATAN PENINSULA. SOME COLD AIR ADVECTION REMAINS OVER THE GULF. IN THE UPPER LEVELS...ZONAL FLOW IS OVER THE GULF WITH SIGNIFICANT UPPER LEVEL MOISTURE AND SCATTERED HIGH CLOUD OVER THE N GULF N OF 28N. STRONG SUBSIDENCE IS OVER THE REMAINDER OF THE GULF. EXPECT THE SURFACE TROUGH TO MOVE TO THE WESTERN BAY OF CAMPECHE OVER THE NEXT 24 HOURS WITH SHOWERS. THE CARIBBEAN SEA... A 1008 MB LOW IS CENTERED INLAND OVER N COLOMBIA NEAR 9N75W. WIDELY SCATTERED MODERATE CONVECTION IS FROM 5N-9N BETWEEN 75W-78W. SCATTERED MODERATE TO ISOLATED STRONG CONVECTION IS OVER THE SW CARIBBEAN FROM 10N-15N BETWEEN 77W-83W. SCATTERED SHOWERS ARE INLAND OVER GUATEMALA...HONDURAS ...COSTA RICA...AND PANAMA. ELSEWHERE...SCATTERED SHOWERS ARE OVER HISPANIOLA... PUERTO RICO...AND THE E CARIBBEAN E OF 75W. 10-15 KT TRADEWINDS ARE OVER THE CENTRAL AND EASTERN CARIBBEAN E OF 80W. 10-25 KT NORTHERLY WINDS ARE OVER THE W CARIBBEAN WITH STRONGEST WINDS ALONG THE COAST OF NICARAGUA. IN THE UPPER LEVELS...AN UPPER LEVEL RIDGE IS OVER THE CARIBBEAN. UPPER LEVEL DIFFLUENCE IS ENHANCING THE CONVECTION AND SHOWERS OVER THE SW AND CENTRAL CARIBBEAN. EXPECT LITTLE CHANGE OVER THE NEXT 24 HOURS. THE ATLANTIC OCEAN... A 1008 MB LOW IS CENTERED OVER THE NW ATLANTIC NEAR 30N75W. A COLD FRONT EXTENDS SW TO THE N BAHAMAS ALONG 29N74W 27N78W. SCATTERED SHOWERS ARE WITHIN 30 NM OF THE FRONT. 20 KT NW WINDS ARE W OF THE FRONT. ANOTHER 1009 MB LOW IS OVER THE W ATLANTIC NEAR 28N73W. A COLD FRONT EXTENDS SW TO THE CENTRAL BAHAMAS ALONG 27N71W 23N76W. THE TAIL END OF ANOTHER COLD FRONT IS OVER THE W ATLANTIC FROM 32N61W TO 25N67W. WIDELY SCATTERED MODERATE CONVECTION IS WITHIN 240 NM E OF THE FRONT. A COLD FRONT HAS DIPPED INTO THE CENTRAL ATLANTIC AND EXTENDS FROM 32N22W TO 29N30W TO 29N40W TO 31N47W. SCATTERED SHOWERS ARE WITHIN 60 NM OF THE FRONT. A 1026 MB HIGH IS FURTHER N OVER THE CENTRAL ATLANTIC NEAR 37N41W PRODUCING FAIR WEATHER. IN THE TROPICS A SURFACE TROUGH EXTENDS FROM 21N47W TO 12N49W. SCATTERED SHOWERS ARE WITHIN 90 NM OF THE TROUGH. IN THE UPPER LEVELS...AN UPPER LEVEL LOW IS CENTERED NEAR 33N67W. UPPER LEVEL DIFFLUENCE IS SE OF THE CENTER...WELL N OF THE LEEWARD ISLANDS...CONTRIBUTING TO THE CONVECTION AND SHOWERS. ANOTHER UPPER LEVEL LOW IS CENTERED OVER THE TROPICAL ATLANTIC NEAR 16N42W. UPPER LEVEL DIFFLUENCE E OF THE LOW IS HELPING TO PRODUCE SCATTERED MODERATE CONVECTION FROM 10N-18N BETWEEN 30W-40W. EXPECT OVER THE NEXT 24 HOURS FOR THE TWO SURFACE LOWS AND ASSOCIATED FRONTS OVER THE W ATLANTIC TO DISSIPATE WHILE THE THIRD W ATLANTIC FRONTAL SYSTEM REMAINS WITH CONVECTION. ALSO EXPECT THE COLD FRONT OVER THE CENTRAL ATLANTIC TO MOVE E WITH SHOWERS. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ FORMOSA