000 AXNT20 KNHC 181738 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 105 PM EST SUN NOV 18 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. ...ITCZ/MONSOON TROUGH... MONSOON TROUGH EXTENDS ACROSS AFRICA INTO THE E TROPICAL ATLC NEAR 11N15W AND CONTINUES TO 7N21W WHERE THE ITCZ AXIS BEGINS AND CONTINUES TO 6N30W TO SOUTH AMERICA NEAR 8N59W. SCATTERED MODERATE TO ISOLATED STRONG CONVECTION IS S OF THE MONSOON TROUGH ALONG THE COAST OF WEST AFRICA FROM 4N-8N BETWEEN 12W-16W. WIDELY SCATTERED MODERATE CONVECTION IS S OF THE ITCZ FROM 2N-5N BETWEEN 29W-32W. ...DISCUSSION... GULF OF MEXICO... A SURFACE TROUGH IS OVER THE SW GULF OF MEXICO FROM 21N97W TO 19N95W. OVERCAST LOW CLOUDS WITH SCATTERED SHOWERS ARE ALONG THE COAST OF MEXICO S OF 24N W OF 96W. ELSEWHERE...BROKEN TO OVERCAST LOW CLOUDS ARE OVER THE NE GULF. RADAR IMAGERY SHOWS SCATTERED SHOWERS OVER THE STRAITS OF FLORIDA S OF KEY WEST. 10-20 KT NE WINDS ARE OVER THE GULF. SOME COLD AIR ADVECTION REMAINS OVER THE N GULF N OF 25N. IN THE UPPER LEVELS...AN UPPER LEVEL TROUGH IS OVER THE GULF WITH AXIS ALONG 84W. STRONG SUBSIDENCE IS OVER MOST OF THE GULF WITH SIGNIFICANT UPPER LEVEL MOISTURE OVER TEXAS. EXPECT THE SHOWERS OVER THE W GULF TO DIMINISH OVER THE NEXT 24 HOURS. CARIBBEAN SEA... A 1010 MB LOW IS CENTERED OVER THE SW CARIBBEAN NEAR 11N76W. ISOLATED MODERATE CONVECTION IS 120 NM OF THE LOW. FURTHER W... WIDELY SCATTERED MODERATE CONVECTION IS OVER THE SW CARIBBEAN FROM 9N-13N BETWEEN 79W-83W. SCATTERED SHOWERS ARE INLAND OVER GUATEMALA...HONDURAS...COSTA RICA...AND PANAMA. ELSEWHERE... SCATTERED SHOWERS ARE OVER THE SE CARIBBEAN S OF 13N E OF 63W. 10-15 KT TRADEWINDS ARE OVER THE CENTRAL AND EASTERN CARIBBEAN E OF 80W. 15-20 KT NORTHERLY WINDS ARE OVER THE W CARIBBEAN. IN THE UPPER LEVELS...AN UPPER LEVEL TROUGH IS OVER THE NW CARIBBEAN N OF 15N W OF 80W WITH STRONG SUBSIDENCE. AN UPPER LEVEL RIDGE IS OVER THE REMAINDER OF THE CARIBBEAN. UPPER LEVEL DIFFLUENCE IS PRODUCING WIDELY SCATTERED MODERATE CONVECTION OVER THE CENTRAL CARIBBEAN FROM 13N-15N BETWEEN 74W-76W. EXPECT LITTLE CHANGE OVER THE NEXT 24 HOURS. ATLANTIC OCEAN... A 1016 MB LOW IS OFF THE COAST OF GEORGIA NEAR 31N78W. A QUASI-STATIONARY FRONT EXTENDS S FROM THE LOW TO THE N BAHAMAS AT 27N79W. SCATTERED SHOWERS ARE WITHIN 30 NM OF THE FRONT. BROKEN TO OVERCAST MULTILAYERED CLOUDS ARE ALSO W OF THE FRONT. FURTHER E...A SURFACE TROUGH EXTENDS FROM 29N66W TO 23N70W. WIDELY SCATTERED MODERATE CONVECTION IS WELL E OF THE TROUGH FROM 24N-32N BETWEEN 59W-63W. A 1024 MB HIGH IS OVER THE CENTRAL ATLANTIC NEAR 32N37W PRODUCING FAIR WEATHER. ANOTHER 1025 MB HIGH IS OVER THE E ATLANTIC NEAR 32N28W. IN THE TROPICS A SURFACE TROUGH EXTENDS FROM 18N41W TO 12N44W. ISOLATED MODERATE CONVECTION IS WITHIN 120 NM OF THE TROUGH AXIS. IN THE UPPER LEVELS...UPPER LEVEL DIFFLUENCE IS N OF THE LEEWARD ISLANDS CONTRIBUTING TO THE WIDELY SCATTERED MODERATE CONVECTION FROM 24N-32N BETWEEN 59W-63W. AN UPPER LEVEL LOW IS CENTERED OVER THE CENTRAL ATLANTIC NEAR 18N43W. UPPER LEVEL DIFFLUENCE SE OF THE LOW IS HELPING TO PRODUCE WIDELY SCATTERED MODERATE CONVECTION FROM 15N-22N BETWEEN 30W-38W. AN OMEGA BLOCK IS NOTED IN THE UPPER LEVELS OVER THE ENTIRE ATLANTIC. THUS LITTLE CHANGE IS EXPECTED OVER THE NEXT 24 HOURS IN THE UPPER LEVELS. THE SURFACE TROUGH OVER THE W ATLANTIC IS EXPECTED TO MOVE W WITH SHOWERS OVER THE NEXT 24 HOURS. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ FORMOSA