000 AXNT20 KNHC 071747 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 105 PM EST WED NOV 07 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 1645 UTC. ...THE ITCZ/THE MONSOON TROUGH... THE MONSOON TROUGH EXTENDS ACROSS WEST AFRICA TO THE COAST OF GUINEA-BISSAU TO NEAR 11N18W. THE ITCZ PICKS UP AT 11N81W AND CONTINUES ALONG 6N30W 10N46W 9N50W. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS FROM 3N-5N BETWEEN 14W-24W...AND FROM 5N-8N BETWEEN 21W-26W. SCATTERED MODERATE/STRONG CONVECTION IS FROM 6N-9N BETWEEN 40W-49W. ...DISCUSSION... THE GULF OF MEXICO... A DRY AIRMASS COVERS THE GULF OF MEXICO IN THE WAKE OF A COLD FRONT THAT HAS NOW PUSHED MAINLY SOUTH AND EAST OF THE BASIN CURRENTLY EXTENDING FROM WESTERN CUBA NEAR 23N81W ACROSS NORTHERN YUCATAN PENINSULA TO 20N91W...AS OF 1500 UTC. FAIR CONDITIONS SPREAD ACROSS THE BASIN WITH STRONG NORTH TO NORTHEAST WINDS OF 15-20 KT BEHIND THE FRONT. SURFACE RIDGING IS BEGINNING TO BUILD ACROSS THE BASIN AND WILL CONTINUE TO DO SO THROUGHOUT THE WEEK. ALOFT...A BROAD UPPER LEVEL TROUGH COVERS THE AREA ALONG WITH DRY AIR ALOFT...WHICH IS HELPING SUPPORT THE FAIR WEATHER. EXPECT LITTLE CHANGE OVER THE NEXT 24 HOURS. THE CARIBBEAN SEA... A COLD FRONT IS JUST MOVING INTO THE EXTREME NW CORNER OF THE CARIBBEAN FROM WESTERN CUBA NEAR 23N81W TO THE YUCATAN PENINSULA AT 20N91W...AS OF 1500 UTC. POSSIBLE ISOLATED SHOWERS ARE WITHIN 60 NM EITHER SIDE OF THE AXIS. A WEAK PRE-FRONTAL TROUGH IS FARTHER EAST ALONG 21N78W TO 16N85W. ISOLATED SHOWERS ARE NEAR THE SW EXTENSION OF THE TROUGH ACROSS NORTHERN HONDURAS AND THE WATERS TO THE NORTH. A RECENT ASCAT SCATTEROMETER PASS INDICATES THAT THE TROUGH MAY NO LONGER BE PRESENT AT THE SURFACE. A LARGE BURST OF SHOWERS/THUNDERSTORMS IS IN THE FAR SW CARIBBEAN FROM 10N-13N BETWEEN 76W-81W. THIS ACTIVITY IS LIKELY ASSOCIATED WITH BOTH THE MONSOON TROUGH TO THE SOUTH OF PANAMA AS WELL AS DIFFLUENCE ALOFT WHERE MOIST SWLY FLOW WRAPS AROUND AN UPPER LEVEL RIDGE COVERING THE MAJORITY OF THE CARIBBEAN. DRY AIR COVERS THE EASTERN CARIBBEAN AROUND THE EAST SIDE OF THE UPPER TROUGH PROVIDING FAIR CONDITIONS ACROSS THIS AREA. EXPECT THE COLD FRONT TO CONTINUE TO MOVE SOUTHEAST WITH POSSIBLE SHOWERS ALONG IT. SHOWERS/THUNDERSTORMS WILL ALSO CONTINUE IN THE SW CARIBBEAN. THE ATLANTIC OCEAN... A DEEP LAYER TROUGH COVERS THE WEST ATLC SUPPORTING A COLD FRONT THAT EXTENDS FROM A STRONG LOW PRESSURE CENTER WELL NORTH OF THE AREA...AND ENTERS THE AREA NEAR 32N69W TO THE NE BAHAMAS AT 25N77W AND CONTINUES TO WESTERN CUBA. POSSIBLE ISOLATED SHOWERS ARE WITHIN 60 NM EITHER SIDE OF THE AXIS. A PRE-FRONTAL TROUGH IS TO THE SE ALONG 27N68W TO CENTRAL CUBA AT 22N77W. ISOLATED SHOWERS/THUNDERSTORMS ARE WITHIN 30 NM EITHER SIDE OF THE AXIS. A LARGER AREA OF SHOWERS/THUNDERSTORMS IS FARTHER EAST IN THE CENTRAL ATLC NORTH OF 25N BETWEEN 56W-64W WHERE THE STRONGEST DIFFLUENCE ALOFT IS BETWEEN THE UPPER TROUGH COVERING THE WESTERN ATLC AND AN UPPER LEVEL RIDGE ALONG 54W COVERING THE CENTRAL ATLC. THE UPPER RIDGE OVER THE CENTRAL ATLC...WITH AN AXIS THAT CONTINUES INTO THE NE ATLC IS SUPPORTING A BROAD SURFACE RIDGE COVERING THE EASTERN ATLC ANCHORED BY A 1036 MB AZORES HIGH. AN UPPER LEVEL TROUGH EAST OF THE RIDGE ALONG 38W IN THE TROPICAL ATLC SUPPORTS A WEAK SURFACE TROUGH ALONG 24N43W TO 19N42W AS WELL AS AN AREA OF SHOWERS/POSSIBLE THUNDERSTORMS FROM 16N-25N BETWEEN 32W-40W. THE FRONT IN THE WEST ATLC IS EXPECTED TO CONTINUE TO MOVE EASTWARD OVER THE NEXT SEVERAL DAYS WITH SURFACE RIDGING CONTINUING TO COVER THE EAST ATLC. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ WALTON