000 AXNT20 KNHC 112305 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 705 PM EST SUN NOV 11 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 2245 UTC. ...THE ITCZ/THE MONSOON TROUGH... THE MONSOON TROUGH EXTENDS FROM THE COAST OF GUINEA-BISSAU AT 12N16W TO 8N18W TO 7N25W. THE ITCZ EXTENDS FROM 7N225W TO 12N42W TO 8N60W. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS FROM 4N-9N BETWEEN 13W-25W. SCATTERED MODERATE CONVECTION IS FROM 7N-11N BETWEEN 42W-47W. ...DISCUSSION... THE GULF OF MEXICO... MOSTLY FAIR WEATHER ASSOCIATED WITH HIGH PRES RIDGE ACROSS THE NE GULF CONTINUES TO COVER MOST OF THE GULF OF MEXICO...WITH A LINE OF SCATTERED SHOWERS MOVING INTO LOUISIANA COASTAL WATERS. SOME MID-LEVEL MOISTURE IS STREAMING INTO THE W GULF AHEAD OF AN APPROACHING TROUGH. THIS UPPER TROUGH SUPPORTS A COLD FRONT THAT IS EXPECTED TO REACH THE TEXAS COAST EARLY MON MORNING. THE RIDGE WILL SHIFT EASTWARD ALLOWING THE COLD FRONT TO PUSH INTO THE NE GULF...STRETCHING FROM THE BIG BEND OF FLORIDA TO THE WESTERN BAY OF CAMPECHE BY TUE MORNING. FRESH TO STRONG SOUTHERLY WINDS ARE PREVALENT ACROSS THE BASIN AHEAD OF THE COLD FRONT. STRONG HIGH PRES SURGING DOWN THE EAST COAST OF MEXICO BEHIND THE FRONT WILL INCREASE WINDS IN THE SW GULF TO 25-30 KT AND INCREASE SEAS TO 8-11 FT MON NIGHT THROUGH TUE NIGHT. THE CARIBBEAN SEA... DRY AIR ALOFT ASSOCIATED WITH AN UPPER LEVEL RIDGE IN THE GULF OF MEXICO AND A TROUGH IN THE W ATLC COVERS MOST OF THE REGION. THIS PATTERN IS SUPPORTING MOSTLY FAIR WEATHER CONDITIONS ACROSS THE BASIN. A FEW EMBEDDED SHOWERS WITHIN STRONG NE FLOW OF 20-25 KT ARE EVIDENT ACROSS MUCH OF THE CENTRAL AND WESTERN CARIBBEAN. MODERATE TO FRESH WINDS AROUND 15 KT PREVAIL ACROSS THE EASTERN CARIBBEAN. ISOLATED SHOWERS ASSOCIATED WITH A SURFACE TROUGH ARE BEGINNING TO REACH THE LEEWARD ISLANDS. THE TROUGH IS EXPECTED TO MOVE WESTWARD AND WILL LIKELY CAUSE SCATTERED SHOWERS AND A FEW THUNDERSTORMS ACROSS THE NE CARIBBEAN. LITTLE CHANGE IS EXPECTED ELSEWHERE. THE ATLANTIC OCEAN... SURFACE RIDGING ACROSS THE EASTERN CONUS CONTINUES INTO THE WEST ATLC MAINTAINING MOSTLY FAIR CONDITIONS ACROSS THE AREA. DRY AIR ALOFT IS SPREADING OVER THE AREA AS IT WRAPS AROUND A RIDGE OVER THE EASTERN SEABOARD AND A TROUGH ALONG 70W. THE TROUGH IS ADDING SUPPORT TO A SHEAR LINE BOUNDARY IN THE CENTRAL ATLC FROM 32N51W TO 21N66W. SCATTERED SHOWERS AND A FEW TSTMS ARE WITHIN 150 NM EITHER SIDE OF THE BOUNDARY. A SURFACE TROUGH OVER THE LEEWARD ISLANDS ALONG 20N62W TO 14N60W IS SUPPORTING ISOLATED SHOWERS WITHIN 120 NM EITHER SIDE OF THE TROUGH AXIS. A RIDGE IN THE CENTRAL ATLC ALONG 50W EXTENDS INTO A LARGER UPPER RIDGE OVER THE NE ATLC...SUPPORTING A BROAD SURFACE RIDGE ANCHORED BY 1031 MB AZORES HIGH NEAR 37N25W. AN UPPER LEVEL LOW SOUTH OF THE RIDGE NEAR 24N38W IS SUPPORTING SCATTERED SHOWERS/ISOLATED TSTMS FROM 18N-27N BETWEEN 32W-37W. A WEAK SURFACE TROUGH W OF THIS AREA IS ALONG 19N44W TO 14N46W BUT NOT CAUSING SIGNIFICANT WEATHER. MODEL GUIDANCE INDICATES A SECOND TROUGH WILL FORM NEAR THE ACTIVE AREA OF CONVECTION ASSOCIATED WITH THE UPPER LOW. THE STATIONARY FRONT IN THE CENTRAL ATLC IS ALSO EXPECTED TO BREAK OFF FROM THE MAIN FRONT AND MOVE WESTWARD AS A SURFACE TROUGH. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ MUNDELL