000 AXNT20 KNHC 181804 RRA TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 105 PM EST TUE NOV 18 2014 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 1745 UTC. ...THE ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS ACROSS AFRICA INTO THE E TROPICAL ATLC NEAR 9N13W TO 6N21W WHERE THE ITCZ BEGINS AND CONTINUES ALONG 6N37W 7N48W TO 9N61W. SCATTERED MODERATE CONVECTION AND ISOLATED TSTMS ARE FROM 2N-8N BETWEEN 18W-30W...FROM 6N-10N BETWEEN 31W-46W AND FROM 8N-12N W OF 49W. ...DISCUSSION... GULF OF MEXICO... A BROAD SURFACE RIDGE ANCHORED BY A 1033 MB HIGH OVER EASTERN TEXAS CONTINUES TO PROVIDE THE GULF WITH NORTHERLY WIND FLOW IN THE RANGE OF 20-30 KT...WHICH DRIVES A COLD FRONT ACROSS SOUTHERN FLORIDA SW INTO THE GULF ALONG 25N81W TO 22N86W TO THE BAY OF CAMPECHE NEAR 17N92W. A BROAD MIDDLE- TO UPPER-LEVEL TROUGH OVER THE CENTRAL...EASTERN CONUS AND PORTIONS OF THE WESTERN ATLC SUPPORT THIS FRONT THAT IS FORECAST TO MOVE OUT OF THE BASIN TONIGHT. DEEP LAYER DRY AIR AND STRONG ENVIRONMENTAL SHEAR INHIBIT CONVECTION N OF 23N. DIFFLUENT FLOW ALOFT BEING GENERATED BY A AN ELONGATED ANTICYCLONE ANCHORED OVER THE NW CARIBBEAN ALONG MODERATE MOISTURE IN THE VICINITY OF THE COLD FRONT ENHANCE SCATTERED SHOWERS WITHIN 100 NM EITHER SIDE OF THE BOUNDARY. SURFACE RIDGING WILL PREVAIL ACROSS THE BASIN THROUGH FRIDAY MORNING AS THE HIGH PRESSURE CENTER DRIFTS EASTWARD ACROSS THE S-SE CONUS. WINDS TURN E-NE AND SUBSIDE TO LESS THAN 25 KT BY THU MORNING. CARIBBEAN SEA... EXCEPT FOR THE NW AND SW CARIBBEAN BASIN...DEEP LAYER DRY AIR SUPPORTS FAIR WEATHER CONDITIONS ACROSS THE BASIN. IN THE UPPER- LEVELS...AN ELONGATED ANTICYCLONIC CIRCULATION ANCHORED WEST OF JAMAICA GENERATES A DIFFLUENT ENVIRONMENT ALOFT THAT ALONG LOW- LEVEL MOISTURE CONVERGENCE SUPPORT SCATTERED MODERATE CONVECTION AND ISOLATED TSTMS ASSOCIATED WITH A PRE-FRONTAL SURFACE TROUGH ALONG 22N83W TO WESTERN HONDURAS NEAR 15N88W. THIS CONVECTION EXTENDS WITHIN 160 NM WEST OF THE TROUGH AND 250 NM EAST OF IT. IN THE SW CARIBBEAN...A 1011 MB LOW IS JUST EAST OF THE BORDER BETWEEN COSTA RICA AND PANAMA...THUS SUPPORTING SCATTERED HEAVY SHOWERS AND TSTMS S OF 12N W OF 80W. IN THE NW BASIN...E-NE WINDS OF 10-15 KT ABOUNDS WHILE TRADES OF 20 KT DOMINATE ELSEWHERE. A COLD FRONT CURRENTLY MOVING ACROSS THE S-SE GULF WILL BE ENTERING THE NW CARIBBEAN TONIGHT...THUS ENHANCING THE CONVECTION IN THIS REGION. BY THU MORNING...THE FRONT IS FORECAST TO STALL OVER WESTERN-CENTRAL CUBA SW TO NORTHERN BELIZE...DISSIPATING OVER NORTHERN CUBA FRIDAY MORNING. HISPANIOLA... DEEP LAYER DRY AIR OVER THE ISLAND AND ADJACENT WATERS SUPPORT FAIR WEATHER...WHICH IS FORECAST TO PERSIST THROUGH WED EVENING. ATLANTIC OCEAN... A BROAD MIDDLE- TO UPPER-LEVEL TROUGH OVER THE CENTRAL...EASTERN CONUS AND PORTIONS OF THE WESTERN ATLC SUPPORT A COLD FRONT ANALYZED FROM 30N75W SW TO 26N80W...ACROSS SOUTHERN FLORIDA INTO THE S-SE GULF OF MEXICO. A PRE-FRONTAL SURFACE TROUGH IS ALSO ANALYZED FROM 31N69W TO 26N72W. SCATTERED SHOWERS AND TSTMS ASSOCIATED WITH THESE FEATURES ARE N OF 27N W OF 73W. AN ELONGATED UPPER TROUGH IS OVER THE EASTERN ATLC EXTENDING SW INTO THE CENTRAL TROPICAL ATLC...THUS SUPPORTING A COLD FRONT ALONG 30N18W TO 25N36W TO 25N52W. SURFACE RIDGING DOMINATES ELSEWHERE N OF 21N BEING ANCHORED BY A 1031 MB HIGH NEAR 34N45W. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ NR