000 AXNT20 KNHC 181129 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 705 AM EST TUE FEB 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1045 UTC. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS ACROSS AFRICA INTO THE TROPICAL ATLC NEAR 8N13W AND CONTINUES TO 4N15W TO 1N20W. THE ITCZ BEGINS NEAR 1N20W AND CONTINUES TO THE EQUATOR ALONG 33W AND 50W. A CLUSTER OF MODERATE/ISOLATED STRONG CONVECTION IS FROM 3N-7N EAST OF 14W. SCATTERED MODERATE CONVECTION AND TSTMS ARE FROM 1N-5N BETWEEN 4W-9W. SCATTERED MODERATE IS ALSO FROM 3S-3N BETWEEN 23W- 35W AND FROM 2S-3N BETWEEN 42W-51W. ...DISCUSSION... GULF OF MEXICO... ZONAL WESTERLY FLOW CONTINUES TO DOMINATE THE GULF ALOFT. A SURFACE RIDGE EXTENDS FROM THE W ATLC SW TO FLORIDA AND ACROSS THE GULF WITH A 1025 MB HIGH NEAR 37N69W. SATELLITE WATER VAPOR IMAGERY SHOW RELATIVELY DRY AND STABLE AIR ACROSS THE BASIN WITH SOME UPPER LEVEL MOISTURE MOVING ACROSS THE FAR N GULF. RETURN FLOW ALONG THE N-NW GULF COAST AND ADJACENT WATERS IS GENERATING ADVECTION FOG N OF 27N WEST OF 89W AND IS KEEPING A FRONTAL SYSTEM STATIONARY OVER TEXAS AND LOUISIANA. SURFACE RIDGING AND RETURN FLOW WILL PREVAIL THROUGH THU AFTERNOON. A COLD FRONT IS EXPECTED TO REACH THE TEXAS COAST THU NIGHT. CARIBBEAN SEA... ZONAL WESTERLY FLOW ALOFT CONTINUES TO DOMINATE OVER THE CARIBBEAN SEA THIS MORNING. SATELLITE WATER VAPOR IMAGERY SHOW DRY AND STABLE AIR IN THE MIDDLE TO UPPER LEVELS ACROSS THE ENTIRE BASIN. A MIDDLE TO UPPER LEVEL TROUGH OVER THE WESTERN ATLC BETWEEN 40W-70W AND WITH BASE OVER NORTHERN HISPANIOLA SUPPORTS A FRONTAL BOUNDARY THAT TRANSITIONS INTO A SHEAR LINE NEAR 21N70W TO NW HAITI TO THE WINDWARD PASSAGE NEAR 18N74W. LINGERING LOW LEVEL MOISTURE ASSOCIATED WITH THE FRONTAL SYSTEM IS WITHIN A LINE EXTENDING FROM SOUTHERN HISPANIOLA NEAR 17N71W SW TO PANAMA NEAR 9N82W AND A LINE FROM EASTERN CUBA NEAR 20N78W TO NW HONDURAS NEAR 15N89W. THIS MOISTURE ALONG WITH NORTHEASTERLY SURFACE FLOW IS ENHANCING ISOLATED SHOWERS OVER NW HONDURAS AS WELL AS SOUTHERN HAITI AND ADJACENT WATERS. EASTERLY TRADE WINDS OF 15 KT CONTINUE DOMINATING ACROSS MUCH OF THE BASIN EXCEPT WITHIN 200 NM OF THE NORTHERN COLOMBIA COAST WHERE WINDS ARE UP TO 30 KT...THE CENTRAL BASIN WITH 20 KT AND THE WINDWARD PASSAGE WITH 20-25 KT. OTHERWISE...A WESTWARD MOVING MOIST AIRMASS ASSOCIATED WITH A SURFACE PRE-FRONTAL TROUGH NE OF PUERTO RICO MAY BRING SHOWERS TO THE EASTERN REGION OF THE ISLAND...THE VIRGIN ISLANDS AND THE LESSER ANTILLES. A RELATIVELY TIGHT PRESSURE GRADIENT IS EXPECTED TO CONTINUE THROUGH THU MORNING WHICH WILL ALLOW FOR TRADES OF 20 KT TO PREVAIL OVER THE CENTRAL BASIN AND EXTEND FURTHER EAST TO THE LESSER ANTILLES. HISPANIOLA... CURRENTLY A SHEAR LINE ACROSS THE WINDWARD PASSAGE IS PUSHING LOW LEVEL MOISTURE AGAINST THE COAST OF HAITI TO GENERATE SHOWERS NOW CONCENTRATED OVER SW HISPANIOLA AND ADJACENT WATERS. WESTERLY FLOW ALOFT AS WELL AS THE PRESENCE OF DRY AIR AT THE LOWER LEVELS IS FORECAST TO REMAIN THROUGH THU THUS INHIBITING THE DEVELOPMENT OF DEEP CONVECTION. ATLANTIC OCEAN... A MIDDLE TO UPPER LEVEL TROUGH COVERS PART OF THE W ATLC N OF 20N BETWEEN 40W-70W AND SUPPORTS A COLD FRONT THAT ENTERS THE AREA OF DISCUSSION NEAR 30N51W AND CONTINUES TO 27N55W WHERE IT TRANSITIONS TO A STATIONARY FRONT ALONG 24N63W TO 21N69W. THEN...A SHEAR LINE CONTINUES TO NW HAITI NEAR 19N73W TO 18N74W. ISOLATED SHOWERS ARE WITHIN 120 NM WEST OF THE FRONTAL BOUNDARY. THE TROUGH ALOFT ALSO SUPPORTS A SURFACE TROUGH FROM 25N58W TO 20N66W WITH ISOLATED SHOWERS WITHIN 60 NM EITHER SIDE OF THE AXIS. A SURFACE RIDGE IS BUILDING S OVER THE W ATLC W OF THE FRONT ANCHORED BY A 1025 MB HIGH OVER THE MID ATLANTIC STATES COASTAL WATERS. THIS RIDGE EXTENDS SW ACROSS FLORIDA INTO THE GULF OF MEXICO. A SECOND SURFACE RIDGE DOMINATES THE REMAINDER OF THE ATLC E OF THE FRONT ANCHORED BY A 1028 MB HIGH NEAR 33N31W. THE REMAINDER PORTION OF THE STATIONARY FRONT IS FORECAST TO TRANSITION TO A SHEAR LINE BY TONIGHT WHILE THE COLD PORTION PUSHES ACROSS THE CENTRAL ATLC DISSIPATING BY EARLY WED. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ NR