000 AXNT20 KNHC 290604 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 205 AM EDT WED OCT 29 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0545 UTC. ...SPECIAL FEATURES... A 1010 MB LOW...FORMERLY ASSOCIATED WITH THE TROPICAL WAVE OVER THE EASTERN CARIBBEAN...IS BEING SUPPORTED BY AN UPPER-LEVEL TROUGH. THE LOW IS EMBEDDED IN A HIGH DEEP LAYER MOIST ENVIRONMENT THAT ALONG WITH DIFFLUENT FLOW ALOFT CONTINUE TO ENHANCE SCATTERED MODERATE/ISOLATED STRONG CONVECTION E OF THE LOW CENTER FROM 16N- 23N BETWEEN 56W-61W. ISOLATED SHOWERS ARE ELSEWHERE WITHIN 180 NM OF THE LOW. DUE TO MARGINAL CONDUCIVE UPPER-LEVEL WINDS...GRADUAL DEVELOPMENT OF THIS DISTURBANCE IS POSSIBLE WHILE IT MOVES W-NW THE NEXT COUPLE OF DAYS. TROPICAL CYCLONE FORMATION CHANCES THROUGH 48 HOURS REMAIN MEDIUM. SEE LATEST NHC TROPICAL WEATHER OUTLOOK UNDER AWIPS/WMO HEADERS MIATWOAT/ABNT20 KNHC FOR MORE DETAILS. ...TROPICAL WAVES... A TROPICAL WAVE IS MOVING ACROSS THE EASTERN CARIBBEAN WITH AXIS EXTENDING FROM 17N63W TO 9N66W...MOVING W AT 15-20 KT. THE WAVE IS BEING SUPPORTED BY A LOW TO MIDDLE LEVEL INVERTED TROUGH AND IT IS EMBEDDED IN A SHALLOW MODERATE MOIST ENVIRONMENT. DRY AIR SUBSIDENCE FROM ALOFT IN THIS REGION OF THE BASIN HINDERS THE DEVELOPMENT OF DEEP CONVECTION AT THE TIME. ...THE ITCZ/THE MONSOON TROUGH... THE MONSOON TROUGH EXTENDS ACROSS AFRICA INTO THE E TROPICAL ATLC NEAR 12N16W AND CONTINUES TO 10N20W. THE ITCZ BEGINS NEAR 10N20W AND CONTINUES ALONG 7N36W TO 7N59W. SCATTERED MODERATE CONVECTION AND ISOLATED TSTMS ARE FROM 4N-12N E OF 35W AND FROM 4N-11N BETWEEN 40W-53W. ...DISCUSSION... GULF OF MEXICO... A BROAD UPPER-LEVEL RIDGE IS OVER THE WEST ATLC...THUS SUPPORTING A SURFACE RIDGE THAT EXTENDS AN AXIS SW ACROSS THE FLORIDA PENINSULA TO THE NW GULF. HOWEVER...IN THE MIDDLE- LEVELS...THE BASE OF A BROAD TROUGH OVER THE EASTERN CONUS EXTENDS S TO THE CENTRAL GULF TO SUPPORT A WEAKNESS IN THE SURFACE RIDGE ANALYZED AS A SURFACE TROUGH ALONG 30N88W TO 25N88W. SHALLOW MOIST AIR FROM THE ATLC FRONT ENVIRONMENT AND FORMER TROPICAL CYCLONE HANNA HAS BEEN STREAMING INTO THE GULF...THUS SUPPORTING CLOUDINESS NEARBY THE SURFACE TROUGH AND BAY OF CAMPECHE. STRONG DRY AIR SUBSIDENCE FROM ALOFT ACROSS THE REMAINDER BASIN SUSTAINS FAIR WEATHER. WINDS ARE FROM THE E-SE IN THE RANGE OF 5-15 KT. A COLD FRONT WILL REACH THE NE BASIN AND NORTHERN FLORIDA BY WED NIGHT...CONTINUING E-SE ACROSS SOUTHERN FLORIDA THROUGH THU NIGHT. CARIBBEAN SEA... THE REMNANTS OF HANNA ARE BEING ANALYZED AS A SURFACE TROUGH EXTENDING FROM 21N84W TO 15N87W...WHICH CONTINUE TO SUPPORT SCATTERED SHOWERS AND ISOLATED TSTMS OVER THE YUCATAN BASIN...BELIZE AND NORTHERN HONDURAS. LINGERING MOISTURE ASSOCIATED WITH A FORMER SURFACE TROUGH ACROSS HISPANIOLA CONTINUE TO ENHANCE ISOLATED SHOWERS AND TSTMS IN THE ISLAND AS WELL AS ADJACENT WATERS. THE SHOWERS ARE BEING SUPPORTED BY AN UPPER LEVEL TROUGH DIPPING ACROSS THE CENTRAL AND EASTERN CARIBBEAN. A TROPICAL WAVE IS MOVING OVER THE EASTERN BASIN. THIS WAVE IS BEING SUPPORTED BY AN INVERTED LOW- TO MIDDLE-LEVEL TROUGH...HOWEVER STRONG DRY AIR SUBSIDENCE FROM ALOFT IN THIS REGION OF THE BASIN IS HINDERING THE DEVELOPMENT OF CONVECTION. SEE TROPICAL WAVES SECTIONS ABOVE FOR MORE DETAILS. A LOW PRESSURE SYSTEM CENTERED NE OF THE LEEWARD ISLANDS IS EXPECTED TO DRIFT WESTWARD TOWARDS HISPANIOLA BY FRIDAY NIGHT. THIS AREA OF LOW PRESSURE IS EXPECTED TO GENERATE SHOWERS ACROSS PUERTO RICO WED THROUGH THU AND FOR HISPANIOLA THU TO SAT. HISPANIOLA... LINGERING MOISTURE ASSOCIATED WITH A FORMER SURFACE TROUGH ACROSS HISPANIOLA CONTINUE TO ENHANCE ISOLATED SHOWERS AND TSTMS IN THE ISLAND AS WELL AS ADJACENT WATERS. THE SHOWERS ARE BEING SUPPORTED BY AN UPPER LEVEL TROUGH DIPPING ACROSS THE CENTRAL AND EASTERN CARIBBEAN. A LOW PRESSURE SYSTEM CENTERED NE OF THE LEEWARD ISLANDS IS EXPECTED TO DRIFT WESTWARD TOWARDS HISPANIOLA BY FRIDAY NIGHT. THIS AREA OF LOW PRESSURE IS EXPECTED TO GENERATE SHOWERS ACROSS HISPANIOLA THU TO SAT. ATLANTIC OCEAN... THE HIGHLIGHT IN THE BASIN IS A DISTURBANCE JUST NE OF THE LEEWARD ISLANDS...WHICH IS DISCUSSED IN THE SPECIAL FEATURES SECTION. A MIDDLE TO UPPER LEVEL TROUGH OVER THE CENTRAL ATLC N OF 28N CONTINUE TO SUPPORT A COLD FRONT ANALYZED FROM 30N45W SW TO 25N57W WHERE A SURFACE TROUGH CONTINUES TO 22N66W. THERE IS NO CONVECTION ASSOCIATED WITH THESE FEATURES AT THE TIME. EAST AND WEST OF THE FRONTAL BOUNDARY...SURFACE RIDGING AND FAIR WEATHER DOMINATE. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ NR