000 AXNT20 KNHC 151753 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 205 PM EDT THU MAY 15 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 1715 UTC. ...SPECIAL FEATURE... ...GULF OF MEXICO GALE WARNING... A COLD FRONT EXTENDS FROM THE FLORIDA BIG BEND TO THE EASTERN BAY OF CAMPECHE NEAR 19N92W. GALE FORCE WINDS WERE NOTED IN THE GULF THIS MORNING WITH BUOYS NEAR THE VERACRUZ HARBOR REPORTING GUSTY WINDS TO 35-36 KT. WINDS ARE EXPECTED TO BE BELOW GALE FORCE EARLY THIS AFTERNOON. FRESH TO STRONG NORTHERLY WINDS ARE BLOWING ELSEWHERE BEHIND THE FRONT. IT WILL REACH FROM NEAR TAMPA FLORIDA TO THE N CENTRAL YUCATAN PENINSULA BY LATE THIS AFTERNOON...FROM NEAR FORT MYERS TO YUCATAN CHANNEL AND NE YUCATAN PENINSULA THIS EVENING...FROM THE FLORIDA KEYS TO NW CUBA AND THE YUCATAN CHANNEL LATE TONIGHT...AND TO E OF THE AREA DURING FRI MORNING. AS THE FRONT MOVES E OF THE AREA...EXPECT IMPROVING CONDITIONS AS HIGH PRES TAKES CONTROL OF THE WEATHER PATTERN ACROSS THE REGION. WINDS AND SEAS WILL GRADUALLY DIMINISH FROM WEST TO EAST. ...TROPICAL WAVE... A TROPICAL WAVE EXTENDS FROM 12N32W TO 03N33W MOVING WEST AT 10- 15 KT. ISOLATED MODERATE CONVECTION IS NOTED WHERE THE WAVE AXIS MEETS THE ITCZ MAINLY FROM 3N TO 6N BETWEEN 31W AND 36W. THE WAVE REMAINS EMBEDDED WITHIN AN AREA OF MOISTURE AS DEPICTED ON THE MIMIC-TPW ANIMATION. IN ADDITION...GLOBAL MODEL INDICATES BROAD TROUGHING AT LOW LEVELS IN ASSOCIATION WITH THIS FEATURE THAT WILL CONTINUE TO MOVE WESTWARD. ...THE ITCZ/THE MONSOON TROUGH... THE MONSOON TROUGH ENTERS THE ATLC OCEAN THROUGH THE COAST OF SIERRA LEONE NEAR 7N12W THEN CONTINUES TO 4N17W. THEN...THE ITCZ IS FROM 4N17W TO 5N31W...BROKEN UP BY THE TROPICAL WAVE...TO 3N36W TO THE EQUATOR AT 50W. SCATTERED MODERATE CONVECTION IS FROM THE EQUATOR TO 6N BETWEEN THE PRIME MERIDIAN AND 20W. ISOLATED CONVECTION IS NOTED ELSEWHERE. ...DISCUSSION... GULF OF MEXICO... A VIGOROUS MIDDLE TO UPPER LEVEL TROUGH IS NOTED ON WATER VAPOR IMAGERY ACROSS THE CENTRAL PLAINS INTO NE MEXICO AND THE FAR NW GULF. SW FLOW AHEAD OF THE TROUGH DOMINATES MOST OF THE GULF REGION. THE TROUGH SUPPORTS THE COLD FRONT PREVIOUSLY MENTIONED IN SPECIAL FEATURE. A WIDE BAND OF CLOUDINESS WITH EMBEDDED SHOWERS AND LIKELY ISOLATED TSTMS IS RELATED TO THE FRONTAL BOUNDARY. A TROUGH PERSIST AHEAD OF THE FRONT AND STRETCHES FROM 29N84W TO 22N87W. DOPPLER RADAR SHOWS AN INCREASE IN SHOWER AND TSTM ACTIVITY OVER FLORIDA AHEAD OF THE FRONT AND PRE-FRONTAL TROUGH. A DIFFLUENT PATTERN ALOFT ASSOCIATED WITH AN UPPER LEVEL RIDGE LOCATED JUST E OF FLORIDA IS HELPING TO INDUCE THIS CONVECTIVE ACTIVITY. WEATHER CONDITIONS ARE BEGINNING TO IMPROVE ACROSS THE NW GULF AS RELATIVELY COOLER AND DRIER AIR CONTINUES TO FILTER IN FROM THE SOUTHERN PLAINS WITH MAINLY CLEAR SKIES ACROSS THE NW GULF. LOOKING AHEAD...THE COLD FRONT IS FORECAST TO CLEAR THE GULF WATERS BY EARLY FRIDAY WITH A SURFACE RIDGE INFLUENCING THE BASIN FOR THE UPCOMING WEEKEND. CARIBBEAN SEA... PRES GRADIENT BETWEEN THE ATLC HIGH PRES RIDGING N-NE OF THE AREA AND THE COLOMBIAN/PANAMANIAN LOW PRES IS SUPPORTING FRESH TO STRONG NE-E WINDS ACROSS THE CENTRAL CARIBBEAN...WITH MODERATE TO FRESH E-SE WINDS ELSEWHERE. THE MOST RECENT ASCAT PASS CONFIRMED THE PRESENCE OF THESE WINDS WHICH ARE FORECAST TO DIMINISH ON FRI AS ATLC HIGH PRES WEAKENS. PATCHES OF LOW LEVEL MOISTURE EMBEDDED IN THE TRADE WIND FLOW ARE NOTED ACROSS THE REGION PRODUCING ISOLATED TO SCATTERED PASSING SHOWERS. ON THE OTHER HAND...SOUTHEASTERLY LOW-LEVEL WINDS WILL CONTINUE TO ENHANCE LATE AFTERNOON AND EARLY EVENING SCATTERED SHOWERS AND ISOLATED TSTMS ACROSS THE GREATER ANTILLES AND THE WINDWARD PASSAGE REGION. A COLD FRONT OVER THE GULF OF MEXICO WILL MOVE SE THROUGH THE YUCATAN CHANNEL BY TONIGHT...GRADUALLY DISSIPATING ALONG 20N THROUGH THROUGH EARLY SAT. ALOFT...A RIDGE/TROUGH PATTER DOMINATES THE BASIN. THE RIDGE...WITH AXIS ALONG 80W COVERS THE WEST-CENTRAL CARIBBEAN AND MOST OF CENTRAL AMERICA. SW FLOW ALOFT IS TRANSPORTING ABUNDANT MID-UPPER LEVEL MOISTURE ACROSS THE YUCATAN PENINSULA INTO THE FAR WESTERN CARIBBEAN AND WESTERN CUBA. A BROAD UPPER LEVEL TROUGHING NOTED ON WATER VAPOR IMAGERY OVER THE EASTERN CARIBBEAN ALONG 67W/68W MAY ENHANCE CONVECTION ACROSS PUERTO RICO AND THE UK/US VIRGIN ISLANDS AS WELL AS OVER THE NORTHERN LEEWARD ISLANDS. THE SAN JUAN DOPPLER RADAR IS SHOWING SCATTERED SHOWERS ACROSS THE REGION. ANOTHER AREA OF CONVECTION WITH A FEW ISOLATED SHOWERS AND TSTMS IS S OF 10N ACROSS THE SW CARIBBEAN AND INLAND PORTIONS OF PANAMA AND COSTA RICA. UPPER DIFFLUENCE COUPLE WITH LOW LEVEL NE WINDS IS HELPING TO INDUCE THIS CONVECTIVE ACTIVITY. ...HISPANIOLA... DIURNAL HEATING AND LOCAL EFFECT WILL COMBINE WITH AVAILABLE LOW- LEVEL MOISTURE FROM THE SE WINDS FLOW TO INDUCE THE DEVELOPMENT OF SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS...PARTICULARLY DURING THE AFTERNOON AND EARLY EVENING HOURS. ATLANTIC OCEAN... SCATTERED SHOWERS AND ISOLATED TSTMS ARE OCCURRING JUST E OF THE STATE OF FLORIDA...PARTICULARLY N OF 24N AND W OF 78W IN ASSOCIATION WITH A SOUTHERLY LOW-LEVEL FLOW AND A DIFFLUENT PATTERN ALOFT. WINDS ARE ALSO ON INCREASE IN THIS AREA DUE THE PRES GRADIENT BETWEEN THE ATLC RIDGE AND THE GULF OF MEXICO COLD FRONT. THE RIDGE NOW EXTENDING FROM BERMUDA TO S FLORIDA WILL WEAKEN AND SHIFT EASTWARD ALLOWING FOR THE COLD FRONT CURRENTLY LOCATED W OF THE AREA TO MOVE INTO THE WESTERN ATLC BY LATE TONIGHT. THE FRONT WILL REACH FROM NEAR 31N78W TO NW CUBA EARLY ON FRI...FROM NEAR 31N75W TO W CENTRAL CUBA FRI NIGHT...AND WEAKEN AS IT REACHES FROM NEAR 31N73W TO CENTRAL CUBA EARLY SAT. THE FRONT IS FORECAST TO MOVE ACROSS THE SE BAHAMAS AND EASTERN CUBA BY SUN. MAINLY MODERATE TO FRESH WINDS WINDS WILL FOLLOW THE FRONT. A SECOND COLD FRONT IS OVER THE CENTRAL ATLC AND ENTERS THE FORECAST AREA NEAR 31N42W THEN CONTINUES ALONG 26N55W TO 31N66W. THIS FRONT IS WELL DEFINED ON VISIBLE SATELLITE IMAGERY AND SCATTEROMETER PASSES. THE FRONT WILL CONTINUE TO PUSH SOUTHWARD FURTHER INTO THE DISCUSSION AREAS REACHING 20N BETWEEN 50W AND 62W BY SAT MORNING. MODERATE TO FRESH NLY WINDS FOLLOW THE FRONT. A WEAK RIDGE COVERS THE REMAINDER OF THE ATLC. IN THE UPPER LEVEL...A RIDGE/TROUGH/RIDGE PATTERN DOMINATES THE REGION. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ GR