000 AXNT20 KNHC 251755 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 205 PM EDT WED JUN 25 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. ...SPECIAL FEATURES... A GALE WARNING REMAINS IN EFFECT FOR THE S CENTRAL CARIBBEAN NEAR THE COAST OF COLOMBIA. A TIGHT PRESSURE GRADIENT BETWEEN HIGH PRES OVER THE WESTERN ATLC AND BROAD LOW PRES OVER THE SW PORTION OF THE CARIBBEAN AND NW COLOMBIA IS RESULTING IN NE TO E GALE FORCE WINDS OF 30-35 KT THERE. THESE WINDS ARE FORECAST TO DIMINISH TO 25-30 KT IN JUST A FEW HOURS AS THE GRADIENT SLACKENS SLIGHTLY. ...TROPICAL WAVES... A TROPICAL WAVE OVER THE EASTERN ATLC EXTENDS FROM 14N32W TO NEAR 06N34.5W. IT IS MOVING W AT 15 KT. STRONG HIGH PRESSURE TO THE N OF THE WAVE IS MAINTAINING A VERY STABLE ENVIRONMENT AROUND THE WAVE SUPPRESSING DEEP CONVECTIVE ACTIVITY FROM DEVELOPING. WITH THE WAVE. THE ONLY CONVECTION NOTED IS OF THE SCATTERED MODERATE/ISOLATED TYPE INTENSITY IN THE ITCZ WITHIN 120 NM E AND 60 NM W OF THE WAVE AXIS FROM 09N TO 10N. A TROPICAL WAVE WITH A VERY GOOD TRACK HISTORY IS MOVING QUICKLY THROUGH THE SE CARIBBEAN SEA WITH ITS AXIS EXTENDING FROM 15N65W TO 11N69W AS RELOCATED AT 12 UTC BASED ON VISIBLE SATELLITE IMAGERY AS WELL AS THE TOTAL PRECIPITABLE WATER (TPW) ANIMATION. ITS WESTWARD MOTION AS ESTIMATED OVER THE PAST 24 HOURS IS OF ABOUT 20 KT WITH HIGHER SPEEDS AT TIMES. THE SATELLITE IMAGERY SHOWS NO DEEP CONVECTION WITH THE WAVE AS DRY AIR FROM A RECENT SAHARAN AIR LAYER (SAL)EVENT HAS DEPLETED ANY AVAILABLE DEEP MOISTURE FAVORABLE FOR CONVECTION TO FORM ALONG OR NEAR THE WAVE. ONLY ISOLATED SHOWERS AND ISOLATED WEAK TSTMS ARE NOTED WITHIN 120 NM W OF THE WAVE S OF 14N. ISOLATED SHOWERS MOVING QUICKLY TO THE WEST ARE SEEN E OF THE WAVE. ...THE ITCZ/THE MONSOON TROUGH... THE MONSOON TROUGH EXTENDS ACROSS AFRICA TO THE COAST OF SENEGAL NEAR 12N16W TO 10N21W. ITCZ EXTENDS FROM 12N21W TO E THE AFOREMENTIONED TROPICAL WAVE NEAR 09N32W. IT RESUMES W OF THE WAVE NEAR 08N35W TO A 1011 MB LOW AT 06N41W AND TO 03N50W. ASIDE FROM CONVECTION DESCRIBED IN ASSOCIATION WITH THE TROPICAL WAVE ABOVE...SCATTERED MODERATE CONVECTION IS NOTED WITHIN 120 NM N AND NW OF THE ITCZ BETWEEN 37W-41W. WIDELY SCATTERED SHOWERS AND TSTMS ARE NW OF THE ITCZ WITHIN 30 NM OF LINE FROM 08N43W TO 06N47W. ...DISCUSSION... ...THE GULF OF MEXICO... THE COMBINATION OF DIFFLUENCE ALOFT DUE TO A SHARP UPPER TROUGH ALONG EASTERN TEXAS AND AN ANTICYCLONE OVER MEXICO NEAR 20N91W ...ALONG WITH A SURFACE TROUGH THAT EXTENDS FROM 23N93W TO 20N96W IN AN ALREADY VERY MOIST AND UNSTABLE AIR MASS IN PLACE OVER THE AREA IS ALLOWING FOR INCREASING SCATTERED SHOWERS AND TSTM ACTIVITY N OF 19N AND W OF 90W. ISOLATED SHOWERS AND TSTMS ARE OVER THE FAR NE GULF TO THE N OF A 1021 SURFACE HIGH CENTERED NEAR 28N86W. THE ASSOCIATED RIDGE EXTENDS SW TO NEAR 26N93W...AND EASTWARD ACROSS FLORIDA ALONG 28N. THE RIDGE IS ALLOWING FOR A SE WIND FLOW OF 5-15 KT ACROSS THE BASIN. SURFACE HIGH PRESSURE AND RETURN FLOW IS EXPECTED TO CONTINUE DURING THE NEXT COUPLE OF DAYS WHICH WILL CONTINUE TO ADVECT MOIST AIR ACROSS THE AREA WITH THE ACTIVE SHOWER AND TSTM ACTIVITY CONTINUING OVER THE WESTERN HALF. ...THE CARIBBEAN SEA... BROAD UPPER LEVEL ANTICYCLONIC FLOW COVERS MOST OF THE CARIBBEAN SEA WITH THE MEAN ANTICYCLONIC CENTER NEAR 13N91W. IN THE NW PORTION...A WEAK UPPER LEVEL TROUGH AXIS EXTENDS FROM EASTERN CUBA TO NE HONDURAS. DIVERGENT FLOW ALOFT BETWEEN THESE TWO FEATURES IS SUPPORTING CLUSTERS OF SCATTERED TSTMS OVER THE SW CARIBBEAN SEA S OF 13N W OF 79W. THIS ACTIVITY IS FURTHER SUSTAINED BY THE MONSOON TROUGH ANALYZED ACROSS NW COLOMBIA TO SOUTHERN PANAMA. OUTSIDE THE SPECIAL FEATURE AREA PERTAINING TO GALE FORCE WINDS...THE PRESSURE GRADIENT SUPPORTS TRADES OF 15-20 KT EXCEPT FOR LIGHTER WINDS OF 10-15 KT IN THE N CENTRAL AND NW SECTIONS. THE TROPICAL WAVE DESCRIBED ABOVE IS FORECAST TO REACH NEAR 71W/72W BY THU MORNING...AND TO THE VICINITY OF JAMAICA AND SOUTHWARD FROM THERE ON FRI. ...HISPANIOLA... THE COMBINATION OF VERY MOIST AIR ACROSS THE NW CARIBBEAN AND DIFFLUENT FLOW ALOFT IS SUPPORTING SCATTERED SHOWERS AND ISOLATED TSTMS OVER PORTIONS OF HAITI...AND WINDWARD PASSAGE. ISOLATED SHOWERS AND TSTMS ARE OVER THE INTERIOR OF THE WESTERN PORTION OF THE DOMINICAN REPUBLIC. LITTLE CHANGE IN THIS ACTIVITY IS EXPECTED THROUGH THE NEXT 24-48 HOURS AS THE UPPER TROUGH MAKES SLOW EASTWARD PROGRESS. ...ATLANTIC OCEAN... AN ELONGATED WEAK UPPER LOW IS SEEN ON WATER VAPOR IMAGERY TO BE NEAR 26N75W WITH A TROUGH STRETCHING SW TO EASTERN CUBA. AT THE SURFACE...A TROUGH IS ANALYZED FROM NEAR 27N72W TO 23N74W. SCATTERED SHOWERS AND TSTMS ARE QUICKLY FORMING FROM 24N TO 28.5N BETWEEN 67W AND 71W. SCATTERED SHOWERS AND ISOLATED TSTMS ARE SE OF THE SURFACE TROUGH TO THE NW COAST OF HAITI. ELSEWHERE ...HIGH PRESSURE DOMINATES THE MAJORITY OF THE AREA AS A SURFACE RIDGE EXTENDS FROM A 1029 MB HIGH NEAR 33N33W WSW TO 28N58W ...AND CONTINUES ALONG 28N TO FLORIDA AND TO THE 1021 MB HIGH OVER THE EASTERN GULF OF MEXICO. THE RIDGE IS ALLOWING FOR S-SW WINDS OF 5-10 KT W OF THE BAHAMAS...AND E-SE WINDS OF 5-15 KT TO THE E OF THE BAHAMAS. THE 1029 MB HIGH IS FORECAST TO SHIFT W TO NEAR 33N38N BY EARLY ON THU WHILE WEAKENING SLIGHTLY. THE RIDGE ALONG 28N IS FORECAST TO SHIFT N TO NEAR 29N BY SAT. A 1011 MB LOW IS EMBEDDED IN THE ITCZ NEAR 06N41W...BUT IS LOSING ITS IDENTITY WITH TIME. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ AGUIRRE