000 AXNT20 KNHC 281045 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 805 AM EDT TUE APR 28 2015 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 1015 UTC. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS ACROSS AFRICA INTO THE TROPICAL ATLC NEAR 8N13W THEN ALONG 6N15W TO 4N19W WHERE THE ITCZ BEGINS AND CONTINUES ALONG 3N27W 2N33W TO S OF THE EQUATOR AND INTO SOUTH AMERICA NEAR 40W. CLUSTERS OF SCATTERED MODERATE/ISOLATED STRONG CONVECTION ARE WITHIN 120/150 NM N OF ITCZ BETWEEN 19W-36W. CLUSTERS OF SCATTERED MODERATE CONVECTION ARE FROM 1N-4N BETWEEN 10W-25W. ...DISCUSSION... GULF OF MEXICO... THE UPPER RIDGE ANCHORED IN THE CARIBBEAN CONTINUES TO DOMINATE MOST OF THE GULF WITH THE STRONG UPPER LOW OVER TEXAS EXTENDING AN UPPER TROUGH OVER THE NW GULF N OF 26N W OF 90W. AT 28/0900 UTC A 1003 MB LOW IS CENTERED NEAR 27N93W WITH A WEAK COLD FRONT EXTENDING S ALONG TO 24N92W TO 22N95W THEN CONTINUES AS STATIONARY FRONT INTO MEXICO JUST S OF TUXPAN. A WARM FRONT EXTENDS FROM THE 1003 LOW ACROSS THE MISSISSIPPI DELTA ALONG 30N87W WHERE IT BECOMES STATIONARY TO ACROSS FLORIDA BETWEEN CEDAR KEY AND TAMPA THEN INTO THE W ATLC NEAR MELBOURNE. SCATTERED TO HEAVY SHOWERS WITH SCATTERED THUNDERSTORMS ARE N OF 27N E OF 89W TO OVER FLORIDA. ISOLATED SHOWERS DOT THE REMAINDER OF THE GULF N OF 25N E OF 92W. THIS IS LEAVING THE SW GULF UNDER CLEAR SKIES THIS MORNING...ALTHOUGH THE LATEST NESDIS HAZARD MAPPING SYSTEM FIRE AND SMOKE ANALYSIS INDICATES THE FIRES OVER S MEXICO AND THE YUCATAN PENINSULA ARE STILL SPREADING SMOKE ACROSS THE SW GULF. THE LOW WILL MOVE TO NEAR MOBILE BAY TONIGHT WITH THE FRONT E OF THE LOW LIFTING N AS A WARM FRONT AND W OF THE LOW EXTENDING AS A COLD FRONT TO THE CENTRAL YUCATAN PENINSULA. THE FRONT WILL PASS SE OF THE AREA WED NIGHT WITH RIDGING BUILDING FROM THE W ON THU. CARIBBEAN SEA... AN UPPER RIDGE IS ANCHORED OVER CENTRAL AMERICA AND EXTENDS OVER THE GULF OF MEXICO WITH WEAK FLOW ALOFT COVERING THE REMAINDER OF THE CARIBBEAN. WATER VAPOR SATELLITE IMAGERY SHOWS STRONG SUBSIDENCE AND DRY AIR ALOFT OVER THE CARIBBEAN E OF 80W. SOME ISOLATED SHOWERS REMAIN OVER NE HAITI. THIS IS LEAVING THE REMAINDER OF THE CARIBBEAN WITH CLEAR SKIES AGAIN THIS MORNING. NESDIS LATEST HAZARD MAPPING SYSTEM FIRE AND SMOKE ANALYSIS INDICATES THE FIRES OVER HONDURAS AND THE YUCATAN ARE SPREADING SMOKE ACROSS THE GULF OF HONDURAS AND N INTO THE YUCATAN CHANNEL. FRESH TO LOCALLY STRONG TRADE WINDS ARE EXPECTED IN THE SE CARIBBEAN TODAY THROUGH EARLY FRI. A COLD FRONT WILL MOVE THROUGH THE YUCATAN CHANNEL WED AND REACH FROM CENTRAL CUBA TO E HONDURAS THU NIGHT. ...HISPANIOLA... SOME LINGERING ISOLATED SHOWERS REMAIN ACROSS NE HAITI THIS MORNING. LOW RAINFALL AND HIGH TEMPERATURES WILL BE THE NORM FOR MOST OF THE ISLAND OVER THE NEXT FEW DAYS WITH THE EXCEPTION OVER THE MOUNTAINOUS REGION WHERE DAYTIME HEATING COUPLED WITH OROGRAPHIC LIFTING COULD CONTINUE TO PRODUCE AFTERNOON/EVENING ISOLATED SHOWERS AND POSSIBLE THUNDERSTORMS. ATLANTIC OCEAN... NEAR ZONAL WESTERLY FLOW ALOFT DOMINATES THE W INTO THE CENTRAL ATLC. A COLD FRONT AT 28/0900 UTC EXTENDS THROUGH 32N61W TO 28N69W WHERE IT BECOMES STATIONARY ALONG 28N74W TO ACROSS FLORIDA NEAR MELBOURNE. SCATTERED SHOWERS AND POSSIBLE ISOLATED THUNDERSTORMS ARE N OF 25N W OF 73W WITH THUNDERSTORMS OVER THE BAHAMA ISLANDS FROM 23N-25N BETWEEN 75W-80W. A PRE-FRONTAL SURFACE TROUGH EXTENDS 30N58W TO 26N69W. SCATTERED SHOWERS/ ISOLATED THUNDERSTORMS ARE FROM 27N-30N BETWEEN 54W-60W. THE REMAINDER OF THE ATLC IS DOMINATED BY A LARGE SURFACE RIDGE ANCHORED IN THE E ATLC BY A 1023 MB HIGH BETWEEN MADIERA AND AZORES ISLANDS AND EXTENDING A RIDGE AXIS THROUGH 32N24W ALONG 23N40W TO HISPANIOLA NEAR 19N70W. THE E PORTION OF THE W ATLC FRONT WILL CONTINUE S TO ALONG 32N54W TO 24N65W TONIGHT WHILE THE W PORTION REMAINS N OF CAPE CANAVERAL IN ADVANCE OF THE NEXT SYSTEM EXPECTED TO EMERGE INTO W ATLC LATE WED. THE NEW COLD FRONT WILL EXTEND FROM 31N79W TO STUART FLORIDA WED NIGHT AND FROM 31N71W TO CENTRAL CUBA THU NIGHT. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ PAW