000 AXNT20 KNHC 261749 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 205 PM EDT THU APR 26 2012 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. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS FROM THE AFRICAN COAST NEAR 09N13W TO 06N17W. THE INTERTROPICAL CONVERGENCE ZONE AXIS EXTENDS FROM 06N17W TO THE EQUATOR NEAR 44W. SCATTERED MODERATE CONVECTION IS FROM 02N-07N BETWEEN 19W-33W. ...DISCUSSION... GULF OF MEXICO... AN UPPER LEVEL TROUGH CONTINUES TO DIG SOUTHWARD OVER THE YUCATAN PENINSULA WITH AN AXIS EXTENDING FROM THE NE GULF NEAR 27N84W TO 16N92W. MOSTLY NORTHERLY FLOW ALOFT IS OVER A MAJORITY OF THE GULF BASIN THIS AFTERNOON WITH WATER VAPOR IMAGERY INDICATING VERY DRY AIR AND STRONG SUBSIDENCE ACCOMPANYING THE TROUGH. AT THE SURFACE...THE STRONG SUBSIDENCE MANIFESTS ITSELF AS A RIDGE ANCHORED BY A 1023 MB HIGH CENTERED OVER THE SW NORTH ATLC WATERS NEAR 29N71W. THE RIDGE AXIS EXTENDS FROM THE HIGH ACROSS THE FLORIDA PENINSULA ALONG 27N TO THE NW GULF NEAR 27N95W. LIGHT ANTICYCLONIC WINDS ARE NOTED E OF 88W...HOWEVER S-SE WINDS IN THE RANGE OF 15 TO 20 KT ARE FOUND W OF 88W ON RECENT SHIP...BUOY...AND OFFSHORE OIL PLATFORMS. VISIBLE SATELLITE IMAGERY SHOWS THAT SKIES REMAIN CLEAR. THE RIDGE IS EXPECTED TO HOLD ALONG 27N THROUGH FRIDAY AND GRADUALLY DRIFT NORTHWARD OVER THE UPCOMING WEEKEND. AS A RESULT...MODERATE TO FRESH E-SE WINDS WILL DOMINATE ACROSS THE SOUTHEASTERN PERIPHERY OF THE RIDGE THROUGH EARLY NEXT WEEK. CARIBBEAN SEA... SOUTHWESTERLY UPPER LEVEL FLOW DOMINATES ACROSS THE CARIBBEAN W OF 67W THIS AFTERNOON BETWEEN AN UPPER LEVEL TROUGH DIGGING SOUTHWARD OVER THE YUCATAN PENINSULA AND SE GULF OF MEXICO AND AN UPPER LEVEL ANTICYCLONIC CIRCULATION CENTERED OVER NORTH- CENTRAL VENEZUELA NEAR 10N67W. MIDDLE TO UPPER LEVEL MOISTURE CONTINUES TO BE CONCENTRATED TO THE SE OF THE TROUGH AXIS THAT SUPPORTS A STATIONARY FRONT EXTENDING FROM THE SW NORTH ATLC ACROSS NW HISPANIOLA TO 19N74W. A SURFACE TROUGH IS ALSO ANALYZED OVER THE SW CARIBBEAN FROM 18N83W TO 12N80W TO 10N76W. WITH THESE BOUNDARIES IN PLACE ACROSS THE CENTRAL AND WESTERN CARIBBEAN...MAXIMUM LOW-LEVEL MOISTURE CONVERGENCE COUPLED WITH FAVORABLE UPPER LEVEL DIFFLUENCE CONTINUES TO GENERATE SCATTERED TO NUMEROUS SHOWERS AND SCATTERED TSTMS FROM 10N-20N BETWEEN 71W-81W. TRADES HAVE INCREASE OVER THE CENTRAL CARIBBEAN DUE TO AN TIGHTENING PRESSURE GRADIENT AS A 1023 MB HIGH HAS SETTLED INTO THE SW NORTH ATLC CENTERED NEAR 29N71W THE PAST 24 HOURS. THE FRONT WILL CONTINUE TO BECOME MORE DIFFUSE BY FRIDAY... HOWEVER LOW-LEVEL MOISTURE WILL LINGER ACROSS THE NORTH-CENTRAL AND SW CARIBBEAN FOR THE NEXT DAY OR TWO. AS A RESULT..AN INCREASED PROBABILITY OF PRECIPITATION FOR HISPANIOLA... JAMAICA...AND EASTERN CUBA INCLUDING THE ADJACENT COASTAL WATERS WILL PERSIST THROUGH THE WEEKEND. THE POTENTIAL FOR LOCALLY HEAVY RAINFALL AND FLOODING ACROSS HAITI AND PORTIONS OF THE DOMINICAN REPUBLIC AND EASTERN CUBA ARE EXPECTED THE NEXT FEW DAYS. OF NOTE...PRECIPITATION TOTALS ACROSS THE DOMINICAN REPUBLIC HAVE TRENDED DOWNWARD FROM A PEAK 24 HOUR RAINFALL TOTAL OF 6.9 INCHES REPORTED AT MONCION ON APR 24 TO 1.5 INCHES REPORTED AT EL SEIBO ON APR 25. ATLANTIC OCEAN... AN UPPER LEVEL SHORTWAVE TROUGH IS PROGRESSING ACROSS THE MID-ATLC STATES THIS AFTERNOON WITH MOST CONVECTION AND STRONGER SOUTHERLY WINDS REMAINING NORTH OF THE DISCUSSION AREA. WATER VAPOR INDICATES THAT DRY AIR ALOFT REMAINS OVER THE SW NORTH ATLC FROM 25N-32N BETWEEN 64W-81W AND CONTINUES TO SUPPORT OVERALL SUBSIDENCE IN THE FORM OF A 1023 MB SURFACE HIGH CENTERED NEAR 29N71W AND ASSOCIATED RIDGE AXIS FROM BERMUDA TO THE FLORIDA PENINSULA. ANOTHER UPPER LEVEL TROUGH IS EAST OF THE SHORTWAVE AND EXTENDS AN AXIS FROM 35N57W TO 30N60W. A COLD FRONT IS ANALYZED FROM 35N56W TO 31N59W THEN BECOMES STATIONARY ALONG 26N61W TO 23N64W AND THEN DIFFUSE TO NW HISPANIOLA NEAR 19N73W. ISOLATED SHOWERS ARE OCCURRING WITHIN 60 NM EITHER SIDE OF THE FRONT N OF 26N AND FROM 19N-26N BETWEEN 58W-77W. FARTHER EAST...A MIDDLE TO UPPER LEVEL LOW IS CENTERED NEAR 21N37W AND SUPPORTS A SURFACE TROUGH EXTENDING FROM 23N34W TO 17N39W ACROSS THE EASTERN ATLC. WHILE THE SURFACE TROUGH REMAINS RELATIVELY WEAK...MIDDLE TO UPPER LEVEL DIFFLUENCE IS MAXIMIZED EAST OF THE LOW WITH SCATTERED SHOWERS AND ISOLATED TSTMS OCCURRING FROM 16N-24N BETWEEN 28W-38W. THIS MIDDLE TO UPPER LEVEL TROUGH IS EXPECTED TO LIFT TO THE NORTHEAST OVER THE NEXT 24 TO 36 HOURS AS A STRONGER POLAR FRONT...CURRENTLY ANALYZED ALONG 30N BETWEEN 19W-36W DIVES SOUTHWARD OVER THE NORTHEASTERN PORTION OF EASTERN ATLC. ISOLATED SHOWERS ARE POSSIBLE WITHIN 90 NM EITHER SIDE OF THE COLD FRONT. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ HUFFMAN