000 AXNT20 KNHC 122352 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 805 PM EDT MON APR 12 2010 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...METEOROLOGICAL ANALYSIS...WEATHER OBSERVATIONS...AND RADAR. BASED ON 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 2315 UTC... ...ITCZ... ITCZ AXIS IS CENTERED ALONG 7N11W 3N20W 4N45W AND INTO NE BRAZIL NEAR 3N51W. WIDELY SCATTERED MODERATE CONVECTION IS FROM THE EQUATOR TO 3N BETWEEN 22W-31W. SIMILAR CONVECTION IS FROM 2N-8N BETWEEN 37W-50W. ...DISCUSSION... GULF OF MEXICO... SURFACE RIDGING EXTENDS ACROSS MUCH OF THE GULF OF MEXICO WITH GENERALLY NE TO E SURFACE WINDS OBSERVED FROM THE FLORIDA PENINSULA WESTWARD TO THE TEXAS AND MEXICO COASTS. TOTAL PRECIPITABLE WATER IMAGERY INDICATES LOW-LEVEL MOISTURE IS HIGHEST OVER THE STRAITS OF FLORIDA REGION WHERE A WEAK SHEARLINE IS ANALYZED FROM THE W ATLC ACROSS EXTREME SE FLORIDA TO NEAR 24N81W. SCATTERED SHOWERS ARE REMAINING S OF 27N E OF 82W. THIS ACTIVITY IS ENHANCED BY AN UPPER LEVEL SHORTWAVE TROUGH AXIS THAT EXTENDS ALONG THE CAROLINA COAST ACROSS NE FLORIDA TO NEAR 26N84W. ALSO HIGHER TPW VALUES ARE LOCATED OVER THE WESTERN GULF W OF 92W. LOW-LEVEL MOISTURE AND INSTABILITY COUPLED WITH AN UPPER LEVEL SHORTWAVE TROUGH ACROSS EASTERN TEXAS IS GENERATING SCATTERED SHOWERS AND ISOLATED TSTMS W OF 95W. THROUGH MIDWEEK THE SURFACE RIDGE IS FORECAST TO GRADUALLY STRENGTHEN AND INCREASE THE PRESSURE GRADIENT ACROSS MUCH OF THE GULF. AS A RESULT...INCREASED EASTERLY SURFACE WINDS OF 20-25 KT ARE EXPECTED THROUGH THURSDAY. CARIBBEAN SEA... GENERALLY W TO NW UPPER LEVEL FLOW IS ACROSS THE WESTERN CARIBBEAN THAT IS PROVIDING MODERATELY DRY AIR AND SUBSIDENCE IN THE MIDDLE TO UPPER LEVELS OF THE ATMOSPHERE. DIFFERENTIAL HEATING ACROSS THE YUCATAN PENINSULA...CUBA...AND HISPANIOLA AIDED IN GENERATING SCATTERED SHOWERS AND ISOLATED TSTMS OVER THESE AREAS...BUT ARE QUICKLY LOSING THEIR ENERGY DUE TO THE LOSS OF DAYTIME HEATING. ISOLATED SHOWERS ARE EXPECTED TO LINGER OVER THE NEXT SEVERAL HOURS ACROSS CUBA...HISPANIOLA...AND PORTIONS OF PUERTO RICO. ELSEWHERE ACROSS THE FAR EASTERN CARIBBEAN AND LESSER ANTILLES...A PAIR OF LOW-LEVEL SURFACE TROUGHS ARE EMBEDDED WITHIN EASTERLY FLOW. ONE IS ANALYZED FROM 19N61W TO 16N63W WHILE THE OTHER IS LOCATED OVER THE TROPICAL NORTH ATLC FROM 13N-16N ALONG 57W. WITHIN THE VICINITY OF THE SURFACE TROUGHS...LOW-LEVEL MOISTURE AND INSTABILITY IS GENERATING ISOLATED SHOWERS COVERING MOST OF THE CARIBBEAN E OF 64W...INCLUDING MANY OF THE LESSER ANTILLES. OTHERWISE THE REMAINDER OF THE CARIBBEAN IS EXPERIENCING MODERATE TRADES AND FAIR SKIES THIS EVENING. ATLANTIC OCEAN... A STATIONARY FRONT IS DRAPED ACROSS THE SW NORTH ATLC AND EXTENDS INTO THE DISCUSSION AREA FROM A 1022 MB LOW CENTERED EAST OF BERMUDA NEAR 33N62W ALONG 29N65W TO 29N71W CONTINUING AS A SHEARLINE TO THE SE FLORIDA COAST NEAR 26N81W. SCATTERED SHOWERS AND ISOLATED TSTMS COVER A LARGE AREA OF THE W ATLC N OF 20N W OF 62W. ALOFT...AN UPPER LEVEL TROUGH AXIS EXTENDS ALONG THE CAROLINA COAST TO THE NORTHERN FLORIDA PENINSULA AND INTO THE EAST-CENTRAL GULF OF MEXICO. UPPER LEVEL DIFFLUENCE EAST OF THIS TROUGH AXIS IS CONTINUING TO ENHANCE THE ONGOING CONVECTION AND SPREAD DEBRIS CLOUDINESS NORTHEASTWARD. ACROSS THE CENTRAL ATLC...A SURFACE RIDGE ANCHORED BY A 1027 MB HIGH CENTERED NEAR 37N47W DOMINATES MUCH OF THE OCEANIC WATERS BETWEEN 40W-60W. HOWEVER...A PAIR OF SURFACE TROUGHS EMBEDDED WITHIN EASTERLY FLOW ACROSS THE TROPICAL NORTH ATLC ARE ANALYZED OVER THE LEEWARD ISLANDS AND FROM 13N-16N ALONG 57W. ISOLATED SHOWERS ARE RESULTING DUE TO LOW-LEVEL CONVERGENCE FROM 12N-21N BETWEEN 53W-63W. THE SURFACE RIDGE TO THE NORTH IS SUPPORTED BY A BROAD UPPER LEVEL RIDGE WITH AXIS ALONG 54W. FARTHER EAST...A COLD FRONT ASSOCIATED WITH AN OCCLUDED 1002 MB LOW NEAR 35N25W ENTERS THE DISCUSSION AREA NEAR 32N16W ACROSS THE CENTRAL CANARY ISLANDS THEN ALONG 25N21W 21N33W. A SECONDARY SURFACE TROUGH IS ALSO ANALYZED WEST OF THE COLD FRONT FROM 31N18W TO 25N28W. ISOLATED SHOWERS ARE WITHIN 75 NM EITHER SIDE OF THE COLD FRONT WHILE SCATTERED SHOWERS ARE WITHIN 90 NM EITHER SIDE OF THE TRAILING SURFACE TROUGH TO THE NW. THESE PAIR OF BOUNDARIES ARE SUPPORTED BY AN UPPER LEVEL LOW CENTERED NORTH OF THE AREA NEAR 35N23W. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ HUFFMAN