000 AXNT20 KNHC 172352 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 805 PM EDT MON MAY 17 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... ...TROPICAL WAVES... TROPICAL WAVE IS ALONG 34W FROM 1N TO 7N MOVING W AT 10-15 KT. EMBEDDED WITHIN THE ITCZ...THE WAVE CONTINUES PROPAGATING WESTWARD AS NE AND SE WINDS CONVERGE ALONG 4N GENERATING SCATTERED MODERATE CONVECTION FROM 4N-7N BETWEEN 33W-36W. TROPICAL WAVE IS ALONG 62W S OF 10N MOVING W AT 15-20 KT. THE WAVE COINCIDES WITH A MAXIMUM OF DEEP LAYER MOISTURE AS INDICATED IN TOTAL PRECIPITABLE WATER IMAGERY OVER THE SE CARIBBEAN SEA. NO SIGNIFICANT ORGANIZED DEEP CONVECTION IS ASSOCIATED WITH THE WAVE ACROSS EASTERN VENEZUELA...HOWEVER INCREASED LOW-LEVEL MOISTURE AND ISOLATED SHOWERS ARE MOVING ACROSS THE SOUTHERN WINDWARD ISLANDS AND SE CARIBBEAN S OF 14N BETWEEN 57W AND 65W. TROPICAL WAVE IS ALONG 70W S OF 10N MOVING W 10-15 KT. SCATTERED MODERATE CONVECTION CONTINUES TO DISSIPATE ACROSS COLOMBIA S OF 9N BETWEEN 70W AND 76W. ...ITCZ... ITCZ AXIS IS CENTERED ALONG 8N13W 4N22W 4N32W 5N36W 1N44W AND INTO NE BRAZIL NEAR 1N50W. SCATTERED MODERATE CONVECTION IS FROM 3N-7N BETWEEN 26W-48W. ISOLATED MODERATE CONVECTION IS FROM 2N-6N BETWEEN 19W-26W. ...DISCUSSION... GULF OF MEXICO... WEAK UPPER LEVEL TROUGHING IS LOCATED ACROSS THE NORTHERN PORTION OF THE GULF THAT SUPPORTS A SURFACE TROUGH EXTENDING FROM THE FLORIDA BIG BEND INTO THE GULF NEAR 30N84W THEN S-SW TO 26N87W. ISOLATED SHOWERS ARE OCCURRING WITHIN 60 NM E OF THE SURFACE TROUGH BETWEEN 84W-86W. THE UPPER LEVEL TROUGH IS ALSO RESPONSIBLE FOR GENERATING SCATTERED SHOWERS AND ISOLATED TSTMS OVER THE FLORIDA PENINSULA THIS EVENING. ELSEWHERE...THE REMAINDER OF THE GULF FALLS UNDER MAINLY ZONAL WESTERLY UPPER LEVEL FLOW ALOFT AND A SURFACE RIDGE ANCHORED BY A 1018 MB HIGH CENTERED NEAR 28N91W. THE SURFACE RIDGE IS FORECAST TO MOVE EAST OF THE AREA WITH A WEAK FRONTAL BOUNDARY SKIRTING THE COASTAL PLAIN LATE TUESDAY. THE FRONTAL TROUGH WILL GRADUALLY WEAKEN AND BECOME DIFFUSE THROUGH THURSDAY WITH SURFACE RIDGING RE-ESTABLISHING ITSELF OVER THE WESTERN GULF AS SOUTHERLY RETURN FLOW IS EXPECTED TO INCREASE EARLY THURSDAY. CARIBBEAN SEA... A WEAK UPPER LEVEL TROUGH AXIS EXTENDS ACROSS THE EASTERN GULF OF MEXICO FROM THE FLORIDA BIG BEND REGION TO THE YUCATAN PENINSULA. EAST OF THIS UPPER LEVEL AXIS...DIVERGENT FLOW IS NOTED ALOFT OVER THE NW CARIBBEAN...MOST OF CUBA AND PORTIONS OF CENTRAL AMERICA E OF 80W THAT CONTINUES TO SUPPORT SCATTERED SHOWERS AND TSTMS WITHIN 200 NM EITHER SIDE OF A LINE FROM 22N80W TO 13N87W. FARTHER EAST...A SURFACE TROUGH IS ANALYZED FROM 22N67W THROUGH THE MONA PASSAGE TO 15N70W. LOW-LEVEL TROPICAL MOISTURE CONTINUES ADVECTING NORTHWESTWARD ACROSS THE LEEWARD ISLANDS AND PUERTO RICO TO THE EAST OF THE SURFACE TROUGH THAT IS GENERATING WIDELY SCATTERED SHOWERS N OF 16N E OF 70W OVER THE NE CARIBBEAN AND INTO THE SW NORTH ATLC. ATLANTIC OCEAN... AN UPPER LEVEL DIFFLUENT ATMOSPHERE IS NOTED ON WATER VAPOR IMAGERY EAST OF AN UPPER LEVEL TROUGH THAT EXTENDS FROM NORTHERN FLORIDA OVER THE SE GULF OF MEXICO TO THE YUCATAN PENINSULA. SCATTERED SHOWERS AND ISOLATED TSTMS ARE OCCURRING EAST OF THIS TROUGH AXIS FROM CUBA TO BEYOND 32N REMAINING W OF 75W. THE REMAINDER OF THE ATLC IS UNDER THE INFLUENCE OF A SURFACE RIDGE WITH AXIS THAT EXTENDS ALONG 28N BETWEEN 40W-75W. IT IS LARGELY ANCHORED BY A 1022 MB SURFACE HIGH CENTERED NEAR 27N54W. A WEAKNESS IN THE FORM OF A SURFACE TROUGH IS FOUND ANALYZED OVER THE SW NORTH ATLC FROM 22N67W THROUGH THE MONA PASSAGE AND INTO THE CENTRAL CARIBBEAN SEA. ISOLATED SHOWERS ARE WITHIN 90 NM EITHER SIDE OF THE SURFACE TROUGH AND IN THE VICINITY OF PUERTO RICO AND THE US/UK VIRGIN ISLANDS THIS EVENING. ACROSS THE EASTERN ATLC...ANOTHER SURFACE RIDGE INFLUENCES THE HIGH SEAS WATERS E OF 40W WITH THE RIDGE AXIS STEMMING SW FROM A 1030 MB HIGH CENTERED NEAR 38N20W TO 27N40W. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ HUFFMAN