000 AXNT20 KNHC 151749 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 205 PM EDT WED MAY 15 2013 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. ...TROPICAL WAVES... TROPICAL WAVE EXTENDS FROM 02N37W TO 07N35W MOVING W AT 15 KT. THE WAVE REMAINS LOW-AMPLITUDE AND EMBEDDED WITHIN THE ITCZ AXIS COINCIDING WITH A GLOBAL MODEL INDICATED MAXIMUM OF POTENTIAL VORTICITY AT 315K. TOTAL PRECIPITATABLE WATER AND SATELLITE IMAGERY ALSO INDICATE A MAXIMUM IN LOW-LEVEL MOISTURE CONVERGENCE AND CLOUDINESS IN THE VICINITY OF THE WAVE AXIS. WIDELY SCATTTERED MODERATE CONVECTION IS FROM 03N-08N BETWEEN 32W-39W. THE WAVE IS EXPECTED TO CONTINUE MOVING WESTWARD WITH PRECIPITATION PROBABILITIES INCREASING BY THE WEEKEND ACROSS THE WINDWARD ISLANDS. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS FROM THE AFRICAN COAST NEAR 11N15W TO 07N19W. THE INTERTROPICAL CONVERGENCE ZONE AXIS EXTENDS FROM 07N19W TO 04N36W TO THE EQUATOR NEAR 50W. SCATTERED MODERATE AND ISOLATED STRONG CONVECTION IS FROM 05N-08N BETWEEN 17W-22W. SCATTERED MODERATE CONVECTION IS FROM 02N-07N BETWEEN 03W-18W... WITHIN 90 NM EITHER SIDE OF A LINE FROM 01N24W TO 06N32W...AND FROM 03N-06N BETWEEN 39W-52W. ...DISCUSSION... GULF OF MEXICO... A MIDDLE TO UPPER LEVEL LOW CENTERED OVER NORTH TEXAS AND ASSOCIATED SHORTWAVE TROUGH AXIS EXTENDING OVER WEST TEXAS AND NW MEXICO IS SUPPORTING ONGOING WIDELY SCATTERED SHOWERS AND ISOLATED TSTMS THIS AFTERNOON ACROSS PORTIONS OF THE NW GULF NORTH OF 22N WEST OF 93W. THIS ACTIVITY IS LOCATED ON THE WESTERN PERIPHERY OF A SURFACE RIDGING ANCHORED BY A 1024 MB HIGH CENTERED NEAR 30N89W. A RIDGE AXIS EXTENDS ALONG 30N INTO THE SW NORTH ATLC AND TO THE SW INTO A 1021 MB HIGH CENTERED OFF THE MEXICO COAST NEAR 21N97W. THE RIDGING IS SUPPORTED ALOFT BY A MIDDLE TO UPPER LEVEL RIDGE AXIS ALONG 88W WHICH IS PROVIDING FOR OVERALL FAIR CONDITIONS AND CLEAR SKIES W OF 92W. LOOKING AHEAD...THE RIDGE IS EXPECTED TO REMAIN NEARLY STATIONARY THROUGH THE REMAINDER OF THE WEEK WITH GENERALLY E-SE WINDS FORECAST IN THE RANGE OF 10 TO 20 KT. CARIBBEAN SEA... AN UPPER LEVEL ANTICYCLONIC CIRCULATION IS CENTERED OVER THE WESTERN CARIBBEAN NEAR 15N84W AND IS PROVIDING MUCH OF THE REMAINDER OF THE CARIBBEAN BASIN WITH DRY NORTHWESTERLY WINDS ALOFT. WATER VAPOR IMAGERY SHOWS THIS DRY AIR ALOFT E OF 90W WITH THE EXCEPTION OF MODERATE MIDDLE TO UPPER LEVEL MOISTURE ASSOCIATED WITH THE SOUTHERN EXTENT OF A TROUGH AXIS OVER THE SW NORTH ATLC GENERALLY ALONG 65W. THIS MOISTURE TRAILS OVER THE NE CARIBBEAN...PUERTO RICO...HISPANIOLA...INCLUDING THE ADJACENT COASTAL WATERS N OF 17N E OF 72W. WIDELY SCATTERED LOW-TOPPED SHOWERS CONTINUE WITHIN 120 NM EITHER SIDE OF A CORRIDOR FROM DOMINICA NEAR 15N61W TO SOUTH OF HISPANIOLA NEAR 17N71W. ELSEWHERE...E-NE TRADES IN THE RANGE OF 10 TO 20 KT ARE OCCURRING WITH SLIGHTLY HIGHER WIND SPEEDS NOTED WITHIN 120 NM NORTH OF THE COAST OF COLOMBIA. A COLD FRONT REMAINS ANALYZED ACROSS PORTIONS OF THE SW NORTH ATLC AND IS FORECAST TO CONTINUE A WEAKENING TREND AS IT APPROACHES THE NORTH-CENTRAL AND NE CARIBBEAN OVER THE NEXT 24 TO 36 HOURS. HISPANIOLA... CURRENTLY A WEAK PRE-FRONTAL SURFACE TROUGH EXTENDS ACROSS A PORTION OF THE SW NORTH ATLC AND EXTENDS INLAND OVER CENTRAL HISPANIOLA TO 19N71W. ISOLATED SHOWERS AND TSTMS ARE EXPECTED THROUGH THE AFTERNOON AS INSTABILITY INCREASES WITH PEAK DAYTIME HEATING. MOST OF THE ONGOING SHOWER AND TSTM ACTIVITY IS OCCURRING OVER THE EASTERN DOMINICAN REPUBLIC AS THE BASE OF A MIDDLE TO UPPER LEVEL TROUGH IN THE VICINITY OF 20N70W CONTINUES TO SHIFT SLOWLY EASTWARD OVER THE NEXT 24 TO 36 HOURS. A COLD FRONT IS ANALYZED WITHIN 150 NM TO THE NORTH OF THE ISLAND... HOWEVER CONTINUES TO SHOW A WEAKENING TREND ON SATELLITE IMAGERY AS IT LOSES THE MIDDLE TO UPPER LEVEL SUPPORT ASSOCIATED WITH THE UPPER LEVEL TROUGH. REMNANT MOISTURE AND CLOUDINESS ASSOCIATED WITH THE COLD FRONT IS EXPECTED TO IMPACT THE NORTHERN COAST OF HISPANIOLA BY EARLY WEDNESDAY WITH GREATER PROBABILITY OF ISOLATED SHOWERS AND TSTMS. ATLANTIC OCEAN... MIDDLE TO UPPER LEVEL RIDGING WITH AXIS CURRENTLY OVER THE GULF OF MEXICO IS PROVIDING MOST OF THE SW NORTH ATLC W OF 65W WITH DRY NW FLOW ALOFT RESULTING IN MOSTLY CLEAR SKIES AND FAIR CONDITIONS THIS AFTERNOON. FURTHERMORE...A 1025 MB HIGH IS CENTERED NEAR 31N75W THAT IS EXPECTED TO SHIFT EASTWARD OVER THE NEXT 24 TO 36 HOURS. FARTHER EAST...WATER VAPOR IMAGERY INDICATES A MIDDLE TO UPPER LEVER TROUGH WITH AXIS EXTENDING INTO THE DISCUSSION AREA NEAR 32N61W TRAILING S-SW TO 25N64W TO A BASE NEAR 20N70W. THIS TROUGHING SUPPORTS A COLD FRONT ANALYZED FROM 32N60W TO 25N65W TO EASTERN CUBA NEAR 21N77W. A PRE-FRONTAL TROUGH IS EXTENDS FROM THE COLD FRONT NEAR 25N64W TO THE NORTHERN COAST OF HISPANIOLA NEAR 20N71W. WIDELY SCATTERED SHOWERS AND ISOLATED TSTMS ARE OCCURRING EAST OF THE COLD FRONT FROM 19N-32N BETWEEN 55W AND THE COLD FRONT BOUNDARY. THE REMAINDER OF THE CENTRAL AND EASTERN ATLC ARE UNDER THE INFLUENCE OF SURFACE RIDGING...HOWEVER AN UPPER LEVEL LOW CENTERED NEAR 30N41W SUPPORTS A SURFACE TROUGH ANALYZED FROM 25N41W TO 32N38W...THAT REMAINS EMBEDDED WITHIN THE SOUTHERN PERIPHERY OF THE RIDGE. EARLY MORNING ASCAT DATA INDICATES A STRONG PRESSURE GRADIENT EXISTS AS WINDS N OF 27N REMAIN IN THE 20 TO 30 KT RANGE IN THE VICINITY OF THE SURFACE TROUGH AXIS. ISOLATED SHOWERS AND TSTMS ARE OCCURRING WITHIN 120 NM EITHER SIDE OF A LINE FROM 27N33W TO 32N42W. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ HUFFMAN