000 AXNT20 KNHC 041114 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 805 AM EDT WED SEP 04 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1015 UTC. ...SPECIAL FEATURE... CONVECTIVE ACTIVITY ASSOCIATED WITH A 1008 MB LOW PRESSURE CENTER NEAR 15N64W LOOKS BETTER ORGANIZED THIS MORNING. A CLUSTER OF MODERATE CONVECTION AND TSTMS IS FROM 14N-17N BETWEEN 63W-65W. ELSEWHERE...SCATTERED SHOWERS ARE FROM 14N-19N BETWEEN 62W-67W. UPPER-LEVEL WINDS APPEAR FAVORABLE FOR SOME DEVELOPMENT OVER THE NEXT FEW DAYS...BUT INTERACTION WITH THE LAND MASSES OF HISPANIOLA AND PUERTO RICO COULD INHIBIT TROPICAL CYCLONE FORMATION AS THE SYSTEM MOVES NORTHWESTWARD AT AROUND 10 MPH. CURRENTLY...THIS SYSTEM HAS A MEDIUM CHANCE...30 PERCENT...OF BECOMING A TROPICAL CYCLONE DURING THE NEXT 48 HOURS. REGARDLESS OF TROPICAL CYCLONE FORMATION...LOCALLY HEAVY RAINFALL AND GUSTY WINDS ARE EXPECTED TO AFFECT THE VIRGIN ISLANDS...AND SPREAD OVER PUERTO RICO LATER TODAY. ...TROPICAL WAVES... A TROPICAL WAVE ASSOCIATED WITH A 1011 MB LOW PRESSURE CENTER IS MOVING ACROSS THE CAPE VERDE ISLANDS. ITS AXIS EXTENDS FROM 17N24W TO THE LOW CENTER NEAR 13N24W TO 09N24W AND IS MOVING WEST NEAR 10 KT. TOTAL PRECIPITABLE WATER IMAGERY SHOW THE LOW PRESSURE HAS BEEN DRAWING MOISTURE FROM THE MONSOON TROUGH WHICH HAS ASSISTED IN THE DEVELOPMENT OF SMALL CLUSTERS OF MODERATE CONVECTION SW OF THE LOW FROM 09N-12N BETWEEN 24W-31W. WIDELY SCATTERED MODERATE CONVECTION PERSIST NE OF THE LOW FROM 16N-19N BETWEEN 16W-22W. A TROPICAL WAVE IS OVER THE CENTRAL TROPICAL ATLC EXTENDING AN AXIS FROM 24N44W TO 10N42W AND MOVING WEST NEAR 10 KT. METEOSAT SAL TRACKING IMAGERY SHOW THIS WAVE IS BETWEEN TWO SAHARAN DRY AIRMASSES WHICH ARE LIMITING CONVECTIVE ACTIVITY. TOTAL PRECIPITABLE WATER IMAGERY SHOW THE WAVE AXIS IS EMBEDDED WITHIN A FINE ELONGATED LINE OF MODERATE MOISTURE. ISOLATED SHOWERS ARE WITHIN 120 NM EITHER SIDE OF THE AXIS FROM 22N-24N AND WITHIN 160 NM W OF THE AXIS FROM 14N-16N. A TROPICAL WAVE IS APPROACHING THE LESSER ANTILLES. ITS AXIS EXTENDS FROM 20N56W TO 12N59W AND IS MOVING W-NW NEAR 10 KT. TOTAL PRECIPITABLE WATER IMAGERY SHOW THAT MOISTURE CONTINUES TO AMPLIFY WITHIN THE WAVE ENVIRONMENT ASSISTING IN THE GENERATION OF NUMEROUS MODERATE CONVECTION AND TSTMS FROM 15N-19N BETWEEN 56W-60W. SCATTERED MODERATE CONVECTION IS ELSEWHERE FROM 11N-21N BETWEEN 53W-60W. A TROPICAL WAVE IS MOVING ACROSS THE CENTRAL CARIBBEAN SEA WITH AXIS EXTENDING FROM 24N72W TO THE WINDWARD PASSAGE NEAR 18N74W TO 10N74W IN NORTHERN COLOMBIA. THE ZONE OF UPPER LEVEL DIFFLUENCE HAS SHIFTED WESTWARD AND NOW SHOWERS AND TSTMS CONCENTRATE OVER THE WINDWARD PASSAGE AND THE TRENCH BETWEEN JAMAICA AND SE CUBA. ...THE ITCZ/THE MONSOON TROUGH... THE MONSOON TROUGH AXIS EXTENDS ACROSS AFRICA INTO THE E TROPICAL ATLC NEAR 19N16W AND CONTINUES ALONG 12N19W TO 06N27W TO 07N36W. BESIDES THE CONVECTION ASSOCIATED WITH THE TROPICAL WAVES ALREADY DISCUSSED...SCATTERED MODERATE CONVECTION IS FROM 07N-11N E OF 17W...FROM 05N-09N BETWEEN 25W-29W AS WELL AS FROM 05N-08N BETWEEN 45W-51W. ...DISCUSSION... THE GULF OF MEXICO... A SURFACE TROUGH EXTENDS FROM 26N90W TO 22N92W TO A 1010 MB LOW IN THE BAY OF CAMPECHE NEAR 19N93W. A REGION OF MIDDLE-LEVEL DIFFLUENCE IS OVER THE WESTERN BAY OF CAMPECHE WHICH IS ENHANCING A LINE OF SCATTERED SHOWERS AND TSTMS S OF 23N W OF 94W. A COL OR AREA OF LOW PRESSURE IN THE UPPER-LEVELS IS ENHANCING SIMILAR CONVECTION EAST OF THE TROUGH OVER THE EASTERN YUCATAN PENINSULA. THE SOUTHERN EXTENSION OF A NARROW UPPER LEVEL TROUGH ALONG THE EASTERN CONUS EXTENDS TO THE NORTH- CENTRAL GULF AND SUPPORTS SCATTERED SHOWERS FROM 24N-27N BETWEEN 88W-93W. A 1015 MB HIGH PRESSURE CENTER DEVELOPED OVER THE NE GULF NEAR 29N85W. THE TROUGH/AREA OF LOW PRESSURE WILL CONTINUE TO MOVE WESTWARD OVER THE BAY OF CAMPECHE AND IS EXPECTED TO PERSIST THROUGH FRIDAY AFTERNOON. THE CARIBBEAN SEA... SCATTERED MODERATE CONVECTION IS OVER THE FAR NW CARIBBEAN SEA S OF 22N W OF 85W BEING ENHANCED BY A COL/AREA OF LOW PRESSURE ALOFT. AN INVERTED TROUGH IS BETWEEN THE WINDWARD PASSAGE AND CENTRAL CUBA. THE WESTERN PERIPHERY OF AN UPPER LEVEL HIGH SPREADS ACROSS THE EASTERN CARIBBEAN TO GENERATE DIFFLUENCE ALOFT OVER THE WINDWARD PASSAGE AND THE TRENCH BETWEEN SE CUBA AND JAMAICA...THUS GENERATING SHOWERS AND TSTMS IN THAT REGION. A TROPICAL WAVE IS MOVING ACROSS THE CENTRAL CARIBBEAN SEA WITH AXIS EXTENDING FROM 24N72W TO THE WINDWARD PASSAGE NEAR 18N74W TO 10N74W IN NORTHERN COLOMBIA. SCATTERED MODERATE CONVECTION IS OVER THE SOUTHERN BASIN S OF 13N E OF 80W ASSOCIATED WITH THE MONSOON TROUGH AND SOUTHERN REGION OF THE TROPICAL WAVE. CONVECTIVE ACTIVITY ASSOCIATED WITH A 1008 MB LOW PRESSURE CENTER NEAR 15N64W LOOKS BETTER ORGANIZED THIS MORNING. A CLUSTER OF MODERATE CONVECTION AND TSTMS IS FROM 14N-17N BETWEEN 63W-65W. ELSEWHERE...SCATTERED SHOWERS ARE FROM 14N-19N BETWEEN 62W-67W. SEE THE SPECIAL FEATURE SECTION FOR MORE INFORMATION ABOUT THIS INVEST AREA. HISPANIOLA... UPPER LEVEL DIFFLUENCE OVER THE REGION CONTINUES TO GENERATE CLOUDINESS AND ISOLATED SHOWERS ACROSS THE ISLAND. HEAVY RAINSHOWERS ARE EXPECTED TO DEVELOP EARLY THURSDAY ASSOCIATED WITH THE CURRENT INVEST AREA IN THE EASTERN CARIBBEAN. THE ATLANTIC OCEAN... BESIDES THE TROPICAL WAVES ALREADY DISCUSSED...SURFACE RIDGING ANCHORED BY A SET OF HIGH PRESSURE CENTERS N OF THE AREA DOMINATES THE REMAINDER BASIN N OF 23N WHICH ALONG WITH DRY STABLE AIR SUPPORTS FAIR WEATHER. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ NR