000 AXNT20 KNHC 110557 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 205 AM EDT THU JUL 11 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0515 UTC. ...TROPICAL WAVES... TROPICAL WAVE EXTENDS FROM 09N28W TO 16N26W MOVING W AT 10-15 KT. THE WAVE REMAINS EMBEDDED WITHIN THE MONSOON TROUGH AND ITCZ AXIS COINCIDING WITH A GLOBAL MODEL INDICATED 700 MB TROUGH AND ASSOCIATED VORTICITY MAXIMUM IN THE VICINITY OF 14N27W. TOTAL PRECIPITABLE WATER IMAGERY SHOWS A RELATIVE MOISTURE MAXIMUM FROM 10N-16N BETWEEN 23W-33W. ISOLATED MODERATE CONVECTION IS FROM 09N-15N BETWEEN 25W-29W. TROPICAL WAVE EXTENDS FROM 06N43W TO 12N39W MOVING W AT 10 KT. THE WAVE REMAINS ON THE WESTERN EXTENT OF THE ITCZ AXIS WITH LOW- LEVEL STREAMLINE ANALYSIS INDICATING CYCLONIC TURNING OF THE LOW- LEVEL WIND FIELD VERTICALLY THROUGH 700 MB S OF 14N BETWEEN 38W- 45W. A SAHARAN AIR LAYER REMAINS ON THE NORTHERN PERIPHERY OF THE WAVE AXIS AND THIS IS RESULTING IN LIMITED CONVECTION AT THIS TIME. ISOLATED MODERATE CONVECTION IS FROM 06N-09N BETWEEN 39W-43W. TROPICAL WAVE EXTENDS FROM 15N73W TO 23N73W MOVING W-NW AT 15-20 KT. THE WAVE...REMNANTS OF CHANTAL...CONTINUES AS AN OPEN WAVE WITH NO DEFINED LOW-LEVEL CIRCULATION CENTER. PLENTY OF LOW- LEVEL MOISTURE CONVERGENCE AND MID-LEVEL VORTICITY ARE AIDING IN GENERATING SCATTERED MODERATE CONVECTION FROM 16N-24N BETWEEN 68W-75W...INCLUDING MUCH OF HISPANIOLA AND PORTIONS OF THE WINDWARD PASSAGE. THE WAVE IS EXPECTED TO TRACK TOWARDS THE FLORIDA STRAITS AND SOUTHERN FLORIDA PENINSULA OVER THE WEEKEND. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS FROM THE AFRICAN COAST NEAR 12N16W TO 11N20W TO 13N24W. THE INTERTROPICAL CONVERGENCE ZONE AXIS EXTENDS FROM 13N27W TO 09N41W. SCATTERED MODERATE CONVECTION IS FROM 08N-14N BETWEEN 15W-19W. ISOLATED MODERATE CONVECTION IS WITHIN 150 NM NORTH AND 210 NM SOUTH OF THE ITCZ AXIS BETWEEN 29W-40W. ...DISCUSSION... GULF OF MEXICO... WATER VAPOR IMAGERY INDICATES EAST-NORTHEASTERLY UPPER LEVEL FLOW NORTH OF A BROAD TROUGH AXIS EXTENDING FROM AN UPPER LEVEL LOW CENTERED OVER THE FLORIDA STRAITS NEAR 23N80W TO OVER EAST- CENTRAL MEXICO NEAR 23N101W. MOSTLY DRY AND STABLE AIR ALOFT IS NOTED OVER THE NORTHERN GULF WATERS THIS EVENING WHILE A SURFACE RIDGE ANCHORED BY A 1018 MB HIGH CENTERED NEAR 28N91W LIES BENEATH PROVIDING FOR OVERALL TRANQUIL CONDITIONS. A SLIGHT WEAKNESS IN THE RIDGE IS ANALYZED AS A SURFACE TROUGH FROM SE GEORGIA NEAR 32N82W TO THE TAMPA BAY REGION TO 26N84W IN THE FAR EASTERN GULF. WIDELY SCATTERED SHOWERS AND ISOLATED TSTMS ARE OCCURRING FROM 27N-29N BETWEEN 82W-85W. ACROSS PORTIONS OF THE FAR SE GULF AND SW GULF...WITHIN MOSTLY WESTERLY FLOW ALOFT ON THE SOUTHERN PERIPHERY OF THE UPPER LEVEL TROUGHING...MIDDLE TO UPPER LEVEL MOISTURE INCREASES WITH ISOLATED SHOWERS OCCURRING S OF 24N...AND MORE AREAL COVERAGE OF SHOWER AND TSTM ACTIVITY ACROSS INLAND SOUTHERN MEXICO AND THE YUCATAN PENINSULA THIS EVENING. LOOKING AHEAD...THE WEAKNESS IN THE SURFACE RIDGING BETWEEN THE SW NORTH ATLC AND GULF WILL PROVIDE FOR THE REMNANTS OF CHANTAL TO TRACK W-NW THROUGH THE WEEKEND ACROSS THE FLORIDA STRAITS AND SOUTHERN FLORIDA PENINSULA. CARIBBEAN SEA... THE PRIMARY FOCUS FOR THE CARIBBEAN IS THE REMNANTS OF CHANTAL...ANALYZED AS AN OPEN TROPICAL WAVE ALONG 73W. MUCH OF THE CONVECTION ASSOCIATED WITH THE WAVE IS LOCATED ON THE EASTERN PERIPHERY DUE TO UPPER LEVEL WESTERLY SHEAR TO THE NW OVER THE FLORIDA STRAITS. SCATTERED TO NUMEROUS SHOWERS AND SCATTERED TSTMS ARE OCCURRING N OF 14N BETWEEN 66W-76W... INCLUDING HISPANIOLA AND PORTIONS OF THE WINDWARD PASSAGE AND EASTERN CUBA. THE WAVE AND AREA OF MOISTURE IS EXPECTED TO TRACK W-NW OVER THE NEXT 24 TO 36 HOURS PROVIDING INCREASED RAINFALL CHANCES FOR HISPANIOLA AND CUBA THROUGH THE WEEKEND. OVER THE WESTERN CARIBBEAN...AN UPPER LEVEL ANTICYCLONIC CIRCULATION IS CENTERED OVER NICARAGUA NEAR 12N85W. MIDDLE TO UPPER LEVEL MOISTURE REMAINS ACROSS MUCH OF CENTRAL AMERICA AND THE NW CARIBBEAN THIS EVENING WITH UPPER LEVEL DIFFLUENCE CONTINUING TO GENERATE ISOLATED SHOWERS AND TSTMS S OF 21N W OF 83W. FARTHER SOUTH ACROSS THE SW CARIBBEAN...THE MONSOON TROUGH AXIS EXTENDS ALONG 10N FROM NORTHERN COLOMBIA TO NORTHERN COSTA RICA AND IS PROVIDING FOCUS FOR WIDELY SCATTERED SHOWERS AND TSTMS S OF 12N BETWEEN 73W-86W. AS THE REMNANTS OF CHANTAL TRACK NORTH OF BASIN OVER THE WEEKEND...THE BEGINNING OF NEXT WEEK WILL SEE A RETURN TO E-SE TRADES IN THE RANGE OF 10 TO 20 KT WITH STRONGER WINDS POSSIBLE IN THE VICINITY OF THE NORTHERN COLOMBIA COAST. HISPANIOLA... CURRENTLY A TROPICAL WAVE...THE REMNANTS OF CHANTAL...ARE PRODUCING SCATTERED SHOWERS AND WIDELY SCATTERED TSTMS ACROSS THE ISLAND THIS EVENING. SOME OF THIS RAINFALL IS LOCALLY HEAVY WITH THE POTENTIAL FOR LOCALIZED FLOODING. THE TROPICAL WAVE IS EXPECTED TO MOVE W-NW OVER THE NEXT 24 TO 36 HOURS AND CONDITIONS ACROSS HISPANIOLA ARE EXPECTED TO GRADUALLY IMPROVE BY LATE FRIDAY INTO EARLY SATURDAY. THEREAFTER...E-SE TRADES WILL RESUME ACROSS THE REGION WITH THE MORE TYPICAL AFTERNOON SHOWERS AND TSTMS OCCURRING ACROSS THE ISLAND DURING THE WEEKEND INTO EARLY NEXT WEEK. ATLANTIC OCEAN... A MIDDLE TO UPPER LEVEL LOW IS CENTERED OVER THE FLORIDA STRAITS NEAR 24N80W THAT IS PROVIDING THE SW NORTH ATLC WITH A WEAKNESS IN THE SURFACE RIDGING TO DRAW THE REMNANTS OF CHANTAL W-NW FROM THE NORTH-CENTRAL CARIBBEAN SEA AND HISPANIOLA ACROSS THE BAHAMAS AND SOUTH FLORIDA THROUGH THE UPCOMING WEEKEND. CURRENTLY ANALYZED AS A TROPICAL WAVE ALONG 73W...SCATTERED SHOWERS AND TSTMS ARE OCCURRING S OF 25N BETWEEN 68W-75W... INCLUDING THE TURKS AND CAICOS ISLANDS. SURFACE RIDGING ANCHORED BY A 1022 MB HIGH CENTERED IN THE VICINITY OF BERMUDA NEAR 33N64W WILL GRADUALLY WEAKEN OVER THE NEXT 24 TO 36 HOURS AND ALLOW THE WAVE TO MAKE ITS WAY TOWARDS THE FLORIDA PENINSULA AND AREAS OFF THE EASTERN COASTLINE. FARTHER EAST...AN UPPER LEVEL LOW IS CENTERED NEAR 31N55W THAT REMAINS AT THE SOUTHWESTERN EXTENT OF A STATIONARY FRONT ANALYZED FROM 36N40W TO 31N49W. MOISTURE ASSOCIATED WITH THE UPPER LEVEL LOW IS GENERATING ISOLATED SHOWERS FROM 23N-32N BETWEEN 49W-57W. GLOBAL MODELS INDICATE THIS UPPER LEVEL FEATURE WILL RETROGRADE AND DRIFT WESTWARD ACROSS THE SW NORTH ATLC OVER THE COMING DAYS. FINALLY...THE EASTERN ATLC IS UNDER THE INFLUENCE OF A SURFACE RIDGE ANCHORED BY A 1021 MB HIGH CENTERED SW OF THE AZORES NEAR 35N32W. A SAHARAN AIR LAYERS CONTINUES TO BE THE OVERALL DOMINATE FEATURE PROVIDING FAIRLY STABLE CONDITIONS N OF 18N E OF 47W. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ HUFFMAN