000 AXNT20 KNHC 050005 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 805 PM EDT THU SEP 04 2014 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 2345 UTC. ...TROPICAL WAVES... A TROPICAL WAVE ASSOCIATED WITH A 1009 MB LOW PRESSURE CENTER IS ABOUT 200 NM EAST OF THE CAPE VERDE ISLANDS. ITS AXIS EXTENDS FROM 18N18W TO THE LOW NEAR 13N20W TO 8N20W...MOVING WEST AT 10- 15 KT. METEOSAT SAHARAN AIR LAYER TRACKING IMAGERY AS WELL AS SSMI TOTAL PRECIPITABLE WATER VAPOR IMAGERY SHOW DRY AIR ENGULFING THE SYSTEM. A CLUSTER OF MODERATE/ISOLATED STRONG CONVECTION AND TSTMS IS FROM 12N-15N BETWEEN 20W- 23W...COINCIDING WITH A REGION OF DEEP LAYER HIGH MOISTURE. A TROPICAL WAVE IS ON THE CENTRAL ATLANTIC WITH AXIS EXTENDING FROM 17N44W TO 9N45W...MOVING W AT 20 KT. MODERATE LOW-LEVEL MOISTURE IS ASSOCIATED WITH THE WAVE WITH SOME SAHARAN DRY AIR AFFECTING ITS NORTHERN ENVIRONMENT. STRONG DEEP LAYER ENVIRONMENTAL WIND SHEAR IN ITS REGION IS HINDERING CONVECTIVE ACTIVITY. A TROPICAL WAVE IS OVER THE EASTERN CARIBBEAN WITH AXIS EXTENDING FROM 21N63W TO 11N64W...MOVING W AT 15-20 KT. MAINLY MODERATE LOW-LEVEL MOISTURE IS ASSOCIATED WITH THE WAVE WHICH ALONG UPPER-LEVEL DIFFLUENCE SUPPORT SCATTERED MODERATE CONVECTION ACROSS THE NE CARIBBEAN AND TSTMS NE OF PUERTO RICO FROM 18N-22N BETWEEN 61W-65W. A TROPICAL WAVE IS ON THE CENTRAL CARIBBEAN WITH AXIS EXTENDING FROM 21N73W TO 11N74W...MOVING W AT 10 KT. SSMI TOTAL PRECIPITABLE WATER VAPOR IMAGERY SHOW MODERATE/HIGH MOISTURE IN ITS SOUTHERN ENVIRONMENT S OF 15N WITH A SLOT OF DRIER AIR NORTHWARD. STRONG DEEP LAYER ENVIRONMENTAL SHEAR IN THE REGION IS INHIBITING THE DEVELOPMENT OF CONVECTION NEARBY THE WAVE AXIS. ISOLATED SHOWERS ARE POSSIBLE IN THE WINDWARD PASSAGE. A TROPICAL WAVE MOVED INLAND THE YUCATAN PENINSULA AND NORTHERN CENTRAL AMERICA EARLIER THIS EVENING. ITS AXIS EXTENDS FROM 21N88W TO 13N88W...MOVING W AT 10-15 KT. SCATTERED MODERATE CONVECTION AND TSTMS ARE OVER NORTHERN AND CENTRAL YUCATAN PENINSULA AND THE YUCATAN CHANNEL. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS FROM THE AFRICAN COAST NEAR 12N16W TO 7N22W TO 8N31W. THE ITCZ EXTENDS FROM 8N31W TO 9N46W TO THE COAST OF VENEZUELA NEAR 8N60W. BESIDES THE CONVECTION MENTIONED IN THE TROPICAL WAVE SECTION...SCATTERED MODERATE CONVECTION IS FROM 6N-9N WEST OF 48W. ...DISCUSSION... GULF OF MEXICO... OVER THE WESTERN BASIN...THE REMNANTS OF DOLLY CONTINUE ENHANCING RAINSHOWERS AND TSTMS ALONG THE MEXICO/TX COAST WEST OF 95W. A MIDDLE-LEVEL INVERTED TROUGH IS ON THE EASTERN GULF SUPPORTING A TROPICAL WAVE THAT IS MOVING ACROSS THE YUCATAN PENINSULA AND NORTHERN CENTRAL AMERICA. SEE TROPICAL WAVES SECTION FOR MORE DETAILS. THE TROUGH ALOFT ALSO SUPPORT A SURFACE TROUGH WITH AXIS EXTENDING ACROSS NORTHERN-CENTRAL FLORIDA TO 27N82W TO 25N83W IN THE SE GULF. A DIFFLUENT ENVIRONMENT ACROSS THE FLORIDA PENINSULA BEING GENERATED BY AN UPPER-LEVEL RIDGE CENTERED OVER SOUTH CAROLINA AND A LOW LOCATED ON THE NW CARIBBEAN IS ENHANCING SCATTERED SHOWERS AND TSTMS ALONG THE WESTERN PENINSULA AND SE GULF S OF 26N E OF 84W. WEAK SURFACE RIDGING PREVAILS ACROSS THE GULF...THUS PROVIDING E-SE WIND FLOW OF 5-10 KT. THE TROPICAL WAVE WILL ENTER THE BAY OF CAMPECHE FRIDAY THROUGH SATURDAY THEN WILL MOVE INLAND MEXICO. NO MAJOR CHANGES ELSEWHERE. CARIBBEAN SEA... TWO TROPICAL WAVES ARE ON THE REGION...ONE OVER THE EASTERN CARIBBEAN AND ANOTHER MOVING ACROSS THE WINDWARD PASSAGE AND CENTRAL BASIN. THE LATTER CONTINUES TO ENHANCE SCATTERED MODERATE CONVECTION ACROSS CENTRAL-SOUTHERN HISPANIOLA AND TSTMS OVER CENTRAL AND SOUTHERN HAITI. SEE THE TROPICAL WAVES SECTION ABOVE FOR MORE DETAILS. MODERATE MOISTURE OVER WESTERN CUBA AS WELL AS A DIFFLUENT ENVIRONMENT BEING GENERATED BY AN UPPER- LEVEL RIDGE CENTERED OVER SOUTH CAROLINA AND A LOW LOCATED ON THE NW CARIBBEAN SUPPORT SCATTERED HEAVY SHOWERS AND TSTMS ON THIS REGION OF THE ISLAND AS WELL AS ADJACENT WATERS. IN THE SW BASIN...DEEP LAYER MOISTURE ALONG WITH A DIFFLUENT ENVIRONMENT GENERATED BY AN UPPER-LEVEL RIDGE ON THE CENTRAL CARIBBEAN SUPPORT HEAVY SHOWERS AND TSTMS S OF 16N WEST OF 77W. TRADES OF 15 KT ABOUNDS ACROSS THE BASIN...EXCEPT ON THE CENTRAL CARIBBEAN WHERE WINDS INCREASE TO 20-25 KT DUE TO A TIGHTER PRESSURE GRADIENT AND THE PASSAGE OF THE TROPICAL WAVE. SHOWERS WILL CONTINUE IN THE SW BASIN...EXTENDING TO THE NW BASIN THROUGH SATURDAY NIGHT. A NEW TROPICAL WAVE WILL MOVE ACROSS THE LESSER ANTILLES SUNDAY MORNING. ...HISPANIOLA... THE PASSAGE OF A TROPICAL WAVE CONTINUE TO ENHANCE SCATTERED MODERATE CONVECTION ACROSS CENTRAL-SOUTHERN HISPANIOLA AND TSTMS OVER CENTRAL AND SOUTHERN HAITI. SEE THE TROPICAL WAVES SECTION ABOVE FOR MORE DETAILS. MOISTURE ASSOCIATED WITH THE NEXT TROPICAL WAVE TO MOVE ACROSS THE ISLAND WILL SUPPORT THE CONTINUATION OF SHOWERS THROUGH FRIDAY. ATLANTIC OCEAN... A MIDDLE-LEVEL INVERTED TROUGH ACROSS THE EASTERN GULF OF MEXICO AND THE FLORIDA PENINSULA SUPPORT A SURFACE TROUGH WHICH AXIS REACHES THE SW N ATLC. THIS SURFACE TROUGH IS ENHANCING SCATTERED SHOWERS WEST OF 75W. A SURFACE RIDGE DOMINATES ELSEWHERE IN THIS REGION OF THE BASIN BEING ANCHORED BY A 1023 MB HIGH NEAR 32N67W. FARTHER EAST...A BROAD MIDDLE TO UPPER LEVEL TROUGH SUPPORT A SURFACE TROUGH ALONG 29N37W SW TO 25N47W WHICH IS ENHANCING SCATTERED SHOWERS AND TSTMS FROM 25N-31N BETWEEN 36W-42W. SEE TROPICAL WAVES SECTION FOR AREAS OF CONVECTION OVER PORTIONS OF THE REMAINDER BASIN. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ NR