000 AXNT20 KNHC 010006 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 805 PM EDT SUN AUG 31 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. ...SPECIAL FEATURE... A TROPICAL WAVE IS OVER THE YUCATAN PENINSULA AND THE BAY OF CAMPECHE WITH AXIS EXTENDING FROM 23N89W TO 12N92W...MOVING W AT 5-10 KT. LOW LEVEL CYCLONIC TURNING IS NOTED ON VISIBLE SATELLITE IMAGERY OVER THE YUCATAN PENINSULA...BELIZE AND GUATEMALA. SCATTERED MODERATE CONVECTION AND TSTMS ARE INLAND IN THE REGIONS MENTIONED ABOVE AS WELL AS SOUTHERN MEXICO AND THE GULF OF MEXICO SOUTH OF 27N. ENVIRONMENTAL CONDITIONS ARE EXPECTED TO BE CONDUCIVE FOR TROPICAL CYCLOGENESIS AS THE SYSTEM CONTINUES TO MOVE ACROSS THE SOUTHWESTERN GULF OF MEXICO. MEDIUM CHANCE FOR TROPICAL CYCLONE DEVELOPMENT IS EXPECTED DURING THE NEXT TWO DAYS. ...TROPICAL WAVES... A TROPICAL WAVE IS ON THE EASTERN ATLC WITH AXIS JUST EAST OF THE CAPE VERDE ISLANDS ALONG 17N22W TO 7N21W. ACCORDING TO UPPER-AIR TIME SECTION ANALYSES FROM DAKAR SENEGAL...THE WAVE CAME OFF THE AFRICAN COAST EARLY TODAY. THE WAVE EXHIBIT A STRONG SIGNAL IN THE MIDDLE AND UPPER LEVELS AND ITS SOUTHERN END IS EMBEDDED IN THE MONSOON TROUGH. A CLUSTER OF MODERATE CONVECTION IS WITHIN 220 NM WEST OF THE AXIS S OF 11N. SCATTERED SHOWERS ARE ELSEWHERE FROM 1N-17N E OF 26W. A TROPICAL WAVE IS ON THE CENTRAL ATLC WITH AXIS EXTENDING FROM 18N36W TO 9N38W...MOVING WEST AT 20 KT. SAHARAN DRY AIR AND DUST IS IN THE NORTHERN WAVE ENVIRONMENT...WHICH IS LIMITING CONVECTION TO SCATTERED SHOWERS S OF 14N BETWEEN 37W-41W. A TROPICAL WAVE IS WITHIN 500 NM EAST OF THE LESSER ANTILLES WITH AXIS EXTENDING FROM 19N51W TO 7N51W...MOVING WEST AT 15 KT. SAHARAN DRY AIR AND DUST IS IN THE NORTHERN WAVE ENVIRONMENT. SCATTERED MODERATE CONVECTION IS LIMITED TO THE SOUTHERN PORTION OF THE WAVE FROM 8N-12N BETWEEN 51W-55W. A TROPICAL WAVE IS OVER THE E CARIBBEAN WITH AXIS EXTENDING FROM 19N64W TO 10N64W MOVING WEST AT 15-20 KT. THE WAVE IS ASSOCIATED WITH MODERATE LOW-LEVEL MOISTURE AS DEPICTED ON TPW IMAGERY. STRONG DEEP LAYER ENVIRONMENTAL SHEAR IS INHIBITING DEEP CONVECTION. ISOLATED/SCATTERED SHOWERS ARE POSSIBLE FOR THE EASTERN CARIBBEAN...INCLUDING PUERTO RICO. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS FROM THE AFRICAN COAST NEAR 11N15W AND CONTINUES ALONG 7N24W 7N35W TO 8N45W. THE ITCZ EXTENDS FROM 8N45W TO 7N58W. FOR INFORMATION ABOUT CONVECTION SEE THE TROPICAL WAVES SECTION. ...DISCUSSION... GULF OF MEXICO... THE MAIN FEATURE IN THE GULF IS A TROPICAL WAVE MOVING ACROSS THE YUCATAN PENINSULA AND EASTERN BAY OF CAMPECHE WITH A MEDIUM POTENTIAL OF BECOMING A TROPICAL CYCLONE WITHIN THE NEXT TWO DAYS. THIS WAVE IS BEING SUPPORTED BY A MIDDLE TO LOWER LEVEL CYCLONIC CIRCULATION AND AN UPPER LEVEL INVERTED TROUGH. THE WAVE IS MAINLY ASSOCIATED WITH MODERATE DEEP LAYER MOISTURE WHICH IS FUELING SCATTERED SHOWERS AND TSTMS ACROSS GREAT PORTIONS OF THE GULF S OF 28N. SEE THE SPECIAL FEATURES SECTION ABOVE. AN ELONGATED UPPER LEVEL INVERTED TROUGH IS SUPPORTING A SURFACE TROUGH ALONG THE WESTERN COAST OF FLORIDA FROM 26N81W TO 29N83W...WHICH IS ENHANCING SHOWERS AND TSTMS THAT EXTEND WITHIN 80 NM OF THE COASTLINE. A MIDDLE TO UPPER LEVEL RIDGE DOMINATE ELSEWHERE ACROSS THE GULF...THUS SUPPORTING WEAK SURFACE RIDGING AND SOUTHEASTERLY FLOW OF 10-15 KT. RAINSHOWERS WILL CONTINUE ACROSS THE W-SW GULF DURING THE NEXT THREE DAYS ASSOCIATED WITH THE SYSTEM IN SPECIAL FEATURES. WEAK SURFACE RIDGING WILL PREVAIL ELSEWHERE WITHIN THAT PERIOD. CARIBBEAN SEA... A BROAD AREA OF LOW PRESSURE ASSOCIATED WITH A TROPICAL WAVE OVER THE S-SW GULF OF MEXICO CONTINUES TO ENHANCE RAINSHOWERS AND ISOLATED TSTMS ACROSS THE NW CARIBBEAN W OF 78W. SEE THE SPECIAL FEATURE SECTION ABOVE. ANOTHER TROPICAL WAVE IS ON THE EAST CARIBBEAN. HOWEVER...STRONG DEEP LAYER ENVIRONMENTAL WIND SHEAR IS HINDERING THE DEVELOPMENT OF CONVECTION IN THAT REGION. A MIDDLE TO UPPER LEVEL ELONGATED CYCLONIC CIRCULATION ANCHORED NEAR THE SOUTHERN BAHAMAS ALONG WITH MODERATE LOW LEVEL MOISTURE IS SUPPORTING SCATTERED MODERATE CONVECTION AND TSTMS ACROSS WESTERN DOMINICAN REPUBLIC AND HAITI. FAIR WEATHER DOMINATES ELSEWHERE. TRADES OF 10-15 KT DOMINATE THE BASIN...EXCEPT FOR THE FAR NW CARIBBEAN W OF 84W AND THE CENTRAL BASIN S OF 17W BETWEEN 68W-80W WHERE 20-25 KT WINDS ABOUND. THE TROPICAL WAVE WILL MOVE ACROSS THE CENTRAL CARIBBEAN MON THROUGH TUE ENHANCING MORE SHOWERS FOR HISPANIOLA. A NEW TROPICAL WAVE ENTERS THE BASIN TUE MORNING. ...HISPANIOLA... A MIDDLE TO UPPER LEVEL ELONGATED CYCLONIC CIRCULATION ANCHORED NEAR THE SOUTHERN BAHAMAS ALONG WITH MODERATE LOW LEVEL MOISTURE IS SUPPORTING SCATTERED MODERATE CONVECTION AND TSTMS ACROSS WESTERN DOMINICAN REPUBLIC AND HAITI. A TROPICAL WAVE CURRENTLY OVER THE EASTERN CARIBBEAN WILL MOVE ACROSS THE CENTRAL BASIN MON THROUGH TUE ENHANCING MORE SHOWERS FOR HISPANIOLA. ATLANTIC OCEAN... AN ELONGATED MIDDLE TO UPPER LEVEL CYCLONIC CIRCULATION ANCHORED NEAR THE SOUTHERN BAHAMAS REFLECTS AT THE SURFACE AS TWO SURFACE TROUGHS...ONE ALONG 27N65W TO 25N69W AND A SECOND TROUGH FROM 23N68W TO 19N72W. SCATTERED MODERATE CONVECTION AND ISOLATED TSTMS ASSOCIATED WITH THESE FEATURES ARE S OF 29N BETWEEN 60W- 72W. FARTHER EAST...A TROUGH ALOFT SUPPORT A DISSIPATING COLD FRONT ANALYZED FROM 30N46W TO A 1016 MB LOW NEAR 28N49W TO 26N51W. SURFACE RIDGING AND FAIR WEATHER DOMINATE ELSEWHERE. 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