000 AXNT20 KNHC 091755 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 205 PM EDT FRI OCT 09 2015 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... A TROPICAL WAVE IS ADDED TO THE 1200 UTC ANALYSIS/SURFACE MAP JUST WEST OF THE CAVE VERDE ISLANDS AND EXTENDS FROM NEAR 20N25W TO 10N27W. VISIBLE SATELLITE IMAGERY INDICATES SOME INVERTED-V PATTERN IN THE CLOUD FIELD. THE WAVE IS REFLECTED IN A SURGE OF MOISTURE ON THE TPW SATELLITE IMAGERY AND IS ALSO WELL DEPICTED IN THE LATEST GFS 700 MB STREAMLINES AND 850 MB VORTICITY ANALYSIS. SCATTERED MODERATE CONVECTION IS NOTED WITHIN AROUND 180 NM AHEAD OF THE WAVE AXIS FROM 13N-16N. A LOW AMPLITUDE TROPICAL WAVE IS REPOSITIONED OVER THE CENTRAL ATLC WITH AXIS EXTENDING FROM 17N44W TO 10N45W. AFRICAN DUST SURROUNDS THE WAVE AS NOTED ON THE SAHARAN AIR LAYER FROM UW- CIMSS. SCATTERED MODERATE CONVECTION IS NEAR THE SOUTHERN END OF THE WAVE AXIS FROM 10N-12N BETWEEN 40W-48W. A TROPICAL WAVE IS OVER THE EASTERN CARIBBEAN. THE WAVE AXIS EXTENDS OVER WESTERN PUERTO RICO AND ALONG 67W. THE TPW IMAGERY INDICATES A BULGE OF MOISTURE IN ASSOCIATION WITH THIS WAVE. THIS SYSTEM IS ALSO WELL DEPICTED IN THE LATEST GFS 700 MB STREAMLINES AND 850 MB VORTICITY ANALYSIS. THE SAN JUAN DOPPLER RADAR SHOWS AND AREA OF SHOWERS WITH EMBEDDED TSTMS N OF PUERTO RICO LIKELY ASSOCIATED WITH A TROUGH LOCATED JUST N OF THE ISLAND AND ALSO OVER THE MONA PASSAGE. THE WAVE WILL CONTINUE TO MOVE WESTWARD ACROSS HISPANIOLA LATER TODAY THROUGH LATE SAT. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH AXIS EXTENDS FROM THE AFRICAN COAST NEAR 11N15W TO NEAR 13N23W. THE ITCZ AXIS BEGINS W OF THE EASTERNMOST TROPICAL WAVE AND EXTENDS FROM 12N32W TO 9N45W TO 9N61W. SCATTERED MODERATE CONVECTION CAN BE FOUND FROM 5N-8N BETWEEN 15W-17W...FROM 7N-9N BETWEEN 18W-21W...AND FROM 8N-12N BETWEEN 48W-51W. A CLUSTER OF MODERATE TO ISOLATED STRONG CONVECTION IS FROM 9N-11N BETWEEN 33W-35W ...DISCUSSION... GULF OF MEXICO... A SURFACE TROUGH PERSISTS OVER THE EASTERN GULF AND STRETCHES FROM 29N85W TO 26N86W TO 24N90W AT 1500 UTC. SCATTERED SHOWERS AND TSTMS ARE OBSERVED ON DOPPLER RADAR NEAR THE NORTHERN END OF THE TROUGH AXIS. A THERMAL TROUGH IS JUST WEST OF THE YUCATAN PENINSULA. THIS TROUGH WILL DRIFT WESTWARD ACROSS THE SW GULF WHERE IT WILL DISSIPATE LATER TODAY BEFORE REDEVELOPING TONIGHT. THE REMAINDER OF THE REGION IS UNDER THE INFLUENCE OF A WEAK RIDGE ANCHORED BY A HIGH LOCATED OVER THE SE CONUS. THIS RIDGE IS PRODUCING LIGHT TO MODERATE NE-E WINDS ACROSS MOST OF THE BASIN. A WEAK COLD FRONT IS FORECAST TO REACH THE NORTHERN GULF BY SAT MORNING EXTENDING ACROSS THE SE AND SOUTH-CENTRAL GULF BY SUN WHERE IT WILL GRADUALLY DISSIPATE. WEAK HIGH PRES WILL FOLLOW THE FRONT. ALOFT...AN ANTICYCLONE CENTERED OVER THE SW GULF EXTENDS A RIDGE ACROSS THE ENTIRE REGION AND THE STATE OF FLORIDA. CARIBBEAN SEA... THE TROPICAL WAVE CURRENTLY LOCATED OVER WESTERN PUERTO RICO ALONG 67W WILL MOVE ACROSS THE CENTRAL CARIBBEAN TONIGHT THROUGH LATE SAT NIGHT AND ACROSS THE WESTERN CARIBBEAN ON SUN. THE WAVE PASSAGE WILL COMBINE WITH THE LOCAL EFFECTS TO ENHANCE THE LIKELIHOOD OF SHOWERS AND TSTMS ACROSS THE GREATER ANTILLES ESPECIALLY DURING THE AFTERNOON AND EARLY EVENING HOURS. THE MOST RECENT SCATTEROMETER PASSES PROVIDED OBSERVATIONS OF MAINLY FRESH TRADE WINDS ACROSS THE SOUTH-CENTRAL CARIBBEAN. GENTLE TO MODERATE TRADES PREVAIL ELSEWHERE. THIS WEATHER PATTERN IS FORECAST TO PERSIST OVER THE NEXT SEVERAL DAYS WITH FRESH TO LOCALLY STRONG TRADE WINDS NEAR THE COAST OF WESTERN VENEZUELA AND NORTHERN COLOMBIA AT NIGHT. THE TRADES WILL CARRY ISOLATED TO SCATTERED SHOWERS. IN THE UPPER LEVELS...A RIDGE DOMINATES WESTERN CUBA AND THE NW CARIBBEAN WHILE AN UPPER-LEVEL LOW IS SPINNING JUST SOUTH OF HISPANIOLA. THIS LOW IS ALREADY PRODUCING SOME SHOWERS WITH EMBEDDED TSTMS OVER THE DOMINICAN REPUBLIC. ...HISPANIOLA... THE UPPER-LEVEL LOW LOCATED S OF HISPANIOLA WILL COMBINE WITH THE PASSAGE OF THE AFOREMENTIONED TROPICAL WAVE AND THE LOCAL EFFECTS AS DAYTIME HEATING...LOCAL SEA BREEZES AND MOUNTAIN SLOPES...TO INCREASE THE SHOWER AND TSTM ACTIVITY ACROSS THE ISLAND THE REST OF TODAY AND TOMORROW. LOCALLY HEAVY RAINFALL COULD BE POSSIBLE AND GUSTY WINDS DUE TO THE PRESENCE OF THE TSTMS. BY SUN...THE UPPER-LEVEL LOW IS EXPECTED TO DISSIPATE BUT A STRONG UPPER-LEVEL TROUGH IS FORECAST TO APPROACH FROM THE WEST. ATLANTIC OCEAN... A WEAK LOW PRES HAS DEVELOPED ALONG THE EAST COAST OF FLORIDA BETWEEN VERO BEACH AND MELBOURNE. SURFACE OBSERVATIONS ACROSS FLORIDA CONFIRMED THE PRESENCE OF THIS LOW. VISIBLE SATELLITE IMAGERY AND DOPPLER RADAR FROM MELBOURNE ALSO SHOWED THE CYCLONIC CIRCULATION ASSOCIATED WITH THIS LOW. THIS SYSTEM IS LIKELY ASSOCIATED WITH AN OLD FRONTAL BOUNDARY THAT IS ANALYZED ON THE 1200 UTC SURFACE MAP FROM 28N80W TO 29N70W TO A LOW PRES LOCATED N OF AREA NEAR 33N64W. THE WEAK LOW IS FORECAST TO DRIFT WESTWARD INLAND. A SURFACE TROUGH...LIKELY PART OF THE ENERGY ASSOCIATED WITH THE TROPICAL WAVE LOCATED OVER THE EASTERN CARIBBEAN...RUNS FROM 23N63W TO 20N66W. SCATTERED MODERATE CONVECTION IS NOTED ON THE EAST SIDE OF THE TROUGH. A 1021 MB HIGH PRES IS LOCATED NEAR 28N48W AND WILL MOVE NE TO A POSITION NEAR 29N44W IN ABOUT 24 HOURS. A WEAK HIGH PRES CENTER OF 1020 MB IS JUST SOUTH OF THE CANARY ISLANDS AND IS FORECAST TO DISSIPATE OVER THE NEXT 24 HOURS WITH A RIDGE REMAINING THERE. ALOFT...A STRONG MID TO UPPER LEVEL TROUGH WILL ENTER THE WESTERN ATLC BY SUN AND COULD INTERACT WITH THE TROPICAL WAVE CURRENTLY MOVING ACROSS THE EASTERN CARIBBEAN TO PRODUCE AN INCREASE IN MOISTURE OVER THE CENTRAL BAHAMAS AND EASTERN CUBA. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ GR