000 AXNT20 KNHC 011754 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 205 PM EDT SUN SEP 01 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1715 UTC. ...SPECIAL FEATURES... TROPICAL WAVE EXTENDS FROM 10N61W TO A 1012 MB LOW CENTERED NEAR 15N61W TO 18N58W MOVING W AT 10-15 KT. THE WAVE REMAINS EMBEDDED WITHIN BROAD SURFACE TO 700 MB TROUGHING BETWEEN 55W-65W WITH A RELATIVE VORTICITY MAXIMUM STRETCHING FROM 16N57W TO 15N63W. THIS AREA COINCIDES WITH THE STRONGEST CONVECTION AT THIS TIME AS SCATTERED MODERATE AND ISOLATED STRONG CONVECTION IS FROM 13N- 18N BETWEEN 53W-66W. ...TROPICAL WAVES... TROPICAL WAVE EXTENDS FROM 12N22W TO A 1011 MB LOW NEAR 17N22W TO 21N21W MOVING W AT 5-10 KT. THE SAHARAN AIR LAYER IS STRONGEST TO THE NORTHEAST OF THE WAVE WITH ISOLATED MODERATE CONVECTION OCCURRING WELL WEST OF THE LOW CENTER FROM 14N-17N BETWEEN 23W-26W. TROPICAL WAVE EXTENDS FROM 09N47W TO A 1013 MB LOW NEAR 11N47W TO 17N46W MOVING W AT 10-15 KT. EXAMINING MULTI-DAY SATELLITE IMAGERY...THIS WAVE EMERGED OFF THE AFRICAN COAST APPROXIMATELY 4 DAYS AGO AND REMAINED A RELATIVELY LOW LATITUDE PIECE OF ENERGY. ONLY RECENTLY...WITHIN THE LAST 36 TO 48 HOURS...HAS THIS ENERGY AMPLIFIED AND DEVELOPED DISORGANIZED AREAS OF CONVECTION. WIDELY SCATTERED MODERATE CONVECTION IS FROM 06N-15N BETWEEN 41W-51W. TROPICAL WAVE EXTENDS FROM 11N88W TO 19N87W MOVING W AT 10-15 KT. THE WAVE CONTINUES TO SHOW A WEAK PRESENCE IN THE LOW TO MIDDLE LEVELS OF THE ATMOSPHERE AS AREAS OF WEAK RELATIVE VORTICITY STRETCH FROM THE EAST PACIFIC REGION NORTHWARD TO OVER PORTIONS OF BELIZE AND NORTHERN GUATEMALA. WHILE NO SIGNIFICANT DEEP CONVECTION IS NOTED AT THIS TIME...SCATTERED SHOWERS AND ISOLATED TSTMS ARE OCCURRING FROM 11N-21N BETWEEN 86W-92W. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS FROM 11N19W TO 12N23W TO 08N35W TO 11N47W. ASIDE FROM THE CONVECTION ASSOCIATED WITH THE TROPICAL WAVES...WIDELY SCATTERED MODERATE CONVECTION IS FROM 05N-10N BETWEEN 08W-26W...AND FROM 04N-08N BETWEEN 31W-39W. ...DISCUSSION... GULF OF MEXICO... MIDDLE TO UPPER LEVEL MOISTURE CONTINUES TO ADVECT SOUTHWESTWARD ON THE NORTHERN PERIPHERY OF AN UPPER LEVEL LOW CENTERED NEAR 23N86W. WHILE NOT IN FAVORABLE UPPER LEVEL DIFFLUENT AREA AT THIS TIME...LOW-LEVEL MOISTURE CONVERGENCE IS HOWEVER GENERATING SCATTERED SHOWERS AND ISOLATED TSTMS WITHIN 120 NM EITHER SIDE OF A LINE FROM THE FLORIDA PANHANDLE NEAR 30N85W TO 26N92W FOCUSED PRIMARILY EAST OF A SURFACE TROUGH ANALYZED FROM 31N86W TO 28N90W. THE REMAINDER OF THE GULF IS UNDER THE INFLUENCE OF A SURFACE RIDGE WITH AXIS EXTENDING FROM THE SW NORTH ATLC REGION WESTWARD ALONG 26N TO 92W THEN SW TO A 1014 MB HIGH CENTERED ACROSS EAST-CENTRAL MEXICO NEAR 21N99W. E-SE WINDS PREVAIL SOUTH OF THE RIDGE AXIS AND REMAIN GENERALLY LESS THAN 20 KT. CARIBBEAN SEA... AN UPPER LEVEL LOW IS CENTERED NORTH OF THE YUCATAN CHANNEL OVER THE SE GULF OF MEXICO NEAR 23N86W. MIDDLE TO UPPER LEVEL DIFFLUENCE CONTINUES SOUTH OF THE UPPER LEVEL CYCLONE OVER THE NW CARIBBEAN THAT IS GENERATING WIDELY SCATTERED SHOWERS AND ISOLATED TSTMS N OF 14N W OF 80W. THE CLOSE PROXIMITY OF A TROPICAL WAVE MOVING WEST ALONG 88W IS ALSO ADDING AN ELEMENT OF LOW-LEVEL MOISTURE CONVERGENCE AIDING IN SHOWER ACTIVITY ACROSS CENTRAL AMERICA AND THE YUCATAN PENINSULA. FARTHER SOUTH...THE MONSOON TROUGH AXIS IS ANALYZED ALONG 09N/10N FROM NORTHERN COLOMBIA WESTWARD TO COSTA RICA WITH SCATTERED SHOWERS AND TSTMS OCCURRING S OF 13N BETWEEN 76W-84W. FINALLY...A TROPICAL WAVE IS ALONG 61W IMPACTING THE LESSER ANTILLES THIS AFTERNOON. WATER VAPOR IMAGERY INDICATES AN AREA OF MAXIMUM UPPER LEVEL DIFFLUENCE IS LOCATED BETWEEN 57W-67W THAT ALONG WITH THE LOW- LEVEL CONVERGENCE ASSOCIATED WITH THE WAVE AXIS IS GENERATING SCATTERED SHOWERS AND TSTMS FROM 12N-18N BETWEEN 54W-67W. THE STRONGEST OF THIS ACTIVITY IS OCCURRING PRIMARILY ACROSS AND DIRECTLY EAST OF MARTINIQUE FROM 15N61W TO 15N57W. HISPANIOLA... CURRENTLY CONDITIONS ARE GENERALLY FAIR WITH ONLY SCATTERED CLOUDINESS ACROSS THE ISLAND. AN UPPER LEVEL LOW IS CENTERED OVER WESTERN PORTIONS NEAR 19N70W THAT CONTINUES TO DRIFT WESTWARD. WITH PEAK HEATING AND INSTABILITY YET TO OCCUR THIS AFTERNOON AND EVENING...MIDDLE TO UPPER LEVEL LIFT ASSOCIATED WITH THE UPPER LEVEL LOW WILL LIKELY STRENGTHEN ANY SURFACE BASED OR ELEVATED CONVECTION THAT INITIATES THIS AFTERNOON. LOOKING AHEAD TO THE NEXT FEW DAYS...A TROPICAL WAVE ALONG 61W IS FORECAST TO REACH HISPANIOLA BY LATE TUESDAY BRINGING WITH IT INCREASED CHANCE FOR PRECIPITATION AND SIGNIFICANT DEEP CONVECTION. ATLANTIC OCEAN... MIDDLE TO UPPER LEVEL MOISTURE CONTINUES TO ADVECT NORTHWARD BETWEEN AN UPPER LEVEL TROUGH AXIS EXTENDING FROM 30N79W TO 22N87W AND AN UPPER LEVEL ANTICYCLONE CENTERED NEAR 26N71W. WHILE WEAK SURFACE RIDGING IS IN PLACE ACROSS THE SW NORTH ATLC ANCHORED BY AS 1019 MB HIGH CENTERED NEAR 27N66W...THE MIDDLE TO UPPER LEVEL DYNAMICS ARE STRONG ENOUGH THIS AFTERNOON TO GENERATE WIDELY SCATTERED SHOWERS AND ISOLATED TSTMS FROM 23N- 29N BETWEEN 71W-80W. TO THE NE OF THE HIGH...A MIDDLE TO UPPER LEVEL SHORTWAVE TROUGH IS NOTED ON WATER VAPOR IMAGERY IN THE VICINITY OF 33N63W THAT SUPPORTS A 1015 MB LOW CENTERED NEAR 33N60W WITH AN ASSOCIATED COLD FRONT EXTENDING SW TO 29N63W. A PRE-FRONTAL SURFACE TROUGH IS ANALYZED FROM THE COLD FRONT NEAR 29N62W TO 27N64W WITH SCATTERED SHOWERS AND ISOLATED TSTMS OCCURRING FROM 25N-29N BETWEEN 60W-64W...AND WITHIN 60 NM EAST OF THE COLD FRONT. OTHERWISE THE REMAINDER OF THE CENTRAL AND EASTERN ATLC IS UNDER THE INFLUENCE OF A SURFACE RIDGE ANCHORED BY A 1021 MB HIGH CENTERED NEAR 34N45W. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ HUFFMAN