000 AXNT20 KNHC 302338 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 805 PM EDT FRI AUG 30 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 2315 UTC. ...SPECIAL FEATURES... TROPICAL WAVE EXTENDS FROM 10N16W TO 20N16W MOVING W AT 5 KT. A 1008 MB LOW IS CENTERED ALONG THE WAVE AXIS NEAR 14N16W. ALTHOUGH THIS WAVE HAS YET TO FULLY EMERGE OFF THE COAST OF WEST AFRICA...IT DISPLAYS PLENTY OF SURFACE TO 700 MB VORTICITY WITH A MAXIMUM IN THE VICINITY OF THE SURFACE LOW AND AREAS TO THE NORTHWEST TO NEAR 17N19W. SCATTERED MODERATE AND ISOLATED STRONG CONVECTION IS FROM 13N-16N BETWEEN 16W-19W...WITH ISOLATED MODERATE CONVECTION ELSEWHERE FROM 06N-12N BETWEEN 08W-18W...AND FROM 12N-17N BETWEEN 15W-23W. ...TROPICAL WAVES... TROPICAL WAVE EXTENDS FROM 09N51W TO 19N50W MOVING W AT 10-15 KT. A WEAK AND BROAD 1011 MB LOW IS CENTERED ALONG THE WAVE AXIS NEAR 12N51W THAT LACKS CONVECTION AT THIS TIME. ACTIVE CONVECTION WITH THE WAVE IS WELL REMOVED FROM THE LOW CENTER TO THE NE AS WIDELY SCATTERED MODERATE CONVECTION IS FROM 14N-19N BETWEEN 42W-50W IN THE AREA OF MAXIMUM LOW-LEVEL MOISTURE CONVERGENCE. TROPICAL WAVE EXTENDS FROM 11N73W TO 22N70W MOVING W-NW AT 10-15 KT. OVERALL THE WAVE COINCIDES WITH WEAK SURFACE TO 700 MB LOW- LEVEL TROUGHING...HOWEVER SOME OF THE ENERGY ASSOCIATED WITH THE WAVE CONTINUES TO FRACTURE AWAY TO THE NORTH-NORTHWEST AS A MID- LATITUDE TROUGH IS LOCATED TO THE NORTH OVER THE SW NORTH ATLC. SCATTERED MODERATE CONVECTION IS OCCURRING ACROSS NORTHERN VENEZUELA FROM 10N-12N BETWEEN 70W-74W...AND ACROSS HISPANIOLA FROM 17N-20N BETWEEN 67W-73W. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS FROM THE AFRICAN COAST NEAR 13N17W TO 11N22W TO 10N40W. ISOLATED MODERATE CONVECTION IS FROM 04N-08N BETWEEN 28W-36W. ...DISCUSSION... GULF OF MEXICO... WATER VAPOR IMAGERY INDICATES NORTHERLY UPPER LEVEL FLOW DOMINATES ACROSS MUCH OF THE GULF THIS EVENING WITH RELATIVELY DRY AND STABLE CONDITIONS ALOFT W OF 84W. THIS OVERALL STABILITY IS SUPPORTING A 1017 MB HIGH CENTERED IN THE VICINITY OF THE MISSISSIPPI RIVER DELTA REGION NEAR 29N90W THAT IS PROVIDING MUCH OF THE BASIN WITH ANTICYCLONIC WINDS GENERALLY LESS THAN 20 KT. THE ONLY AREA OF INTERESTING WEATHER THIS EVENING IS ASSOCIATED WITH A MIDDLE TO UPPER LEVEL LOW CENTERED OVER THE FLORIDA STRAITS NEAR 24N81W. THIS UPPER LEVEL LOW IS GENERATING ISOLATED SHOWERS AND TSTMS FROM 26N-28N BETWEEN 81W- 84W...INCLUDING PORTIONS OF THE INTERIOR CENTRAL FLORIDA PENINSULA. LOOKING AHEAD...THE GULF IS EXPECTED TO REMAIN FAIRLY TRANQUIL THIS WEEKEND WITH DRY AIR AND STABILITY ALOFT...AND A SURFACE RIDGE ANCHORED OVER EASTERN PORTIONS THROUGH THE UPCOMING WEEKEND. THE RIDGE AXIS IS FORECAST ALONG 26N/27N WITH GENERALLY LIGHT E-SE WINDS SOUTH OF THE AXIS. CARIBBEAN SEA... MIDDLE TO UPPER LEVEL TROUGHING DIPS SOUTHWARD OVER PORTIONS OF THE WESTERN CARIBBEAN N OF 16N BETWEEN 77W-85W. WITH A WEAKNESS IN THE SURFACE PRESSURE PATTERN EXTENDING FROM THE SW NORTH ATLC AND THE OVERALL MID-LEVEL LIFTING DYNAMICS...WIDELY SCATTERED SHOWERS AND ISOLATED TSTMS ARE OCCURRING N OF 17N BETWEEN 71W- 86W. THIS AREA OF CONVECTION REMAINS MOST ACTIVE IN THE VICINITY OF THE GREATER ANTILLES ACROSS JAMAICA...HISPANIOLA...AND CUBA. FARTHER WEST...SCATTERED SHOWERS AND TSTMS ARE OCCURRING ACROSS INTERIOR PORTIONS OF THE YUCATAN PENINSULA...WESTERN HONDURAS... AND GUATEMALA. TO THE SOUTH...THE MONSOON TROUGH AXIS EXTENDING ALONG 10N EXTENDING FROM NORTHERN COLOMBIA TO COSTA RICA WITH WIDELY SCATTERED SHOWERS AND ISOLATED TSTMS OCCURRING S OF 13N BETWEEN 70W-85W. LASTLY...UPPER LEVEL TROUGHING IS NOTED ON WATER VAPOR IMAGERY OVER THE EASTERN CARIBBEAN E OF 72W. LOW- LEVEL MOISTURE CONVERGENCE WITHIN THE EASTERLY TRADES ALONG WITH MIDDLE TO UPPER LEVEL LIFT IS GENERATING WIDELY SCATTERED SHOWERS AND ISOLATED SHOWERS GENERALLY EAST OF A LINE FROM HISPANIOLA NEAR 18N73W TO NE VENEZUELA NEAR 10N65W. THE MOST INTENSE CONVECTION THIS EVENING IS NOTED OVER HISPANIOLA IN ASSOCIATION WITH THE TROPICAL WAVE ALONG 72W AND ACROSS PORTIONS OF NE VENEZUELA S OF 11N BETWEEN 60W-65W. HISPANIOLA... CURRENTLY SCATTERED SHOWERS AND TSTMS REMAIN ACROSS WESTERN PORTIONS OF THE ISLAND DUE TO PEAK DAYTIME HEATING... INSTABILITY...AND A TROPICAL WAVE ANALYZED ACROSS THE ISLAND ALONG 71W. THIS ACTIVITY IS EXPECTED TO GRADUALLY DIMINISH SOMEWHAT OVER THE NEXT FEW HOURS DUE TO THE LOSS OF DAYTIME HEATING...HOWEVER THE TROPICAL WAVE...AS IT CONTINUES TO MOVE OFF TO THE WEST...WILL CONTINUE TO GENERATE ISOLATED SHOWERS AND TSTMS THROUGH THE OVERNIGHT HOURS. WATER VAPOR IMAGERY INDICATES AN UPPER LEVEL ANTICYCLONE IS CENTERED SOUTHWEST OF THE ISLAND NEAR 17N77W AND UPPER LEVEL TROUGHING DOMINATES E OF 72W PROVIDING FOR PRIMARILY NORTHERLY FLOW ALOFT. MOISTURE CONTINUES TO ADVECT SOUTHWARD FROM THE SW NORTH ATLC REGION ACROSS THE GREATER ANTILLES THAT WILL SUSTAIN MOISTURE AND CONVECTIVE ACTIVITY ACROSS HISPANIOLA ON SATURDAY AND SUNDAY. ATLANTIC OCEAN... A MIDDLE TO UPPER LEVEL LOW IS CENTERED OVER THE FLORIDA KEYS NEAR 24N81W THAT SUPPORTS A SURFACE TROUGH EXTENDING FROM 25N80W TO 28N81W WITH ISOLATED SHOWERS OCCURRING FROM 23N-28N BETWEEN 74W-78W. STRONGER CONVECTION IS LOCATED OVER INTERIOR PORTIONS OF CUBA THIS EVENING. FARTHER EAST...OVER THE REMAINDER OF THE SW NORTH ATLC...MID-LEVEL TROUGHING IS NOTED ON WATER VAPOR IMAGERY BETWEEN 60W-80W AND IS PROVIDING AN OVERALL UNSTABLE ENVIRONMENT. A STATIONARY FRONT EXTENDS ALONG 32N BETWEEN 70W- 81W WITH THE ASSOCIATED SURFACE TROUGHING DIPPING SOUTHWARD TO 27N AND A TROPICAL WAVE ALONG 72W EXTENDING NORTHWARD FROM CENTRAL HISPANIOLA TO 22N70W THAT IS PROVIDING A BROAD AREA OF WIDELY SCATTERED SHOWERS AND ISOLATED TSTMS FROM 21N-32N BETWEEN 59W-80W. ASIDE FROM THE TROPICAL WAVE PROGRESSING WESTWARD S OF 20N ALONG 51W...A SURFACE RIDGE INFLUENCES THE REMAINDER OF THE CENTRAL AND EASTERN ATLC ANCHORED BY A 1024 MB HIGH CENTERED NEAR 33N46W AND A 1029 MB HIGH CENTERED NORTH OF THE AZORES NEAR 43N24W. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ HUFFMAN