000 AXNT20 KNHC 141802 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 205 PM EDT THU AUG 14 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1745 UTC. ...TROPICAL WAVES... A TROPICAL WAVE CAME OFF THE WEST AFRICAN COAST EARLIER THIS MORNING. CURRENTLY...ITS AXIS EXTENDS FROM 17N17W TO 9N16W WITH AN EXPECTED MOTION OF 15 KT IN THE NEXT 24 HOURS. THE WAVE IS EMBEDDED IN THE MONSOON TROUGH WHERE DEEP LAYER MOISTURE AND UPPER-LEVEL DIFFLUENCE SUPPORT SCATTERED MODERATE CONVECTION FROM 6N-16N E OF 20W. A TROPICAL WAVE IS ON THE EASTERN ATLC WITH AXIS EXTENDING FROM 17N27W TO A 1012 MB LOW NEAR 11N27W TO 7N27W...MOVING W AT 10 KT. METEOSAT PSEUDO NATURAL AND SAL TRACKING IMAGERY INDICATE SAHARAN DUST AND DRY AIR IN THE WAVE ENVIRONMENT N OF THE LOW CENTER...WHICH IS SUPPRESSING CONVECTION IN THE NORTHERN AND CENTRAL PORTIONS OF THE WAVE. SCATTERED MODERATE CONVECTION IS MOSTLY LIMITED S OF THE MONSOON TROUGH FROM 5N-12N BETWEEN 25W- 34W. A TROPICAL WAVE IS WEST OF THE MONSOON TROUGH WITH AXIS EXTENDING FROM 17N47W TO 9N48W...MOVING W AT 20 KT. MODERATE MOISTURE IS ASSOCIATED WITH THIS WAVE AT THE LOWER LEVELS. HOWEVER...STRONG DRY AIR SUBSIDENCE ALOFT SUPPRESS CONVECTION. ISOLATED SHOWERS ARE WITHIN 340 NM W OF THE WAVE AXIS FROM 11N- 17N. A TROPICAL WAVE IS MOVING ACROSS THE YUCATAN PENINSULA AND CENTRAL AMERICA WITH AXIS EXTENDING FROM 19N88W TO 9N89W...MOVING W AT 15 KT. THERE IS NO DEEP CONVECTION ASSOCIATED WITH THIS WAVE. ISOLATED SHOWERS ARE OVER BELIZE AND GUATEMALA. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS FROM THE WEST AFRICAN COAST NEAR 12N16W TO 11N27W 9N38W TO 7N47W. THE INTERTROPICAL CONVERGENCE ZONE AXIS BEGINS W OF A TROPICAL WAVE NEAR 10N51W AND CONTINUES TO 9N61W. BESIDES THE CONVECTION ASSOCIATED WITH THE TROPICAL WAVES...SCATTERED MODERATE CONVECTION IS WITHIN 115 NM S OF THE MONSOON TROUGH BETWEEN 38W-48W. ...DISCUSSION... GULF OF MEXICO... A MIDDLE TO UPPER LEVEL TROUGH CONTINUES ACROSS THE EASTERN CONUS WITH BASE EXTENDING INTO THE NORTHERN GULF COASTLINE. THIS TROUGH ALOFT SUPPORTS A FRONTAL SYSTEM ANALYZED AS A STATIONARY FRONT FROM 30N82W SW TO 28N91W TO SOUTHERN TEXAS NEAR 27N97W. A SURFACE PRE-FRONTAL TROUGH EXTENDS FROM NORTHERN FLORIDA NEAR 30N82W SW TO 27N90W TO 25N95W. SCATTERED HEAVY SHOWERS AND TSTMS ASSOCIATED WITH THESE FEATURES ARE N OF 24N E OF 96W. SIMILAR CONVECTION IS ON THE SE GULF N OF 23N E OF 85W BEING ENHANCED BY LOW-LEVEL MOISTURE CONVERGENCE ALONG THE WESTERN FLORIDA COAST. A MIDDLE-LEVEL INVERTED TROUGH IS OVER THE WESTERN GULF WHICH SUPPORTS A SURFACE TROUGH ALONG 22N95W TO 18N94W AS WELL AS SCATTERED MODERATE CONVECTION AND TSTMS S OF 24N W OF 92W. WEAK SURFACE RIDGING DOMINATES ELSEWHERE ACROSS THE BASIN AND PROVIDES VARIABLE WINDS OF 5-10 KT. THE STATIONARY FRONT IS FORECAST TO DISSIPATE BY FRIDAY MORNING. SURFACE RIDGING WILL DOMINATE ELSEWHERE FOR THE REST OF THE WEEKEND. CARIBBEAN SEA... THE TROPICAL WAVE FORMERLY ON THE FAR WESTERN CARIBBEAN IS NOW MOVING ACROSS THE YUCATAN PENINSULA AND CENTRAL AMERICA. SEE TROPICAL WAVE SECTION ABOVE. AN ELONGATED UPPER-LEVEL LOW IS ON THE NW CARIBBEAN WHICH ALONG MODERATE DEEP LAYER MOISTURE SUPPORT SCATTERED SHOWERS FROM 18N-20N BETWEEN 80W-86W. DEEP LAYER MOISTURE IS ON THE SW BASIN WHICH ALONG UPPER LEVEL DIFFLUENCE SUPPORT SCATTERED HEAVY SHOWERS AND TSTMS S OF 15N W OF 78W. FARTHER EAST...A 1011 MB LOW IS OFF THE COAST OF COLOMBIA NEAR 9N76W SUPPORTING SCATTERED SHOWERS S OF 13N BETWEEN 73W-78W. ELSEWHERE...DRY AIR AND DUST ASSOCIATED WITH A SAHARAN AIRMASS SUPPORT HAZE. A TIGHT PRESSURE GRADIENT ACROSS THE CENTRAL AND SW CARIBBEAN SUPPORT TRADES OF 20-25 KT WITH WINDS UP TO 30 KT ALONG THE COAST OF COLOMBIA. ELSEWHERE...TRADES OF 10-15 KT DOMINATE. A NEW TROPICAL WAVE ENTERS THE E BASIN SATURDAY MORNING. HISPANIOLA... MOSTLY DEEP LAYER DRY AIR IS ACROSS THE ISLAND WHICH IS PROVIDING AN OVERALL STABLE ENVIRONMENT. A DRY SAHARAN AIRMASS WILL CONTINUE TO MOVE ACROSS THE ISLAND THROUGH SATURDAY AFTERNOON THUS SUPPORTING FAIR WEATHER BUT SOME HAZINESS. ATLANTIC OCEAN... A MIDDLE TO UPPER LEVEL TROUGH CONTINUES ACROSS THE EASTERN CONUS AND FAR WESTERN ATLC SUPPORTING A COLD FRONT N OF THE AREA OF DISCUSSION AND A PRE-FRONTAL TROUGH EXTENDING FROM 32N73W TO 29N77W...ACROSS THE NORTHERN BAHAMAS TO 24N78W. HEAVY SHOWERS AND TSTMS ASSOCIATED WITH THESE FEATURES ARE N OF 28N BETWEEN 74W-78W. SIMILAR CONVECTION IS NOTED FROM 22N-27N BETWEEN 74W- 78W AND FROM 24N-28N BETWEEN 64W-73W. THE CENTRAL AND EASTERN ATLC ARE UNDER THE INFLUENCE OF A SURFACE RIDGE ANCHORED BY A 1020 MB HIGH CENTERED NEAR 25N61W AND A PAIR OF HIGHS NEAR N-NE OF THE AZORES ISLANDS. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ NR