000 AXNT20 KNHC 240004 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 805 PM EDT TUE SEP 23 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. ...TROPICAL WAVES... A TROPICAL WAVE IS ON THE EASTERN ATLC WITH AXIS EXTENDING FROM 22N27W TO A 1011 MB LOW NEAR 17N28W TO 12N29W...MOVING W AT 10 KT. THE GOES-R SEVIRI AIRMASS PRODUCT DEPICT WARM DRY AIR IN THE WAVE ENVIRONMENT...ALSO CONFIRMED IN THE METEOSAT SAL AND THE SSMI TPW IMAGERY. SAHARAN DUST IS ALSO IN THE NORTHERN AND WESTERN WAVE ENVIRONMENT AS DEPICTED IN THE GOES-R DUST PRODUCT. AS A RESULT CONVECTION REMAINS MINIMAL AND NE OF THE WAVE AXIS AS SCATTERED MODERATE WITH ISOLATED TSTMS FROM 17N-23N BETWEEN 21W-27W. A TROPICAL WAVE IS ON THE CENTRAL ATLC WITH AXIS EXTENDING FROM 19N48W TO 10N50W...MOVING W AT 15-20 KT. THE GOES-R SEVIRI AIRMASS PRODUCT DEPICT DRY CONDITIONS AT HIGH LEVELS IN THE CENTRAL AND SOUTHERN WAVE ENVIRONMENT...WHICH SUBSIDENCE IS SUPPRESSING CONVECTION. METEOSAT SAL TRACKING IMAGERY ALSO SHOW SAHARAN DRY AIR IN THE NORTHERN WAVE ENVIRONMENT...HOWEVER THE GOES-R DUST PRODUCT SHOW MINIMAL DUST IN THE WAVE. A TROPICAL WAVE IS MOVING ACROSS THE CENTRAL CARIBBEAN WITH AXIS EXTENDING FROM 23N71W TO 12N70W...MOVING W AT 15 KT. HIGH MIDDLE TO LOWER LEVELS MOISTURE IS BEHIND THE WAVE AXIS ACROSS THE EASTERN CARIBBEAN WHILE DEEP LEVEL MOISTURE IS ACROSS HISPANIOLA. HEAVY SHOWERS AND TSTMS ARE ACROSS HISPANIOLA WHILE SCATTERED MODERATE CONVECTION AND ISOLATED TSTMS ARE E OF THE WAVE AXIS ACROSS THE BASIN...INCLUDING THE LEEWARD ISLANDS. A TROPICAL WAVE IS MOVING ACROSS THE YUCATAN PENINSULA AND CENTRAL AMERICA WITH AXIS EXTENDING FROM 21N90W TO 12N87W. THE WAVE IS ASSOCIATED WITH MODERATE MIDDLE TO UPPER-LEVEL MOISTURE BUT HIGH MOISTURE IN THE UPPER LEVEL AS DEPICTED IN WATER VAPOR IMAGERY. UPPER LEVEL DIFFLUENCE EAST OF THE BASE OF AN UPPER LEVEL TROUGH EXTENDING ACROSS THE EASTERN GULF TO THE YUCATAN SUPPORT SCATTERED MODERATE CONVECTION AND TSTMS ACROSS THE YUCATAN PENINSULA AND CHANNEL AS WELL AS NORTHERN CENTRAL AMERICA. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS FROM THE AFRICAN COAST NEAR 17N16W TO A 1012 MB LOW CENTERED NEAR 10N21W TO 8N24W. IT THEN RESUMES NEAR 13N30W TO 11N37W. THE INTERTROPICAL CONVERGENCE ZONE AXIS EXTENDS FROM 11N37W TO 12N44W TO 08N52W. ASIDE FROM CONVECTION OCCURRING WITH THE TROPICAL WAVES...SCATTERED MODERATE CONVECTION AND ISOLATED TSTMS ARE FROM 4N-15N BETWEEN 20W- 28W...AND FROM 12N-16N BETWEEN 40W-45W. ...DISCUSSION... GULF OF MEXICO... A MIDDLE TO UPPER LEVEL LOW IS ON THE CAROLINAS EXTENDING A TROUGH ACROSS THE FLORIDA PENINSULA AND EASTERN GULF AND SUPPORTING A FRONTAL BOUNDARY ANALYZED AS A COLD FRONT ON THE SW N ATLC TO THE EASTERN COAST OF CENTRAL FLORIDA. FROM THERE THE FRONT TRANSITIONS TO A STATIONARY BOUNDARY FROM 27N82W SW TO THE CENTRAL GULF NEAR 25N90W TO 24N92W. SCATTERED MODERATE CONVECTION AND ISOLATED TSTMS ARE WITHIN 100 NM EITHER SIDE OF THE FRONT. A TROPICAL WAVE IS MOVING ACROSS THE YUCATAN PENINSULA AND NORTHERN CENTRAL AMERICA ENHANCING SIMILAR CONVECTION IN THAT REGION AND IN THE YUCATAN CHANNEL. OTHERWISE...A BROAD SURFACE HIGH PRESSURE ON THE NE CONUS EXTENDS A RIDGE S-SW TO THE N AND WESTERN GULF WHERE DRY AIR SUBSIDENCE INHIBITS CONVECTIVE ACTIVITY. THE STATIONARY FRONT WILL WEAKEN BUT PREVAIL ACROSS THE FLORIDA PENINSULA THROUGH FRIDAY MORNING WHILE THE TROPICAL WAVE MOVES ACROSS THE BAY OF CAMPECHE ENHANCING SHOWERS. CARIBBEAN SEA... DEEP LAYER TRAILING MOISTURE ASSOCIATED WITH THE PASSAGE OF A TROPICAL WAVE CONTINUES TO ENHANCE SCATTERED SHOWERS AND ISOLATED TSTMS ACROSS THE WESTERN BASIN W OF 73W. A TROPICAL WAVE IS ON THE CENTRAL CARIBBEAN WITH AXIS ALONG 71W WITH HIGH MIDDLE TO LOWER LEVELS TRAILING MOISTURE SUPPORTING SCATTERED SHOWERS AND ISOLATED TSTMS E OF THE AXIS. HOWEVER A REGION OF DIFFLUENCE ALOFT IS SUPPORTING HEAVY SHOWERS AND TSTMS ACROSS HISPANIOLA AND ADJACENT WATERS. THIS WAVE WILL CONTINUE TO BRING SHOWERS TO HISPANIOLA THROUGH THURSDAY. THE NEXT TROPICAL WAVE WILL ENTER THE EASTERN CARIBBEAN FRIDAY MORNING. ...HISPANIOLA... CURRENTLY...A TROPICAL WAVE LIES ALONG 71W BRINGING HEAVY SHOWERS AND TSTMS ACROSS THE ISLAND AND ADJACENT WATERS. CONVECTIVE ACTIVITY ASSOCIATED WITH THE WAVE IS FORECAST THROUGH WED. ATLANTIC OCEAN... AN ELONGATED MIDDLE TO UPPER LEVEL TROUGH IS OVER THE EASTERN CONUS SUPPORTING A FRONTAL BOUNDARY ANALYZED AS A COLD FRONT ALONG 30N78W TO THE EASTERN COAST OF CENTRAL FLORIDA WHERE IT TRANSITIONS INTO A STATIONARY FRONT ACROSS THE NE GULF OF MEXICO. SCATTERED MODERATE CONVECTION AND TSTMS ARE OCCURRING N OF 26N W OF 77W. FARTHER EAST...AN UPPER LEVEL LOW IS CENTERED NEAR 25N55W THAT SUPPORTS A BROAD AREA OF CLOUDINESS WITH EMBEDDED AREAS OF ISOLATED SHOWERS AND TSTMS OCCURRING FROM 23N- 30N BETWEEN 50W-60W. A MIDDLE TO UPPER LEVEL TROUGH ACROSS THE REMAINDER CENTRAL AND EASTERN ATLC SUPPORT A SURFACE TROUGH ALONG 29N30W TO 28N37W TO 26N43W WITH SCATTERED SHOWERS OCCURRING FROM 28N-31W BETWEEN 27W-31W. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ NR