000 AXNT20 KNHC 271800 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 205 PM EDT SAT SEP 27 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 IS IN THE E ATLANTIC WITH AXIS EXTENDING FROM 16N23W TO 5N24W MOVING W AT 15 KT. THE SSMI TPW AND WATER VAPOR IMAGERY SHOW PATCHES OF HIGH DEEP LAYER MOISTURE COINCIDING WITH A REGION OF MIDDLE TO UPPER LEVEL DIFFLUENCE THAT ENHANCES SCATTERED MODERATE CONVECTION AND ISOLATED CONVECTION FROM 11N- 14N BETWEEN 23W-28W. THE GOES-R AIRMASS PRODUCT SHOW MIDDLE TO UPPER LEVEL DRY AIR IN THE REMAINDER WAVE ENVIRONMENT...WHICH IS DEVOID OF CONVECTION. A TROPICAL WAVE IS IN THE CENTRAL CARIBBEAN WITH AXIS EXTENDING FROM 22N70W TO 11N70W...MOVING WESTWARD AT 15 KT. THE WAVE IS BEING SUPPORTED BY A MIDDLE LEVEL INVERTED TROUGH AND AN UPPER LEVEL LOW WHICH ALONG DEEP LAYER MODERATE MOISTURE SUPPORT SCATTERED MODERATE CONVECTION FROM 13N-22N BETWEEN 58W-73W. A TROPICAL WAVE IS MOVING ACROSS THE BAY OF CAMPECHE...SOUTHERN MEXICO AND E PAC WATERS WITH AXIS EXTENDING FROM 24N93W TO 10N93W...MOVING W AT 10 TO 15 KT. A MIDDLE-LEVEL INVERTED TROUGH SUPPORT THIS WAVE WHILE DEEP LAYER HIGH MOISTURE AND AN UPPER- LEVEL DIVERGENT ENVIRONMENT ENHANCE SCATTERED MODERATE CONVECTION AND ISOLATED TSTMS S OF 17N BETWEEN 89W AND 97W. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS FROM THE AFRICAN COAST NEAR 8N13W TO 7N24W TO 6N33W. THE ITCZ EXTENDS FROM 6N34W TO 6N47W. ISOLATED MODERATE CONVECTION IS FROM 2N-9N BETWEEN 26W-35W. ...DISCUSSION... GULF OF MEXICO... A STATIONARY FRONT EXTENDS ACROSS NORTHERN FLORIDA AND THEN IN THE NORTHERN GULF ALONG 29N83W TO 28N90W TO 25N96W. IN THE UPPER- LEVELS THE EASTERN PERIPHERY OF A RIDGE ANCHORED OVER MEXICO COVERS THE SOUTHERN GULF WHILE THE WESTERN PERIPHERY OF A RIDGE ANCHORED ON CENTRAL FLORIDA IS OVER THE REMAINDER GULF. THIS RIDGE ARRANGEMENT IN THE UPPER LEVELS IS GENERATING A DIFFLUENT ENVIRONMENT THAT ALONG DEEP LAYER HIGH MOISTURE SUPPORT SCATTERED MODERATE CONVECTION AND TSTMS N OF 24N BETWEEN 83W-90W AND WITHIN 100 NM EITHER SIDE OF THE FRONT W OF 90W. IN THE SW GULF...A MIDDLE-LEVEL INVERTED TROUGH SUPPORT A TROPICAL WAVE. SEE THE TROPICAL WAVES SECTION FOR MORE DETAILS. THE FRONT IS FORECAST TO TRANSITION INTO A WARM FRONT AND BE OVER THE NORTHERN GULF COASTLINE BY SUNDAY MORNING WHILE THE WAVE CONTINUES TO MOVE ACROSS THE E PAC WATERS LEAVING SHOWERS INLAND MEXICO. CARIBBEAN SEA... AN ELONGATED UPPER-LEVEL LOW IS CENTERED ON THE MONA PASSAGE EXTENDING A TROUGH AXIS SW INTO THE SW CARIBBEAN WHILE NE WIND FLOW COVERS THE REMAINDER WESTERN BASIN. THE LOW ALOFT SUPPORT A TROPICAL WAVE AND ASSOCIATED CONVECTION. SEE THE TROPICAL WAVES SECTION FOR MORE DETAILS. OTHERWISE...A WEAK PRESSURE GRADIENT ACROSS THE REGION SUPPORT TRADES OF 10-15 KT. THE TROPICAL WAVE IS FORECAST TO MOVE ACROSS THE YUCATAN PENINSULA BY MONDAY NIGHT. ...HISPANIOLA... SCATTERED SHOWERS AND THUNDERSTORMS CONTINUE OVER HISPANIOLA AND OFFSHORE WATERS AS AN UPPER LOW INTERACTS WITH A TROPICAL WAVE MOVING ACROSS THE ISLAND. SHOWERS AND THUNDERSTORMS ARE EXPECTED TO CONTINUE OVER THE WEEKEND AS THE UPPER LOW REMAINS NEARLY STATIONARY WHILE THE TROPICAL WAVE CONTINUES TO MOVE WESTWARD. ATLANTIC OCEAN... A STATIONARY FRONT IS ANALYZED FROM 30N79W TO 29N81W...ACROSS NORTHERN FLORIDA INTO THE NORTHERN GULF. SCATTERED SHOWERS ARE N OF 29N W OF 80W. THIS FRONT IS EXPECTED TO GRADUALLY DISSIPATE OVER THE WEEKEND. AN UPPER-LEVEL TROUGH IS OVER THE CENTRAL ATLC SUPPORT THREE LOW PRESSURE CENTERS WITH LITTLE TO NONE CONVECTION ASSOCIATED WITH IT...A 1015 MB LOW NEAR 29N47W...A 1015 MB LOW NEAR 23N36W AND A 1013 MB LOW NEAR 13N43W. OTHERWISE...TWO TROPICAL WAVES ARE AFFECTING THE BASIN. SEE THE TROPICAL WAVES SECTION. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ NR