000 AXNT20 KNHC 261748 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 205 PM EDT FRI SEP 26 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 1715 UTC. ...TROPICAL WAVES... TROPICAL WAVE IN THE E CARIBBEAN EXTENDS ALONG 65W FROM 12N OVER THE VIRGIN ISLANDS TO 22N MOVING W NEAR 15 KT OVER THE PAST 24 HOURS. WAVE IS EMBEDDED WITHIN A SURGE OF DEEP MOISTURE AS DEPICTED ON TOTAL PRECIPITABLE WATER IMAGERY. THIS WAVE IS MOVING BENEATH AN UPPER LOW THAT IS CENTERED OVER PUERTO RICA WHICH IS GENERATING THE ACTIVITY IN THE VICINITY OF THE WAVE. TROPICAL WAVE IS EXITING THE W CARIBBEAN AND IS OVER THE YUCATAN PENINSULA FROM 21N87W TO OVER EL SALVADOR NEAR 13N89W MOVING W NEAR 20 KT OVER THE PAST 24 HOURS. THIS WAVE IS MOVING W OF AN UPPER RIDGE WITH SCATTERED STRONG CONVECTION IN THE GULF OF HONDURAS S OF 18N W OF 87W TO INLAND OVER BELIZE. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS OVER AFRICA INTO THE TROPICAL ATLC NEAR 21N16W AND CONTINUES OVER THE CAPE VERDE ISLANDS ALONG 16N23W THEN 13N29W THROUGH A 1013 MB LOW NEAR 13N42W TO 11N48W. SCATTERED MODERATE CONVECTION IS FROM 3N-6N BETWEEN 12W-17W. ISOLATED MODERATE CONVECTION IS WITHIN 75 NM EITHER SIDE OF THE MONSOON TROUGH BETWEEN 40W-46W. ...DISCUSSION... GULF OF MEXICO... A BROAD UPPER TROUGH IS OVER THE CENTRAL PLAIN STATES FROM THE UPPER MISSISSIPPI VALLEY TO W TEXAS GIVING THE GULF W-SW FLOW ALOFT. AN UPPER RIDGE OVER THE NW CARIBBEAN AND THE FAR SW GULF OF MEXICO IS PROVIDING DIFFLUNCE ALOFT TO GENERATE SCATTERED SHOWERS/ISOLATED THUNDERSTORMS ACROSS THE GULF FROM 24N-29N. THIS ACTIVITY IS FURTHER ENHANCED BY A QUASI-STATIONARY FRONT ACROSS CENTRAL FLORIDA BETWEEN MELBOURNE AND TAMPA BAY TO 27N85W WHERE IT DISSIPATES ALONG 25N86W TO 24N88W AND A SURFACE TROUGH OVER THE W GULF FROM 29N94W 27N96W TO 24N97W. SCATTERED SHOWERS/ ISOLATED THUNDERSTORMS ARE S OF 22N TO OVER THE YUCATAN PENINSULA AND INTO THE YUCATAN CHANNEL DUE TO THE TROPICAL WAVE MOVING OVER THE YUCATAN. THE FRONT WILL DRIFT N AND DISSIPATE THROUGH TONIGHT. CARIBBEAN SEA... AN UPPER RIDGE OVER THE NW CARIBBEAN COVERS THE AREA W OF 82W AND IS PROVIDING DIFFLUNCE ALOFT TO GENERATE SCATTERED SHOWERS/ ISOLATED THUNDERSTORMS FROM 15N-22N W OF 80W TO INLAND OVER HONDURAS AND THE YUCATAN PENINSULA. AN UPPER LOW IS CENTERED OVER PUERTO RICO WITH THE RESULTING UPPER TROUGH DOMINATING THE REMAINDER OF THE CARIBBEAN AND THE TROUGH AXIS EXTENDING TO COLOMBIA. SCATTERED TO NUMEROUS SHOWERS/SCATTERED THUNDERSTORMS ARE N OF 14N BETWEEN 59N-70W INCLUDING THE LEEWARD ISLANDS FROM DOMINICA TO OVER THE VIRGIN ISLANDS AND PUERTO RICO. THIS UPPER TROUGH IS GENERATING A SECOND AREA OF ACTIVITY WITH SCATTERED TO NUMEROUS SHOWERS/SCATTERED THUNDERSTORMS S OF 12N E OF 80W TO INLAND OVER PANAMA AND COLOMBIA WITH SCATTERED SHOWERS/ISOLATED THUNDERSTORMS S OF 14N BETWEEN 70W-76W. TROPICAL WAVE IN THE E CARIBBEAN WILL REACH THE CENTRAL CARIBBEAN TONIGHT AND THE W CARIBBEAN SAT. ...HISPANIOLA... CURRENTLY SKIES ARE RELATIVELY CLEAR ACROSS THE ISLAND. HOWEVER...THE ABUNDANCE OF MOISTURE ACCOMPANYING THE TROPICAL WAVE AND THE UPPER LOW OVER PUERTO RICO WILL BE MOVING W FROM OVER THE VIRGIN ISLANDS SPREADING SHOWERS ACROSS PUERTO RICO AND THE MONA PASSAGE THIS AFTERNOON THEN ACROSS HISPANIOLA THROUGH THE WEEKEND. ATLANTIC OCEAN... A NARROW UPPER TROUGH EXTENDS ALONG THE SE U.S. COAST FROM NORTH CAROLINA TO FLORIDA SUPPORTING A WEAK 1016 MB LOW OFF THE COAST OF SOUTH CAROLINA WITH A QUASI-STATIONARY FRONT ENTERING THE REGION THROUGH 32N78W THEN ACROSS FLORIDA NEAR MELBOURNE CONTINUING INTO THE GULF OF MEXICO. SCATTERED SHOWERS/ISOLATED THUNDERSTORMS ARE WITHIN 90 NM EITHER SIDE OF THE FRONT. THE UPPER LOW OVER PUERTO RICO COVERS THE SW ATLC GENERATING SCATTERED TO NUMEROUS SHOWERS/SCATTERED THUNDERSTORMS FROM 15N- 19N W OF 50W ACROSS THE LESSER ANTILLES WITH SCATTERED SHOWERS/ ISOLATED THUNDERSTORMS FROM 19N-22N BETWEEN 59W-68W. AN UPPER TROUGH IS IN THE CENTRAL ATLC SUPPORTING A SURFACE TROUGH THAT EXTENDS 32N42W ALONG 29N46W TO 26N49W WITH SCATTERED SHOWERS/ ISOLATED THUNDERSTORMS N OF 28N BETWEEN 41W-44W. A WEAK LOW LEVEL 1014 MB LOW IS CENTERED NEAR 22N34W WITH A SURFACE TROUGH EXTENDING ALONG 19N36W TO 17N40W AND ISOLATED SHOWERS WITHIN 90 NM OF THE SURFACE LOW. W ATLC FRONT WILL LIFT N ALONG THE FLORIDA COAST AND GRADUALLY DISSIPATE THROUGH SAT. N EXTENT OF A E CARIBBEAN TROPICAL WAVE WILL MOVE ACROSS THE FAR S WATERS TODAY THROUGH SUN. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ PAW