000 AXNT20 KNHC 050005 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 805 PM EDT SAT OCT 04 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 OVER THE FAR E ATLC WITH AXIS EXTENDING FROM 19N25W TO 9N21W...MOVING W AT 15 KT. SSMI TPW IMAGERY SHOW MODERATE MOISTURE IN THE LOW TO MIDDLE LEVELS WHILE THE GOES-R SEVIRI IMAGERY SHOW MIDDLE TO UPPER LEVEL DRY AIR IN THE NORTHERN WAVE ENVIRONMENT AND SOME DUST MOVING ACROSS THE CORE OF THE WAVE. THE WAVE IS IN A STRONG DEEP LAYER ENVIRONMENTAL SHEAR REGION WHICH IS INFLUENCING TO THE LACK OF CONVECTION AT THE TIME. A TROPICAL WAVE IS ON THE CENTRAL CARIBBEAN WITH AXIS EXTENDING FROM 19N73W TO 10N73W...MOVING W AT 20 KT. A COMBINATION OF DEEP LAYER DRY AIR AND STRONG ENVIRONMENTAL SHEAR ARE INHIBITING CONVECTION AT THE TIME. A TROPICAL WAVE IS MOVING ACROSS CENTRAL AMERICA WITH AXIS EXTENDING FROM 16N84W TO 9N86W...MOVING W AT 15-20 KT. PATCHES OF MODERATE MOISTURE IN SOME SECTORS OF THE WAVE ENVIRONMENT ALONG A DIFFLUENT ENVIRONMENT AT THE UPPER LEVELS SUPPORT SCATTERED SHOWERS AND TSTMS OVER GUATEMALA...EL SALVADOR...HONDURAS AND NORTHERN NICARAGUA. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS ACROSS AFRICA FROM 11N15W TO 9N28W. THE ITCZ BEGINS FROM 9N28W AND CONTINUES ALONG 9N42W TO 8N56W. SCATTERED MODERATE CONVECTION IS FROM 7N-14N E OF 18W. SIMILAR CONVECTION IS FROM 6N-12N BETWEEN 30W-42W. ...DISCUSSION... GULF OF MEXICO... A MIDDLE TO UPPER LEVEL TROUGH IS ACROSS THE EASTERN U.S. WITH A BASE EXTENDING TO THE CENTRAL GULF. THIS TROUGH ALOFT SUPPORTS A COLD FRONT ALONG 30N76W SW ACROSS SOUTHERN FLORIDA TO 26N82W 23N90W TO 23N97W WHERE A SURFACE TROUGH CONTINUES TO 19N97W. RIDGING ALOFT ACROSS THE REMAINDER BASIN GENERATES A DIFFLUENT ENVIRONMENT THAT ENHANCES SCATTERED SHOWERS AND ISOLATED TSTMS WITHIN 120 NM EITHER SIDE OF THE FRONT...EXCEPT IN THE EASTERN GULF WHERE THE CONVECTION IS ONLY AHEAD OF THE FRONT. SHOWERS AND TSTMS ARE ALSO OBSERVED EXTENDING TO THE WESTERN BAY OF CAMPECHE. HIGH SURFACE PRESSURE...DEEP LAYER DRY AIR AND STRONG ENVIRONMENTAL SHEAR SUPPORT CLEAR SKIES N OF THE FRONT. NORTHERLY WIND FLOW OF 15 KT IS N OF THE FRONTAL BOUNDARY WHILE 5-10 KT WINDS DOMINATE ELSEWHERE. THE FRONT IS EXPECTED TO REACH THE STRAITS OF FLORIDA TONIGHT THROUGH SUNDAY MORNING WHEN IT IS EXPECTED TO STALL UNTIL DISSIPATION MONDAY MORNING. CARIBBEAN SEA... ONE OF THE TROPICAL WAVES FORMERLY OVER THE FAR WESTERN CARIBBEAN HAS MOVED OVER CENTRAL AMERICA...HOWEVER IS ENHANCING ISOLATED SHOWERS AND TSTMS WITHIN 150 NM N OF THE HONDURAS COASTLINE. FARTHER EAST...AN ELONGATED UPPER-LEVEL CYCLONIC CIRCULATION CENTERED OVER JAMAICA ALONG PATCHES OF SHALLOW MOISTURE SUPPORT SCATTERED SHOWERS AND TSTMS N OF 15N BETWEEN 75W-82W...INCLUDING JAMAICA AND CUBA. SIMILARLY...A MIDDLE LEVEL LOW IN THE SW BASIN SUPPORT ISOLATED SHOWERS AND TSTMS S OF 14N. A TROPICAL WAVE IS MOVING ACROSS THE CENTRAL BASIN. SEE THE TROPICAL WAVES SECTION ABOVE FOR DETAILS. SAHARAN DRY AIR AND DUST ARE ACROSS THE REMAINDER N-NE CARIBBEAN PROVIDING HAZY CONDITIONS. THE PASSAGE OF THE TROPICAL WAVE SUPPORT TRADES OF 20 KT WITHIN 150 NM OF THE S AMERICA COAST BETWEEN 64W-73W. TRADES OF 10-15 KT DOMINATE ELSEWHERE. SCATTERED SHOWERS AND THUNDERSTORMS AHEAD OF THE COLD FRONT IN THE GULF OF MEXICO ARE FORECAST FOR THE YUCATAN CHANNEL AND THE NORTHWESTERN CARIBBEAN SUNDAY. ...HISPANIOLA... FAIR WEATHER CONTINUES ACROSS THE ISLAND BEING SUPPORTED BY DEEP LAYER DRY AIR. HAZY CONDITIONS ARE EXPECTED THROUGH MONDAY NIGHT AS THE DRY AIR...PARTLY ASSOCIATED WITH A SAHARAN AIR MASS...MOVES OVER THE ISLAND. ATLANTIC OCEAN... A MIDDLE TO UPPER LEVEL TROUGH IS ACROSS THE EASTERN U.S. EXTENDING TO THE CENTRAL GULF AND THE FAR WESTERN ATLC WATERS. THIS TROUGH ALOFT SUPPORTS A COLD FRONT ALONG 30N76W SW ACROSS SOUTHERN FLORIDA CONTINUING ALONG THE CENTRAL GULF OF MEXICO. SCATTERED SHOWERS AND TSTMS ARE OCCURRING N OF 22N W OF 74W...INCLUDING THE NORTHERN AND CENTRAL BAHAMAS. FARTHER EAST...A SHORT-WAVE UPPER TROUGH BETWEEN 50W-60W SUPPORT A SECOND COLD FRONT ANALYZED ALONG 30N51W TO 27N56W WHERE IT TRANSITIONS TO A STATIONARY FRONT ALONG 27N62W TO A 1010 MB LOW NEAR 27N68W. SCATTERED SHOWERS AND TSTMS ARE WITHIN 200 NM AHEAD OF THE LOW AND THE FRONTAL BOUNDARY. A MIDDLE TO UPPER LEVEL LOW OVER THE CENTRAL ATLC REFLECTS AS A SURFACE TROUGH THAT ENHANCES SCATTERED MODERATE CONVECTION AND TSTMS FROM 21N-30N BETWEEN 32W- 39W. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ RAMOS