000 AXNT20 KNHC 251019 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 805 AM EDT SAT OCT 25 2008 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...METEOROLOGICAL ANALYSIS...WEATHER OBSERVATIONS...AND RADAR. BASED ON 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0945 UTC. ...TROPICAL WAVES... TROPICAL WAVE IS ALONG 25W S OF 13N MOVING W 10-15 KT. WAVE IS EMBEDDED WITHIN AN AREA OF DEEP LAYER MOISTURE WITH CLUSTERS OF SCATTERED MODERATE/ISOLATED STRONG CONVECTION FROM 5N-12N BETWEEN 21W-27W. TROPICAL WAVE IS ALONG 36W/37W S OF 12N MOVING W 10-15 KT. WAVE IS BENEATH AN UPPER LOW AND IS EMBEDDED WITHIN DRY AIR WHICH IS LIMITING ANY SHOWERS/DEEP CONVECTION. TROPICAL WAVE IS ALONG 59W S OF 18N MOVING W NEAR 5 KT. WAVE HAS MOVED INTO AN AREA OF STRONG SUBSIDENCE AND DRY/STABLE AIR THUS LIMITING ANY SHOWERS/DEEP CONVECTION. ...THE ITCZ... ITCZ AXIS IS ANALYZED ALONG 10N12W 8N18W 6N44W 10N58W. SCATTERED MODERATE/STRONG CONVECTION IS 75/90 NM OF THE ITCZ FROM 29W-32W. CLUSTERS OF SCATTERED MODERATE/ISOLATED STRONG CONVECTION COVER THE REMAINDER OF THE AREA FROM THE EQUATOR TO 13N BETWEEN 24W-34W. ...DISCUSSION... GULF OF MEXICO... A DEEP LAYERED TROUGH IS MOVING OFF THE E US INTO THE W ATLC WHILE THE GULF WATERS ARE DOMINATED BY AN UPPER RIDGE ANCHORED IN THE NW CARIBBEAN. A WEAK COLD FRONT EXTENDS OVER FLORIDA FROM JUST W OF JACKSONVILLE INTO THE GULF NEAR CEDAR KEY TO 26N85W CONTINUING AS A STATIONARY FRONT TO 22N89W WHICH IS JUST W OF A 1012 MB LOW OFF THE NE COAST OF THE YUCATAN NEAR 22N87W. DENSE CLOUD COVER WITH SCATTERED SHOWERS AND POSSIBLE ISOLATED THUNDERSTORMS ARE E OF THE FRONTAL BOUNDARY ACROSS THE FLORIDA PENINSULA AND THROUGH THE FLORIDA STRAITS. THE UPPER RIDGE IS DRAWING UPPER MOSITURE FROM THE E PACIFIC ACROSS MEXICO TO OVER THE W GULF MOSTLY IN THE FORM OF HIGH CLOUDS. THE FRONT IS EXPECTED TO CLEAR THE GULF LATE SUN/EARLY MON. CARIBBEAN SEA... BROAD UPPER RIDGE COVERS MOST OF THE CARIBBEAN ANCHORED JUST W OF THE CAYMAN ISLANDS EXTENDING OVER THE GULF OF MEXICO AND INTO THE W ATLC. AN UPPER TROUGH EXTENDS INTO THE FAR E CARIBBEAN ACROSS THE LESSER ANTILLES NEAR MARTINIQUE TO THE ABC ISLANDS. UPPER DIFFLUENCE IS GENERATING SCATTERED SHOWERS/ISOLATED THUNDERSTORMS OVER THE NW CARIBBEAN N OF 21N W OF 77W TO OVER CUBA AND THE YUCATAN AND OVER THE S CARIBBEAN S OF A LINE FROM COLOMBIA NEAR 11N73W TO THE GULF OF HONDURAS NEAR 17N86W. THE REMAINDER OF THE CARIBBEAN IS UNDER STRONG SUBSIDENCE AND DRY STABLE WITH POSSIBLE ISOLATED LOW LEVEL SHOWERS USHERED IN ON MODERATE EASTERLY TRADE WINDS MAINLY OVER THE ABC ISLANDS. ATLANTIC OCEAN... THE BROAD UPPER RIDGE ANCHORED IN THE NW CARIBBEAN EXTENDS ACROSS THE W ATLC W OF 60W AND PROVIDING UPPER DIFFLUENCE TO GENERATE SCATTERED SHOWERS/ISOLATED THUNDERSTORMS WITHIN 150 NM OF LINE FROM CUBA NEAR 23N80W TO BEYOND 32N74W WITH GALE FORCE WINDS N OF 28N W OF 75W. A NARROWING DEEP LAYERED TROUGH EXTENDS INTO THE CENTRAL ATLC NEAR 32N52W ALONG 23N52W THEN SW INTO THE E CARIBBEAN ACROSS THE LESSER ANTILLES NEAR MARTINIQUE. THE ASSOCIATED COLD FRONT ENTERS THE REGION NEAR 32N46W EXTENDING ALONG 26N52W TO 22N61W WHERE IT CONTINUES AS A STATIONARY BOUNDARY TO E OF THE TURKS AND CAICOS NEAR 22N68W. A PRE-FRONTAL SURFACE TROUGH EXTENDS FROM 25N51W TO 17N55W. A LOWER LEVEL SWIRL IS ALONG THIS TROUGH NEAR 19N. SCATTERED SHOWERS/ISOLATED THUNDERSTORMS ARE WITHIN 200 NM E OF THE FRONT N OF 24N. A SURFACE RIDGE HAS BRIDGED THE FRONT WITH A RIDGE AXIS EXTENDING S TO BERMUDA THEN SW ACROSS THE BAHAMAS TO 22N77W AND ANCHORED BY A 1030 MB HIGH OFF THE NEW ENGLAND COAST. A NARROW UPPER RIDGE IS JUST TO THE E OF THE UPPER TROUGH ENHANCING THE ABOVE ACTIVITY. A CUT OFF UPPER LOW IS IN THE E ATLC NEAR 19N33W AMPLIFYING AN UPPER RIDGE TO THE E TO 24N E OF 25W. A SECOND SURFACE RIDGE COVERS THE E ATLC N OF 17N E OF 42W ANCHORED BY A 1031 MB HIGH E OF THE AZORES. $$ WALLACE