000 AXNT20 KNHC 221748 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 205 PM EDT MON OCT 22 2007 TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL AMERICA...THE GULF OF MEXICO...THE CARIBBEAN SEA...NORTHERN SECTIONS OF SOUTH AMERICA...AND THE 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1715 UTC. ...TROPICAL WAVES... TROPICAL WAVE IS ALONG 57W/58W S OF 21N MOVING W NEAR 10 KT. VIS SATELLITE IMAGERY CONTINUES TO SHOW SOME CYCLONIC TURNING ALONG THE WAVE AXIS NEAR 14N. SHOWER AND TSTM ACTIVITY REMAINS DISORGANIZED AND MAINLY DISPLACED TO THE EAST DUE TO STRONG UPPER-LEVEL WLY WINDS OVER THE AREA. SCATTERED SHOWERS AND ISOLATED TSTMS ARE FROM 10N-18N BETWEEN 52W-58W. THIS TROPICAL WAVE WILL MOVE INTO THE ERN CARIBBEAN EARLY TUE...AND ACROSS THE UK/US VIRGIN ISLANDS AND PUERTO RICO LATE TUE THROUGH WED. ...THE ITCZ... ITCZ AXIS IS CENTERED ALONG 10N14W 6N30W 7N45W 11N58W 10N64W. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS WITHIN 140 NM N OF AXIS E OF 28W. WIDELY SCATTERED MODERATE CONVECTION IS FROM 2N-8N BETWEEN 30W-40W. DISCUSSION... GULF OF MEXICO... A STRONG COLD FRONT IS ENTERING THE NW PORTION OF THE GULF FOLLOWED BY MODERATE TO STRONG WINDS. SUSTAINED WINDS OF 20 TO 30 KT WITH HIGHER GUSTS ARE ALREADY OBSERVED ALONG THE LOWER TEXAS COAST. A LINE OF SHOWERS AND TSTMS IS JUST AHEAD OF THE FRONTAL SYSTEM ASSOCIATED WITH A PRE-FRONTAL TROUGH THAT RUNS FROM 29N95W TO 26N98W. THE FRONT WILL EXTEND FROM SE LOUISIANA TO NEAR TAMPICO MEXICO THIS EVENING THEN WEAKEN FROM THE FL PANHANDLE TO E BAY OF CAMPECHE BY TUE EVENING. AS PREVIOUSLY MENTIONED...A GALE EVENT IS FORECAST TO BEGIN LATE THIS AFTERNOON ACROSS THE GULF BEHIND THE FRONT...AND LOOKS TO BE A VERY STRONG EVENT ON THE ORDER OF 40-45 KT OVER THE SW GULF TONIGHT BECOMING A STORM ON TUE. A GALE WARNING IS NOW IN EFFECT FOR THE NW AND SW GULF. SLY RETURN FLOW AHEAD OF THE FRONT COMBINED WITH UPPER DIFFLUENCE BETWEEN AN UPPER-LEVEL TROUGH OVER WESTERN TEXAS AND AN UPPER HIGH OVER THE GULF WATERS IS GENERATING SCATTERED SHOWERS AND THUNDERSTORMS FROM 22N-29N BETWEEN 90W-95W. THE UPPER TROUGH SUPPORTS THE ABOVE MENTIONED COLD FRONT WHILE THE UPPER HIGH DOMINATES THE ENTIRE GULF WITH A RIDGE EXTENDING EWD ACROSS THE FLORIDA PENINSULA INTO THE W ATLC. A WARM FRONT CONTINUES TO PUSH N OVER THE N GULF EXTENDING FROM A STATIONARY FRONT IN THE W ATLC ACROSS CENTRAL FLORIDA TO NEAR MOBILE AL. HEAVY SHOWERS WITH EMBEDDED THUNDERSTORMS ARE SOUTH OF THE WARM FRONT MOVING N FROM THE N GULF TO INLAND BETWEEN PANAMA CITY FLORIDA AND SE LOUISIANA. CARIBBEAN SEA... NELY WINDS AROUND THE SE PERIPHERY OF THE UPPER HIGH LOCATED OVER THE EASTERN GULF OF MEXICO DOMINATES CUBA...THE NW CARIBBEAN AND NORTHERN CENTRAL AMERICA WITH DRY STABLE AIR RESULTING IN MODERATE TO STRONG SUBSIDENCE. AN UPPER LEVEL TROUGH IS OVER THE CENTRAL CARIBBEAN EXTENDING ACROSS E HISPANIOLA/MONA PASSAGE TO THE BORDER OF NICARAGUA/COSTA RICA. SWLY WINDS AHEAD OF THIS TROUGH ARE DRAWING MOIST TROPICAL AIR ACROSS THE SW AND CENTRAL CARIBBEAN WHERE SCATTERED SHOWERS ARE DEVELOPING. THE LIGHTNING DATA DEPICTS ISOLATED TSTMS EMBEDDED IN THIS AREA. SHOWER ACTIVITY IS ALSO SEEN OVER THE ABC ISLANDS AND THE ISLANDS OFF OF THE VENEZUELA COAST. THE COLOMBIAN OR PANAMANIAN LOW PAIRED WITH THE ITCZ IS GENERATING SCATTERED SHOWERS/ISOLATED THUNDERSTORMS ALONG THE COAST OF PANAMA AND COSTA RICA. MODERATE TRADE WINDS ARE BLOWING ACROSS THE BASIN. A TROPICAL WAVE IS APPROACHING THE LESSER ANTILLES. SEE TROPICAL WAVE SECTION FOR DETAILS. ATLANTIC OCEAN... A DEEP LAYERED TROUGH N OF THE REGION IS DRAPING A COLD FRONT INTO THE W/CENTRAL ATLC SE OF BERMUDA NEAR 32N58W SW TO 29N66W BECOMING NEAR STATIONARY TO OVER FLORIDA JUST N OF LAKE OKEECHOBEE CONTINUING INTO THE GULF OF MEXICO AS A WARM FRONT. UPPER RIDGE AXIS EXTENDS ACROSS THE FLORIDA PENINSULA OVER LAKE OKEECHOBEE AND INTO THE W ATLC ENHANCING SHOWER ACTIVITY ALONG THE FRONTAL BOUNDARY. A SURFACE RIDGE IS BUILDING BEHIND THE FRONT ANCHORED BY A 1029 MB NEAR 37N69W. AN UPPER-LEVEL TROUGH EXTENDS FROM THE CENTRAL ATLC NEAR 23N52W INTO THE CARIBBEAN OVER E HISPANIOLA/MONA PASSAGE WITH A SWATH OF DRY STABLE AIR OVER THE REMAINDER OF THE W ATLC. A CUT-OFF LOW IS IN THE E/CENTRAL ATLC NEAR 27N40W. A SFC LOW HAS DEVELOPED IN THIS AREA NEAR 28N35W WITH A TROUGH EXTENDING SW TO NEAR 20N42W. A 200 NM WIDE BAND OF MAINLY SHOWERS IS AHEAD OF THE LOW/TROUGH. WEAK SURFACE RIDGE COVERS THE EASTERN ATLC ANCHORED BY A 1023 MB HIGH LOCATED WELL N OF THE FORECAST REGION. DRY STABLE AIR COVERS THE FAR E ATLC. BROAD UPPER RIDGE COVERS MUCH OF THE TROPICAL ATLC S OF 21N FROM THE E CARIBBEAN TO THE CAPE VERDE ISLANDS. $$ GR