000 AXNT20 KNHC 052341 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 805 PM EDT THU OCT 05 2006 TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL AMERICA...THE GULF OF MEXICO...THE CARIBBEAN SEA...NORTHEASTERN 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...WEATHER OBSERVATIONS...RADAR... AND METEOROLOGICAL ANALYSIS. BASED ON 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 2315 UTC. ...TROPICAL WAVES... TROPICAL WAVE IS ALONG 22W S OF 15N MOVING W NEAR 15 KT. THE WAVE SHOWS AN INVERTED-V SIGNATURE ON SATELLITE IMAGERY. WIDELY SCATTERED MODERATE CONVECTION IS ASSOCIATED WITH THE WAVE MAINLY AHEAD OF THE AXIS. TROPICAL WAVE IS ALONG 48W S OF 16N MOVING W 10 TO 15 KT. SOME CYCLONIC TURNING IS SEEN ALONG THE WAVE AXIS NEAR 12N. SCATTERED MODERATE/ISOLATED STRONG CONVECTION HAS FLARED UP OVER THE LAST FEW HOURS FROM 10N-13N BETWEEN 43W-50W...PARTICULARLY BEHIND THE WAVE AXIS. TROPICAL WAVE IS ALONG 56W S OF 16N MOVING W NEAR 10 KT. A WEAK INVERTED V PATTERN IS SEEN ON SATELLITE IMAGERY. ISOLATED SHOWERS/TSTMS ARE RELATED TO THE WAVE. TROPICAL WAVE IS ALONG 80W/81W S OF 20N MOVING W NEAR 15 KT. WELL DEFINED LOW LEVEL INVERTED-V SHAPE IS NOTED ON SATELLITE IMAGERY. THE WAVE IS ENHANCING THE DEVELOPMENT OF SCATTERED MODERATE CONVECTION OVER THE SW CARIBBEAN...JAMAICA AND CENTRAL CUBA. ...THE ITCZ... ITCZ AXIS IS CENTERED ALONG 11N16W 6N30W 11N45W 10N55W 9N61W. OUTSIDE OF CONVECTION NEAR THE TROPICAL WAVES...ISOLATED SHOWERS/TSTMS ARE FROM 4N-9N BETWEEN 17W-30W AND FROM 2N-7N BETWEEN 30W-37W. CLUSTERS OF MODERATE/ISOLATED STRONG CONVECTION HAVE DEVELOPED ALONG THE WEST COAST OF AFRICA FROM 7N-16N. SIMILAR CONVECTION IS ALSO NOTED OVER NORTHERN GUYANA AND NE VENEZUELA. T ...DISCUSSION... GULF OF MEXICO... AN UPPER TROUGH EXTENDS ALONG THE TEXAS COAST AND NE MEXICO TO AN UPPER LOW LOCATED NEAR 22N100W. BROAD UPPER RIDGE COVERS THE YUCATAN PENINSULA AND MOST OF THE GULF. UPPER DIFFLUENCE BETWEEN THESE TWO FEATURES IS HELPING TO SUPPORT AN AREA OF DISORGANIZED SHOWERS AND THUNDERSTORMS OVER THE BAY OF CAMPECHE AND THE SOUTHWESTERN GULF OF MEXICO. A SURFACE TROUGH IS IN THIS REGION ALONG 18N93W 25N96W. SURFACE PRESSURES REMAIN HIGH AND UPPER LEVEL WINDS ARE ONLY MARGINALLY CONDUCIVE FOR TROPICAL DEVELOPMENT. THIS TROUGH WILL REMAIN STATIONARY DURING THE NEXT FEW DAYS KEEPING A GOOD CHANCE OF RAIN ALONG THE MEXICAN GULF COAST... INCLUDING ALSO THE BAY OF CAMPECHE AND THE YUCATAN PENINSULA. THE UPPER WESTERLY FLOW OVER THE REGION IS SPREADING THE HIGH CLOUDS EWD TO 85W...WITH DRY MID TO UPPER AIR PERSISTING OVER THE NE AND FAR ERN GULF. A 1020 MB SURFACE HIGH LOCATED OVER THE GEORGIA/ALABAMA BORDER IS KEEPING THE SE U.S. RATHER SHOWER FREE INCLUDING THE STATE OF FLORIDA. THIS FEATURE WILL WEAKEN TONIGHT AS A COLD FRONT MOVES OFF THE N GULF COAST. CARIBBEAN SEA... UPPER LEVEL FEATURES REMAIN UNCHANGED OVER THE CARIBBEAN. A RIDGE/TROUGH/RIDGE PATTERN DOMINATES THE BASIN. A BROAD RIDGE COVERS MOST OF THE WEST-CENTRAL CARIBBEAN. AN UPPER TROUGH EXTENDS FROM HISPANIOLA TO NORTHERN COLOMBIA. THE E CARIBBEAN IS UNDER THE INFLUENCE OF ANOTHER UPPER LEVEL RIDGE. THE SWLY WIND FLOW AHEAD OF THE TROUGH IS ADVECTING ABUNDANT UPPER LEVEL MOISTURE OVER THE EASTERN CARIBBEAN...PUERTO RICO AND THE LEEWARD ISLANDS. CLUSTERS OF MODERATE CONVECTION HAVE FLARED UP OVER HISPANIOLA AND NORTHERN COLOMBIA THANKS TO THE TROUGH. SCATTERED SHOWERS/ISOLATED TSTMS ARE OVER THE VIRGIN ISLANDS AND PUERTO RICO. LOW PRESSURE NEAR THE COLOMBIAN COAST AND ATLANTIC RIDGE NEAR 30N WILL MAINTAIN MODERATE ELY TRADE WINDS ACROSS THE CARIBBEAN TONIGHT THROUGH SUNDAY. ATLANTIC OCEAN... A LARGE AREA OF MODERATE/ISOLATED STRONG CONVECTION PERSISTS ALONG A BROAD TROUGH OF LOW PRESSURE EXTENDING FROM THE EASTERN BAHAMAS NORTHEASTWARD TO NEAR BERMUDA. THE CONVECTIVE ACTIVITY IS MAINLY EAST OF THE TROUGH AXIS AND COVERS FROM 21N-30N BETWEEN 66W-71W. UPPER-LEVEL WINDS ARE FORECAST TO REMAIN UNFAVORABLE FOR TROPICAL CYCLONE DEVELOPMENT. ACCORDING TO THE GFS MODEL...A NON-TROPICAL LOW COULD FORM WITHIN THIS AREA DURING THE NEXT COUPLE OF DAYS. A DEEP UPPER LEVEL TROUGH THAT EXTENDS OVER THE W ATLC AND THE BAHAMAS INTO THE CARIBBEAN SEA ACROSS HISPANIOLA IS SUPPORTING THIS CONVECTION. AN UPPER HIGH IS JUST E OF THIS TROUGH NEAR 29N60W. ABUNDANT UPPER LEVEL MOISTURE IS FOUND BETWEEN THESE TWO FEATURES COVERING FROM 65W-75W. A DEEP LAYER TROUGH ENTERS THE AREA NEAR 31N31W THEN CONTINUES SW ALONG 23N37W 18N51W WHERE THERE IS ANOTHER UPPER LEVEL LOW. DRY UPPER AIR RESULTING IN MODERATE TO STRONG SUBSIDENCE COVERS FROM 15N-29N BETWEEN 40W-60W...THUS VERY LIMITED SHOWER ACTIVITY. A SURFACE TROUGH... PROBABLY REFLECTION OF THE UPPER TROUGH LIES ALONG 30W/31W. SCATTERED SHOWERS/ISOLATED TSTMS ARE AHEAD OF THE TROUGH. AN UPPER HIGH IS OVER THE CAPE VERDE ISLANDS WITH A RIDGE EXTENDING NE TO BEYOND THE CANARY ISLANDS. $$ GR