000 AXNT20 KNHC 301138 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 705 AM EST MON OCT 30 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1115 UTC. ...TROPICAL WAVES... A LOW AMPLITUDE TROPICAL WAVE IS ALONG 57W/58W S OF 14N MOVING W NEAR 10 KT. SCATTERED SHOWERS AND TSTMS ARE AHEAD OF THE WAVE AXIS OVER THE SOUTHERN WINDWARD ISLANDS. A STRONG TROPICAL WAVE IS OVER THE CENTRAL CARIBBEAN ALONG 76W SOUTH OF 21N MOVING W NEAR 15 KT. DISORGANIZED SHOWER ACTIVITY COVERS MUCH OF THE CENTRAL AND WESTERN CARIBBEAN SEA AND ADJACENT LAND AREAS. TROPICAL CYCLONE FORMATION IS NOT EXPECTED...ALTHOUGH LOCALLY HEAVY RAINS ARE POSSIBLE THROUGHOUT THE AREA. THIS WAVE IS INTERACTING WITH A FRONTAL SYSTEM THAT CROSSES CENTRAL BAHAMAS AND EASTERN CUBA. SCATTERED PATCHES OF MODERATE/ISOLATED STRONG CONVECTION ARE FROM 15N-20N BETWEEN 74W-80W. ONE OF THESE PATCHES IS BETWEEN EASTERN CUBA AND JAMAICA. A TROPICAL WAVE IS MAINLY INLAND ALONG 84W S OF 16N MOVING W 15 TO 20 KT. THE WAVE IS GENERATING SCATTRED SHOWERS WITH EMBEDDED TSTMS OVER THE CARIBBEAN PLAINS OF NICARAGUA AND ADJACENT COASTAL WATERS. SCATTERED MODERATE CONVECTION IS OVER THE NW CARIBBEAN. ...THE ITCZ... ITCZ AXIS IS CENTERED ALONG 10N14W 9N30W 7N40W 6N50W 6N56W. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS FROM 4N-13N EAST OF 26W. SIMILAR CONVECTION IS WITHIN 60-80 NM ON EITHER SIDE OF THE AXIS BETWEEN 37W-50W. ...DISCUSSION... THE GULF OF MEXICO... A SURFACE RIDGE ANCHORED ON A 1022 MB HIGH OVER SE GEORGIA COVERS THE ENTIRE GULF OF MEXICO AND THE SE OF U.S. INCLUDING THE STATE OF FLORIDA. A VERY DRY AIR MASS DOMINATES THE AREA. ONLY COLD AIR STRATOCUMULUS CLOUDS ARE SEEN OVER THE GULF. IN THE UPPER LEVELS...THE BASE OF AN UPPER LEVEL TROUGH IS OVER THE GULF GIVING THE AREA MOSTLY WLY FLOW. THE SURFACE HIGH PRESSURE WILL MOVE EAST AND THE RIDGE WILL PERSIST OVER THE N GULF DURING THE NEXT FEW DAYS. 15-20 KT SLY RETURN FLOW IS ALREADY IN PLACE OVER THE WESTERN GULF. THE CARIBBEAN SEA... THE MAIN WEATHER MAKER OVER THE AREA IS THE INTERACTION BETWEEN A FRONTAL BOUNDARY OVER EASTERN CUBA AND A TROPICAL WAVE ALONG 76W. THESE TWO FEATURES ARE PRODUCING A LARGE AREA OF SHOWERS WITH EMBEDDED TSTMS OVER THE CENTRAL AND WEST CARIBBEAN. IN THE UPPER LEVELS...SWLY FLOW IS OVER THE W CARIBBEAN W OF 80W. AN UPPER LEVEL HIGH IS OVER HISPANIOLA NEAR 20N71W. A DIFFLUENT PATTERN ALOFT IS SUPPORTING THE SHOWER/TSTM ACTIVITY ASSOCIATED WITH THE TROPICAL WAVE/FRONT. 15-20 KT TRADE WINDS WILL BLOW ACROSS THE BASIN EAST OF 75W. UNDER THE ELY FLOW...PATCHES OF LOW LEVEL MOISTURE ARE MOVING ACROSS THE LEEWARD/VIRGIN ISLANDS AND PUERTO RICO. THE SAN JUAN DOPPLER RADAR SHOWS SCATTERED SHOWERS AND ISOLATED TSTMS OVER THESE ISLANDS AND LOCAL WATERS. N TO NE WINDS ARE OBSERVED OVER THE NW CARIBBEAN AND WESTERN CUBA. THE ATLANTIC OCEAN... A COLD FRONT ENTERS THE AREA NEAR 31N59W...THEN CONTINUES SW TO 26N69W. A STATIONARY FRONT EXTENDS FROM THIS POINT ACROSS THE CENTRAL BAHAMAS AND EASTERN CUBA. CLUSTERS OF SCATTERED MODERATE TO ISOLATED STRONG CONVECTION ARE FROM 23N-28W BETWEEN 66W-71W. A 1022 MB IS BEHIND THE FRONT NEAR 31N75W COVERING THE W ATLC AND THE FLORIDA PENINSULA. THE GFS MODEL DEVELOPS A SURFACE LOW ALONG THE FRONTAL BOUNDARY JUST EAST OF THE BAHAMAS. INCREASED PRESSURE GRADIENT BETWEEN THE LOW AND THE SURFACE HIGH MENTIONED ABOVE THAT IS FORECAST TO MOVE NEWD WILL PRODUCE STRONG NE WIND OVER W ATLC WEST OF 70W BEGINNING TONIGHT. ANOTHER COLD FRONT IS OVER THE E ATLANTIC ALONG 31N24W 23N35W 22N45W. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS WITHIN 70-90 NM AHEAD OF THE FRONT FROM 25N-31N. IN BETWEEN THESE FRONTAL SYSTEMS THERE IS A WEAK SURFACE RIDGE. IN THE UPPER LEVELS...A TROUGH IS OVER THE W ATLANTIC N OF 26N AND W OF 75W. AN UPPER HIGH OVER HISPANIOLA EXTENDS A RIDGE BETWEEN 60W-75W. ANOTHER UPPER LEVEL HIGH IS OVER THE CENTRAL ATLANTIC NEAR 25N55W. AN ELONGATED UPPER LEVEL TROUGH IS OVER THE E ATLANTIC N OF 10N E OF 45W WITH A STRONG UPPER LEVEL LOW NEAR 32N30W. SWLY WINDS AHEAD OF THIS TROUGH ARE ADVECTING ABUNDANT UPPER LEVEL MOISTURE ACROSS THE E ATLC E OF 35W AND THE CAPE VERDE ISLANDS. $$ GR