000 AXNT20 KNHC 221747 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 205 PM EDT WED OCT 22 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1715 UTC. ...TROPICAL WAVES... A TROPICAL WAVE IS ALONG 24W S OF 14N MOVING W NEAR 5-10 KT. THIS WAVE CONTINUES TO REMAIN WEAK AND EMBEDDED WITHIN THE ITCZ. NO ORGANIZED SHOWERS OR DEEP CONVECTION ASSOCIATED WITH THE WAVE. A TROPICAL WAVE IS ALONG 52W/53W S OF 21N MOVING W NEAR 10 KT. THE SSMI-TPW PRODUCT FROM CIMSS INDICATES A NORTHWARD SURGE OF MOISTURE ALONG THE WAVE AXIS. THE WAVE IS INTERACTING WITH AN UPPER-LEVEL LOW NEAR 22N55W. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS FROM 11N-21N BETWEEN 44W-49W. A TROPICAL WAVE IS ALONG 79W S OF 17N MOVING W NEAR 10-15 KT. THE WAVE IS EMBEDDED WITHIN STRONG EASTERLY SURFACE FLOW ACROSS THE CARIBBEAN AND IS ENHANCING CONVECTION ACROSS THE WRN CARIBBEAN FROM 11N-16N BETWEEN 77W-82W. ...THE ITCZ... ITCZ AXIS IS CENTERED ALONG 10N13W 9N22W 7N26W 11N51W 11N55W 11N65W. CLUSTERS OF SCATTERED MODERATE CONVECTION ARE FROM 5N-10N BETWEEN 29W-48W. SIMILAR CONVECTION IS FROM 10N-13N BETWEEN 59W-62W ACROSS THE SRN WINDWARD ISLANDS. ...DISCUSSION... GULF OF MEXICO... A BROAD UPPER-LEVEL HIGH CENTERED OVER JAMAICA EXTENDS WEAK RIDGING ACROSS THE ENTIRE GULF AND FLORIDA PENINSULA PRODUCING SW UPPER-LEVEL FLOW. MODERATE TO STRONG SUBSIDENCE/DRY AIR IS NOTED OVER MUCH OF THE SW AND NE GULF. AT THE SURFACE...A SURFACE TROUGH EXTENDS FROM A 1012 MB LOW NEAR 23N95W ALONG 95W TO NEAR 28N. CYCLONIC TURNING IS OBSERVED ALONG THE TROUGH AXIS WITH ISOLATED SHOWERS FROM 25N29N BETWEEN 92W-95W. ELSEWHERE... A 1011 MB LOW IS LOCATED OFF THE NRN BELIZE COAST NEAR 18N88W AND EXTENDS A SURFACE TROUGH ACROSS THE YUCATAN PENINSULA AND SE GULF TO NEAR 25N83W. SCATTERED/NUMEROUS SHOWERS COVER THE SE GULF AND FLORIDA STRAITS FROM 20N-26N E OF 88W...INCLUDING THE SRN FLORIDA PENINSULA. A SURFACE HIGH PRESSURE RIDGE EXTENDS FROM THE W ATLC ACROSS NRN FLORIDA AND THE NRN GULF WATERS N OF 27N. A COLD FRONT IS FORECAST TO ENTER THE NW GULF WATERS BY EARLY THURSDAY BRINGING MODERATE TO STRONG NORTHERLY WINDS IN WAKE OF THE FRONT. CARIBBEAN SEA... A 1011 MB SURFACE LOW PRESSURE IS CENTERED OFF THE NRN BELIZE COAST NEAR 18N88W WITH A SURFACE TROUGH EXTENDING NWD ACROSS THE ERN YUCATAN PENINSULA. SCATTERED SHOWERS COVER MUCH OF THE NW CARIBBEAN WITH MOST INTENSE ACTIVITY FROM 17N-20N BETWEEN 83W-88W. THIS LOW IS EXPECTED TO MOVE N-NW AHEAD OF THE COLD FRONT FORECAST TO ENTER THE NW GULF OF MEXICO EARLY THURSDAY. AN UPPER-LEVEL HIGH CENTERED OVER JAMAICA DOMINATES THE ENTIRE CARIBBEAN SEA IS HELPING TO INDUCE THE CONVECTIVE ACTIVITY OVER THE NW CARIBBEAN AND ALSO THE TROPICAL WAVE ALONG 79W. MODERATE TRADE WINDS OF 15 TO 20 KT ARE BLOWING ACROSS THE BASIN. AN AREA OF SCATTERED SHOWERS AND ISOLATED TSTMS ARE MOVING ACROSS THE SRN WINDWARD ISLANDS AND FAR SE CARIBBEAN. THIS ACTIVITY APPEARS TO BE THE RESULT OF THE UPPER DIFFLUENT PATTERN IN PLACE. ATLANTIC OCEAN... ZONAL UPPER-LEVEL FLOW IS ACROSS THE W ATLC W OF 60W. WEAK UPPER-LEVEL RIDGING EXTENDS FROM THE CARIBBEAN N TO ACROSS THE BAHAMAS. MULTILAYERED CLOUDINESS AND ISOLATED SHOWERS ARE ACROSS THE NRN BAHAMAS AS LOW-MIDDLE LEVEL MOISTURE STREAMS NE FROM THE SURFACE TROUGH ACROSS THE SE GULF OF MEXICO. A DEEP LAYERED TROUGH IS OVER THE CENTRAL ATLC WITH AN UPPER LOW CENTERED NEAR 22N55W. THE ATTENDANT COLD FRONT ENTERS THE AREA NEAR 32N51W EXTENDING TO NEAR 23N59W. SCATTERED SHOWERS RELATED TO THIS FRONT ARE FROM 25N-31N BETWEEN 48W-54W. A SURFACE TROUGH EXTENDS NWD FROM THE TROPICAL WAVE ALONG 52W/53W FROM 22N52W TO 28N51W. POSSIBLE SCATTERED SHOWERS ARE EAST OF THIS TROUGH FROM 21N-27N BETWEEN 42W-49W. ELSEWHERE...MODERATE TO STRONG SUBSIDENCE IS IN PLACE ACROSS THE W ATLC N OF 27N AND W OF THE COLD FRONT. AREAS OF LOW-LEVEL CLOUDS AND MODERATE TRADE WINDS ARE OBSERVED OVER THE E ATLC LARGELY IN PART TO A SURFACE RIDGE COVERING THE E ATLC E OF 40W. AN UPPER-LEVEL TROUGH WITH AXIS JUST WEST OF THE THE CANARY AND CAPE VERDE ISLANDS IS SUPPORTING A COLD FRONT ENTERING THE DISCUSSION AREA NEAR 32N9W OVER MOROCCO EXTENDING WWD TO NEAR 31N23W. POSSIBLE ISOLATED SHALLOW SHOWERS ARE WITHIN 120 NM OF THE FRONT. $$ HUFFMAN