000 AXNT20 KNHC 011800 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 205 PM EDT WED OCT 01 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. ...SPECIAL FEATURES... TROPICAL STORM LAURA IS CENTERED NEAR 46.5N 46.5W AT 01/1500 UTC OR ABOUT 270 NM EAST OF CAPE RACE NEWFOUNDLAND MOVING NNE AT 16 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 995 MB. MAXIMUM SUSTAINED WIND SPEED IS 40 KT WITH GUSTS TO 50 KT. PLEASE SEE THE LATEST NHC FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCPAT2/WTNT32 KNHC FOR MORE DETAILS. LAURA IS EXPECTED TO LOSE ITS TROPICAL CHARACTERISTICS THIS AFTERNOON BUT MAINTAIN ITS STRENGTH AND BECOME EXTRATROPICAL LATER THIS AFTERNOON. NO DEEP CONVECTION REMAINS ASSOCIATED WITH LAURA. ADDITIONAL INFORMATION ON THIS SYSTEM CAN BE FOUND IN THE HIGH SEAS FORECASTS ISSUED BY THE NWS/OCEAN PREDICTION CENTER UNDER AWIPS/ WMO HEADERS NFDHSFAT1/FZNT01. ...TROPICAL WAVES... TROPICAL WAVE IS ALONG 38W S OF 19N MOVING W 10-15 KT. THIS WAVE REMAINS EMBEDDED WITHIN DEEP LAYERED MOISTURE AS INDICATED ON THE MIMIC-TPW ANIMATION WITH SCATTERED MODERATE CONVECTION FROM 14N-17N BETWEEN 35W-41W. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS FROM 6N-11N BETWEEN 36W-42W. TROPICAL WAVE IS ALONG 49W FROM 12N-21N MOVING W NEAR 10 KT AND IS BECOMING MORE TILTED IN A NE/SW ORIENTATION DUE TO AN UPPER TROUGH/LOW AXIS ALONG 50W. CYCLONIC CURVATURE IN LOW-LEVEL CLOUDS IS OBSERVED ON SATELLITE IMAGERY N OF 14N. NO ASSOCIATED SHOWERS OR DEEP CONVECTION WITH THE WAVE. TROPICAL WAVE IS ALONG 65W S OF 16N MOVING W 10-15 KT. WEAK WAVE SIGNATURE IS NOTED ACROSS THE SW CARIBBEAN SEA WITH NO DEEP CONVECTION OBSERVED. ...THE ITCZ... THE ITCZ AXIS IS ANALYZED ALONG 10N13W 7N20W 11N35W 9N41W 7N60W. CLUSTERS OF SCATTERED MODERATE/ISOLATED STRONG CONVECTION ARE FROM 6N-9N BETWEEN 10W-16W AND FROM 5N-11N BETWEEN 19W-26W. SIMILAR CONVECTION IS FROM 4N-9N BETWEEN 49W-55W. ...DISCUSSION... GULF OF MEXICO... DEEP UPPER TROUGH OVER THE ERN US EXTENDS OVER THE GULF WITH MODERATE/STRONG SUBSIDENCE AND DRY STABLE AIR COVERING MUCH OF THE REGION WITH THE EXCEPTION OF THE FLORIDA STRAITS. A SURFACE TROUGH EXTENDS FROM THE W ATLC ACROSS EXTREME SRN FLORIDA AND THE FLORIDA KEYS ALONG 25N80W TO OVER FAR WRN CUBA AND THE NRN YUCATAN PENINSULA. A RE-ENFORCING COLD FRONT EXTENDS ACROSS THE NRN GULF THROUGH THE BIG BEND AREA OF FLORIDA TO 28N90W AND INLAND OVER TEXAS NEAR CORPUS CHRISTI. STRONG AND MOIST SW MID-UPPER FLOW IS E OF THE SURFACE TROUGH PROVIDING SUPPORT FOR SCATTERED SHOWERS/ISOLATED TSTMS OVER THE FLORIDA STRAITS. SCATTERED LOW CLOUDS WITH POSSIBLE ISOLATED SHOWERS ARE NOTED ACROSS THE SW GULF S OF 22N WHILE THE REMAINDER OF THE REGION IS RELATIVELY CLOUD FREE THIS AFTERNOON. CARIBBEAN SEA... AN UPPER RIDGE IS ANCHORED IN THE WRN CARIBBEAN NEAR 16N84W WITH A RIDGE AXIS EXTENDING NE TO CENTRAL CUBA PRODUCING UPPER LEVEL DIFFLUENCE TO GENERATE SCATTERED SHOWERS/ISOLATED TSTMS NW OF A LINE FROM THE WINDWARD PASSAGE TO THE NICARAGUA/COSTA RICA BORDER. A SECOND UPPER RIDGE EXTENDS INTO THE N/CENTRAL AND NE CARIBBEAN N OF 15N E OF 75W ANCHORED BY AN UPPER HIGH OVER THE W ATLC. SOMEWHAT STABLE CONDITIONS AND DRYER AIR ARE BENEATH THIS RIDGE WITH ONLY A FEW ISOLATED SHOWERS FROM 14N-18N BETWEEN 63W-73W. A THIRD UPPER RIDGE IS OVER THE SE CARIBBEAN ANCHORED OVER SOUTH AMERICA AND EXTENDING A RIDGE AXIS FROM NE VENEZUELA ACROSS THE LESSER ANTILLES TO NEAR GRENADA. THE ITCZ AXIS EXTENDS ALONG 9N IN THE SW CARIBBEAN SEA AND ACROSS CENTRAL PANAMA INTO THE ERN PACIFIC GENERATING SCATTERED SHOWERS WITHIN 120 NM ALONG THE COAST OF NRN COLOMBIA AND PANAMA BETWEEN 67W-82W. ATLANTIC OCEAN... TROPICAL STORM LAURA IS LOCATED WELL N OF THE REGION...SEE SPECIAL FEATURES ABOVE. THE DEEP UPPER TROUGH OVER THE ERN US AND GULF OF MEXICO EXTENDS INTO THE W ATLC W OF 75W WITH THE ASSOCIATED COLD FRONT ENTERING THE REGION NEAR 32N69W SW TO GRAND BAHAMA ISLAND WHERE A SURFACE TROUGH CONTINUES INTO A 1010 MB LOW NEAR 26N80W ALONG THE COAST OF FLORIDA NEAR PALM BEACH. THE SW UPPER FLOW IS DRAWING ABUNDANT MOISTURE ACROSS THE AREA PROVIDING THE UPPER SUPPORT FOR SCATTERED SHOWERS/ISOLATED TSTMS WITHIN 150 NM E OF THE FRONT. A BROAD UPPER HIGH COVERS THE REMAINDER OF THE W ATLC INTO THE CENTRAL ATLC AND S OVER THE NE CARIBBEAN SEA CENTERED NEAR 25N64W. STRONG SUBSIDENCE AND DRY STABLE AIR COVER THE AREA S OF 30N BETWEEN 59W-69W RESULTING IN FAIR WEATHER OVER THAT AREA. A CUT-OFF UPPER LOW IS IN THE WRN TROPICAL ATLC NEAR 18N51W TO THE W OF THE TROPICAL WAVE ALONG 49W. NEARLY ZONAL FLOW COVERS THE REMAINDER OF THE ATLC N OF 20N E OF 44W. MULTILAYERED CLOUDINESS IS ACROSS THE CENTRAL ATLC WITH POSSIBLE ISOLATED SHOWERS N OF 25N BETWEEN 36W-45W. THE TYPICAL E/W UPPER RIDGE THAT DOMINATES THE TROPICAL ATLC EXTENDS ALONG 15N TO 45W ANCHORED BY AN UPPER HIGH CENTERED NEAR 15N30W. A SURFACE RIDGE EXTENDS FROM THE E ATLC THROUGH 32N29W SSE TO THE CAPE VERDE ISLANDS AND A SECOND SURFACE RIDGE EXTENDS SW TO NEAR 23N67W. VISIBLE SATELLITE IMAGERY SHOWS AFRICAN DUST COVERING THE ERN ATLC FROM 10N-20N E OF 30W. $$ HUFFMAN