000 AXNT20 KNHC 241759 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 205 PM EDT WED OCT 24 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... A NEW TROPICAL TROPICAL WAVE IS ADDED TO THE 1200 UTC SURFACE MAP ALONG 22W/23W BASED ON SATELLITE IMAGERY AND THE HOVMOLLER DIAGRAM THAT SHOWS THE WESTWARD PROPAGATION OF THE WAVE. IN ADDITION...THE WAVE SHOWS UP WELL ON THE UW-CIMSS TPW PRODUCT AND 850 MB VORTICITY. THIS SYSTEM MOVED OUT OF AFRICA YESTERDAY...AND NOW IS APPROACHING THE CAPE VERDE ISLANDS. SCATTERED MODERATE TO ISOLATED STRONG CONVECTION IS FROM 4N-10N BETWEEN 21W-25W. TROPICAL WAVE IS ALONG 32W/33W MOVING W NEAR 10 KT. THIS WAVE ALSO SHOWS UP WELL ON THE MIMIC-TPW PRODUCT AND 850 MB VORTICITY WITH MOST OF THE CONVECTIVE ACTIVITY EAST OF THE WAVE AXIS. SCATTERED MODERATE CONVECTION IS FROM 6N-12N BETWEEN 28W-32W. TROPICAL WAVE IS ALONG 66W MOVING W 5-10 KT. NO DEEP CONVECTION IS ASSOCIATED WITH THE WAVE. ...THE ITCZ... ITCZ AXIS IS CENTERED ALONG 7N12W 8N26W 7N40W 8N60W. BESIDES FOR THE CONVECTION ASSOCIATED WITH THE TROPICAL WAVES...SCATTERED MODERATE CONVECTION IS FROM 4N-7N BETWEEN 10W-15W...AND WITHIN 100 NM SOUTH OF AXIS 35W-40W. DISCUSSION... GULF OF MEXICO... A COLD FRONT CONTINUES TO PUSH E ACROSS THE E GULF AND THE FAR WEST CARIBBEAN BUT IS LOSING MUCH OF ITS PUNCH AND SPEED. AS OF 1500 UTC...THE FRONT EXTENDS FROM A 1007 MB LOW OVER NORTH CAROLINA TO 31N81W THEN ACROSS FLORIDA CROSSING THE TAMPA BAY AREA AND CONTINUING OVER THE SE GULF INTO THE WEST CARIBBEAN TO THE GULF OF HONDURAS. MOSAIC DOPPLER RADAR FROM THE SE U.S. DEPICTS A BAND OF SHOWERS WITH EMBEDDED TSTMS AFFECTING THE WESTERN COAST OF FLORIDA BETWEEN TAMPA BAY AND FORT MYERS. SHOWERS AND TSTMS ARE ALSO SEEN OVER SE FLORIDA IN A HUMID AND UNSTABLE ATMOSPHERE AHEAD OF THE FRONT. DEEP LAYERED TROUGH ASSOCIATED WITH THE FRONT EXTENDS FROM AN UPPER LOW OVER THE LOWER MISSISSIPPI VALLEY INTO THE GULF AND NE MEXICO. THE STRONG WINDS THAT HAVE BEEN BLOWING BEHIND THE FRONT ARE EXPECTED TO DIMINISHED LATE THIS AFTERNOON AND TONIGHT. AN EARLIER QUIKSCAT PASS SHOWED NLY WINDS OF 25 TO 35 KT JUST BEHIND THE FRONT. DRY STABLE CONTINENTAL AIR CONTINUES TO PUSH E OVER THE NW PORTION OF THE GULF CLEARING SKIES FROM SE LOUISIANA TO NEAR JALAPA MEXICO. THE FRONT WILL CONTINUE TO MOVE SLOWLY THIS AFTERNOON THEN STALL ACROSS FLORIDA AND THE STRAITS OF FLORIDA TONIGHT AND THU. CARIBBEAN SEA... AN AREA OF DISTURBED WEATHER...ANALYZED 1009 MB SFC LOW...IS LOCATED OVER THE CARIBBEAN SEA BETWEEN COLOMBIA AND JAMAICA. SATELLITE IMAGERY SHOWS THE CLOUD PATTERN EXHIBITING CYCLONIC CIRCULATION DUE TO THE PRESENCE OF THE LOW PRESSURE. CLUSTERS OF MODERATE TO STRONG CONVECTION ARE OVER THE CENTRAL CARIBBEAN SOUTH OF JAMAICA. THERE ARE CURRENTLY NO SIGNS OF ORGANIZATION BUT UPPER-LEVEL ARE FORECAST TO SLOWLY BECOME A LITTLE MORE FAVORABLE FOR DEVELOPMENT DURING THE NEXT COUPLE OF DAYS. SCATTERED SHOWERS AND TSTMS ARE OVER THE NW CARIBBEAN JUST AHEAD OF THE AFOREMENTIONED COLD FRONT. THE FRONT IS EXPECTED TO PUSH SLOWLY EWD THIS AFTERNOON AND NW WINDS WILL INCREASE TO 20-25 KT TONIGHT BEHIND THE FRONTAL BOUNDARY TONIGHT. UPPER DIFFLUENCE BETWEEN AN UPPER LOW LOCATED OVER HONDURAS AND A RIDGE EXTENDING NW FROM NORTHERN SOUTH AMERICA ACROSS THE CENTRAL CARIBBEAN INTO E CUBA IS HELPING TO INDUCE ALL THE CONVECTIVE ACTIVITY OBSERVED IN THE CENTRAL AND WESTERN CARIBBEAN SEA. A WEAK AREA OF LOW PRESSURE...ANALYZED 1010 MB SFC LOW...IS JUST EAST OF THE NORTHERN LEEWARD ISLANDS NEAR 17N60W. THIS FEATURE IS PRODUCING A LARGE AREA OF CLOUDINESS AND SHOWERS. WHILE THIS SYSTEM HAS A WELL-DEFINED LOW-LEVEL CIRCULATION...SHOWERS AND THUNDERSTORMS REMAIN POORLY ORGANIZED AND PRIMARILY DISPLACED TO THE EAST DUE TO STRONG UPPER WLY WINDS OVER THE AREA. UPPER-LEVEL WINDS ARE EXPECTED TO REMAIN UNFAVORABLE FOR SIGNIFICANT DEVELOPMENT OF THIS SYSTEM AS IT MOVE SLOWLY WESTWARD DURING THE NEXT COUPLE OF DAYS. A TROPICAL WAVE IS MOVING ACROSS THE E CARIBBEAN. SEE TROPICAL WAVE SECTION FOR DETAILS. LIGHT TRADES PREVAIL ACROSS THE BASIN. ATLANTIC OCEAN... BROAD UPPER HIGH SITUATED N OF AREA CLIPS THE W-CENTRAL ATLC WITH ELY WINDS AND DRY STABLE AIR N OF 26N FROM 55W TO 65W. AN UPPER LOW IS NE OF THE VIRGIN ISLANDS NEAR 21N62W. AN UPPER TROUGH EXTENDS NW FROM THIS LOW TO JUST N OF THE NW BAHAMAS. THE RIDGE THAT DOMINATES THE CARIBBEAN SEA ALSO ENVELOPS EASTERN CUBA...HISPANIOLA AND THE BAHAMAS. A LARGE DEEP LAYERED TROUGH COVERS THE E/CENTRAL ATLC WITH A 1002 MB SURFACE LOW CENTERED NEAR 32N33W AND A SURFACE TROUGH EXTENDING S TO 22N40W. SCATTERED SHOWERS/ISOLATED THUNDERSTORMS ARE WELL E OF THIS SYSTEM. A BAND OF TRANSVERSE HIGH CLOUDS ASSOCIATED WITH A JET STREAM BRANCH WITH CORE WINDS UP TO 70 KT CROSSES THE E-CENTRAL ATLC ALONG 20N50W 24N35W 23N26W. WEAK UPPER RIDGE EXTENDS ALONG THE COAST OF W AFRICA N OF 15N ACROSS THE CANARY ISLANDS TO BEYOND 32N20W COVERING THE REMAINDER OF THE E ATLC. A SFC RIDGE ANCHORED BY A 1024 HIGH LOCATED N OF AREA NEAR 34N58W DOMINATES MOST OF THE W AND CENTRAL ATLC. WEAK SFC RIDGE COVERS THE E ATLC WITH A 1017 HIGH LOCATED NEAR 25N22W. IN BETWEEN...IS THE ABOVE MENTIONED SFC LOW. $$ GR