000 AXNT20 KNHC 170553 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 205 AM EDT MON SEP 17 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0615 UTC. ...SPECIAL FEATURE... TROPICAL DEPRESSION INGRID WEAKENS JUST EAST OF THE NORTHERN LEEWARD ISLANDS. AT 17/0300 UTC IT IS CENTERED NEAR 17.4N 59.4W OR ABOUT 140 NM E OF THE LESSER ANTILLES MOVING WEST AT 8 KT. MAXIMUM SUSTAINED WIND SPEED IS 25 KT WITH GUSTS TO 35 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 1010 MB. SEE LATEST NHC FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMAT3/WTNT23 KNHC. DEEP CONVECTION ASSOCIATED WITH INGRID HAS DISAPPEARED AND THE SHOWER ACTIVITY CONTINUES TO DISSIPATE SINCE SUNDAY EVENING. A SMALL AREA OF SCATTERED MODERATE CONVECTION IS WITHIN 35 NM RADIUS OF 17N56W. SCATTERED SHOWERS AND POSSIBLE ISOLATED THUNDERSTORMS ARE FROM 14N-16N BETWEEN 57W-59W. THE NEW OFFICIAL INTENSITY FORECAST KEEPS THE CYCLONE AS A 25-KT DEPRESSION THROUGHOUT THE FIVE-DAY PERIOD...BUT IT MIGHT NOT BE A TROPICAL CYCLONE FOR NEARLY THAT LONG. INTERESTS IN THE NORTHERN LEEWARD ISLANDS SHOULD MONITOR THE PROGRESS OF INGRID. ...TROPICAL WAVES... THE TROPICAL WAVE THAT WAS PREVIOUSLY ALONG 40W/41W IS RELOCATED AHEAD NEAR 43W BASED ON LATEST SATELLITE IMAGERY AND EARLIER ASCAT PASS THAT SHOWS A BROAD CYCLONIC TURNING NEAR 12N43W. 850 MB MODEL GUIDANCE SUGGESTS STRONG VORTICITY MAXIMUM IN THIS AREA. CLUSTERS OF SCATTERED MODERATE CONVECTION ARE FROM 11N-15N BETWEEN 42W-46W. DEVELOPMENT OF THIS SYSTEM...IF ANY...IS EXPECTED TO BE SLOW TO OCCUR IT MOVES WESTWARD AT 10 TO 15 MPH. THE WEAK TROPICAL WAVE THAT WAS ANALYZED ALONG 48W/49W ON THE 00Z SURFACE MAP IS NO LONGER IDENTIFIABLE BASED ON LATEST SATELLITE IMAGERY AND EARLIER QUIKSCAT PASS THAT SHOWS A NELY WIND FLOW OVER THE AREA...AHEAD OF THE TROPICAL WAVE LOCATED NEAR 43W. IN ADDITION...THE TOTAL PRECIPITABLE WATER PRODUCT ONLY DEPICTS THE BULGE OF MOISTURE ASSOCIATED WITH THE TROPICAL WAVE ALONG 43W. TROPICAL WAVE IS ALONG 74W S OF 18N MOVING W 10-15 KT. SHOWER ACTIVITY HAS DECREASED TONIGHT OVER THE CENTRAL CARIBBEAN SEA IN ASSOCIATION WITH THIS TROPICAL WAVE AND AN UPPER-LEVEL TROUGH. UPPER-LEVEL WINDS ARE CURRENTLY UNFAVORABLE FOR DEVELOPMENT OF THIS SYSTEM...BUT THEY COULD BECOME A LITTLE MORE FAVORABLE FOR SLOW DEVELOPMENT OVER THE WESTERN CARIBBEAN IN A COUPLE OF DAYS AS THE SYSTEM MOVES WESTWARD AT 10 TO 15 MPH. ...THE ITCZ... ITCZ AXIS IS CENTERED ALONG 12N17W 8N26W 11N39W 11N46W 8N62W. IN ADDITION TO CONVECTION ASSOCIATED WITH THE TROPICAL WAVE... SCATTERED MODERATE CONVECTION IS ALONG 5N BETWEEN 20W-25W...AND NEAR 5N33W. CLUSTERS OF MODERATE CONVECTION ARE FROM 6N-11N EAST OF 16W TO JUST INLAND OVER W AFRICA. DISCUSSION... GULF OF MEXICO... AN ELONGATED UPPER LOW IS OVER THE SW GULF/ W BAY OF CAMPECHE NEAR 20N96W COVERING MOST OF THE WESTERN HALF OF THE GULF. AN UPPER HIGH IS IN THE SE GULF NEAR 23N85W. DIFFLUENCE BETWEEN THESE TWO UPPER FEATURES IS HELPING TO INDUCE AN AREA OF SHOWERS AND TSTMS OVER THE YUCATAN PENINSULA. A DEEP LAYERED UPPER TROUGH IS OVER THE E US INTO THE NE GULF. THE ASSOCIATED COLD FRONT ENTERS THE W ATLC NEAR 31N72W BECOMING NEAR STATIONARY ACROSS THE NORTH-CENTRAL FLORIDA PENINSULA AND THE CENTRAL GULF TO THE LOWER TEXAS COAST. A NARROW BAND OF SHOWERS WITH ISOLATED TSTMS IS RELATED TO THE FRONT ACROSS THE GULF. DRY AIR IS OVER THE NORTHERN GULF WATERS JUST BEHIND THE FRONT. AS OF 0300 UTC...A SFC TROUGH IS ANALYZED ALONG 81W/82W JUST WEST OF THE FLORIDA KEYS. THIS TROUGH CROSSES WESTERN CUBA GENERATING A CLUSTER OF MODERATE TO ISOLATED STRONG CONVECTION OVER THE ISLE OF YOUTH. THE FRONT IS EXPECTED TO BECOME DIFFUSE TODAY. CARIBBEAN SEA... THE UPPER HIGH IN THE SE GULF OF MEXICO COVERS THE NW CARIBBEAN. AN UPPER LOW IS OVER THE WINDWARD PASSAGE WITH A TROUGH EXTENDING SW TO NEAR 13N82W. ABUNDANT MID/UPPER LEVEL MOISTURE IS BEING ADVECTED EAST OF THE LOW/TROUGH ACROSS THE EAST-CENTRAL CARIBBEAN INTO THE W ATLC THROUGH PUERTO RICO AND HISPANIOLA. DIFFLUENCE BETWEEN THIS UPPER HIGH AND THE BROAD UPPER LOW IN THE CARIBBEAN IS HELPING TO GENERATE CLUSTERS OF SCATTERED SHOWERS/THUNDERSTORMS MAINLY OVER THE ISLANDS OF HISPANIOLA... CUBA...AND JAMAICA. AN UPPER RIDGE DOMINATES THE E CARIBBEAN ANCHORED ON A HIGH OVER NORTHERN VENEZUELA. LIGHT TO MODERATE TRADE WINDS ARE BLOWING ACROSS THE BASIN. THE UPPER LOW IS FORECAST TO MOVE TOWARD THE SE BAHAMAS/NORTHERN HISPANIOLA WITH THE TRAILING UPPER TROUGH. THIS WEATHER PATTERN WILL CONTINUE TO ENHANCE CONVECTION OVER THE GREATER ANTILLES DURING THE NEXT FEW DAYS. ATLANTIC OCEAN... THE UPPER TROUGH THAT COVERS THE E US AND THE NE GULF OF MEXICO EXTENDS INTO THE W ATLC N OF 27N W OF 72W WITH AN ASSOCIATED COLD FRONT ENTERING THE REGION NEAR 31N72W ACROSS THE FLORIDA PENINSULA AND THE GULF OF MEXICO AS NEAR STATIONARY FRONT. SCATTERED SHOWERS AND WIDELY ISOLATED THUNDERSTORMS ARE WITHIN 90 NM AHEAD OF THE FRONT. AN UPPER RIDGE EXTENDS FROM THE SE GULF INTO THE STATE OF FLORIDA AND THE WESTERN GULF W OF 70W. AN UPPER LOW IS NEAR 27N61W COVERING THE REMAINDER OF THE W ATLC INTO CENTRAL ATLC. THIS LOW IS GENERATING SCATTRED SHOWERS AND TSTMS MAINLY FROM 24N-29N BETWEEN 54W-61W. ANOTHER UPPER LOW IS SITUATED NEAR 32N35W. A SURFACE TROUGH IS ASSOCIATED WITH THIS FEATURE EXTENDING FROM A WEAK 1016 MB LOW NEAR 33N36W THROUGH 29N36W TO 27N41W WITH SCATTERED SHOWERS AND ISOLATED TSTMS PARTICULARLY EAST OF THE SFC LOW. BROAD ILL-DEFINED UPPER RIDGE DOMINATES THE E AND MOST OF THE TROPICAL ATLC EXTENDING ALONG 16N FROM W AFRICA TO JUST SE OF INGRID NEAR 52W. THE REMAINDER OF THE ATLC IS ENJOYING RATHER DRY CONDITIONS TONIGHT. $$ GR