000 AXNT20 KNHC 071044 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 805 AM EDT SUN OCT 07 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1030 UTC. ...TROPICAL WAVES... TROPICAL WAVE IS ALONG 52W/53W S OF 18N MOVING W 10 KT. A 1008 MB LOW IS LOCATED ALONG THE WAVE AXIS NEAR 16N. BUOY 41040 HAS BEEN VERY HELPFUL IN ANALYZING THIS LOW. IR IMAGERY SHOWS A BALL OF CONVECTION THAT HAS BEEN MAINTAINED THROUGHOUT THE OVERNIGHT HOURS. HOWEVER...ALL OF THIS CONVECTION IS SITUATED TO THE E/SE OF AN EXPOSED LOW-LEVEL CIRCULATION CENTER. THIS LOW PRES SYSTEM IS OBVIOUSLY FEELING THE EFFECTS OF WLY SHEAR WHICH IS HAMPERING FURTHER ORGANIZATION. ...THE ITCZ... AXIS IS CENTERED ALONG 12N16W 8N24W 9N40W 10N51W 9N62W. THE ITCZ HAS BECOME MUCH MORE ACTIVE THIS MORNING WITH SCATTERED MODERATE CONVECTION WITHIN 90 NM N AND 120 NM S OF THE AXIS BETWEEN 23W-45W. A CLUSTER OF SCATTERED MODERATE IS NEAR THE COAST OF AFRICA FROM 7N-9N E OF 15W. DISCUSSION... THE GULF OF MEXICO... THE SFC FLOW IS ON THE BRISK SIDE IN THE E GULF IN RESPONSE TO A TIGHTENED PRES PATTERN BETWEEN LOW PRES TO THE S IN THE NW CARIBBEAN AND HIGH PRES OVER AND OFF THE MID-ATLANTIC COASTLINE. THIS STIFF FLOW IS BLOWING ISOLATED STREAMS OF SHOWERS FROM THE ATLC ACROSS FLORIDA AND INTO THE E GULF WATERS. THE SFC FLOW SIGNIFICANTLY SLACKENS W OF 92W AS THE GRADIENT RELAXES. SCATTERED SHOWERS AND TSTMS ARE EXPANDING SOME IN THE CENTRAL GULF FROM 24N-29N BETWEEN 88W-92W. THIS ACTIVITY IS ASSOCIATED WITH DEEP LAYER INVERTED TROUGHING WHICH EXTENDS NWD FROM THE AFOREMENTIONED LOW IN THE NW CARIB. SKY CONDITIONS ACROSS MOST OF THE W GULF ARE FAIR TO MOSTLY CLEAR UNDER A MODERATE SUBSIDENT ENVIRONMENT SUPPORTED BY A SOMEWHAT CONFLUENT UPPER PATTERN. LOOKING AHEAD A DAY OR SO...WINDS ARE EXPECTED TO REMAIN MODERATE TO FRESH IN THE E GULF AND THE MOISTURE PLUME IS ANTICIPATED TO CONTINUE PIVOTING WWD. THE CARIBBEAN SEA... THE MAIN AREA OF FOCUS CONTINUES TO BE THE BROAD LOW PRES TROUGH OBSERVED ACROSS THE WRN HALF OF THE CARIB SEA. YESTERDAY AND EARLIER THIS MORNING...INCLUDING ON THE 06Z ANALYSIS...WE HAVE BEEN TRACKING A BROAD AREA OF LOW PRES IN THE NW CARIB. BASED ON THE LATEST SATELLITE IMAGERY AND SFC DATA THERE APPEARS TO BE TWO LOWS EMBEDDED IN THE TROUGH. AS OF 09Z...THE NRN LOW IS ANALYZED ABOUT 75 NM SE OF COZUMEL MEXICO NEAR 20N86W. THE SRN LOW IS LOCATED ABOUT 150 NM NE OF ERN HONDURAS NEAR 17N82W...BOTH OF THESE ARE ESTIMATED TO BE 1004 MB. SYNOPTIC SFC PRESSURES ARE RUNNING 2-4 MB LOWER ACROSS THIS GENERAL VICINITY COMPARED TO THIS TIME YESTERDAY. THE LOW OF INTEREST THIS MORNING IS THE SRN ONE AS CONVECTION HAS FORMED AND EXPANDED SINCE COMING OUT OF THE GOES-E SAT ECLIPSE A FEW HOURS AGO. CURRENTLY...SCATTERED MODERATE IS WITHIN 150 NM S SEMICIRCLE. THIS AREA IS BEING MONITORED AS ENVIRONMENTAL CONDITIONS APPEAR TO SUPPORT FURTHER DEVELOPMENT. ELSEWHERE...WIDELY SCATTERED MODERATE CONVECTION IS BETWEEN 69W-77W. A GLANCE AT WATER VAPOR IMAGERY SUGGESTS THAT MUCH OF THIS IS SUPPORTED BY MID-UPPER LEVEL FEATURES. THE PATTERN CONSISTS OF BROAD INVERTED TROUGHING W OF 75W AND WLY FLOW E OF 75W ON THE S SIDE OF AN UPPER LOW CENTERED JUST N OF HISPANIOLA. WIDESPREAD MID TO HIGH LEVEL CLOUDINESS COVERS THE BULK OF THE AREA. THE TYPICAL TRADE WIND FLOW IS INTERRUPTED IN THE WRN CARIB DUE TO THE PRESENCE OF THE LOW PRES TROUGH. ELY TRADES ARE STILL FAIRLY LIGHT...10-15 KT IN THE E CARIB...DUE TO ANOTHER SFC TROUGH LOCATED TO THE N OF THE REGION. THE ATLANTIC OCEAN... ACTIVE WEATHER CONTINUES N OF PUERTO RICO ASSOCIATED WITH A STRETCHED OUT SFC TROUGH...ANALYZED ALONG 27N50W 23N60W TO THE ERN BAHAMAS NEAR 22N73W...AND AN UPPER LOW CENTERED ABOVE THE N SHORE OF HISPANIOLA. IR IMAGERY CONTINUES TO SHOW SOME ROTATION TO THE MID-LEVEL CLOUDINESS...ALTHOUGH CONVECTION HAS DECREASED SINCE EARLIER THIS MORNING. CURRENTLY...SCATTERED MODERATE IS FROM 19N-23N BETWEEN 64W-68W. THIS AREA IS BEING MONITORED FOR FURTHER DEVELOPMENT. ANOTHER BLOB OF SIMILAR CONVECTION IS LOCATED FROM 21N-27N BETWEEN 48W-53W. THIS LARGE PATCH OF ACTIVITY IS BEING ENHANCED BY THE SAME SFC TROUGH COUPLED WITH DIFFLUENCE ALOFT ON THE E SIDE OF A SHORTWAVE MID TO UPPER TROUGH. THE TIGHTENED PRES GRADIENT BETWEEN THIS FAIRLY HORIZONTAL SFC TROUGH AND A HIGH PRES RIDGE N OF BERMUDA IS GENERATING A RATHER LARGE AREA OF 20-25 KT ELY WINDS ROUGHLY N OF 24N W OF 55W. SCATTERED QUICK MOVING SHOWERS ARE POSSIBLE JUST ABOUT ANYWHERE UNDER THIS STRONG LOW-LEVEL FLOW REGIME. MUCH QUIETER WEATHER EXISTS E OF 45W. THE MAIN MID TO UPPER LEVEL FEATURE IS A HIGH PRES AREA CENTERED NEAR 12N38W. THIS SYSTEM IS HELPING TO SINK THE AIR ACROSS MOST OF THE TROPICS KEEPING CONVECTION CONFINED TO THE ITCZ. IN THE SUBTROPICS...THE UPPER FLOW IS QUITE STRONG OUT OF THE W TO SW ON THE N SIDE OF THE TROPICAL RIDGE AND ENHANCED E OF A TROUGH WHICH EXTENDS TO 27N28W. THIS SWIFT FLOW IS SPREADING DEBRIS MOISTURE ACROSS MUCH OF THE AREA N OF 23N W OF THE CANARY ISLANDS. THE SFC PATTERN IS RATHER TRANQUIL GOVERNED BY A 1020 MB HIGH CENTERED NEAR 28N33W. THIS IS KEEPING WINDS LIGHT IN THE SUBTROPICS AND MODERATE IN THE TROPICS...EXCEPT SLIGHTLY STRONGER 20-25 KT NLY WINDS BETWEEN THE CAPE VERDE ISLANDS AND THE AFRICAN COAST FROM 17N-23N WHERE THE GRADIENT IS TYPICALLY TIGHT BETWEEN THE SUBTROPICAL RIDGE AND INVERTED TROUGHING OVER THE CONTINENT. $$ CANGIALOSI