000 AXNT20 KNHC 061108 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 805 AM EDT SAT OCT 06 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 IN THE CENTRAL ATLANTIC ALONG 50W S OF 19N MOVING W 10 KT OVER THE PAST 24 HOURS. A 1009 MB LOW IS ALONG THE WAVE AXIS NEAR 14N. THE INTERACTION BETWEEN THIS WAVE AND DIFFLUENCE ALOFT TO THE E OF AN UPPER TROUGH HAS CAUSED CONVECTION TO FLARE UP ALONG AND TO THE E OF THE WAVE/LOW FROM 13N-16N BETWEEN 47W-50W. HOWEVER...SIGNIFICANT DEVELOPMENT IS UNLIKELY DUE TO UNFAVORABLE UPPER WINDS. ...THE ITCZ... AXIS CENTERED ALONG 10N14W 7N26W 8N37W 9N48W 11N62W. BESIDES FOR THE CONVECTION ASSOCIATED WITH THE TROPICAL WAVE...ISOLATED MODERATE IS WITHIN 120 NM N AND 90 NM S OF THE AXIS BETWEEN 31W-38W. DISCUSSION... THE GULF OF MEXICO... THE AREA OF LOW PRES THAT WE HAVE BEEN TRACKING FOR SEVERAL DAYS HAS NOW MOVED INLAND OVER SE TEXAS. ASSOCIATED SHOWER AND TSTM ACTIVITY IS MINIMAL WITH DOPPLER RADAR ONLY DEPICTING A FEW SHOWERS AND TSTMS IN VERY CLOSE TO THE CENTER. THE MORE WIDESPREAD SHOWER ACTIVITY IS OVER FLORIDA AND THE EXTREME SE GULF. DOPPLER RADAR IN THIS AREA IS SHOWING STREAMS OF SCATTERED SHOWERS AND TSTMS PUSHING IN FROM THE ATLC WATERS S OF 30N E OF 85W. THIS ACTIVITY IS TRIGGERED BY STRONG MOIST LOW-LEVEL FLOW AND SOME CONVERGENCE NEAR THE CREST OF A W CARIB TROUGH. IN ADDITION...WATER VAPOR IMAGERY SHOWS A WEAK DISTURBANCE OVER THE STATE WHICH IS ADDING INSTABILITY. THE REMAINDER OF THE REGION IS FAIRLY QUIET UNDER THE INFLUENCE OF UPPER RIDGING RUNNING N-S ALONG 92W WITH LARGE SCALE STABLE SINKING AIR. A MID TO UPPER LEVEL LOW LIES ABOVE CENTRAL MEXICO GENERATING CLOUDINESS AND SHOWERS OVER PORTIONS OF MEXICO AND THE TROPICAL EPAC. THE CARIBBEAN SEA... COMPLEX ELONGATED LOW-LEVEL TROUGHING EXISTS ACROSS THE CARIBBEAN THIS MORNING. ONE TROUGH IS IN THE W PORTION EXTENDING FROM THE STRAITS OF FLORIDA TO 12N77W. SFC OBSERVATIONS AT 09Z SHOW A BROAD AREA OF FAIRLY LOW PRES WITH AN ESTIMATED 1006 MB LOW CENTERED ALONG THE AXIS NEAR 17N81W. A 0312 Z ASCAT PASS SHOWED GOOD TURNING IN THE NW CARIB BUT REVEALED THAT THE WINDS ARE CURRENTLY VERY LIGHT. AN INFRARED ANIMATION SHOWS SOME INCREASE IN CONVECTION OVERNIGHT BUT THE ACTIVITY STILL REMAINS DISORGANIZED FROM 19N-22N BETWEEN 78W-83W AND WITHIN 60 NM OF 17N84W. SOME SLOW DEVELOPMENT IS POSSIBLE OVER THE NEXT FEW DAYS AS THE LOW DRIFTS TO THE W OR SW. ANOTHER LOW-LEVEL TROUGH IS LOCATED OVER THE GREATER ANTILLES EXTENDING FROM ERN CUBA ACROSS HISPANIOLA AND THEN NEWARD N OF THE LEEWARD ISLANDS. THE INTERACTION WITH AN UPPER LOW IS PRODUCING A SWATH OF SHOWERS AND TSTMS N OF THE AREA...MORE ON THIS FEATURE IN THE ATLANTIC DISCUSSION BELOW. ELSEWHERE IN THE MID AND UPPER LEVELS...RIDGING DOMINATES MUCH OF THE BASIN EXTENDING SE FROM THE CENTRAL GOMEX. THE UPPER FLOW IS LIGHTER IN THE ERN CARIB DUE TO THE AFOREMENTIONED UPPER LOW LOCATED N OF THE DOMINICAN REPUBLIC. THIS OVERALL PATTERN IS PRODUCING A LOT OF CLOUDINESS ACROSS THE REGION. HOWEVER...DEEP MOISTURE IS CONFINED TO NEAR THE LOW-LEVEL BOUNDARIES AND IN THE S CENTRAL CARIB S OF 16N BETWEEN 69W-72W. THE TRADE WIND FLOW IS SIGNIFICANTLY INTERRUPTED ACROSS THE CARIB DUE TO THE PRESCIENCE OF THE SFC BOUNDARIES. THESE MAINLY LIGHT AND CHANGEABLE WINDS ARE EXPECTED TO PERSIST ACROSS THE BULK OF THE AREA OVER THE NEXT DAY OR SO. THE ATLANTIC OCEAN... AN ELONGATED SFC TROUGH ANALYZED FROM 22N63W TO ERN CUBA DOMINATES THE SW PORTION OF THE ATLC BASIN. THERE ARE A FEW EMBEDDED VORT MAXES ALONG THIS STRETCHED OUT TROUGH AXIS. HOWEVER...THE MAIN ENERGY APPEARS TO BE NEAR THE UPPER LOW LOCATED JUST N OF THE DOMINICAN REPUBLIC. THIS INTERACTION IS PRODUCING SCATTERED SHOWERS AND TSTMS S OF 24N BETWEEN 62W-72W. PRECIP APPEARS MOST CONCENTRATED JUST N OF THE LEEWARD ISLANDS FROM 19N-21N BETWEEN 63W-65W. ENVIRONMENTAL CONDITIONS ARE GENERALLY FAVORABLE FOR SOME DEVELOPMENT OVER THE NEXT COUPLE OF DAYS AS IT MOVES SLOWLY NORTHWARD. THE TIGHTENED PRES GRADIENT BETWEEN THIS E-W TROUGHING AND HEALTHY RIDGING OFF THE MID-ATLANTIC COASTLINE IS PRODUCING MODERATE TO STRONG ELY WINDS AND STEEP WIND WAVES/SWELL N OF 25N W OF 50W. IN THE CENTRAL ATLC...A PIECE OF AN OLD FRONTAL ZONE THAT ABSORBED THE REMNANTS OF MELISSA IS ANALYZED ALONG 29N42W 23N56W. THE COMBINATION OF LOW-LEVEL CONVERGENCE NEAR THIS BOUNDARY...A TROPICAL WAVE TO ITS S ALONG 50W AND INSTABILITY ALOFT NEAR A TROUGH ALONG 51W/52W IS PRODUCING SCATTERED MODERATE CONVECTION FROM 18N-25N BETWEEN 45W-54W. STRONG UPPER WLY WINDS E OF THE TROUGH IS SPREADING DEBRIS MOISTURE INTO THE E ATLC N OF 25N W OF 25W. THE REMAINDER OF THE E ATLC IS MUCH QUIETER...WITH STABLE CONDITIONS UNDER THE INFLUENCE OF UPPER RIDGING AND A 1019 MB SFC HIGH NEAR 25N29W. $$ CANGIALOSI