000 AXNT20 KNHC 080528 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 205 AM EDT MON OCT 08 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 0515 UTC. ...SPECIAL FEATURE... A BROAD AREA OF LOW PRES IS CENTERED IN THE NW CARIB NEAR 18N83W...ANALYZED 1005 MB AT 03Z. THIS LOW SITS ALONG A SFC TROUGH WHICH EXTENDS NE ACROSS THE YUCATAN PENINSULA AND INTO THE S CENTRAL OR SW GULF. SYNOPTIC 24-HOUR TENDENCIES SHOW VERY LITTLE TO NO DEEPENING SINCE YESTERDAY AT THIS TIME. SATELLITE IMAGES REVEAL A BROAD SLOPPY CLOUD PATTERN WITH CONVECTION SCATTERED ABOUT THE TROUGH AXIS...CURRENTLY WIDELY SCATTERED MODERATE IS FROM 14N-19N BETWEEN 82W-89W. UPPER-LEVEL WINDS ARE FAVORABLE FOR SLOW DEVELOPMENT OF THIS SYSTEM DURING THE NEXT COUPLE OF DAYS AS IT MOVES VERY SLOWLY WESTWARD OR NORTHWESTWARD. AN AIR FORCE HURRICANE HUNTER AIRCRAFT IS SCHEDULED TO INVESTIGATE THIS SYSTEM ON MONDAY...IF NECESSARY. ...TROPICAL WAVES... TROPICAL WAVE IS ADDED TO THE 00Z ANALYSIS ALONG 37W/38W S OF 12N ESTIMATED TO BE MOVING W 15 KT. THIS LOW AMPLITUDE WAVE HAS BEEN DIFFICULT TO SEE SINCE EMERGING OFF THE AFRICAN COAST...LIKELY A FEW DAYS AGO...AS IT HAS BEEN EMBEDDED WITHIN THE LINEAR ITCZ CLOUDINESS. THE WAVE IS MORE VISIBLE ON TONIGHT'S IMAGERY WITH THE ASSOCIATED DEEP CLOUDINESS REACHING A POLEWARD CREST ALONG THE ANALYZED AXIS. THE MIMIC TPW ANIMATION SHOWS A NARROW RATHER QUICK WWD MOVING MOISTURE BUMP PERTURBING THE ITCZ...RELATED TO THIS WEAK FEATURE. SCATTERED SHOWERS AND TSTMS ARE WITHIN 210 NM EITHER SIDE OF THE AXIS. TROPICAL WAVE IS ALONG 55W S OF 20N MOVING W TO NW NEAR 10 KT. A 1010 MB LOW IS LOCATED ALONG THE WAVE AXIS NEAR 17N. THIS LOW ONLY CONSISTS OF LOW-LEVEL CLOUDS...AND IN FACT MAY BE OPENING UP. WEAKENING SCATTERED MODERATE CONVECTION IS WELL REMOVED TO THE E OF THE WAVE FROM 15N-18N BETWEEN 51W-53W...SHEARED OFF BY STRONG UPPER SWLY FLOW. ...THE ITCZ... ITCZ AXIS IS CENTERED ALONG 11N15W 6N24W 8N36W 9N45W 10N53W 9N62W. THE AXIS REMAINS ACTIVE TONIGHT. IN ADDITION TO THE CONVECTION ASSOCIATED WITH THE TROPICAL WAVES...SCATTERED MODERATE IS WITHIN 180 NM EITHER SIDE OF THE AXIS BETWEEN 25W-49W. DISCUSSION... THE GULF OF MEXICO... QUITE BREEZY WEATHER CONTINUES IN THE CENTRAL AND EASTERN GULF WATERS THIS EARLY MORNING. DATA FROM SHIPS...BUOYS AND A RECENT QSCAT PASS REVEAL ELY WINDS MAINLY IN THE 15-20 KT RANGE E OF ABOUT 92W. THIS MODERATE TO FRESH FLOW IS ASSOCIATED WITH A TIGHTENED PRES PATTERN BETWEEN A BROAD LOW PRES TROUGH IN THE NW CARIB AND A HIGH PRES RIDGE PARKED OVER THE MID-ATLANTIC STATES. THIS MOIST FLOW IS PICKING UP STREAMS OF SHALLOW QUICK MOVING SHOWERS FROM THE ATLC AND STEERING THEM ACROSS FLA AND THE GULF WATERS. SLIGHTLY DEEPER MOISTURE IS IN PLACE ACROSS THE CENTRAL GULF...ROUGHLY S OF 27N BETWEEN 85W-93W...ASSOCIATED WITH DEEP LAYER INVERTED TROUGHING RELATED TO THE NW CARIB LOW. CURRENTLY...IR IMAGES ARE NOT INDICATING MUCH IN THE WAY OF ORGANIZED TSTM ACTIVITY EXCEPT FOR A QUICKLY WEAKENING PATCH OVER THE ERN BAY OF CAMPECHE AND THE YUCATAN PENINSULA WHERE LOW-LEVEL CONVERGENCE IS A LITTLE MORE PRONOUNCED. THE WEATHER ACROSS THE WRN-MOST GULF REMAINS TRANQUIL...SITUATED TO THE W OF THE INVERTED TROUGHING...WITH FAIR TO MOSTLY CLEAR SKIES AND RATHER LIGHT SFC FLOW . THE CARIBBEAN SEA... THE SLOW MOVING BROAD AREA OF LOW PRES IN THE NW CARIB BETWEEN BELIZE... HONDURAS...AND THE CAYMAN ISLANDS IS THE MAIN FEATURE OF INTEREST TONIGHT. FOR DETAILS REFER TO THE SPECIAL FEATURE SECTION ABOVE. ELSEWHERE...SCATTERED MODERATE CONVECTION HAS MOVED LITTLE OVER THE PAST FEW HOURS N OF 16N BETWEEN 74W-77W...WHICH INCLUDES PORTIONS OF JAMAICA...ERN CUBA AND THE WINDWARD PASSAGE. THIS ACTIVITY IS ASSOCIATED WITH MOIST SLY LOW-LEVEL FLOW AND SOME CONVERGENCE IN THE LOW-LEVELS TO THE S OF AN ATLC SFC TROUGH. UPPER-LEVEL FLOW IS ALSO DIFFLUENT OVER THIS REGION BETWEEN TROUGHING OVER THE BAHAMAS AND RIDGING OVER THE CENTRAL CARIBBEAN. THIS UPPER PATTERN IS HELPING TO GENERATE AND SPREAD WIDESPREAD HIGH LEVEL CLOUDINESS ACROSS THE ENTIRE REGION. THE SFC TRADE WIND FLOW HAS BEEN GREATLY INTERRUPTED OVER THE PAST COUPLE OF DAYS ESP W OF 70W...DUE TO THE BROAD LOW PRES TROUGH. THIS IS EXPECTED TO CONTINUE TO BE THE CASE FOR A COUPLE MORE DAYS AS THE LOW MOVES VERY SLOWLY. E OF 70W...TRADES ARE FAIRLY LIGHT BUT THEY MIGHT INCREASE SLIGHTLY BY MID-WEEK AS THE SUBTROPICAL ATLC HIGH RIDGES FURTHER W. THE ATLANTIC OCEAN... AN ELONGATED SFC TROUGH PERSISTS ACROSS MUCH OF THE SW AND CENTRAL ATLC EXTENDING FROM THE SE BAHAMAS NEWARD ALONG 22N75W 24N64W 31N49W. A WEAK LOW...ANALYZED 1011 MB...HAS FORMED ALONG THE TROUGH AXIS NEAR 26N54W. A MID TO UPPER-LEVEL TROUGH WITH A SERIES OF EMBEDDED SHORTWAVES ARE SUPPORTING THIS LONG STRETCHED OUT SURFACE FEATURE. THERE ARE A COUPLE OF AREAS ALONG THE TROUGHING WHERE LOW TO MID-LEVEL VORTICITY APPEARS TO BE MAXIMIZED. ONE IS LOCATED SEVERAL HUNDRED MILES NORTH-NORTHWEST OF PUERTO RICO...WHERE THERE IS A CLUSTER OF SCATTERED MODERATE CONVECTION FROM 23N-25N BETWEEN 66W-69W. THE SECOND VORT MAX IS TO THE E OF THE WEAK SFC LOW GENERATING SCATTERED MODERATE CONVECTION FROM 23N-28N BETWEEN 47W-53W. UPPER-LEVEL WINDS REMAIN STRONG WHICH ARE INHIBITING ANY TROPICAL DEVELOPMENT OF THESE SYSTEMS. N AND W OF THE TROUGH AXIS...ELY SFC WINDS REMAIN MODERATE TO FRESH DUE TO THE TIGHTENED GRADIENT BETWEEN THE TROUGH AND HIGH PRES OVER THE MID ATLC STATES. MUCH QUIETER WEATHER EXISTS E OF 40W UNDER THE INFLUENCE OF A SFC RIDGE EXTENDING SW FROM A 1025 MB HIGH SE OF THE AZORES NEAR 35N22W. THIS IS KEEPING WINDS LIGHT IN THE SUBTROPICS AND MODERATE IN THE TROPICS...EXCEPT SLIGHTLY STRONGER 20-25 KT NLY WINDS OFF THE COAST OF NW AFRICA WHERE THE GRADIENT REMAINS TIGHTER PER USUAL. THE MAIN MID TO UPPER LEVEL FEATURE OVER THE TROPICS IS AN UPPER HIGH LOCATED NEAR 12N39W. THE UPPER-LEVEL FLOW IS QUITE STRONG OUT OF THE W TO SW ON THE NORTHERN SIDE OF THE TROPICAL RIDGE WHICH IS SPREADING SOME HIGH DEBRIS CLOUDINESS...FROM ITCZ CONVECTION...S OF 20N BETWEEN 32W-47W. A SHARP UPPER TROUGH IS BEGINNING TO CUT OFF JUST TO THE NE OF THE MADEIRA ISLANDS. THIS FEATURE IS GENERATING SOME CLOUDINESS AND SHOWERS OVER THOSE ISLANDS AND NE TOWARD SRN PORTUGAL WITH A TAIL OF MOISTURE PASSING THROUGH THE CANARY ISLANDS. $$ CANGIALOSI