000 AXNT20 KNHC 051745 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 205 PM EDT WED SEP 05 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. ...SPECIAL FEATURES... A NON-TROPICAL AREA OF LOW PRES LOCATED ABOUT 350 NM WEST-SOUTHWEST OF BERMUDA NEAR 29N71W...ANALYZED 1008 MB...HAS GENERALLY CHANGED LITTLE IN STRUCTURE TODAY. VISIBLE IMAGES SHOW AN EXPOSED LOW-LEVEL CENTER WITH MOST OF THE SHOWER AND TSTMS ACTIVITY STRETCHED OUT TO THE NE OF THE LOW FROM 29N-32N BETWEEN 68W-71W AND ALONG THE TRAILING TROUGH AXIS. A NEW BURST OF CONVECTION HAS FORMED NEAR THE CENTER. A QSCAT PASS AROUND 11Z DEPICTED STRONG WINDS TO THE E OF THE CIRCULATION ALTHOUGH SEVERAL OF THE WIND BARBS WHERE RAIN FLAGGED...HOWEVER IT IS LIKELY THAT NEAR GALE FORCE WINDS ARE OCCURRING AS THERE IS SEVERAL 20-25 KT UNCONTAMINATED VECTORS. THIS LOW HAS BEEN MOVING SLOWLY EWD OR JUST S OF E OVER THE PAST 24-48 HOURS BUT LITTLE MOVEMENT IS EXPECTED DURING THE NEXT DAY OR SO. AN AIR FORCE RESERVE HURRICANE HUNTER AIRCRAFT IS EN ROUTE TO INVESTIGATE THE SYSTEM THIS AFTERNOON. STAYED TUNED. ...TROPICAL WAVES... LONG WAVELENGTH TROPICAL WAVE IS ALONG 37W/38W S OF 23N MOVING W NEAR 20 KT OVER THE PAST 24 HOURS. THIS WAVE HAS CHANGED LITTLE IN STRUCTURE SINCE MOVING OFF THE AFRICAN COAST WITH ABOUT A 15 DEG LONGITUDE AREA OF LOW-LEVEL CYCLONIC TURNING. THE WEAK LOW THAT WAS STATIONARY ALONG 40W FOR THE PAST FEW DAYS HAS BEEN DRAWN E INTO THE WAVE'S ROTATION AND IS CURRENTLY CENTERED ALONG THE WAVE AXIS NEAR 12N...ANALYZED 1013 MB. WHILE THE SATELLITE PRESENTATION OF THIS WAVE IS IMPRESSIVELY LARGE AND WELL DEFINED...DEEP SHOWER ACTIVITY IS VERY LIMITED AND CONFINED TO THE INTERSECTION OF THE ITCZ. LOW AMPLITUDE TROPICAL WAVE IS ALONG 68W S OF 17N MOVING W 15 KT. THE UW-CIMSS TPW ANIMATION TELLS THE STORY BEST...SHOWING THIS WEAK WAVE (WHICH APPEARED TO HAVE SOME ROTATION) SPLITTING YESTERDAY JUST PAST 60W. THE NRN PART OF THE WAVE IS ROTATING NWD AROUND THE ATLC SUBTROPICAL RIDGE AND DISSIPATING. THE SRN PORTION CONTINUES ITS WWD MOVEMENT BUT IS VERY WEAK AND NOT PRODUCING ANY SENSIBLE WEATHER. ...THE ITCZ... ITCZ AXIS IS CENTERED ALONG 10N14W 8N22W 13N35W 10N40W 8N55W 10N62W. SCATTERED SHOWERS AND TSTMS COVER A LARGE AREA FROM 5N-13N E OF 20W PARTIALLY ASSOCIATED WITH THE NEXT TROPICAL WAVE STILL INLAND OVER AFRICA. SCATTERED SHOWERS AND ISOLATED TSTMS ARE WITHIN 180 NM S OF THE AXIS BETWEEN 20W-36W. DISCUSSION... GULF OF MEXICO... THE PATTERN HAS CHANGED LITTLE ACROSS THE GULF OVER THE PAST FEW DAYS. AN ELONGATED UPPER HIGH HAS DRIFTED S A BIT CENTERED NEAR THE S COAST OF LOUISIANA. SOME DIFFLUENCE ALOFT BETWEEN THIS RIDGE AND DEEP LAYER TROUGHING OVER THE W ATLC HAS SPARKED ISOLATED TO SCATTERED TSTMS ACROSS PARTS OF THE E GULF ROUGHLY FROM 25N-28N BETWEEN THE FL COAST AND 87W. THIS ACTIVITY IS GENERALLY MOVING S-SW DRIVEN BY THE UPPER FLOW. ENHANCED CONFLUENCE BETWEEN THE STRETCHED HIGH AND AN INVERTED TROUGH OVER THE BAY OF CAMPECHE IS DRYING OUT THE AIR IN THE MID AND UPPER LEVELS...PROVIDING MOSTLY FAIR WEATHER ACROSS MUCH OF THE CENTRAL AND SW GULF. AT THE SFC...A WEAK 1016 MB HIGH HAS BEEN QUASI-STATIONARY NEAR 28N91W. THIS WEAK HIGH IS ALLOWING WINDS TO BE LIGHT AND ANTICYCLONIC ACROSS THE REGION. CARIBBEAN SEA... THE REMNANTS OF ONCE CATEGORY FIVE HURRICANE FELIX IS NOW WELL INLAND NEAR THE BORDER OF NORTHEASTERN GUATEMALA AND NORTHWESTERN HONDURAS. EVEN THOUGH STRONG WINDS ARE NO LONGER A CONCERN HEAVY RAINFALL OVER PORTIONS OF CENTRAL AMERICA COULD RESULT IN LIFE-THREATENING FLASH FLOODS AND MUD SLIDES. RAINFALL REPORTS FOR THE HONDURAS WEATHER SERVICE INDICATE SEVERAL STATIONS WITH OVER 4 INCHES OF RAIN. THE MAXIMUM ACCUMULATION REPORTED WAS IN LA CEIBA WHERE 6.2 INCHES OF RAIN FELL. THE REMNANT CIRCULATION OF FELIX AND BROAD SELY FLOW OVER THE S CARIB IS DRAWING AMPLE MOISTURE FROM THE ITCZ ACROSS THE SW CARIB AND INTO LIKELY ALREADY SATURATED ERN NICARAGUA ...ROUGHLY SE OF A LINE ALONG 15N84W 12N73W. LESS ORGANIZED SCATTERED SHOWERS AND TSTMS ARE OVER PORTIONS OF THE NW CARIB FROM 17N-20N BETWEEN 78W-84W. THIS ACTIVITY IS ASSOCIATED WITH INSTABILITY NEAR AN UPPER LOW. IN THE E CARIB...A SLOW MOVING UPPER LOW IS CENTERED NEAR 15N67W. OVERALL...THIS FEATURE IS ADVECTING DRIER AIR INTO THE E CARIB E OF 72W THOUGH THERE IS A NARROW SWATH OF CLOUDINESS AND ISOLATED SHOWERS ON IT'S ERN SIDE JUST W OF THE WINDWARD ISLANDS. ATLANTIC OCEAN... THE MAIN FEATURE OF INTEREST IN THE ATLC DISCUSSION IS THE LOW PRES SYSTEM LOCATED ABOUT 350 NM WEST-SOUTHWEST OF BERMUDA. FOR DETAILS ON THIS SYSTEM REFER TO THE SPECIAL FEATURE SECTION ABOVE. OTHERWISE...THE ATLC DISCUSSION AREA IS FAIRLY QUIET WITH A 1023 MB HIGH CENTERED NEAR 29N30W CONTROLLING THE SFC PATTERN. THIS HIGH IS PRODUCING LIGHT TO MODERATE WINDS ACROSS MUCH OF THE AREA...EXCEPT STRONGER WINDS NEAR THE LARGE TROPICAL WAVE IN THE E ATLC AS SUGGESTED BY THE TIGHTENED PRES PATTERN ANALYZED. ALOFT...A RIDGE IS STRETCHED OUT ACROSS THE SUBTROPICS WITH A ROUGH AXIS RUNNING ALONG 24N BETWEEN 25W-65W WITH SEVERAL EMBEDDED ANTICYCLONES. THE MAIN ANTICYCLONE IS CENTERED NEAR 23N38W. OVERALL...DRY STABLE AIR IS ASSOCIATED WITH THIS RIDGE. THERE IS AN AN AREA OF SCATTERED SHOWERS AND ISOLATED TSTMS NEAR OUR NRN BORDER N OF 28N BETWEEN 45W-52W ASSOCIATED WITH INSTABILITY NEAR A RETREATING SHORTWAVE TROUGH. UPPER TROUGHING ALSO COVERS THE E ATLC TO THE S OF A LARGE UPPER LOW N OF THE MADEIRA ISLANDS. THERE IS AN ASSOCIATED SHIELD OF HIGH CLOUDINESS N OF 29N BUT NOT MUCH WEATHER TO TALK ABOUT. $$ CANGIALOSI