000 AXNT20 KNHC 091703 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 205 PM EDT FRI JUN 09 2006 TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL AMERICA...THE GULF OF MEXICO...THE CARIBBEAN SEA...NORTHEASTERN 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...WEATHER OBSERVATIONS...RADAR... AND METEOROLOGICAL ANALYSIS. BASED ON 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1700 UTC. ...TROPICAL WAVES... TROPICAL WAVE IS ALONG 29W S OF 11N MOVING W 15 KT. A SLIGHT INVERTED V-PATTERN IS EVIDENT EMBEDDED WITHIN THE ITCZ...ALTHOUGH IT IS NOT AS WELL-DEFINED AS YESTERDAY. THIS WAVE HAS FAIR CURVATURE ASSOCIATED WITH IT. THERE ARE NO AREAS OF DEEP CONVECTION DIRECTLY ASSOCIATED. GFS HAS THE WAVE SOMEWHAT INITIALIZED AND CARRIES IT QUICKLY WWARD AS A FAIRLY WEAK FEATURE. TROPICAL WAVE IS ALONG 56W S OF 9N MOVING W 10-15 KT. WAVE IS MOSTLY INLAND OVER SOUTH AMERICA AND HAS BECOME DIFFICULT TO LOCATE. LITTLE...IF ANY WAVE SIGNATURE IS NOTED ON SATELLITE IMAGERY. ASSOCIATED CONVECTION IS WITHIN THE ITCZ AND IS DISCUSSED IN THAT SECTION. TROPICAL WAVE IS ALONG 69W S OF 12N MOVING W 10 KT. WAVE REMAINS INLAND OVER SOUTH AMERICA AND HAS BECOME VERY CHALLENGING TO TRACK OVER THE PAST FEW DAYS. NO WAVE SIGNATURE IS EVIDENT. TROPICAL WAVE IS ALONG 79W/80W S OF 13N MOVING W 10 KT. THE SOUTHERN EXTENSION OF THE WAVE IS ACROSS THE EPAC AND CUTS ACROSS PANAMA INTO THE W CARIBBEAN. MUCH OF THE CONVECTION IS ALONG AND TO THE SOUTH OF THE ITCZ IN THE E PACIFIC REGION. THIS WAVE HAS SOME SIGNATURE ESPECIALLY S OF PANAMA. ITCZ... ITCZ AXIS IS CENTERED ALONG 9N13W 6N23W 5N40W 6N54W. CLUSTERS OF MODERATE CONVECTION LIES FROM 4N-10N BETWEEN 15W-19W. SCATTERED SHOWERS AND ISOLATED TSTMS ARE WITHIN 60 NM EITHER SIDE OF THE AXIS W OF 34W. SCATTERED MODERATE CONVECTION IS OFF THE COAST OF AFRICA E OF 4W N OF 1N TO INLAND OVER AFRICA. ...DISCUSSION... GULF OF MEXICO... THE DEEP UPPER TROUGH THAT HAS BEEN ESTABLISHED ACROSS THE GULF OVER THE PAST FEW DAYS HAS MOVED TO THE NE NOW COVERING ONLY THE NE SECTOR. UPPER RIDGING EXTENDS FROM AN UPPER ANTICYCLONE OVER S MEXICO NWARD TO TEXAS. THIS UPPER RIDGE IS BUILDING EWARD INTO THE W GULF. ESSENTIALLY...THIS UPPER LEVEL CONFLUENT PATTERN IS GENERATING STRONG SUBSIDENCE ACROSS NEARLY THE ENTIRE GULF OF MEXICO. AT THE SFC...A WEAK DISSIPATING TROUGH LIES FROM LAKE OKEECHOBEE FLORIDA SWWARD TO 24N87W. THIS TROUGH IS MARKED BY A NARROW THIN BAND OF CLOUDS AND A WIND SHIFT. A WEAK 1015 MB HIGH IS CENTERED IN THE NW GULF NEAR 27N95W. MAINLY FAIR AND DRY WEATHER EXTENDS ACROSS THE GULF WITH LIGHT SFC WINDS. THE DRY WEATHER IN THE REGION OVER THE PAST FEW DAYS MAY COME TO AN END FOR A PORTION OF THE GULF THIS WEEKEND AS A SLOWLY DEVELOPING SYSTEM IN THE NW CARIBBEAN MOVES NWARD DRAWING TROPICAL MOISTURE INTO THE E/CENTRAL GULF. THIS SYSTEM MAY DEVELOP INTO THE FIRST TROPICAL DEPRESSION OF THE ATLANTIC SEASON IN THE NEXT DAY OR TWO. CARIBBEAN SEA... THE MAIN WEATHER INTEREST IN THIS AREA IS A 1006 MB LOW IN THE NW CARIBBEAN CENTERED NEAR 17N86W. THIS LOW SITS ON A SLOW MOVING SFC TROUGH WHICH EXTENDS FROM W CUBA TO HONDURAS. SCATTERED MODERATE CONVECTION IS LOCATED FROM 15N-21N BETWEEN 78W-87W. SHOWERS AND TSTMS HAVE BEEN IN THIS REGION FOR MUCH OF THE WEEK...BUT TODAY THERE IS MORE ORGANIZATION TO THE ACTIVITY. THIS BROAD/ELONGATED AREA OF LOW PRES IS SHOWING SIGNS OF DEVELOPING WITH BUOY OBS REPORTING 15-20 KT WINDS AROUND THE LOW CENTER. IN ADDITION...COMPUTER MODELS HAVE BECOME IN FAIR AGREEMENT SLOWLY STRENGTHENING THIS SYSTEM OVER THE NEXT COUPLE OF DAYS AS IT MIGRATES NWARD TOWARDS THE GULF OF MEXICO. IN THE E CARIBBEAN...FAIR WEATHER PREVAILS UNDER STRONG SUBSIDENCE GENERATED BY AN UPPER HIGH CENTERED NE OF PUERTO RICO. LITTLE CHANGE IS EXPECTED IN THE E CARIBBEAN THIS WEEKEND AS A CENTRAL ATLANTIC SFC RIDGE REMAINS IN PLACE AND THE UPPER HIGH NEARLY STATIONARY. THE NW CARIBBEAN WEATHER WILL REMAIN UNSTABLE AS THE SFC TROUGH AND LOW MOVE NWD OR NNWARD THIS WEEKEND. ATLANTIC OCEAN... AN UPPER LEVEL TROUGH/RIDGE/TROUGH/RIDGE PATTERN EXTENDS ACROSS THE ATLANTIC BASIN. AN UPPER TROUGH IS PULLING NWARD IN THE EXTREME W ATLC N OF 26N W OF 73W. A NEARLY STATIONARY UPPER HIGH IS LOCATED TO THE SE OF THE TROUGH CENTERED NEAR 22N65W. BETWEEN THESE FEATURES...SWLY FLOW IS ADVECTING CONSIDERABLE MOISTURE FROM THE CARIBBEAN INTO THE W ATLC WITHIN 360 NM SE OF A LINE FROM THE FLORIDA STRAITS NEWARD TO 32N69W. FARTHER EAST...A LARGE NEARLY STATIONARY UPPER LOW IS CENTERED NEAR 27N44W WITH ITS CYCLONIC CIRCULATION COVERING THE AREA BETWEEN 38W-54W N OF 14N. THE REMAINDER OF THE ATLANTIC IS COVERED BY A BROAD UPPER HIGH ALONG THE AFRICA COAST NEAR 18N17W. AT THE SFC...A SPRAWLING 1025 MB HIGH NEAR 33N47W DOMINATES THE SFC PRES PATTERN ACROSS THE CENTRAL AND EASTERN ATLC. THE ONLY FEATURE CONTAMINATING THE SPRAWLING SFC RIDGE IS A RATHER ILL-DEFINED SFC REFLECTION AS A TROUGH OF THE LARGE UPPER LOW. THIS TROUGH IS ALONG 28N43W 24N45W. SCATTERED SHOWERS ARE SPIRALING AROUND THE UPPER LOW WITHIN 180 NM OF THE CENTER. ELSEWHERE...MAINLY FAIR WEATHER COVERS THE CENTRAL AND E ATLC N OF THE ITCZ'S ASSOCIATED CONVECTION. $$ CANGIALOSI