000 AXNT20 KNHC 200541 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 205 AM EDT SAT MAY 20 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0515 UTC. ...TROPICAL WAVES... TROPICAL WAVE IS ALONG 18W S OF 8N MOVING W NEAR 10 KT. WELL DEFINED CYCLONIC TURNING IS EVIDENT ON SATELLITE IMAGERY ASSOCIATED WITH THE WAVE. SCATTERED MODERATE CONVECTION IS W OF THE WAVE AXIS FROM 1N-5N BETWEEN 19W-25W. SCATTERED SHOWERS AND ISOLATED TSTMS ARE TO THE E OF THE AXIS. TROPICAL WAVE IS ALONG 44W S OF 5N MOVING W 10-15 KT. THIS WAVE HAS AN INVERTED V PATTERN EMBEDDED WITHIN THE ITCZ. SCATTERED MODERATE CONVECTION IS WITHIN A FEW HUNDRED NM EITHER SIDE OF THE WAVE AXIS. MODELS HAVE THE WAVE INITIALIZED FAIRLY WELL AND TRACK THE FEATURE QUICKLY WWD ACROSS S AMERICA UNDER THE STRONG CNTRL ATLC RIDGE. TROPICAL WAVE IS ALONG 80W S OF 12N DRIFTING W. THIS WAVE HAS SLOWED CONSIDERABLY OVER THE PAST 24 HOURS DUE TO WEAK STEERING. THE WAVE HAS BECOME RATHER DIFFICULT TO LOCATE AS IT IS EMBEDDED WITHIN AREAS OF CONVECTION ASSOCIATED WITH AN UPPER LEVEL RIDGE AND THE TAIL END OF SFC TROUGH IN THE CARIBBEAN. ...ITCZ... ITCZ AXIS IS CENTERED ALONG 6N10W 4N20W 3N30W 2N42W EQ50W. SCATTERED MODERATE/STRONG CONVECTION IS FROM 1N-5N BETWEEN 19W-25W TRIGGERED BY THE TROPICAL WAVE ALONG 18W. SIMILAR CONVECTION IS WITHIN 240 NM EITHER SIDE OF THE AXIS W OF 35W ASSOCIATED WITH THE TROPICAL WAVE ALONG 44W. ELSEWHERE... ISOLATED/SCATTERED SHOWERS ARE WITHIN 240 NM EITHER SIDE OF THE AXIS. ...DISCUSSION... GULF OF MEXICO... PLEASANT WEATHER CONTINUES ACROSS THE GULF OF MEXICO THANKS TO A 1016 MB HIGH CENTERED IN THE CNTRL GULF NEAR 26N88W. SKIES ARE GENERALLY FAIR TO MOSTLY CLEAR ACROSS THE REGION. SFC WINDS ARE LIGHT EXCEPT FOR AN AREA OF 15-20 KT SLY RETURN FLOW IN THE NW GULF. IN THE UPPER LEVELS...A DEEP LAYERED TROUGH THAT IS GRADUALLY MOVING OUT OF THE NEW ENGLAND STATES EXTENDS SWWD INTO THE NE GULF. AN UPPER RIDGE IS BUILDING OVER MEXICO AND THE W/CNTRL U.S. DRY/STABLE AIR ALOFT IS WIDESPREAD WITH A SWATH OF ENHANCED SUBSIDENCE DUE TO UPPER LEVEL CONFLUENCE FROM 26N-28N ACROSS THE WIDTH OF THE GULF. COMPUTER MODELS SUGGEST THAT WEAK SFC HIGH PRES WILL REMAIN IN THE REGION FOR THE NEXT SEVERAL DAYS MAINTAINING FAIR WEATHER AND LIGHT TO MODERATE WINDS. HOWEVER...SOME MOISTURE WILL BACK INTO THE SE GULF FROM THE CARIBBEAN BEGINNING ON SUN. CARIBBEAN SEA AND ATLANTIC OCEAN W OF 55W... AN UPPER LEVEL TROUGH/RIDGE PATTERN REMAINS IN PLACE ACROSS THIS AREA. A DEEP LAYERED LOW OVER VERMONT HAS A LONGWAVE TROUGH THAT DIGS INTO THE DISCUSSION AREA IN THE W ATLC. THE COLD FRONT HAS BECOME STATIONARY ALONG 32N60W 25N73W TO A 1012 MB LOW S OF CUBA NEAR 18N79W. A WEAK SFC TROUGH IS DRAPED SWD FROM THE LOW TO 15N80W. SFC FORCING AND UPPER LEVEL DIVERGENCE IS PRODUCING CLUSTERS OF SCATTERED MODERATE CONVECTION WITHIN 240 NM E OF THE FRONTAL BOUNDARY. CURRENTLY...THE STRONGEST CLUSTER IS NE OF THE SFC LOW OVER E CUBA WHERE CLOUD TOP TEMPS ARE COLDER THAN -85C. SCATTERED SHOWERS ARE S OF THE LOW...NEAR THE SFC TROUGH...W OF 78W. FARTHER EAST...A SHARP UPPER RIDGE STRETCHES FROM COLOMBIA TO THE CENTRAL ATLC. AN UPPER LEVEL ANTICYCLONE S OF HISPANIOLA NEAR 18N72W IS EMBEDDED WITHIN THIS UPPER RIDGE. STRONG SUBSIDENCE COVERS THE E CARIBBEAN AND MUCH OF COLOMBIA... STRETCHING WWD MINIMIZING ANY TSTM ACTIVITY E OF 76W. A FEW PATCHES OF LOW LEVEL TRADE WIND SHOWERS ARE OVER THE LESSER ANTILLES MOVING TOWARDS PUERTO RICO. SFC WINDS REMAIN WEAK IN THE W CARIBBEAN WHILE MORE MODERATE TRADES ARE E OF 75W. TRADEWINDS ARE LIKELY TO BECOME MORE UNIFORM AND STRENGTHEN AS THE SFC TROUGH DISSIPATES IN THE CARIBBEAN AND THE SPRAWLING CNTRL ATLC RIDGE BUILDS INTO THE AREA. MODELS ANTICIPATE THE STUBBORN FRONTAL BOUNDARY TO SLOWLY WEAKEN AND CONTINUE TO LIFT NWD THIS WEEKEND FINALLY DISSIPATING BY EARLY NEXT WEEK. UNTIL THEN...SHOWERS AND TSTMS ARE LIKELY TO PERSIST E OF THE BOUNDARY. THE REMAINDER OF ATLANTIC OCEAN... A SHARP UPPER LEVEL TROUGH IS OVER THE CNTRL ATLC WITH THE AXIS EXTENDING THRU 30N35W THROUGH AN UPPER LOW NEAR 20N43W INTO THE DEEP TROPICS NEAR 10N50W. THE SFC REFLECTION OF THE UPPER LOW APPEARS TO BE HAVE DISSIPATED AS SFC WINDS DO NOT SHOW ANY SIGNAL. AN UPPER RIDGE EXTENDS OVER THE E ATLC FROM AN UPPER HIGH LOCATED NEAR THE CAPE VERDE ISLANDS N TO 30N25W. UPPER DIFFLUENCE TO THE S OF THE HIGH IS ENHANCING CONVECTION ALONG THE ITCZ E OF 28W. MODERATE TO STRONG SUBSIDENCE COVERS THE E ATLC E OF 30W FROM 10N-22N. AT THE SFC...A SPRAWLING 1031 MB HIGH CENTERED NEAR 34N28W COVERS THE ENTIRE REGION SUPPLYING FAIR WEATHER ACROSS A GOOD PORTION OF THE ATLANTIC OCEAN. TRADE WINDS ARE RATHER STRONG ACROSS THE AREA AND WILL LIKELY REMAIN THAT WAY FOR THE NEXT FEW DAYS. $$ CANGIALOSI