000 AXNT20 KNHC 240533 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 205 AM EDT TUE JUN 24 2008 TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL AMERICA...GULF OF MEXICO...CARIBBEAN SEA...NORTHERN SECTIONS OF SOUTH AMERICA...AND 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 0445 UTC. ...TROPICAL WAVES... TROPICAL WAVE IS ALONG 38W S OF 12N MOVING W NEAR 20 KT. NO INDICATION OF THE TYPICAL INVERTED-V CURVATURE IN EITHER THE LOW OR MID LEVELS. THE MIMIC-TPW ANIMATION DOES NOT SHOW ANY INDICATION OF A SURGE IN MOISTURE IN THE VICINITY OF THIS WAVE N OF THE ITCZ BUT SOME TO THE SOUTH OF THE ITCZ. THE PREVIOUS SHIFT INDICATED AN ACTIVE TROPICAL WAVE THAT WAS PREVIOUSLY ALONG 62W HAS BEEN RELOCATED AHEAD NEAR 71W BASED ON UPPER AIR TIME SERIES DATA FROM SAN JUAN ONLY. THIS DATA INDICATED A WELL-DEFINED WAVE PASSAGE PRIOR TO 00Z 23 JUNE BUT HAD NO INDICATIONS OF THE WAVE PASSAGE OVER THE REMAINDER OF THE LESSER ANTILLES...FOLLOWED BY A SURGE OF LOW-LEVEL MOISTURE AND A MAXIMUM IN THE LOW-LEVEL WINDS. IN FACT...THE SOUNDING IN SAN JUAN YESTERDAY MORNING REVEALED A 35 KT PEAK WIND AROUND 850 MB AND A STRONG LAYER OF 30+ KT WINDS BETWEEN 700 MB AND 850 MB. HOWEVER...PW VALUES DID NOT INCREASE INITIALLY BUT INSTEAD DID SO DURING THE LAST 12 TO 24 HOURS AT THE SAME TIME THE LOW-LEVEL FLOW VEERED SE. TROPICAL WAVE IS IN THE BAY OF CAMPECHE ALONG 93W S OF 21N MOVING W 20-25 KT. SATELLITE IMAGERY SHOWS WEAK LOW/MID LEVEL INVERTED-V CURVATURE MOVING OVER S MEXICO AND THE BAY OF CAMPECHE WITH SCATTERED SHOWERS/ISOLATED THUNDERSTORMS S OF 20N TO INLAND OVER MEXICO BETWEEN 92W-96W. ...ITCZ... ITCZ AXIS IS CENTERED ALONG 12N13W 7N22W 9N31W 5N46W 5N53W. SCATTERED STRONG CONVECTION HAS MOVED OFF THE AFRICAN COAST FROM 10N-13N BETWEEN 17W-21W. SCATTERED MODERATE/STRONG CONVECTION IS WITHIN 60/75 NM OF LINE FROM 8N53W TO 11N59W. SCATTERED CLUSTERS OF SCATTERED MODERATE/ISOLATED STRONG CONVECTION ARE FROM 5N-10N E OF 43W TO THE COAST OF AFRICA. CLUSTERS OF SCATTERED MODERATE CONVECTION ARE FROM 3N-8N BETWEEN 44W-53W. ...DISCUSSION... GULF OF MEXICO... UPPER TROUGH EXTENDS FROM OVER THE E US INTO THE W/CENTRAL GULF NEAR MOBILE ALABAMA TO S MEXICO AND THE W BAY OF CAMPECHE ANCHORED BY AN UPPER LOW MOVING INTO NEW ENGLAND. AN UPPER LEVEL RIDGE EXTENDS FROM THE CARIBBEAN OVER THE REMAINDER OF THE GULF INTO THE W ATLC TO OVER THE N BAHAMA ISLANDS. THIS IS SUPPLYING THE E GULF WITH ABUNDANCE OF TROPICAL MOISTURE. THE ACTIVITY IN THE BAY OF CAMPECHE ASSOCIATED WITH THE TROPICAL WAVE IS ENHANCED BY THE UPPER LEVEL FEATURES WHILE SCATTERED CLUSTERS SCATTERED SHOWERS/ISOLATED THUNDERSTORMS DOT THE SE GULF S OF A LINE FROM THE BIG BEND AREA OF FLORIDA SW TO NEAR TAMPICO MEXICO. THE REMAINDER OF THE GULF REMAINS CLEAR TONIGHT. WEAK SURFACE RIDGE EXTENDS FROM THE W ATLC OVER THE GULF WITH A WEAK 1020 MB HIGH LOCATED NEAR 27N87W AND CREATING A WEAK PRESSURE PATTERN THAT CONTINUES TO PROVIDE LIGHT WINDS ACROSS THE REGION. CARIBBEAN... AN UPPER RIDGE ANCHORED IN THE E PACIFIC REGION EXTENDS ACROSS CENTRAL AMERICA AND W/CENTRAL CUBA INTO THE W ATLC COVERING THE AREA N OF 13N W OF 80W WHILE A SECOND UPPER RIDGE ANCHORED IN THE TROPICAL ATLC COVERS THE E CARIBBEAN. AN UPPER TROUGH IS BETWEEN THESE UPPER RIDGES EXTENDING FROM ACROSS THE CENTRAL ATLC INTO THE CARIBBEAN NEAR THE WINDWARD PASSAGE SW TO 14N79W. UPPER LEVEL DIFFLUENCE CONTINUES TO GENERATE SCATTERED SHOWERS/ THUNDERSTORMS N OF 20N TO OVER CUBA BETWEEN 79W-84W AND SCATTERED SHOWERS/ISOLATED THUNDERSTORMS OVER THE NE CARIBBEAN N OF 15N BETWEEN 63W-71W. THE ITCZ APPEARS TO CROSS THE S CARIBBEAN FROM COLOMBIA N OF PANAMA INTO THE E PACIFIC OVER COSTA RICA GENERATING SCATTERED SHOWERS/ISOLATED THUNDERSTORMS OVER THE AREA S OF 14N W OF 80W TO INLAND OVER CENTRAL AMERICA WITH SCATTERED SHOWERS WITHIN 75 NM OF 12N BETWEEN 71W-80W. MODERATE/STRONG EASTERLY TRADE WINDS DOMINATE MOST OF THE CARIBBEAN DUE TO THE TIGHT PRESSURE GRADIENT BETWEEN THE SURFACE RIDGE OVER THE ATLC AND LOWER PRESSURE OVER SOUTH AMERICA AND ARE USHERING IN ISOLATED SHOWERS OVER THE E CARIBBEAN E OF 72W. ATLANTIC... NARROW UPPER RIDGE EXTENDS FROM THE CARIBBEAN ACROSS W/CENTRAL CUBA TO OVER THE N BAHAMA ISLANDS TO NEAR 26N77W PROVIDING UPPER DIFFLUENCE AND GENERATING CLUSTERS OF SCATTERED SHOWERS/ THUNDERSTORMS S OF 26N W OF 76W INTO THE FLORIDA STRAITS. A BROAD UPPER RIDGE DOMINATES THE REMAINDER OF THE W ATLC INTO THE N/CENTRAL ATLC ANCHORED BY AN UPPER HIGH NEAR 32N61W AGAIN PROVIDING UPPER DIFFLUENCE AND GENERATING CLUSTERS OF SCATTERED SHOWERS/THUNDERSTORMS ALONG THE E COAST OF THE US N OF 28N W OF 76W. OTHERWISE THE MOST PROMINENT UPPER LEVEL FEATURE REMAINS THE UPPER TROUGH THAT CONTINUES ACROSS THE BASIN EXTENDING FROM 28N27W THROUGH 22N43W 25N63W THEN SW INTO THE CARIBBEAN THROUGH THE WINDWARD PASSAGE. SCATTERED SHOWERS/ISOLATED THUNDERSTORMS ARE ON THE SE SIDE OF THE UPPER TROUGH AS IT ENTERS THE CARIBBEAN S OF 22N TO OVER THE VIRGIN ISLANDS TO HISPANIOLA BETWEEN 62W-71W. A SURFACE RIDGE REMAINS ACROSS THE ENTIRE ATLC BASIN FROM AFRICA INTO THE GULF OF MEXICO ANCHORED BY A 1030 MB HIGH CENTERED JUST N OF THE REGION NEAR 33N52W. MODERATE SUBSIDENCE AND A FAIR AMOUNT OF DRY STABLE AIR ALSO DOMINATES THE ATLC E OF 70W GIVING THE AREA FAIR WEATHER AGAIN TONIGHT. BROAD E/W UPPER RIDGE REMAINS ACROSS THE TROPICAL ATLC FROM THE CAPE VERDE ISLANDS TO OVER THE E CARIBBEAN ENHANCING ANY CONVECTION ASSOCIATED WITH THE ITCZ. THE LAST VISIBLE SATELLITE IMAGES SHOW A WIDE SWATH OF AFRICAN DUST TRANSVERSING THE ATLC S OF 23N INTO THE E CARIBBEAN. $$ WALLACE