000 AXNT20 KNHC 210514 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 205 AM EDT THU JUN 21 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 0445 UTC. ...TROPICAL WAVES... TROPICAL WAVE WAS ADDED ALONG 24W S OF 12N MOVING W NEAR 15 KT. BROAD MID LEVEL ROTATION IS OBSERVED ON SATELLITE IMAGERY. NO ASSOCIATED CONVECTION. TROPICAL WAVE IS ALONG 41W S OF 13N MOVING W NEAR 10 KT. WEAK LOW LEVEL INVERTED-V CURVATURE IS OBSERVED ON SATELLITE IMAGERY. NO ASSOCIATED CONVECTION. CARIBBEAN TROPICAL WAVE IS ALONG 69W S OF 20N MOVING W NEAR 15 KT. THIS WAVE BROUGHT HEAVY RAINS TO PUERTO RICO EARLIER TODAY AND IS MOVING OVER HISPANIOLA. ...THE ITCZ... ITCZ AXIS IS CENTERED ALONG 10N13W 8N22W 6N34W 6N43W 4N53W. CLUSTERS OF SCATTERED MODERATE/ISOLATED STRONG CONVECTION ARE WITHIN 150 NM OF THE AXIS FROM 28W-40W AND WITHIN 180 NM S OF THE AXIS FROM 12W-19W. ...DISCUSSION... GULF OF MEXICO... AN UPPER RIDGE EXTENDS FROM MEXICO ACROSS THE SW GULF TO THE YUCATAN PENINSULA COVERING THE AREA W OF 86W. A SECOND UPPER RIDGE EXTENDS FROM A SMALL UPPER HIGH OVER S GEORGIA TO OVER FLORIDA. AT THE SURFACE...A WEAK 1013 MB LOW IS MOVING ACROSS NE FLORIDA INTO THE W ATLC DRAPING A SURFACE TROUGH S ACROSS FLORIDA GENERATING SCATTERED SHOWERS/ISOLATED THUNDERSTORMS OVER THE FAR E GULF WITH THE STRONGEST THUNDERSTORMS ALONG THE COAST N OF TAMPA TO THE BIG BEND AREA. THE UPPER RIDGE OVER MEXICO IS ADVECTING MOISTURE WITH SIMILAR ACTIVITY OVER THE FAR W GULF FROM 20N28N W OF 95W. A SURFACE RIDGE IS BUILDING S FROM A 1021 MB HIGH OVER NE TEXAS COVERING THE REMAINDER OF THE GULF. CARIBBEAN SEA... AN UPPER TROUGH FROM THE W ATLC EXTENDS SW OVER THE NW CARIBBEAN TO THE GULF OF HONDURAS WITH AN UPPER RIDGE DOMINATING THE REMAINDER OF THE AREA EXTENDING FROM AN UPPER HIGH NEAR THE ABC ISLANDS INTO THE S/CENTRAL ATLC. A 1009 MB SURFACE LOW IS IN THE SW CARIBBEAN GENERATING SCATTERED/MODERATE STRONG CONVECTION ACROSS THE AREA FROM 10N-14W W OF 79W TO INLAND OVER NICARAGUA. THE UPPER LEVEL RIDGE IS ADVECTING TROPICAL MOISTURE ACROSS THE CENTRAL CARIBBEAN ADDING FUEL TO THE HEAVY SHOWERS AND POSSIBLE ISOLATED THUNDERSTORMS OVER PUERTO RICO AND HISPANIOLA ASSOCIATED WITH THE TROPICAL WAVE ALONG 69W. SOME ISOLATED SHOWERS ARE OVER THE NW CARIBBEAN WHILE THE E CARIBBEAN REMAINS SHOWER FREE. ATLANTIC OCEAN... A DEEP LAYERED TROUGH IS OVER THE NE US MOVING INTO THE NW ATLC EXTENDING A FRONTAL BOUNDARY ALONG THE CAROLINA COAST TO CENTRAL GEORGIA. A 1013 MB LOW IS MOVING OFF THE NE FLORIDA COAST CLEARLY OBSERVED ON RADAR. A SECOND UPPER TROUGH EXTENDS OVER THE W ATLC THROUGH 32N69W TO A WEAK UPPER LOW NEAR 28N71W ACROSS CUBA NEAR 22N78W INTO THE NW CARIBBEAN. BETWEEN THESE UPPER TROUGHS IS AN UPPER RIDGE ENHANCING SCATTERED SHOWERS/ THUNDERSTORMS WITHIN 90/120 NM OF A LINE FROM THE E FLORIDA COAST NEAR DAYTONA BEACH TO BEYOND 32N77W AND TO THE W OF THE UPPER LOW FROM 26N-31N BETWEEN 72W-75W. A LARGE DEEP LAYERED LOW IS IN THE N/CENTRAL ATLC DRAPING AN UPPER TROUGH INTO THE REGION N OF 25N FROM 40W-55W. THE ASSOCIATED COLD FRONT ENTERS THE CENTRAL ATLC NEAR 32N46W TO 30N47W CONTINUING AS A SURFACE TROUGH SW TO 26N64W. SCATTERED SHOWERS/ISOLATED THUNDERSTORMS ARE WITHIN 120/150 NM E OF THE FRONT AND WITHIN 90/120 NM SE OF THE SURFACE TROUGH. AT THE BASE OF THIS UPPER TROUGH IS THE UPPER RIDGE THAT EXTENDS FROM THE CARIBBEAN GENERATING SCATTERED SHOWERS/THUNDERSTORMS FROM 19N-23N BETWEEN 57W-68W. A WEAK REMNANT SURFACE TROUGH REMAINS IN THE E/CENTRAL ATLC FROM 31N38W TO 19N44W BUT IS ONLY GENERATING ISOLATED SHOWERS WITHIN 90 NM OF THE TROUGH. THE E ATLC IS DOMINATED BY AN UPPER HIGH AND A SURFACE RIDGE ANCHORED BY A 1029 MB HIGH JUST S OF THE AZORES. THE COMBINATION OF THIS SURFACE RIDGE ALONG WITH DRY STABLE AIR ALOFT ASSOCIATED WITH AN UPPER RIDGE IS PROVIDING TRANQUIL CONDITIONS ACROSS THE REMAINDER OF THE ATLC. $$ WALLACE