000 AXNT20 KNHC 211022 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 805 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0945 UTC. ...TROPICAL WAVES... TROPICAL WAVE IS ALONG 26W S OF 12N MOVING W 15-20 KT. BROAD MID LEVEL ROTATION IS OBSERVED ON SATELLITE IMAGERY. NO ASSOCIATED CONVECTION. TROPICAL WAVE IS ALONG 42W/43W S OF 13N MOVING W 15 KT. WEAK LOW LEVEL INVERTED-V CURVATURE IS OBSERVED ON SATELLITE IMAGERY. NO ASSOCIATED CONVECTION. CARIBBEAN TROPICAL WAVE IS ALONG 70W S OF 20N MOVING W NEAR 10 KT. THIS WAVE IS BRINGING HEAVY RAINS TO HISPANIOLA. ...THE ITCZ... ITCZ AXIS IS CENTERED ALONG 10N14W 7N22W 6N34W 8N45W 5N55W. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS WITHIN 120 NM N OF THE AXIS FROM 51W-55W. CLUSTERS OF SIMILAR CONVECTION ARE WITHIN 120/150 NM OF THE AXIS FROM 31W-42W AND WITHIN 120 NM OF 5N FROM 11W-24W. ...DISCUSSION... GULF OF MEXICO... AN UPPER RIDGE EXTENDS FROM MEXICO ACROSS THE SW GULF TO THE YUCATAN PENINSULA COVERING THE AREA W OF 87W. A SMALL UPPER HIGH OVER FLORIDA NEAR TAMPA. AT THE SURFACE...A SMALL 1012 MB LOW IS ALONG THE NE FLORIDA COAST WITH A SURFACE TROUGH EXTENDING ACROSS CENTRAL FLORIDA GENERATING A NARROW LINE OF THUNDERSTORMS ALONG THE SURFACE TROUGH AND SCATTERED SHOWERS/ ISOLATED THUNDERSTORMS OVER THE FAR E GULF. THE UPPER RIDGE OVER MEXICO IS ADVECTING MOISTURE WITH SIMILAR ACTIVITY OVER THE FAR W GULF FROM 19N-27N W OF 95W. A SURFACE RIDGE IS WEAKENING WITH A 1020 MB HIGH ALONG THE LOUISIANA/TEXAS COAST. CARIBBEAN SEA... NARROW 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 OVER SOUTH AMERICA INTO THE S/CENTRAL ATLC. A 1009 MB SURFACE LOW IS IN THE SW CARIBBEAN OVER COSTA RICA GENERATING SCATTERED/MODERATE STRONG CONVECTION ACROSS THE AREA FROM 11N-16W W OF 78W TO INLAND OVER NICARAGUA AND WITHIN 60 NM OF LINE FROM COLOMBIA NEAR 9N76W TO 11N81W. THE UPPER LEVEL RIDGE IS ADVECTING TROPICAL MOISTURE ACROSS THE CENTRAL CARIBBEAN ADDING FUEL TO THE HEAVY SHOWERS AND POSSIBLE ISOLATED THUNDERSTORMS OVER HISPANIOLA ASSOCIATED WITH THE TROPICAL WAVE ALONG 70W AND GENERATING SCATTERED SHOWERS WITHIN 75 NM OF LINE FROM 16N77W TO TO OVER HISPANIOLA NEAR 18N72W. SOME WIDELY 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 1012 MB LOW IS ALONG THE NE FLORIDA COAST NEAR JACKSONVILLE CLEARLY OBSERVED ON RADAR. A SECOND UPPER TROUGH EXTENDS OVER THE W ATLC THROUGH 32N68W TO A WEAK UPPER LOW NEAR 26N70W ACROSS CUBA NEAR 22N77W INTO THE NW CARIBBEAN. BETWEEN THESE UPPER TROUGHS IS AN UPPER RIDGE ENHANCING SCATTERED SHOWERS/THUNDERSTORMS WITHIN 90 NM OF A LINE FROM THE E FLORIDA COAST JUST N OF DAYTONA BEACH TO BEYOND 32N75W AND TO THE W OF THE UPPER LOW FROM 27N-31N BETWEEN 71W-75W AS WELL AS OVER THE N BAHAMA ISLANDS. A LARGE DEEP LAYERED LOW IS IN THE N/CENTRAL ATLC DRAPING AN UPPER TROUGH INTO THE REGION N OF 24N FROM 40W-55W. THE ASSOCIATED COLD FRONT ENTERS THE CENTRAL ATLC NEAR 32N45W TO 28N50W WITH A PRE-FRONTAL SURFACE TROUGH EXTENDING FROM 31N43W SW TO 25N58W. SCATTERED SHOWERS/ISOLATED THUNDERSTORMS ARE 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 54W-68W. THE E ATLC IS DOMINATED BY AN UPPER HIGH AND A SURFACE RIDGE ANCHORED BY A 1028 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