000 AXNT20 KNHC 191034 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 805 AM EDT SAT AUG 19 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1015 UTC. ...TROPICAL WAVES... TROPICAL WAVE OFF THE COAST OF W AFRICA IS ALONG 21W S OF 16N MOVING W 15 KT. LOW AMPLITUDE WAVE WITH WELL DEFINED INVERTED-V CURVATURE OBSERVED ON VISIBLE SATELLITE IMAGERY S OF 13N. CONVECTION IS WITHIN THE ITCZ AXIS. TROPICAL WAVE IS ALONG 40W/41W S OF 20N MOVING W 10 KT. WELL DEFINED INVERTED-V CURVATURE IS OBSERVED ON INFRARED SATELLITE IMAGERY. CONVECTION IS WITHIN THE ITCZ AXIS. TROPICAL WAVE IS APPROACHING THE WINDWARD ISLANDS ALONG 59W/60W S OF 19N MOVING W 15 KT. NORTH PORTION OF THE WAVE IS NOW ANALYZED AS A SURFACE TROUGH. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS FROM 11N-14N BETWEEN 58W-61W INCLUDING THE ISLAND OF BARBADOS. TROPICAL WAVE IS OVER CENTRAL AMERICA ALONG 92W S OF 20N MOVING W 15 KT. WAVE IS MOSTLY INLAND OVER S MEXICO AND THE E PACIFIC REGION WITH THE ASSOCIATED CONVECTION ALONG THE S COAST OF MEXICO. ...THE ITCZ... ITCZ AXIS IS CENTERED ALONG 11N14W 7N21W 8N37W 7N50W 8N58W THEN ACROSS N PORTION OF SOUTH AMERICA AND E PANAMA INTO THE E PACIFIC REGION. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS WITHIN 125 NM OF THE AXIS FROM 20W-28W AND WITHIN 90 NM OF THE AXIS FROM 30W-41W. ...DISCUSSION... GULF OF MEXICO... BROAD UPPER RIDGE ANCHORED OVER THE CENTRAL MISSISSIPPI VALLEY EXTENDS OVER THE N GULF N OF 26N. THE UPPER LOW IN THE W ATLC IS PROVIDING ENOUGH DIFFLUENCE TO GENERATE CLUSTERS OF SCATTERED SHOWERS/THUNDERSTORMS FROM THE W ATLC ACROSS THE FLORIDA PENINSULA INTO THE E GULF N OF 26N E OF 86W. AN UPPER LOW IN THE SW GULF IS CENTERED NEAR 22N96W BUT IS EMBEDDED WITHIN DRY AIR PRODUCING ISOLATED SHOWERS OVER THE NW GULF N OF 24N W OF 90W. A SECOND UPPER LOW OVER THE W CARIBBEAN IS PRODUCING SCATTERED SHOWERS/ISOLATED THUNDERSTORMS S OF 25N TO OVER CUBA FROM 81W-87W. CARIBBEAN SEA... THE UPPER LOW IN THE W CARIBBEAN IS JUST W OF JAMAICA NEAR 18N80W COVERING THE AREA N OF 16N W OF 74W TO THE YUCATAN PENINSULA. THIS IS GENERATING CLUSTERS OF SCATTERED SHOWERS/ISOLATED THUNDERSTORMS N OF 18N FROM THE WINDWARD PASSAGE TO OVER THE YUCATAN CHANNEL AND INTO THE SE GULF OF MEXICO. BROAD UPPER RIDGE EXTENDS ACROSS THE S CARIBBEAN FROM COSTA RICA/NICARAGUA TO ACROSS THE LESSER ANTILLES NEAR 15N61W INTO THE W TROPICAL ATLC. THIS IS ADVECTING A GENEROUS AMOUNT OF TROPICAL MOISTURE ACROSS THE S CARIBBEAN AND WITH IT SCATTERED SHOWERS/ISOLATED THUNDERSTORMS OVER MOST OF THE AREA WITH SCATTERED MODERATE/STRONG CONVECTION OFF THE COAST OF COLOMBIA AND E PANAMA WITHIN 90 NM OF LINE 12.5N74W-10N78.5W DUE TO THE CLOSE PROXIMITY OF THE ITCZ AXIS. MODERATE TRADEWINDS ARE ACROSS THE AREA. ATLANTIC OCEAN... THE UPPER LOW IN THE W ATLC IS CENTERED NEAR 28N77W COVERING THE AREA N OF 22N W OF 71W WITH AN ASSOCIATED 1012 MB LOW JUST OFF THE COAST NEAR JACKSONVILLE FLORIDA DRIFTING WSW. THE UPPER LOW IS GENERATING THE SCATTERED SHOWERS/THUNDERSTORMS FROM 28N-31N W OF 77W ACROSS FLORIDA INTO THE E GULF OF MEXICO AND TO THE E OF THE UPPER LOW WITHIN 75 NM OF 27N FROM 71W-75W. AN UPPER LOW IS BETWEEN BERMUDA AND THE VIRGIN ISLANDS NEAR 25N63W INDUCING AN UPPER RIDGE BETWEEN THESE TWO UPPER LOWS. THE N EXTENSION OF THE TROPICAL WAVE ALONG 59W/60W IS NOW A SURFACE TROUGH EXTENDING FROM 20N59W TO NEAR 31N52W GENERATING SCATTERED SHOWERS/ISOLATED THUNDERSTORMS FROM 21N-31N BETWEEN 49W-64W. THE UPPER RIDGE EXTENDING FROM THE S CARIBBEAN ACROSS THE LESSER ANTILLES NEAR 15N61W INTO THE W TROPICAL ATLC TO NEAR 18N50W IS ENHANCING THE CONVECTION ASSOCIATED WITH THE TROPICAL WAVE ALONG 59W-60W. AN UPPER TROUGH IS IN THE E/CENTRAL ATLC EXTENDING THROUGH 32N36W S TO 21N41W WITH THE ASSOCIATED SURFACE FEATURE N OF THE REGION. THE REMAINDER OF THE ATLC IS MOSTLY DOMINATED BY AN UPPER HIGH CENTERED N OF THE CAPE VERDE ISLANDS NEAR 20N24W WITH A WEAK UPPER TROUGH EXTENDING S OVER THE CANARY ISLANDS TO INLAND OVER NW AFRICA. DRY AIR REMAINS IN PLACE OVER THE E ATLC SO NO SIGNIFICANT CLOUDS OR SHOWERS ARE ASSOCIATED WITH THESE FEATURES. THE FIRST VISIBLE IMAGERY SHOWERS SHOWS SIGNIFICANT AMOUNT OF AFRICA DUST CONTINUING TO MOVE OFF THE COAST OF W AFRICA S OF 25N TO NEAR 35W INCLUDING THE CAPE VERDE ISLANDS. $$ WALLACE