000 AXNT20 KNHC 181746 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 205 PM EDT SUN JUN 18 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1715 UTC. ...TROPICAL WAVES... TROPICAL WAVE IS ALONG 22W/23W S OF 15N MOVING W 10-15 KT. BROAD MID LEVEL CIRCULATION IS OBSERVED ON VISIBLE SATELLITE IMAGERY. MOST OF THE CONVECTIVE ACTIVITY IS CONFINED TO THE ITCZ AXIS. A GOOD LOOKING TROPICAL WAVE IS ALONG 50W/51W S OF 16N MOVING W 15-20 KT. BROAD LOW/MID LEVEL CURVATURE SIGNATURE IS OBSERVED ON VISIBLE SATELLITE IMAGERY. GRIDDED QUIKSCAT DATA HAS SHOWN THAT THE WAVE IS VERY WELL DEFINED IN THE WIND FIELD. A CLUSTER OF SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS FROM 11N-15N BETWEEN 47W-52W. COMPUTER MODELS HAVE MOISTURE FROM THIS WAVE AFFECTING THE LESSER ANTILLES LATE MONDAY AND THE VIRGIN ISLANDS AND PUERTO RICO ON TUESDAY. ACCORDING TO THE 18/1500 UTC CIMSS SAHARAN AIR LAYER A HUGE AREA OF AFRICAN DUST IS BEHIND THIS WAVE. TROPICAL WAVE THAT WAS PREVIOUSLY ANALYZED ALONG 66W/67W ON THE 06Z SURFACE MAP WAS RELOCATED ALONG 65W/66W BASED ON THE SAN JUAN 12Z SOUNDING AND LATEST VISIBLE SATELLITE IMAGERY. THIS WAVE IS MOVING SLOWLY WESTWARD AT AROUND 10 KT. WAVE SIGNATURE CURVATURE REMAINS WEAK AS IT CROSSES THE E CARIBBEAN. THE WAVE AND ITS ASSOCIATED MOISTURE IS ENHANCING THE SHOWER/TSTM ACTIVITY OVER THE VIRGIN INLAND AND PUERTO RICO...INCLUDING THE SAN JUAN METRO AREA. ...ITCZ... ITCZ AXIS IS CENTERED ALONG 11N15W 4N30W 7N40W 7N50W 7N60W. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS WITHIN 100-120 NM N OF THE AXIS BETWEEN 24W-32W AND S OF THE AXIS BETWEEN 32W-37W. SIMILAR CONVECTION IS ALSO FOUND WITHIN 100 NM SOUTH OF THE AXIS BETWEEN 40W-46W. SCATTERED MODERATE SHOWERS AND TSTMS ARE WEST OF 50W. ...DISCUSSION... GULF OF MEXICO... MID/UPPER LEVEL TROUGH REMAINS OVER THE CENTRAL US INTO TEXAS AND THE NW CORNER OF THE GULF. THIS LEAVES THE REMAINDER OF THE GULF UNDER A MID/UPPER HIGH LOCATED NEAR 26N90W WITH A SHARP RIDGE AXIS EXTENDING NE OVER SE U.S.. DRY AIR ALOFT COVERS A GOOD PORTION OF THE AREA. A SQUALL LINE IS MOVING THROUGH LOUISIANA AND THE TEXAS COAST AND ADJACENT COASTAL WATERS. THE AFOREMENTIONED TROUGH IS SUPPORTING THIS CONVECTIVE ACTIVITY. AT THE SURFACE...A RIDGE DOMINATES THE GULF. SE WINDS OF 10-15 KT BLOW OVER THE WESTERN GULF WHILE E-SE WINDS DOMINATES THE REMAINDER OF THE AREA. THE RIDGE ALONG THE NORTHERN GULF COAST WILL REMAIN STATIONARY THROUGH MON. CARIBBEAN SEA... THE CARIBBEAN IS DOMINATED BY TWO UPPER HIGHS...THE ONE OVER THE GULF OF MEXICO AND THE SECOND OVER THE W TROPICAL ATLC. BROAD UPPER TROUGH OVER THE W ATLC DIPS INTO THE CENTRAL CARIBBEAN N OF 16N FROM 70W-80W. SWLY WINDS AHEAD OF THE UPPER TROUGH ARE FAVORING THE DEVELOPMENT OF SHOWERS AND TSTMS OVER THE NE CARIBBEAN. SCATTERED SHOWERS ARE BETWEEN JAMAICA AND EASTERN CUBA RELATED TO THE BASE OF THE UPPER TROUGH. DRY AIR ALOFT DOMINATES THE BASIN WEST OF 70W AND S OF 15N. MODERATE TRADE WINDS ARE OBSERVED OVER THE CARIBBEAN SEA. WINDS WILL INCREASE TO 20-25 KT OFF THE NW COAST OF VENEZUELA AND COLOMBIA TONIGHT TROUGH MONDAY. ATLANTIC OCEAN... THE ATLANTIC HAS A TROUGH/RIDGE/TROUGH PATTERN. BROAD DEEP LAYERED TROUGH CONTINUES TO DIG S ACROSS THE W ATLC INTO THE N CENTRAL CARIBBEAN FROM W OF 60W. THE ASSOCIATED SURFACE TROUGH EXTENDS ALONG 31N64W 29N68W. SCATTERED SHOWERS ARE WITHIN AROUND 5O NM SE OF THE TROUGH AXIS. A RIDGE IS BETWEEN THE W ATLC TROUGH AND A BROAD UPPER LOW CENTERED NEAR 30N35W WITH THE UPPER TROUGH EXTENDING S TO 20N35W. THE DEEP TROPICS IS DOMINATED BY AN UPPER HIGH OVER THE W TROPICAL ATLC NEAR 16N48W AND A SECOND RIDGE EXTENDING OFF THE AFRICAN COAST TO THE CAPE VERDE ISLANDS. DIFFLUENCE ON THE E SIDE OF THE W ATLC TROUGH IS GENERATING AN AREA OF OVERCAST CLOUDINESS WITH SCATTERED SHOWERS/ISOLATED THUNDERSTORMS FROM 19N-27N BETWEEN 55W-60W. AS IS TYPICAL FOR THIS TIME OF THE YEAR...THE BERMUDA-AZORES HIGH WITH A 1036 MB CENTER IN THE VICINITY OF 41N41W EXTENDS OVER MOST OF THE ATLC OCEAN...WITH A RIDGE COVERING THE GULF OF MEXICO AND THE SE PORTION OF THE U.S.. A SECONDARY HIGH PRESSURE CENTER OF 1026 MB IS NEAR 35N-68W. $$ GR