000 AXNT20 KNHC 082349 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 805 PM EDT SAT JUL 08 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 2315 UTC. ...TROPICAL WAVES... WELL-DEFINED TROPICAL WAVE IS ALONG 35W/36W S OF 15N MOVING W 15-20 KT. CONVECTION CONTINUES IN ASSOCIATION WITH THIS WAVE AND IS SPREADING S OF THE ITCZ. WEAK TURNING IS ALSO NOTED ALONG THE WAVE AXIS NEAR 8N36W. CLUSTERS OF MODERATE CONVECTION ARE FROM 8N-10N BETWEEN 35W-38W. SIMILAR CONVECTION IS FOUND AHEAD OF THE WAVE AXIS AND WITHIN 60/90 NM ON EITHER SIDE OF THE ITCZ FROM 38W-42W. THE GFS MODEL FORECAST THE WAVE TO AFFECT THE LESSER ANTILLES LATE WEDNESDAY. TROPICAL WAVE IS ALONG 54W/55W S OF 14N MOVING W 15 KT. BROAD LOW LEVEL SIGNATURE CURVATURE IS OBSERVED ON VISIBLE SATELLITE IMAGERY. SCATTERED SHOWERS/TSTMS ARE JUST BEHIND THE WAVE AXIS FROM 8.5N-10N. THIS FEATURE WILL MOVE INTO THE EASTERN CARIBBEAN SUNDAY EVENING...BRINGING AN INCREASE IN SHOWER ACTIVITY ACROSS PUERTO RICO AND THE VIRGIN ISLANDS LATE SUNDAY TROUGH MONDAY. TROPICAL WAVE THAT WAS PREVIOUSLY ANALYZED ALONG 72W ON THE 12Z SURFACE MAP IS RELOCATED ALONG 79W/80W BASED ON SATELLITE IMAGERY AND SURFACE DATA. A 1008 MB SURFACE LOW IS ALONG THE WAVE AXIS OVER PANAMA. CLUSTERS OF MODERATE/STRONG CONVECTION ARE SEEN OVER WESTERN PANAMA AND PARTS OF COSTA RICA. THIS CONVECTION IS ENHANCING BY THE CLOSE PROXIMITY OF THE ITCZ AXIS ON THE PACIFIC SIDE. TROPICAL WAVE IS INLAND OVER MEXICO ALONG 97W S OF 22N MOVING W 15 KT. WIDELY SCATTERED MODERATE CONVECTION IS ASSOCIATED WITH THE WAVE. ...ITCZ... ITCZ AXIS IS CENTERED ALONG 10N14W 8N33W 7N40W 8N53W 8N60W. CLUSTERS OF SCATTERED MODERATE/STRONG CONVECTION ARE WITHIN 80/100 NM SOUTH OF THE AXIS BETWEEN 25W-30W AND BETWEEN 40W-43. ...DISCUSSION... GULF OF MEXICO... DEEP LAYERED TROUGH IS OVER THE E U.S. EXTENDING INTO THE NE GULF N OF 25N. THIS STRONG TROUGH ALONG WITH ABUNDANT TROPICAL MOISTURE CONTINUES TO ENHANCE THE SHOWER/TSTM ACTIVITY OVER THE CENTRAL AND SOUTH FLORIDA. AN UPPER RIDGE COVERS THE REMAINDER OF THE GULF. AT THE SURFACE...A STATIONARY FRONT IS OVER THE NORTHERN GULF OF MEXICO AND CENTRAL FLORIDA. A BAND OF MODERATE SHOWERS AND TSTM EXTENDS EAST TO WEST JUST AHEAD OF THE FRONTAL BOUNDARY FROM 25N-27N EAST OF 90W. WIND VELOCITIES ARE BASICALLY ONLY 10 KT ON BOTH SIDES OF THE FRONT. THE FRONT IS FORECAST TO BECOME DIFFUSE LATER TONIGHT. THE UPPER LOW THAT WAS YESTERDAY OVER THE BAY OF CAMPECHE IS CURRENTLY OVER SOUTH-CENTRAL MEXICO. CONSIDERABLE UPPER LEVEL MOISTURE COVERS THE MAJORITY OF THE GULF AND THE YUCATAN PENINSULA. CARIBBEAN SEA... A LARGE UPPER-LEVEL LOW IS STILL PRODUCING DISORGANIZED CLOUDINESS...SHOWERS AND TSTMS OVER HISPANIOLA AND PUERTO RICO. THERE ARE NO SIGNS OF A SURFACE CIRCULATION AT THIS TIME AND TROPICAL CYCLONE FORMATION IS NOT EXPECTED. THIS SYSTEM IS EXPECTED TO MOVE NWWD...SPREADING THE SHOWER ACTIVITY TO THE SOUTHEASTERN BAHAMAS. MODERATE TO STRONG TRADEWINDS COVERS THE CARIBBEAN SEA WITH THE HIGHEST VELOCITIES OF 20-25 KT ACROSS THE S CENTRAL CARIBBEAN. CONVECTION HAS DEVELOPED ALONG THE EASTERN HALF OF NICARAGUA AND NE HONDURAS. THE TRADE WINDS ARE BRINGING LOW LEVEL MOISTURE TO THE AREA. IN THE UPPER LEVELS...A RIDGE WITH ABUNDANT MOISTURE REMAINS OVER CENTRAL AMERICA AND THE W CARIBBEAN BETWEEN 80W-90W. A DIFFLUENT PATTERN ALOFT IS ENHANCING THE CONVECTIVE ACTIVITY OVER PANAMA AND NICARAGUA. ATLANTIC OCEAN... A WEAK SURFACE LOW IS NEAR 31N36W. A STATIONARY FRONT EXTENDS SW FROM THE SURFACE LOW ACROSS CENTRAL FLORIDA...JUST NORTH OF LAKE OKEECHOBEE AND THE E GULF. WIDELY SCATTERED MODERATE CONVECTION IS WITHIN 80 NM SE OF THE FRONT. A 1029 MB HIGH IS OVER THE CENTRAL ATLANTIC NEAR 33N52W. ELY FLOW AND MOSTLY FAIR WEATHER IS N OF 15N BETWEEN 15W-60W. THE LEADING EDGE OF A LARGE AREA OF AFRICAN DUST IS REACHING 55W. IN THE UPPER LEVELS...UPPER RIDGE EXTENDS FROM THE W CARIBBEAN ACROSS W/CENTRAL CUBA AND THE BAHAMAS. BROAD UPPER LOW COVERS THE W/CENTRAL ATLC FROM 57W-74W CENTERED NNW OF PUERTO RICO NEAR 22N68W EXTENDING S INTO THE E CARIBBEAN. THIS LOW IS DRIFTING NW...PULLING A BAND OF MOISTURE ACROSS HISPANIOLA...PUERTO RICO AND THE VIRGIN ISLANDS. BROAD UPPER HIGH DOMINATES MOST OF THE E ATLC CENTERED NEAR 22N34W AND COVERS THE AREA FROM 25W-55W. UPPER TROUGH COVERS THE REMAINDER OF THE E ATLC EAST OF 25W. $$ GR