000 AXNT20 KNHC 151804 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 205 PM EDT TUE AUG 15 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. ...SPECIAL FEATURE... A 1013 MB SURFACE LOW PRESSURE CENTER NOW IS NEAR 30N75W. WIDELY SCATTERED MODERATE SHOWERS TO ISOLATED STRONG THUNDERSTORMS COVER THE BAHAMAS AND THE ATLANTIC OCEAN WATERS FROM 25N TO 33N BETWEEN 73W AND 79W. ENVIRONMENTAL CONDITIONS ARE EXPECTED TO BECOME SOMEWHAT MORE FAVORABLE FOR A TROPICAL DEPRESSION TO FORM DURING THE NEXT 48 HOURS OR SO AS THIS SYSTEM MOVES SLOWLY NORTHWARD. AN AIR FORCE RESERVE RECONNAISSANCE AIRCRAFT IS SCHEDULED TO INVESTIGATE THE SYSTEM ON WEDNESDAY IF NECESSARY. ...TROPICAL WAVES... AN ATLANTIC OCEAN 1012 MB SURFACE LOW PRESSURE CENTER IS NEAR 12N22W MOVING WEST 10 TO 15 KT. ISOLATED TO WIDELY SCATTERED MODERATE SHOWERS AND POSSIBLE THUNDERSTORMS COVER THE ATLANTIC OCEAN WATERS FROM 10N TO 17N BETWEEN 20W AND 30W. AN ATLANTIC OCEAN TROPICAL WAVE IS ALONG 37W/38W SOUTH OF 20N MOVING WEST 10 TO 15 KT. A BROAD FIELD OF LOW TO MIDDLE LEVEL CLOUDS AND POSSIBLE SHOWERS COVERS THE WATERS FROM 10N TO 20N BETWEEN 30W AND 40W. A CARIBBEAN SEA TROPICAL WAVE IS ALONG 67W/68W...PASSING OVER PUERTO RICO...SOUTH OF 20N MOVING WEST 15 KT. ISOLATED MODERATE SHOWERS AND POSSIBLE THUNDERSTORMS ARE OCCURRING FROM 15N TO 20N BETWEEN 65W AND 70W. ...THE ITCZ... ITCZ 17N16W 14N20W 11N25W 9N35W 8N40W 11N52W 11N60W. ISOLATED MODERATE SHOWERS AND POSSIBLE THUNDERSTORMS ARE WITHIN 60 TO 90 NM ON EITHER SIDE OF 10N30W 6N40W 8N47W 12N54W 11N62W. ...DISCUSSION... THE GULF OF MEXICO AND THE ATLANTIC OCEAN NORTH OF 20N WEST OF 70W... THE MAIN FEATURE IS THE MIDDLE TO UPPER LEVEL LOW PRESSURE CENTER THAT IS JUST OFF THE NORTHEASTERN FLORIDA COAST IN THE ATLANTIC OCEAN WATERS. THE CYCLONIC FLOW AROUND THIS LOW CENTER COVERS THE ATLANTIC OCEAN AND THE GULF OF MEXICO NORTH OF 24N BETWEEN 78W AND 90W. MIDDLE TO UPPER LEVEL DRY AIR COVERS FLORIDA AND THE ATLANTIC OCEAN BETWEEN 79W AND 83W. ANOTHER MIDDLE TO UPPER LEVEL LOW CENTER IS IN THE ATLANTIC OCEAN WATERS NEAR 28N73W. PRECIPITATION IN GENERAL COVERS THE WATERS NORTH OF 24N BETWEEN 72W AND 90W. SCATTERED STRONG SHOWERS AND THUNDERSTORMS IN PARTICULAR ARE OCCURRING FROM 25N TO 28N BETWEEN 87W AND 90W. A WEAK MIDDLE TO UPPER LEVEL LOW CENTER IN THE SOUTH CENTRAL GULF WATERS IS NOT PRODUCING ANY PRECIPITATION...AS IT IS SURROUNDED BY MIDDLE TO UPPER LEVEL DRY AIR. A DISSIPATING STATIONARY FRONT EXTENDS 30N69W TO 31N73W TO A SURFACE 1013 MB LOW PRESSURE CENTER NEAR 30N75W. A TROUGH CONNECTS THE FIRST LOW CENTER WITH ANOTHER 1013 MB LOW PRESSURE CENTER NEAR 26N78W IN THE NORTHERN BAHAMAS. THE TROUGH CONTINUES FROM 26N78W TO THE STRAITS OF FLORIDA...TO KEY WEST FLORIDA...AND IT CONTINUES TO CURVE NORTHWESTWARD TO 29N89W. A WEAK MIDDLE TO UPPER LEVEL LOW/TROUGH OVER TEXAS IS MATCHED BY A SURFACE 1017 MB HIGH PRESSURE CENTER IN SOUTHWESTERN LOUISIANA...AND A WEAK PRESSURE GRADIENT IN TEXAS. THE CARIBBEAN SEA... A NARROW MIDDLE TO UPPER LEVEL TROUGH/SHEAR AXIS COVERS THE NORTHWESTERN CARIBBEAN SEA WITH NO PRECIPITATION. MORE MIDDLE TO UPPER LEVEL DRY AIR COVERS THE AREA BETWEEN A LINE FROM THE MONA PASSAGE TO SOUTHEASTERN NICARAGUA AND A LINE FROM SOUTHEASTERN CUBA TO NORTHEASTERN NICARAGUA. UPPER LEVEL ANTICYCLONIC FLOW MOVES FROM COLOMBIA AND CENTRAL AMERICA TOWARD THE WESTERN AND CENTRAL CARIBBEAN SEA WATERS. A MIDDLE TO UPPER LEVEL LOW CENTER IS IN THE ATLANTIC OCEAN WATERS NEAR 20N56W. CYCLONIC FLOW AROUND THIS FEATURE IS STARTING TO BE FELT IN THE NORTHEASTERN CORNER OF THE AREA. ISOLATED MODERATE SHOWERS AND POSSIBLE THUNDERSTORMS COVER THE AREA FROM 16N TO 19N BETWEEN 60W AND THE EASTERN SHORES OF THE CARIBBEAN SEA ISLANDS FROM GUADELOUPE TO AT LEAST ANGUILLA. A TROPICAL WAVE ALONG 67W/68W SOUTH OF 20N IS PASSING OVER PUERTO RICO. ISOLATED MODERATE SHOWERS AND POSSIBLE THUNDERSTORMS ARE OCCURRING FROM 15N TO 20N BETWEEN 65W AND 70W. ISOLATED MODERATE SHOWERS ARE FROM 14N TO 15N BETWEEN 70W AND 73W IN AN AREA OF WEAK MIDDLE TO UPPER LEVEL LOW PRESSURE/TROUGH UNDER THE UPPER RIDGE FROM SOUTH AMERICA NORTHWARD. THE ATLANTIC OCEAN... A REALLY WELL-DEFINED MIDDLE TO UPPER LEVEL LOW CENTER IS NEAR 20N56W. A MUCH MUCH SMALLER LOW CENTER IS NEAR 30N58W. A SURFACE STATIONARY FRONT GOES FROM 30N54W TO A 1013 MB LOW PRESSURE CENTER NEAR 29N62W. THE STATIONARY FRONT CONTINUES TO 29N67W AND 30N69W. ISOLATED MODERATE SHOWERS AND POSSIBLE THUNDERSTORMS ARE WITHIN 30 TO 60 NM ON EITHER SIDE OF THE FRONT BETWEEN 56W AND 70W...PRECISELY IN THE AREA IN BETWEEN THE TWO MIDDLE TO UPPER LEVEL LOW CENTERS. CLOUDINESS AND POSSIBLE PRECIPITATION ARE FROM 16N TO 23N BETWEEN 52W AND 58W. A MIDDLE TO UPPER LEVEL TROUGH RUNS FROM A LOW CENTER AT LEAST 200 NM SOUTH OF THE AZORES TO 30N28W TO A MUCH SMALLER-SIZED LOW CENTER NEAR 25N31W TO 10N39W. MIDDLE TO UPPER LEVEL DRY AIR IS IN THE AREA...EAST OF THE 20N56W LOW CENTER AND WEST OF THE AZORES-TO-10N39W TROUGH. AN UPPER LEVEL RIDGE IS ON TOP OF THE CAPE VERDE ISLANDS. IT APPEARS THAT A SMALL MIDDLE TO UPPER LEVEL LOW CENTER IS MOVING OFF THE COAST OF MAURITANIA. A WEAK SURFACE RIDGE PASSES OVER THE CANARY ISLANDS TO 26N28W. A SURFACE TROUGH PASSES THROUGH 31N25W TO 27N36W. A 1019 MB HIGH PRESSURE CENTER IS NEAR 27N50W. $$ MT