000 AXNT20 KNHC 101754 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 205 PM EDT THU AUG 10 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... AN ATLANTIC OCEAN TROPICAL WAVE IS ALONG 41W SOUTH OF 20N MOVING WEST NEAR 15 KT. CYCLONIC CURVATURE WITH AN INVERTED V PATTERN IS MAINLY NOTED IN THE LOW CLOUD MOTIONS N OF 10N BETWEEN 35W AND 48W. OVERALL THERE IS LITTLE SIGNIFICANT CONVECTION ASSOCIATED WITH THIS WAVE. A CLUSTER OF MODERATE CONVECTION THAT WAS NOTED W OF THE AXIS NEAR 9N45W THIS MORNING HAS SINCE DIMINISHED IN COVERAGE AND INTENSITY. ONLY ISOLATED SHOWERS AND THUNDERSTORMS ARE NOTED AS OF 1700 UTC WITHIN 200NM OF EITHER SIDE OF THE AXIS. AN EASTERN CARIBBEAN TROPICAL WAVE IS ALONG 63W S OF 21N MOVING WEST 20 TO 25 KT. THIS WAVE CONTINUES TO PRODUCE SHOWERS AND SQUALLS WITH WIND GUSTS TO TROPICAL STORM FORCE OVER PORTIONS OF THE LESSER ANTILLES...THE LEEWARD ISLANDS...AND THE ADJACENT WATERS. WHILE THIS SYSTEM REMAINS POORLY ORGANIZED...IT STILL HAS THE POTENTIAL TO DEVELOP INTO A TROPICAL DEPRESSION DURING THE NEXT DAY OR SO. AN AIR FORCE RESERVE HURRICANE HUNTER AIRCRAFT IS SCHEDULED TO INVESTIGATE THE SYSTEM LATER TODAY...IF NECESSARY. THIS MORNINGS QUIKSCAT PASS DID NOT SHOW A CLOSED LOW AND LOW CLOUD MOTIONS DO NOT SUGGEST A SURFACE LOW IS PRESENT. THUS...THE LOW THAT WAS PREVIOUSLY ALONG THIS WAVE HAS BEEN REMOVED. ISOLATED MODERATE CONVECTION ASSOCIATED WITH THIS WAVE IS NOTED WITHIN 300NM OF EITHER SIDE OF THE AXIS. CLOUD TOPS ASSOCIATED WITH THE CLUSTER OF MODERATE TO STRONG CONVECTION THAT DEVELOPED JUST SOUTH OF THE LEEWARD ISLANDS THIS MORNING HAVE WARMED THIS AFTERNOON. A TROPICAL WAVE EXTENDING THROUGH THE BAY OF CAMPECHE...SRN MEXICO..AND INTO THE GULF OF TEHUANTEPEC IS PRODUCING MINIMAL SHOWER ACTIVITY IN THE SW GULF OF MEXICO. THE SCATTERED SHOWERS AND TSTMS NORTH OF THE WAVE MOVING INTO THE WRN GULF FROM 22N TO 29N BETWEEN 90W AND 97W SEEM MORE ASSOCIATED WITH INSTABILITY AROUND THE BASE OF THE THE UPPER TROUGH IN THE VICINITY. ...THE ITCZ... ITCZ IS CENTERED ALONG 12N15W 11N39W 11N43W TO THE SOUTH AMERICAN COAST NEAR 10N62W. SCATTERED SHOWERS AND TSTMS WITH EMBEDDED ISOLATED MODERATE CONVECTION LIES MAINLY S OF THE AXIS FROM 4N TO 11N BETWEEN THE AFRICAN COAST AND 43W. SCATTERED SHOWERS AND TSTMS ALSO EXIST FROM 7N TO 13N BETWEEN 43W AND THE VENEZUELAN COAST...WITH THE STRONGEST CLUSTER OF MODERATE CONVECTION IN THIS REGION NOTED NEAR 10N53W. ...DISCUSSION... THE GULF OF MEXICO... A MIDDLE TO UPPER LEVEL LOW CENTER IS SEEN IN WV IMAGERY MOVING FROM THE CENTRAL TO WESTERN GULF. THIS IS PRODUCING CYCLONIC FLOW OVER MUCH OF THE GULF. SCATTERED SHOWERS AND TSTMS NEAR THE BASE OF THE UPPER LOW ARE MOVING INTO THE WRN GULF FROM 22N TO 29N BETWEEN 90W AND 97W. ISOLATED SHOWERS ARE ALSO NOTED WEST OF SW FLORIDA THROUGH 88W. FAIRLY LIGHT E/SE WINDS AT THE SURFACE CONTINUE IN THE GULF THIS AFTERNOON ON THE W/SW PORTION OF HIGH PRESSURE EXTENDING FROM THE ATLC. THE EXCEPTION IS THE NE GULF WHERE LIGHT/VARIABLE TO LIGHT WSW WINDS DOMINATE...JUST N OR IN THE VICINITY OF THE RIDGE AXIS. SIMILAR CONDITIONS EXPECTED THE NEXT COUPLE OF DAYS...THOUGH SHOWER ACTIVITY ASSOCIATED WITH THE UPPER LOW WILL MOVE TOWARDS AND INTO SRN TEXAS AND NE MEXICO. THE CARIBBEAN SEA... PARTS OF THE NORTHWESTERN CARIBBEAN SEA AND THE YUCATAN PENINSULA ARE COVERED BY MIDDLE TO UPPER LEVEL CYCLONIC FLOW FROM THE CENTRAL GULF OF MEXICO LOW CENTER. A VAGUE UPPER HIGH IS LOCATED OVER NE NICARAGUA. THIS IS LIKELY AIDING THE SCATTERED MODERATE CONVECTION MOVING THROUGH CENTRAL AMERICA AND THE SW CARIBBEAN. THIS ACTIVITY HAS BEEN SURGING WESTWARD OVER THE LAST COUPLE OF DAYS WITHIN EASTERLY FLOW. HOWEVER THERE IS NO CURVATURE ASSOCIATED WITH THIS SURGE AND THUS DO NOT THINK THERE IS A TROPICAL WAVE EMBEDDED. UPPER LEVEL ANTICYCLONIC NE/E FLOW DOMINATES MUCH OF THE CARIBBEAN E OF 80W. THE EXCEPTION IS THE AREA JUST S OF THE LEEWARD ISLANDS WHICH IS ON THE SRN PORTION OF AN ATLC UPPER TROUGH. UPPER WSW FLOW IN THIS AREA IS SHEARING THE TSTMS ASSOCIATED WITH THE ERN CARIBBEAN TROPICAL WAVE ALONG 63W. 15 TO 25 KT EASTERLY TRADE FLOW CONTINUES TO DOMINATE MUCH OF THE CARIBBEAN THIS AFTERNOON...DUE TO THE INTERACTION BETWEEN THE ATLC HIGH NORTH OF THE AREA WITH THE COLOMBIAN LOW. THE STRONGEST WINDS ARE LOCATED BETWEEN THE COLOMBIAN/VENEZUELAN COASTS AND PUERTO RICO/HISPANIOLA DUE TO THIS INTERACTION AND PERHAPS SOME ENHANCEMENT BY THE APPROACHING TROPICAL WAVE. THE ATLANTIC OCEAN... AN UPPER LEVEL HIGH OVER THE SE US IS PRODUCING NE FLOW IN THE SW ATLC OFF THE COAST OF FLORIDA. THESE WINDS ARE BLOWING THE HIGH CLOUDS OFF THE SCATTERED SHOWERS AND THUNDERSTORMS OCCURRING MAINLY SOUTH OF A STATIONARY FRONT EXTENDING EAST FROM THE CAROLINAS. A FAIRLY DRY UPPER LEVEL LOW IS SEEN SPINNING NORTH OF THE LEEWARD ISLANDS...WITH ITS CENTER NEAR 21N63W. LARGE SCALE UPPER RIDGING DOMINATES MUCH OF THE REMAINDER OF THE TROPICAL ATLC...WITH THE RIDGE EXTENDING W FROM AFRICA TO NEAR 55W...WITH THE AXIS MORE OR LESS ALONG 20N. FAIR WEATHER WITH MINIMAL SHOWER ACTIVITY DOMINATES THIS AREA OUTSIDE OF THE ITCZ/TROPICAL WAVE VICINITY. SURFACE HIGH PRESSURE CENTERS ARE ANALYZED AT 1022MB NEAR 27N32W AND 1020MB NEAR 27N54W...WITH THE RIDGE AXIS EXTENDING W THROUGH SOUTH CENTRAL FLORIDA. $$ WILLIS