000 AXNT20 KNHC 071149 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 805 AM EDT WED JUL 07 2010 TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL AMERICA...GULF OF MEXICO...CARIBBEAN SEA...NORTHERN SECTIONS OF SOUTH AMERICA...AND ATLANTIC OCEAN TO THE AFRICAN COAST FROM THE EQUATOR TO 32N. THE FOLLOWING INFORMATION IS BASED ON SATELLITE IMAGERY...METEOROLOGICAL ANALYSIS...WEATHER OBSERVATIONS...AND RADAR. BASED ON 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1115 UTC... ...SPECIAL FEATURES... A BROAD AREA OF LOW PRESSURE...ANALYZED AS A SURFACE TROUGH OVER THE CENTRAL GULF OF MEXICO AND ASSOCIATED LOW JUST W OF THE YUCATAN PENINSULA COAST...IS PRODUCING SCATTERED SHOWERS AND TSTMS NEAR THE LOW CENTER FROM 21N-22N BETWEEN 91W-93W...AND SCATTERED SHOWERS AND ISOLATED TSTMS FROM THE YUCATAN PENINSULA AND CHANNEL NORTHWARD TO THE MISSISSIPPI RIVER DELTA REGION BETWEEN 85W-93W. SIMILAR ACTIVITY ALSO COVERS SRN MEXICO S OF 22N BETWEEN 92W-101W. A STRONG PRESSURE GRADIENT EXISTS ACROSS MUCH OF THE EASTERN GULF OF MEXICO WITH THIS SYSTEM. MARINE OBSERVATIONS INDICATE SUSTAINED WINDS OF 20 TO 25 KT BETWEEN 87W-92W OVER THE CENTRAL GULF WATERS. THERE IS A MEDIUM CHANCE OF THIS SYSTEM BECOMING A TROPICAL CYCLONE DURING THE NEXT 48 HOURS. ...TROPICAL WAVES... A TROPICAL WAVE WILL BE EMERGING FROM THE WEST AFRICAN COAST INTO THE TROPICAL ATLANTIC OVER THE NEXT 6 TO 12 HOURS WITH CONVECTION. TROPICAL WAVE IS ALONG 39W FROM 4N TO 13N MOVING W AT 10-15 KT. THE WAVE LIES ON THE LEADING EDGE OF A DEEP LAYER MOISTURE MAXIMUM INDICATED BY TOTAL PRECIPITABLE WATER IMAGERY. THIS WAVE IS MOVING AHEAD OF A BROAD AREA OF SAHARAN DUST NOTED ON SATELLITE IMAGERY EAST OF 35W. VERY WEAK CONVECTION IS OBSERVED IN THE VICINITY OF THE WAVE. INSTEAD...SCATTERED MODERATE TO STRONG CONVECTION IS SOUTH OF THIS SYSTEM FROM 2S-5N BETWEEN 35W-44W. TROPICAL WAVE IS ALONG 58W S OF 12N TO INLAND EAST GUYANA MOVING W AT 15-20 KT. THIS WAVE REMAINS EMBEDDED WITHIN THE ITCZ AND A DEEP LAYER MOISTURE MAXIMUM EVIDENT IN TOTAL PRECIPITABLE WATER IMAGERY. SCATTERED MODERATE AND ISOLATED STRONG CONVECTION IS FROM 5N-12N BETWEEN 52W-60W. TROPICAL WAVE EXTENDS FROM 22N71W ACROSS WESTERN HISPANIOLA TO THE COASTAL WATERS OF NORTH CENTRAL COLOMBIA NEAR 12N75W MOVING W AT 5 KT. THE WAVE IS EMBEDDED WITHIN AN AREA OF DEEP LAYER MOISTURE EVIDENT ON TPW IMAGERY. MOST OF THE ENERGY GENERATED BY THE TROPICAL WAVE IS BEING TRANSFERRED TO AN UPPER LEVEL LOW/TROUGH CENTERED OVER THE WESTERN ATLANTIC. THEREFORE...WEAK SCATTERED CONVECTION IS IN THE VICINITY OF THE WAVE. ...ITCZ... ITCZ AXIS IS ANALYZED FROM THE WEST AFRICA...OFF THE COAST OF GUINEA NEAR 10N14W...WESTWARD ALONG 7N20W 6N30W 8N40W 6N50W 7N55W. ASIDE AREAS OF CONVECTION RELATED TO TROPICAL WAVES...AN AREA OF SCATTERED MODERATE TO STRONG CONVECTION IS FROM 2N-9N BETWEEN 22W-30W. CLUSTERS OF SCATTERED MODERATE TO STRONG CONVECTION ARE FROM THE 2S TO 5N W OF 32W. ...DISCUSSION... GULF OF MEXICO... SIGNIFICANT DEEP LAYER MOISTURE CONTINUES TO IMPACT MUCH OF THE GULF OF MEXICO. WITHIN THIS AREA OF ABUNDANT MOISTURE...A SURFACE TROUGH IS ANALYZED FROM THE WESTERN LOUISIANA COAST NEAR 30N93W SOUTHWARD TO A SURFACE LOW LOCATED OVER THE COASTAL WATERS OF THE WESTERN YUCATAN PENINSULA NEAR 21N91W. SCATTERED SHOWERS AND ISOLATED TSTMS EXTEND FROM THE YUCATAN PENINSULA AND CHANNEL NORTHWARD TO THE MISSISSIPPI RIVER DELTA REGION BETWEEN 84W-95W. THIS AREA OF CONVECTION CONTINUES TO BE ENHANCED BY A DRY UPPER LEVEL LOW POSITIONED OVER THE TEXAS COAST NEAR 28N96W. THIS UPPER LEVEL LOW IS PRODUCING A SHARP GRADIENT BETWEEN MODERATE DRY AIR ALOFT TO THE WEST OF THE SURFACE TROUGH AND UNSTABLE MOIST AIR EAST OF THE TROUGH...SUPPORTING ISOLATED MODERATE TO HEAVY SHOWERS MOVING INTO THE TEXAS COAST. ELSEWHERE ACROSS THE BASIN...SCATTERED SHOWERS ARE MOVING SW ACROSS THE FLORIDA STRAIGHTS DUE TO A THIN AND WEAK UPPER LEVEL LONGWAVE MOVING W ACROSS THE FLORIDA PENINSULA. STRONG SUBSIDENCE IS NOTED BEHIND THE LONGWAVE...BRINGING CLEAR SKIES WITH A FEW HIGH CLOUDS TO THE FLORIDA PENINSULA THIS MORNING. CARIBBEAN SEA... SCATTERED SHOWERS AND TSTMS ARE WITHIN 100 NM OFF THE COAST OF BELIZE AND THE EASTERN YUCATAN PENINSULA. THIS ACTIVITY IS ENHANCED BY SURFACE CYCLONIC FLOW AROUND A SURFACE LOW LOCATED OUTSIDE THE AREA OF DISCUSSION OVER THE FAR WESTERN YUCATAN PENINSULA NEAR 21N91W. A TROPICAL WAVE EXTENDS ACROSS THE WESTERN HISPANIOLA TO NEAR THE COASTAL WATERS OF COLOMBIA ALONG 75W. MOST OF THE ENERGY GENERATED BY THE TROPICAL WAVE IS BEING TRANSFERRED TO AN UPPER LEVEL LOW/TROUGH CENTERED OVER THE WESTERN ATLANTIC...NORTH OF THE DISCUSSION AREA...LEAVING ONLY WEAK SCATTERED SHOWERS S OF 20N BETWEEN 71W-76W. ELSEWHERE ACROSS THE REGION...FAIR WEATHER IS OBSERVED WITH A FEW ISOLATED SHOWERS EMBEDDED IN THE EASTERLY TRADES. ATLANTIC OCEAN... A DEEP LAYERED LOW/TROUGH CENTERED OVER THE WESTERN ATLANTIC...NORTH OF THE DISCUSSION AREA NEAR 35N67W...SUPPORTS A SERIES OF SURFACE TROUGHS GENERATING SCATTERED MODERATE TO STRONG CONVECTION OVER A LARGE PORTION OF THE W ATLC FROM 20N TO BEYOND 32N BETWEEN 61W TO 77W. DIFFLUENCE FLOW IN THE FAR UPPER LEVELS OF THE ATMOSPHERE ARE FURTHER SUPPORTING THIS SYSTEM. FARTHER EAST...A BROAD SURFACE RIDGE DOMINATES THE CENTRAL AND EASTERN ATLC ANCHORED BY A BROAD 1029 MB HIGH CENTERED W OF THE AZORES NEAR 39N33W PROVIDING OVERALL FAIR CONDITIONS. HOWEVER...AN UPPER LEVEL LOW SPINNING NEAR 24N46W IS SUPPORTING A WEAK SURFACE TROUGH EXTENDS FROM 32N47W TO 22N47W. ISOLATED SHOWERS ARE WITHIN 90 NM ON EITHER SIDE OF THE SURFACE TROUGH. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ GARCIA