000 AXNT20 KNHC 310004 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 805 PM EDT FRI JUL 30 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 2345 UTC. ...TROPICAL WAVES... TROPICAL WAVE IS EMBEDDED IN THE ITCZ APPROACHING THE CAPE VERDE ISLANDS ALONG 21W S OF 18N MOVING W NEAR 10-15 KT. THIS WAVE IS EMBEDDED WITHIN AN AREA OF A HIGH AMPLITUDE MOISTURE MAXIMUM. A WELL DEFINED LOW TO MID LEVEL CYCLONIC FLOW SURROUNDS THE WAVE AXIS EVIDENT ON INFRA RED SATELLITE DATA. SCATTERED MODERATE CONVECTION IS WITHIN 35 NM ON EITHER SIDE OF THE WAVE AXIS NORTH OF 12N. THE REST OF THE CONVECTION SOUTH OF 12N IS ASSOCIATED WITH THE ITCZ. TROPICAL WAVE IS ALONG 44W MOVING W NEAR 15 KT. THIS WAVE IS MOVING THROUGH AN REGION OF STRONG DOWNWARD MOTION OF AIR NOTED ON WATER VAPOR IMAGERY. THEREFORE...ANY ACTIVITY ASSOCIATED WITH THIS WAVE IS ASSOCIATED WITH THE ITCZ. TROPICAL WAVE IS IN THE EASTERN CARIBBEAN EXTENDING FROM 16N63W TO THE COASTAL WATERS OF VENEZUELA NEAR 11N67W MOVING W 15-20 KT. WAVE REMAINS POSITIVELY TILTED AND EMBEDDED WITHIN A MOISTURE MAXIMUM WITH SCATTERED MODERATE TO STRONG CONVECTION WITHIN 120 NM OF WAVE AXIS. TROPICAL WAVE IS IN THE WESTERN CARIBBEAN ALONG 81W S OF 20N MOVING W 5-10 KT. WAVE IS EMBEDDED WITHIN AN AREA OF HIGH AMPLITUDE MOISTURE MAXIMUM. SCATTERED MODERATE TO STRONG CONVECTION IS OVER THE NORTHWEST BASIN NORTH OF 11N WEST OF 74W...INCLUDING INLAND PORTIONS OF CENTRAL AMERICA NORTH OF 11N...JAMAICA...AND CUBA. ...THE ITCZ... THE ITCZ AXIS IS ANALYZED FROM THE WESTERN AFRICAN COAST OF SENEGAL NEAR 14N17W...WESTWARD ALONG 10N25W 8N30W 9N40W 8N50W 12N60W...CONTINUING ACROSS NORTHERN SOUTH AMERICA. A 1010 MB SURFACE LOW IS EMBEDDED IN THE ITCZ NEAR 9N33W. CLUSTERS OF SCATTERED MODERATE TO STRONG CONVECTION ARE FROM 7N TO 13N BETWEEN 20W AND 31W AND FROM 10N TO 16N BETWEEN 57 AND 61W INCLUDING THE LESSER ANTILLES SOUTH OF 15N. SMALL CLUSTERS OF SCATTERED MODERATE CONVECTION DOT THE AREA FROM 2N TO 10N BETWEEN 35W AND 48W. ...DISCUSSION... GULF OF MEXICO... A BROAD UPPER LEVEL LONGWAVE/TROUGH EXTENDS ACROSS THE NORTHWEST ATLANTIC AND MOST OF THE NORTHEAST GULF BASIN...ENHANCING AN AREA OF SCATTERED WEAK TO MODERATE SHOWERS OVER THE CENTRAL BASIN FROM 24N TO 28N BETWEEN 86W AND 91W. THIS UPPER LEVEL FEATURE IS ALSO INTERACTING WITH AN UPPER RIDGE OF HIGH PRESSURE OVER THE NORTHWEST BASIN THAT IS CREATING ANTI CYCLONIC FLOW AROUND A SURFACE HIGH CENTER NEAR 27N94W...TO PRODUCE A WEAK AREA OF SURFACE CONVERGING WINDS ACROSS THE SOUTHEAST AND SOUTHERN PORTIONS OF THE BASIN. THUS...WEAK ISOLATED SHOWERS ARE DEVELOPING WITHIN 30 NM ON EITHER SIDE OF THE CONVERGENCE LINE ALONG 26N82W 23N87W 21N94W. THE REMAINDER AREAS ACROSS THE BASIN ARE EXPERIENCING FAIR WEATHER THIS EVENING. CARIBBEAN SEA... A TROPICAL WAVE IS PRODUCING SCATTERED SHOWERS AND THUNDERSTORMS OVER THE NORTHWEST BASIN NORTH OF 11N WEST OF 74W...INCLUDING INLAND PORTIONS OF CENTRAL AMERICA NORTH OF 11N...JAMAICA...AND CUBA. ANOTHER TROPICAL WAVE IS OVER THE EASTERN BASIN PRODUCING SCATTERED SHOWERS AND THUNDERSTORMS FROM 12N TO 15N BETWEEN 61W AND 70W. SEE TROPICAL WAVES DISCUSSION ABOVE FOR MORE DETAILS REGARDING THESE WAVES. SCATTERED MODERATE TO HEAVY SHOWERS ARE OVER THE FAR SOUTHWEST BASIN SOUTH OF 11N WEST OF 74W...PRODUCED BY AN EXTENSION OF THE PACIFIC ITCZ ACROSS COSTA RICA...PANAMA AND NORTHERN COLOMBIA. SURFACE AND MARINE OBSERVATIONS SHOW A TIGHT PRESSURE GRADIENT ACROSS THE BASIN...GENERATING MODERATE TO FRESH TRADEWINDS ACROSS MUCH OF THE DISCUSSION AREA. ATLANTIC OCEAN... A BROAD UPPER LEVEL LONGWAVE/TROUGH IS OVER THE NORTHWEST ATLC. THE LEADING EDGE OF THE UPPER LEVEL FEATURE IS GENERATING AN AREA OF MODERATE TO STRONG SURFACE CONVERGENCE OF WINDS FROM 27N TO 32N BETWEEN 71W AND 75W. SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS ARE OVER THIS AREA. NO SIGNIFICANT WEATHER IS OCCURRING ELSEWHERE ACROSS THE ATLANTIC NORTH OF 15N DUE TO DRY SAHARAN AIR EMBEDDED IN THE BROAD UPPER LEVEL RIDGE OF HIGH PRESSURE DOMINATING THE AREA OF DISCUSSION. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ GARCIA