000 AXNT20 KNHC 162353 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 805 PM EDT SAT JUL 16 2011 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...WEATHER OBSERVATIONS...RADAR...AND METEOROLOGICAL ANALYSIS. BASED ON 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 2315 UTC. ...TROPICAL WAVES... TROPICAL WAVE IS ANALYZED FROM 10N22W TO 17N21W MOVING W AT 15-20 KT. EXAMINING RECENT HOVMOLLER DIAGRAM DATA AND THE UPPER AIR TIME SECTION ANALYSES...IT INDICATES THE WAVE PASSED DAKAR SENEGAL AROUND 15/1200 UTC. GLOBAL MODEL DATA ALSO INDICATES THE WAVE AXIS COINCIDES WITH AN 850-700 MB LOWER ATMOSPHERIC TROUGH THAT IS FORECAST TO DRIFT WESTWARD OVER THE NEXT COUPLE OF DAYS. CURRENTLY CONVECTION REMAINS LIMITED TO ISOLATED MODERATE ALONG THE W AFRICA COAST FROM 09N-15N BETWEEN 15W-19W. TROPICAL WAVE IS ANALYZED FROM 10N41W TO 18N44W MOVING W AT 15-20 KT. THE WAVE IS FAIRLY BROAD COVERING A LARGE PORTION OF THE CENTRAL ATLC THIS EVENING AND ALSO COINCIDES WITH A 700 MB TROUGH WITH AXIS ALONG 44W. MOSTLY DRY CONDITIONS ARE NOTED AT THE SURFACE AND ALOFT...WHICH IS PROVIDING FOR ONLY LOW-LEVEL CLOUDINESS AND A LACK OF ANY CONVECTION. THE CIMSS SAHARAN AIR LAYER TRACKING PRODUCT SHOWS A STRONG DUST LAYER FOLLOWS TO THE EAST OF THE WAVE AXIS TO THE WEST OF THE WAVE MENTIONED ABOVE. TROPICAL WAVE IS ANALYZED FROM 08N58W TO 13N54W MOVING W AT 15-20 KT. THE WAVE IS LOCATED IN THE VICINITY OF THE LEADING EDGE OF A ENHANCED LOW-LEVEL MOISTURE AS DEPICTED ON TOTAL PRECIPITABLE WATER IMAGERY. SCATTERED MODERATE CONVECTION IS FROM 11N-15N BETWEEN 51W-58W. TROPICAL WAVE IS ANALYZED FROM 18N93W TO 23N91W IN THE SW GULF OF MEXICO MOVING W AT 15-20 KT. THE WAVE HAS BECOME DIFFICULT TO DISCERN AND IS EXPECTED TO BECOME DIFFUSE OVER THE NEXT 24 HOURS AS IT APPROACHES THE EASTERN MEXICO COAST. TOTAL PRECIPITABLE WATER SHOWS THAT LOW-LEVEL MOISTURE IS ENHANCED IN THE VICINITY OF THE WAVE ACROSS THE SW GULF S OF 23N AND IS GENERATING A FEW ISOLATED AREAS OF SCATTERED MODERATE CONVECTION...ONE OVER THE YUCATAN PENINSULA FROM 17N-21N BETWEEN 88W-92W AND THE OTHER FROM 21N-24N BETWEEN 96W-98W. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS FROM THE AFRICAN COAST NEAR 21N17W THEN RESUMES WEST OF THE TROPICAL WAVE ALONG 22W NEAR 09N24W TO 07N32W. THE INTERTROPICAL CONVERGENCE ZONE AXIS EXTENDS FROM 07N32W TO 05N53W. ISOLATED MODERATE CONVECTION IS FROM 03N-06N BETWEEN 47W-51W. ...DISCUSSION... GULF OF MEXICO... AN LARGE AND EXPANSIVE UPPER LEVEL ANTICYCLONE IS CENTERED OVER THE CENTRAL CONUS AND THE SOUTHERN PERIPHERY OF THIS RIDGE EXTENDS SOUTHWARD ACROSS THE NORTHERN GULF WATERS NORTH OF 25N. WATER VAPOR IMAGERY INDICATES MIDDLE TO LOW-LEVEL MOISTURE EXTENDS FROM THE W ATLC WATERS EASTWARD ACROSS NORTHERN FLORIDA AND THE NORTHERN GULF COAST ALONG 30N TO EASTERN TEXAS. WEAK TROUGHING ALSO EXTENDS ALONG THE EASTERN SEABOARD SW OF THE CAROLINAS AND IS SUPPORTIVE OF A FRONTAL TROUGH FROM CAPE CANAVERAL TO 29N85W THEN INLAND TO A 1012 MB LOW CENTERED OVER SW ALABAMA. LOW-LEVEL CONVERGENCE AND PEAK DAYTIME INSTABILITY IS SUPPORTING SCATTERED SHOWERS AND WIDELY SCATTERED TSTMS ACROSS THE SOUTHERN FLORIDA PENINSULA AND NE GULF N OF 28N. ELSEWHERE...BRIDGED BETWEEN THE TROPICAL WAVE MENTIONED ABOVE ACROSS THE SW GULF S OF 23N AND THE FRONTAL TROUGHING ACROSS THE NE GULF...A SURFACE RIDGE AXIS EXTENDS FROM THE FLORIDA KEYS TO NEAR GALVESTON TEXAS ANCHORED ON A 1017 MB HIGH CENTERED NEAR 27N87W. E-SE WINDS ARE EXPECTED TO REMAIN DOMINATE OVER MUCH OF THE GULF THROUGH THE TUESDAY AS THE SURFACE RIDGING HOLDS ALONG 27N. CARIBBEAN SEA... BROAD UPPER LEVEL CYCLONIC FLOW COVERS MUCH OF THE CARIBBEAN WITH PRIMARILY NORTHEASTERLY FLOW W OF 63W. THE UPPER LEVEL LOW IS CENTERED OVER ARUBA AND CONTINUES TO GENERATE WIDELY SCATTERED SHOWERS AND ISOLATED TSTMS IN THE VICINITY OF THE MONA PASSAGE...EASTERN HISPANIOLA FROM 18N-20N BETWEEN 71W-75W...AND ALONG THE SOUTHERN COAST OF CUBA BETWEEN 77W-82W. E TO SE SURFACE WINDS GENERALLY IN THE 15-20 KT RANGE ARE EXPECTED ACROSS MUCH OF THE WATERS THROUGH THE OVERNIGHT PERIOD INTO SUNDAY. AN APPROACHING TROPICAL WAVE CURRENTLY SE OF THE WINDWARD ISLANDS ALONG 56W WILL INCREASE PRECIPITATION CHANCES FOR THE EASTERN CARIBBEAN THROUGH MONDAY AND CONTINUE WESTWARD THROUGH THE REMAINDER OF THE UPCOMING WEEK. ELSEWHERE THIS EVENING...SCATTERED SHOWERS AND TSTMS ARE OCCURRING OVER INLAND PORTIONS OF CENTRAL AMERICA AS AN ACTIVE MONSOON TROUGH IN THE EAST PACIFIC REGION CONTINUES TO GENERATE LOCALLY HEAVY RAINFALL ACROSS WESTERN PANAMA...COSTA RICA...NICARAGUA...AND HONDURAS. ATLANTIC OCEAN... WATER VAPOR IMAGERY INDICATES A LONGWAVE TROUGH IS LOCATED OFF THE NEW ENGLAND AND MID-ATLC COAST WITH AXIS ALONG 65W THAT EXTENDS SOUTHWARD TO 30N...WITH INFLUENCE BETWEEN 60W-82W. ALONG THE SOUTHERN PERIPHERY OF THIS TROUGH...MIDDLE TO LOW-LEVEL MOISTURE CONTINUES TO POOL ALONG A STATIONARY BOUNDARY ANALYZED FROM 32N58W W-SW ALONG 29N65W TO A 1014 MB LOW CENTERED NEAR 29N79W. A FRONTAL TROUGH CONTINUES WESTWARD ACROSS FLORIDA FROM CAPE CANAVERAL INTO THE NE GULF OF MEXICO WATERS NEAR 28N83W. SCATTERED SHOWERS AND ISOLATED TSTMS ARE OCCURRING WITHIN 180 NM EITHER SIDE OF THE FRONT. THE REMAINDER OF THE CENTRAL AND EASTERN ATLC CONTINUES TO BE UNDER THE INFLUENCE OF A SURFACE RIDGE WITH AXIS ALONG 32N42W TO 25N57W THEN WESTWARD TO 24N70W. WITH THE EXCEPTION OF THE TROPICAL WAVE ALONG 44W PERTURBING THE SURFACE FLOW...MOSTLY NE WINDS OF 20 KT ARE OCCURRING EAST OF THE RIDGE AXIS. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ HUFFMAN 000 AXNT20 KNHC 162353 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 805 PM EDT SAT JUL 16 2011 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...WEATHER OBSERVATIONS...RADAR...AND METEOROLOGICAL ANALYSIS. BASED ON 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 2315 UTC. ...TROPICAL WAVES... TROPICAL WAVE IS ANALYZED FROM 10N22W TO 17N21W MOVING W AT 15-20 KT. EXAMINING RECENT HOVMOLLER DIAGRAM DATA AND THE UPPER AIR TIME SECTION ANALYSES...IT INDICATES THE WAVE PASSED DAKAR SENEGAL AROUND 15/1200 UTC. GLOBAL MODEL DATA ALSO INDICATES THE WAVE AXIS COINCIDES WITH AN 850-700 MB LOWER ATMOSPHERIC TROUGH THAT IS FORECAST TO DRIFT WESTWARD OVER THE NEXT COUPLE OF DAYS. CURRENTLY CONVECTION REMAINS LIMITED TO ISOLATED MODERATE ALONG THE W AFRICA COAST FROM 09N-15N BETWEEN 15W-19W. TROPICAL WAVE IS ANALYZED FROM 10N41W TO 18N44W MOVING W AT 15-20 KT. THE WAVE IS FAIRLY BROAD COVERING A LARGE PORTION OF THE CENTRAL ATLC THIS EVENING AND ALSO COINCIDES WITH A 700 MB TROUGH WITH AXIS ALONG 44W. MOSTLY DRY CONDITIONS ARE NOTED AT THE SURFACE AND ALOFT...WHICH IS PROVIDING FOR ONLY LOW-LEVEL CLOUDINESS AND A LACK OF ANY CONVECTION. THE CIMSS SAHARAN AIR LAYER TRACKING PRODUCT SHOWS A STRONG DUST LAYER FOLLOWS TO THE EAST OF THE WAVE AXIS TO THE WEST OF THE WAVE MENTIONED ABOVE. TROPICAL WAVE IS ANALYZED FROM 08N58W TO 13N54W MOVING W AT 15-20 KT. THE WAVE IS LOCATED IN THE VICINITY OF THE LEADING EDGE OF A ENHANCED LOW-LEVEL MOISTURE AS DEPICTED ON TOTAL PRECIPITABLE WATER IMAGERY. SCATTERED MODERATE CONVECTION IS FROM 11N-15N BETWEEN 51W-58W. TROPICAL WAVE IS ANALYZED FROM 18N93W TO 23N91W IN THE SW GULF OF MEXICO MOVING W AT 15-20 KT. THE WAVE HAS BECOME DIFFICULT TO DISCERN AND IS EXPECTED TO BECOME DIFFUSE OVER THE NEXT 24 HOURS AS IT APPROACHES THE EASTERN MEXICO COAST. TOTAL PRECIPITABLE WATER SHOWS THAT LOW-LEVEL MOISTURE IS ENHANCED IN THE VICINITY OF THE WAVE ACROSS THE SW GULF S OF 23N AND IS GENERATING A FEW ISOLATED AREAS OF SCATTERED MODERATE CONVECTION...ONE OVER THE YUCATAN PENINSULA FROM 17N-21N BETWEEN 88W-92W AND THE OTHER FROM 21N-24N BETWEEN 96W-98W. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS FROM THE AFRICAN COAST NEAR 21N17W THEN RESUMES WEST OF THE TROPICAL WAVE ALONG 22W NEAR 09N24W TO 07N32W. THE INTERTROPICAL CONVERGENCE ZONE AXIS EXTENDS FROM 07N32W TO 05N53W. ISOLATED MODERATE CONVECTION IS FROM 03N-06N BETWEEN 47W-51W. ...DISCUSSION... GULF OF MEXICO... AN LARGE AND EXPANSIVE UPPER LEVEL ANTICYCLONE IS CENTERED OVER THE CENTRAL CONUS AND THE SOUTHERN PERIPHERY OF THIS RIDGE EXTENDS SOUTHWARD ACROSS THE NORTHERN GULF WATERS NORTH OF 25N. WATER VAPOR IMAGERY INDICATES MIDDLE TO LOW-LEVEL MOISTURE EXTENDS FROM THE W ATLC WATERS EASTWARD ACROSS NORTHERN FLORIDA AND THE NORTHERN GULF COAST ALONG 30N TO EASTERN TEXAS. WEAK TROUGHING ALSO EXTENDS ALONG THE EASTERN SEABOARD SW OF THE CAROLINAS AND IS SUPPORTIVE OF A FRONTAL TROUGH FROM CAPE CANAVERAL TO 29N85W THEN INLAND TO A 1012 MB LOW CENTERED OVER SW ALABAMA. LOW-LEVEL CONVERGENCE AND PEAK DAYTIME INSTABILITY IS SUPPORTING SCATTERED SHOWERS AND WIDELY SCATTERED TSTMS ACROSS THE SOUTHERN FLORIDA PENINSULA AND NE GULF N OF 28N. ELSEWHERE...BRIDGED BETWEEN THE TROPICAL WAVE MENTIONED ABOVE ACROSS THE SW GULF S OF 23N AND THE FRONTAL TROUGHING ACROSS THE NE GULF...A SURFACE RIDGE AXIS EXTENDS FROM THE FLORIDA KEYS TO NEAR GALVESTON TEXAS ANCHORED ON A 1017 MB HIGH CENTERED NEAR 27N87W. E-SE WINDS ARE EXPECTED TO REMAIN DOMINATE OVER MUCH OF THE GULF THROUGH THE TUESDAY AS THE SURFACE RIDGING HOLDS ALONG 27N. CARIBBEAN SEA... BROAD UPPER LEVEL CYCLONIC FLOW COVERS MUCH OF THE CARIBBEAN WITH PRIMARILY NORTHEASTERLY FLOW W OF 63W. THE UPPER LEVEL LOW IS CENTERED OVER ARUBA AND CONTINUES TO GENERATE WIDELY SCATTERED SHOWERS AND ISOLATED TSTMS IN THE VICINITY OF THE MONA PASSAGE...EASTERN HISPANIOLA FROM 18N-20N BETWEEN 71W-75W...AND ALONG THE SOUTHERN COAST OF CUBA BETWEEN 77W-82W. E TO SE SURFACE WINDS GENERALLY IN THE 15-20 KT RANGE ARE EXPECTED ACROSS MUCH OF THE WATERS THROUGH THE OVERNIGHT PERIOD INTO SUNDAY. AN APPROACHING TROPICAL WAVE CURRENTLY SE OF THE WINDWARD ISLANDS ALONG 56W WILL INCREASE PRECIPITATION CHANCES FOR THE EASTERN CARIBBEAN THROUGH MONDAY AND CONTINUE WESTWARD THROUGH THE REMAINDER OF THE UPCOMING WEEK. ELSEWHERE THIS EVENING...SCATTERED SHOWERS AND TSTMS ARE OCCURRING OVER INLAND PORTIONS OF CENTRAL AMERICA AS AN ACTIVE MONSOON TROUGH IN THE EAST PACIFIC REGION CONTINUES TO GENERATE LOCALLY HEAVY RAINFALL ACROSS WESTERN PANAMA...COSTA RICA...NICARAGUA...AND HONDURAS. ATLANTIC OCEAN... WATER VAPOR IMAGERY INDICATES A LONGWAVE TROUGH IS LOCATED OFF THE NEW ENGLAND AND MID-ATLC COAST WITH AXIS ALONG 65W THAT EXTENDS SOUTHWARD TO 30N...WITH INFLUENCE BETWEEN 60W-82W. ALONG THE SOUTHERN PERIPHERY OF THIS TROUGH...MIDDLE TO LOW-LEVEL MOISTURE CONTINUES TO POOL ALONG A STATIONARY BOUNDARY ANALYZED FROM 32N58W W-SW ALONG 29N65W TO A 1014 MB LOW CENTERED NEAR 29N79W. A FRONTAL TROUGH CONTINUES WESTWARD ACROSS FLORIDA FROM CAPE CANAVERAL INTO THE NE GULF OF MEXICO WATERS NEAR 28N83W. SCATTERED SHOWERS AND ISOLATED TSTMS ARE OCCURRING WITHIN 180 NM EITHER SIDE OF THE FRONT. THE REMAINDER OF THE CENTRAL AND EASTERN ATLC CONTINUES TO BE UNDER THE INFLUENCE OF A SURFACE RIDGE WITH AXIS ALONG 32N42W TO 25N57W THEN WESTWARD TO 24N70W. WITH THE EXCEPTION OF THE TROPICAL WAVE ALONG 44W PERTURBING THE SURFACE FLOW...MOSTLY NE WINDS OF 20 KT ARE OCCURRING EAST OF THE RIDGE AXIS. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ HUFFMAN