Tropical Weather Discussion
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000 AXNT20 KNHC 240548 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 205 AM EDT THU JUL 24 2014 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0515 UTC. ...SPECIAL FEATURES... A STRENGTHENING PRESSURE GRADIENT ACROSS THE SW CARIBBEAN SEA WATERS IS EXPECTED OVERNIGHT INTO EARLY THURSDAY RESULTING IN MINIMAL GALE FORCE NE TO E WINDS FROM 11N-13.5N BETWEEN 73-77W. SEE LATEST NWS HIGH SEAS FORECAST UNDER AWIPS/WMO HEADERS MIAHSFAT2/FZNT02 KNHC FOR MORE DETAILS. ...TROPICAL WAVES... TROPICAL WAVE EXTENDS FROM 03N44W TO 12N43W MOVING W AT 15-20 KT. THE WAVE APPEARS TO BE A SOUTHERN POTENTIAL VORTICITY MAXIMUM ALONG A BROADER 700 MB TROUGH AXIS EXTENDING FROM 18N54W TO THE NW OF THE WAVE AXIS SE TO THE LOCATION OF THE WAVE AXIS NEAR 04N44W. THE WAVE REMAINS SOUTH OF A LOWER TO MIDDLE LEVEL EASTERLY JET N OF 09N THAT IS LARGELY EMBEDDED WITHIN THE SAHARAN AIR LAYER ACROSS THE TROPICAL ATLC. AS A RESULT OF THE SAL...CONVECTION REMAINS SUPPRESSED S OF 10N WITH ISOLATED MODERATE CONVECTION OCCURRING FROM 06N-10N BETWEEN 40W-47W. TROPICAL WAVE EXTENDS FROM 11N59W TO 19N56W MOVING W AT 15 KT. THE WAVE CONTAINS THE REMNANTS OF TROPICAL DEPRESSION TWO AND HAS INCORPORATED THE NORTHERN POTENTIAL VORTICITY MAXIMUM OF A 700 MB TROUGH EXTENDING FROM 18N54W TO 04N44W. WIDELY SCATTERED MODERATE CONVECTION IS FROM 13N-16N BETWEEN 58W-63W...INCLUDING A PORTION OF THE LESSER ANTILLES. A LARGE AREA OF SAHARAN DUST FOLLOWS IN WAKE OF THE WAVE WITH THE LEADING EDGE NOTED E OF 55W. TROPICAL WAVE EXTENDS FROM 09N93W TO 20N94W MOVING W AT 15 KT. ISOLATED MODERATE CONVECTION IS FROM 15N-20N BETWEEN 90W-95W. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS FROM THE AFRICAN COAST NEAR 19N17W TO 11N23W TO 10N26W. THE INTERTROPICAL CONVERGENCE ZONE AXIS EXTENDS FROM 10N26W TO 09N35W TO 02N50W. ASIDE FROM CONVECTION ASSOCIATED WITH THE TROPICAL WAVES...ISOLATED MODERATE CONVECTION IS FROM 08N-14N BETWEEN 15W-21W. ...DISCUSSION... GULF OF MEXICO... A MIDDLE TO UPPER LEVEL TROUGH AXIS EXTENDS FROM OVER TENNESSEE S-SW TO OVER THE MEXICO COAST NEAR 25N97W AND INTO AN UPPER LEVEL LOW CENTERED NEAR 18N103W. MID-LEVEL ENERGY IS FOCUSED OVER THE MISSISSIPPI RIVER DELTA REGION AND COASTAL LOUISIANA THAT SUPPORTS A WEAK 1014 MB SURFACE LOW CENTERED NEAR 29N92W. A DISSIPATING STATIONARY FRONT MEANDERS FROM THE LOW CENTER WEST TO THE TEXAS COAST NEAR GALVESTON BAY. WEAK LOW-LEVEL MOISTURE CONVERGENCE ALONG WITH THE MIDDLE TO UPPER LEVEL LIFTING DYNAMICS IS GENERATING ISOLATED SHOWERS N OF 28N BETWEEN 89W- 92W. FARTHER SOUTH...A SURFACE RIDGE EXTENDS FROM THE CENTRAL FLORIDA PENINSULA W-SW TO 25N90W TO THE EAST-CENTRAL MEXICO COAST NEAR 22N98W. A FEW ISOLATED SHOWERS AND TSTMS ARE OCCURRING JUST NORTH OF THE RIDGE AXIS WITHIN 45 NM EITHER SIDE OF A LINE FROM 28N82W TO 25N94W. LOOKING AHEAD...THE OVERALL SYNOPTIC PATTERN WILL RETAIN THE SURFACE RIDGE AXIS EXTENDING FROM THE SW NORTH ATLC ACROSS THE SOUTHERN FLORIDA PENINSULA TO THE EAST-CENTRAL MEXICO COAST THROUGH THE OVERNIGHT INTO THURSDAY. THE RIDGE WILL GRADUALLY SHIFT NORTHWARD AND ANCHOR ALONG 27N THROUGH THE REMAINDER OF THE WEEK INTO THE WEEKEND. CARIBBEAN SEA... AN UPPER LEVEL LOW IS CENTERED OVER THE NW CARIBBEAN NEAR 21N84W THAT CONTINUES TO GENERATE A FEW ISOLATED SHOWERS ACROSS CUBA AND ACTIVITY IN THE VICINITY OF 19N84W. WHILE MOST OF THE MIDDLE TO UPPER LEVEL MOISTURE REMAINS OVER THE WESTERN CARIBBEAN... FARTHER EAST...AN UPPER LEVEL ANTICYCLONE IS CENTERED NEAR 18N71W. WATER VAPOR IMAGERY INDICATES THIS UPPER LEVEL FEATURE REMAINS VERY DRY AND SUBSIDENT PROVIDING MOSTLY FAIR CONDITIONS ACROSS THE NE CARIBBEAN...HISPANIOLA...PUERTO RICO...AND THE LEEWARD ISLANDS. ON THE SOUTHERN PERIPHERY OF THIS RIDGING...A STREAM OF LOW TO MIDDLE LEVEL MOISTURE IS ADVECTING WESTWARD WITH EMBEDDED WIDELY SCATTERED SHOWERS AND TSTMS OCCURRING FROM 12N-16N BETWEEN 58W-68W. MOST OF THIS MOISTURE IS A WESTWARD EXTENSION OF THE REMNANTS OF TROPICAL DEPRESSION TWO WHICH IS NOTED AS A TROPICAL WAVE ALONG 58W THIS EVENING. THE WAVE IS EXPECTED TO MOVE WEST AND BRING INCREASED PRECIPITATION PROBABILITIES TO THE LESSER ANTILLES DURING THE NEXT 12 TO 24 HOURS. FINALLY...FRESH TO STRONG TRADES ARE EXPECTED TO PERSIST ACROSS MUCH OF THE CARIBBEAN S OF 17N THROUGH THE REMAINDER OF THE WEEK. ...HISPANIOLA... CURRENTLY OVERALL CONDITIONS REMAIN FAIR THIS EVENING DUE TO MODERATELY DRY AIR ALOFT AS AN UPPER LEVEL ANTICYCLONE IS CENTERED OVER THE ISLAND NEAR 18N71W. MOSTLY FAIR CONDITIONS LIE TO THE EAST OF THE ISLAND AS WELL WITH A WEAK RIDGE PRECEDING A TROPICAL WAVE EXPECTED TO IMPACT HISPANIOLA WITH PRECIPITATION BY LATE THURSDAY INTO EARLY FRIDAY. ATLANTIC OCEAN... AN UPPER LEVEL ANTICYCLONIC CIRCULATION IS CENTERED OVER THE SW NORTH ATLC NEAR 30N76W THAT IS SUPPORTIVE OF A SURFACE RIDGE AXIS EXTENDING FROM 28N57W TO THE SOUTHERN FLORIDA PENINSULA NEAR 27N80W. MOSTLY FAIR SKIES AND CONDITIONS PREVAIL THIS EVENING S OF 28N. MOST MOISTURE AND CLOUDINESS REMAINS N OF 28N ON THE NORTHERN PERIPHERY OF THE UPPER LEVEL RIDGE WITH LOW- LEVEL MOISTURE CONVERGENCE AND AMPLE UPPER LEVEL DIFFLUENCE GENERATING ISOLATED SHOWERS N OF 28N BETWEEN 63W-77W. FARTHER EAST ACROSS THE REMAINDER OF THE CENTRAL AND EASTERN ATLC...THE SURFACE RIDGE PREVIOUSLY MENTIONED FOR THE SW NORTH ATLC ALONG 28N IS ANCHORED BY A 1025 MB HIGH CENTERED NEAR 31N31W AND A 1024 MB HIGH CENTERED NEAR 28N57W. FINALLY...A LARGE AREA OF THE CENTRAL AND EASTERN TROPICAL ATLC IS UNDER THE INFLUENCE OF THE SAHARAN DUST STRETCHING REMAINING MOSTLY NORTH OF 10N AND EAST OF 55W. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ HUFFMAN

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