000 AXNT20 KNHC 190554 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 205 AM EDT MON AUG 19 2013 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. ...TROPICAL WAVES... A TROPICAL WAVE EXTENDS FROM 08N24W TO 19N25W MOVING W AT 10-15 KT. THE WAVE IS EMBEDDED WITHIN A BROAD 700 MB TROUGH S OF 17N BETWEEN 15W-32W AND IS LOCATED IN AN AREA OF MAXIMUM DEEP LAYER MOISTURE WITHIN 210 NM EITHER SIDE OF A LINE FROM 13N17W TO 06N24W AS NOTED ON TOTAL PRECIPITABLE WATER IMAGERY. NO SIGNIFICANT CONVECTION IS NOTED WITH THE WAVE AT THIS TIME. A TROPICAL WAVE EXTENDS FROM 11N64W TO 20N63W MOVING W AT 10-15 KT. THE WAVE REMAINS EMBEDDED WITHIN A MOISTURE MAXIMUM ACCORDING TO TOTAL PRECIPITABLE WATER IMAGERY FROM 10N-21N BETWEEN 58W-64W. THE WAVE ALSO COINCIDES WITH A WEAK 700 MB TROUGH MOVING ACROSS THE NE CARIBBEAN AND PORTIONS OF THE SW NORTH ATLC IN THE VICINITY OF THE NORTHERN EXTENSION OF THE WAVE AXIS. ISOLATED MODERATE CONVECTION IS FROM 19N-21N BETWEEN 61W- 63W. TROPICAL WAVE EXTENDS FROM 12N84W TO 22N82W MOVING W AT 10-15 KT. THE WAVE COINCIDES WITH A WEAK 700 MB TROUGH AXIS EXTENDING FROM CENTRAL CUBA TO EASTERN HONDURAS WITH THE STRONGEST RELATIVELY VORTICITY LOCATED OVER THE OPEN WATERS OF THE NW CARIBBEAN WEST OF THE CAYMAN ISLANDS. ISOLATED MODERATE CONVECTION IS OCCURRING MOSTLY NEAR THE NORTHERN EXTENT OF THE WAVE AXIS FROM 20N-24N BETWEEN 83W-87W. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS FROM THE AFRICAN COAST NEAR 18N16W TO 08N20W TO 06N26W TO 07N38W. THE INTERTROPICAL CONVERGENCE ZONE AXIS EXTENDS FROM 07N38W TO 10N47W TO 13N51W TO 14N58W. SCATTERED MODERATE CONVECTION IS FROM 03N-08N BETWEEN 27W-32W. A SURFACE TROUGH IS ANALYZED ON THE WESTERN EXTENT OF THE ITCZ AXIS FROM 09N60W TO 13N60W. ISOLATED MODERATE CONVECTION ALONG WITH ISOLATED SHOWERS ARE OCCURRING FROM 08N-14N BETWEEN 52W- 63W. MOST OF THE STRONGEST CONVECTION IS OCCURRING INLAND OVER PORTIONS OF NE VENEZUELA. ...DISCUSSION... GULF OF MEXICO... A MIDDLE TO UPPER LEVEL TROUGH IS NOTED ON WATER VAPOR IMAGERY WITH AXIS EXTENDING FROM NORTH TEXAS NEAR 32N95W TO A BASE OVER EAST-CENTRAL MEXICO NEAR 20N100W. TO THE EAST OF THIS TROUGH AXIS AN UPPER LEVEL RIDGE EXTENDS WESTWARD FROM OVER THE SW NORTH ATLC INTO THE EASTERN GULF RESULTING IN PRIMARILY SOUTHERLY UPPER LEVEL DIFFLUENT FLOW BETWEEN 88W-95W. A SURFACE TROUGH REFLECTS THE INFLUENCE OF THE MIDDLE TO UPPER LEVELS ANALYZED FROM THE MISSISSIPPI RIVER DELTA NEAR 30N89W SW TO 27N94W THEN S TO THE SOUTHERN MEXICO COAST NEAR 19N94W. WHILE MIDDLE TO UPPER LEVEL MOISTURE IS PREVALENT...ONLY A FEW ISOLATED SHOWERS ARE OCCURRING WITHIN 90 NM EITHER SIDE OF THE SURFACE TROUGH. A FEW ISOLATED SHOWERS WITH EMBEDDED TSTMS ARE HOWEVER OCCURRING S OF 21N IN THE BAY OF CAMPECHE. THE REMAINDER OF THE GULF IS UNDER THE INFLUENCE OF THE NORTHERN EXTENT OF A TROPICAL WAVE MOVING ACROSS THE WESTERN CARIBBEAN SEA ALONG 84W. MID-LEVEL ENERGY CONTINUES TO FRACTURE NORTHWARD DUE TO THE WEAKNESS IN THE MID-LEVEL RIDGING OVER THE GULF THAT IS GENERATING WIDELY SCATTERED SHOWERS AND TSTMS E OF 86W... INCLUDING PORTIONS OF WESTERN FLORIDA PENINSULA. OTHERWISE...E- SE WINDS PREVAIL AND ARE FORECAST TO REMAIN GENERALLY BELOW 20 KT FOR MOST OF THE WEEK AHEAD. THE SURFACE TROUGH OVER THE WESTERN GULF IS EXPECTED TO DRIFT SLOWLY WESTWARD AND DISSIPATE INLAND OVER SOUTHERN TEXAS AND EASTERN MEXICO LATE MONDAY INTO TUESDAY. CARIBBEAN SEA... AN UPPER LEVEL LOW IS CENTERED OVER THE NW CARIBBEAN NEAR 17N85W AND ALONG WITH A TROPICAL WAVE ALONG 84W IS GENERATING WIDELY SCATTERED SHOWERS AND ISOLATED TSTMS N OF 20N BETWEEN 83W-87W... INCLUDING THE YUCATAN CHANNEL. THE ENERGY AND MOISTURE ASSOCIATED WITH THE TROPICAL WAVE IS EXPECTED TO MOVE WESTWARD OVER THE NEXT 24 TO 36 HOURS AND INFLUENCE THE YUCATAN PENINSULA AS WELL AS AREAS ACROSS THE SOUTHERN GULF OF MEXICO. FARTHER EAST...AN UPPER LEVEL RIDGE AXIS EXTENDS FROM THE TROPICAL ATLC OVER THE CENTRAL AND EASTERN CARIBBEAN ALONG 15N. WATER VAPOR IMAGERY INDICATES MOSTLY DRY AIR ACCOMPANIES THIS RIDGE AND PRIMARILY LOW-LEVEL MOISTURE AND MARGINAL MIDDLE TO UPPER LEVEL DIFFLUENCE ARE GENERATING ISOLATED LOW-TOPPED ISOLATED SHOWERS AND TSTMS E OF 80W. A TROPICAL WAVE ALONG 64W REMAINS A FOCAL POINT FOR MOST OF THIS SHOWER ACTIVITY BRINGING INCREASE PRECIPITATION CHANCES TO THE LESSER ANTILLES...PUERTO RICO...AND HISPANIOLA OVER THE NEXT 24 TO 48 HOURS. HISPANIOLA... CURRENTLY AFTERNOON AND LATE EVENING CONVECTION HAS DIMINISHED WITH ONLY A FEW REMAINING ISOLATED SHOWERS OCCURRING THE ACROSS THE ISLAND. WITH AN UPPER LEVEL DIFFLUENT ENVIRONMENT REMAINING OVER THE ISLAND DUE TO SOUTHWEST TO WESTERLY FLOW ALOFT...AND AN APPROACHING TROPICAL WAVE ANALYZED ACROSS THE EASTERN CARIBBEAN SEA...ISOLATED SHOWERS ARE EXPECTED TO PERSIST OVER THE NEXT FEW DAYS WITH STRONGER SCATTERED CONVECTION EXPECTED TO INIATATE DURING THE AFTERNOON HOURS DUE TO PEAK DAYTIME HEATING AND INSTABILITY. ANY ACTIVITY THAT FORMS WILL LIKELY LAST INTO THE EVENING HOURS AND DIMINISH THEREAFTER. ATLANTIC OCEAN... A MIDDLE TO UPPER LEVEL ANTICYCLONIC CIRCULATION IS CENTERED OVER THE SW NORTH ATLC NEAR 34N69W THAT IS PROVIDING OVERALL STABLE CONDITIONS FOR THE SW NORTH ATLC W OF 70W. WATER VAPOR IMAGERY INDICATES THIS AREA REMAINS DRY ALOFT WITH SATELLITE IMAGERY INDICATING ISOLATED LOW-TOPPED SHOWERS ARE OCCURRING PRIMARILY W OF 50W...AND MORE CONCENTRATED OVER THE BAHAMAS AND AREAS IMMEDIATELY OFFSHORE OF THE FLORIDA PENINSULA THIS EVENING. OTHERWISE...A 1023 MB HIGH CENTERED NEAR 33N65W IS FURTHER PROVIDING OVERALL FAIR CONDITIONS FOR MUCH OF THE WESTERN ATLC. FARTHER EAST...A MIDDLE TO UPPER LEVEL LOW IS CENTERED NEAR 27N51W THAT IS GENERATING A FEW ISOLATED SHOWERS FROM 25N-28N BETWEEN 45W-52W...AND CONTAINS THE REMNANT SURFACE LOW PRESSURE AREA OF ERIN...ANALYZED AS A 1010 MB LOW CENTERED NEAR 20N40W. NO SIGNIFICANT DEEP CONVECTION IS NOTED WITH THIS LOW HOWEVER. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ HUFFMAN