000 AXNT20 KNHC 191049 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 805 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1015 UTC. ...TROPICAL WAVES... TROPICAL WAVE EXTENDS FROM 10N26W TO A 1007 MB LOW NEAR 14N27W TO 20N24W 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 WITHIN A BROAD LOW-LEVEL MONSOONAL GYRE FROM 07N-20N BETWEEN 20W- 37W. NO SIGNIFICANT CONVECTION IS NOTED WITH THE WAVE AT THIS TIME. TROPICAL WAVE EXTENDS FROM 14N67W TO 23N63W MOVING W AT 15 KT. THE WAVE REMAINS EMBEDDED WITHIN A MOISTURE MAXIMUM ACCORDING TO TOTAL PRECIPITABLE WATER IMAGERY FROM 10N-21N BETWEEN 60W-65W. 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-65W. TROPICAL WAVE EXTENDS FROM 15N85W TO 23N83W MOVING W AT 10-15 KT. THE WAVE COINCIDES WITH A WEAK 700 MB TROUGH AXIS EXTENDING FROM WESTERN CUBA TO NORTH-CENTRAL HONDURAS WITH THE STRONGEST RELATIVELY VORTICITY LOCATED OVER THE OPEN WATERS OF THE NW CARIBBEAN. ISOLATED MODERATE CONVECTION IS OCCURRING MOSTLY NEAR THE NORTHERN EXTENT OF THE WAVE AXIS FROM 20N-24N BETWEEN 84W- 87W. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS FROM THE AFRICAN COAST NEAR 20N16W TO 18N24W THEN FROM 10N27W TO 07N30W TO 07N41W. THE INTERTROPICAL CONVERGENCE ZONE AXIS EXTENDS FROM 07N41W TO 09N53W. SCATTERED MODERATE CONVECTION IS FROM 15N-20N BETWEEN 16W-19W...AND FROM 03N-07N BETWEEN 28W-33W. A SURFACE TROUGH IS ANALYZED ON THE WESTERN EXTENT OF THE ITCZ AXIS FROM 09N62W TO 15N59W. ISOLATED MODERATE CONVECTION ALONG WITH ISOLATED SHOWERS ARE OCCURRING FROM 07N-15N BETWEEN 49W-65W. MOST OF THE STRONGEST CONVECTION IS OCCURRING OVER PORTIONS OF INLAND NORTHEASTERN VENEZUELA THIS MORNING. ...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 90W-96W. A SURFACE TROUGH REFLECTS THE INFLUENCE OF THE MIDDLE TO UPPER LEVELS ANALYZED FROM THE MISSISSIPPI RIVER DELTA NEAR 29N90W SW TO 26N95W THEN SOUTH TO NEAR 20N95W. WIDELY SCATTERED SHOWERS AND ISOLATED TSTMS ARE OCCURRING WITHIN 120 NM EITHER SIDE OF THE SURFACE TROUGH. THE REMAINDER OF THE GULF IS UNDER THE INFLUENCE OF THE NORTHERN EXTENT OF A TROPICAL WAVE MOVING ACROSS THE WESTERN CARIBBEAN SEA ALONG 85W. MID-LEVEL ENERGY CONTINUES TO FRACTURE NORTHWARD DUE TO THE WEAKNESS IN THE MID-LEVEL RIDGING OVER THE BASIN THAT IS GENERATING WIDELY SCATTERED SHOWERS AND TSTMS BETWEEN 83W-87W....INCLUDING PORTIONS OF THE FLORIDA STRAITS. 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 17N84W AND ALONG WITH A TROPICAL WAVE ALONG 85W 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 THE RIDGE AND PRIMARILY LOW-LEVEL MOISTURE AND MARGINAL MIDDLE TO UPPER LEVEL DIFFLUENCE ARE GENERATING ISOLATED LOW-TOPPED ISOLATED SHOWERS AND TSTMS N OF 17N E OF 81W. A TROPICAL WAVE ALONG 66W REMAINS A FOCAL POINT FOR SOME OF THIS SHOWER ACTIVITY BRINGING INCREASED PRECIPITATION CHANCES TO THE PUERTO RICO AND HISPANIOLA OVER THE NEXT 24 TO 48 HOURS. ALSO OF NOTE...A SURFACE TROUGH...LIKELY AN EXTENSION OF THE ITCZ AXIS...IS ANALYZED FROM 10N62W TO 15N59W. WIDELY SCATTERED SHOWERS AND TSTMS ARE OCCURRING ACROSS THE WINDWARD ISLANDS AND SE CARIBBEAN S OF 15N E OF 68W. HISPANIOLA... CURRENTLY EARLIER CONVECTION HAS DIMINISHED WITH ONLY A FEW REMAINING ISOLATED SHOWERS OCCURRING THE ACROSS THE ISLAND THIS MORNING. 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 INITIATE 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 33N71W 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 ACTIVITY OVER THE BAHAMAS AND AREAS WITHIN THE FLORIDA STRAITS THIS MORNING. OTHERWISE...A 1022 MB HIGH CENTERED NEAR 33N67W IS FURTHER PROVIDING OVERALL FAIR CONDITIONS FOR MUCH OF THE WESTERN ATLC. FARTHER EAST...A MIDDLE TO UPPER LEVEL LOW IS CENTERED NEAR 27N52W THAT IS GENERATING A FEW ISOLATED SHOWERS FROM 25N-29N BETWEEN 47W-53W. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ HUFFMAN