000 AXNT20 KNHC 220546 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 205 AM EDT THU AUG 22 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... TROPICAL WAVE EXTENDS FROM 07N41W TO 19N40W MOVING W AT 15 KT. THE WAVE REMAINS EMBEDDED WITHIN THE MONSOON TROUGH AT THE SURFACE AND WITHIN A LOWER AMPLITUDE 700 MB TROUGH BETWEEN 40W- 50W. TO THE EAST OF THIS AREA...GLOBAL MODEL GUIDANCE INDICATES ANOTHER HIGHER AMPLITUDE IMPULSE OF 700 MB TROUGHING IS LOCATED BETWEEN 30W-40W. AT THIS TIME ANY SIGNIFICANT CONVECTION REMAINS CONFINED SOUTH OF THE MONSOON TROUGH. TROPICAL WAVE EXTENDS FROM 11N80W TO 21N80W MOVING W AT 10-15 KT. THE WAVE REMAINS WITHIN BROAD LOW-LEVEL...SURFACE TO 700 MB...TROUGHING LOCATED ACROSS THE WESTERN CARIBBEAN SEA WITH TOTAL PRECIPITABLE WATER IMAGERY INDICATING MAXIMUM VALUES GENERALLY BETWEEN 72W-81W. WIDELY SCATTERED MODERATE CONVECTION IS FROM 14N-20N BETWEEN 75W-83W. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS FROM 19N17W TO 10N35W TO 09N48W TO 07N53W. ISOLATED MODERATE CONVECTION IS FROM 08N-11N BETWEEN 20W- 28W...FROM 08N-10N BETWEEN 36W-41W...AND FROM 06N-10N BETWEEN 44W-47W. ...DISCUSSION... GULF OF MEXICO... UPPER LEVEL DIFFLUENT FLOW IS NOTED ON WATER VAPOR IMAGERY OCCURRING BETWEEN AN UPPER LEVEL LOW CENTERED OVER NORTHERN MEXICO NEAR 27N103W AND AN UPPER LEVEL ANTICYCLONE CENTERED OVER THE EAST PACIFIC REGION NEAR 15N99W. MIDDLE TO UPPER LEVEL MOISTURE AND POSSIBLE ISOLATED SHOWERS ARE OCCURRING OVER THE WESTERN GULF THIS EVENING WEST OF A LINE FROM 28N96W TO 19N92W. FARTHER EAST...AN UPPER LEVEL LOW IS CENTERED OVER WESTERN CUBA NEAR 23N82W. THIS UPPER LEVEL FEATURE ALONG WITH A MID-LEVEL VORTICITY MAXIMUM OVER THE NE GULF NEAR 26N86W IS GENERATING SCATTERED SHOWERS AND WIDELY SCATTERED TSTMS N OF 23N E OF 90W...INCLUDING PORTIONS OF THE FLORIDA PENINSULA. MOST OF THIS CONVECTIVE ACTIVITY IS FOCUSED IN THE VICINITY OF A SURFACE TROUGH ANALYZED FROM 25N83W TO 29N85W. LOOKING AHEAD...GENERALLY E-SE WINDS ARE EXPECTED TO PREVAIL THROUGH THE UPCOMING WEEKEND AND REMAIN 20 KT OR LESS AS A SURFACE RIDGE CONTINUES TO BE ANCHORED OVER THE SW NORTH ATLC WITH A RIDGE AXIS EXTENDING WESTWARD ALONG 30N. CARIBBEAN SEA... AN UPPER LEVEL LOW IS CENTERED OVER WESTERN CUBA NEAR 23N82W AND ALONG WITH A TROPICAL WAVE ALONG 80W CONTINUES TO GENERATE SCATTERED SHOWERS AND TSTMS ACROSS PORTIONS OF CUBA THIS EVENING AS WELL AS AN AREA IN THE VICINITY OF THE TROPICAL WAVE AXIS FROM 14N-20N BETWEEN 75W-83W. THE WAVE IS EXPECTED TO CONTINUE WESTWARD OVER THE NEXT 24 TO 48 HOURS BRINGING INCREASED PRECIPITATION CHANCES TO CENTRAL AMERICA AND THE NW CARIBBEAN WATERS. TO THE SOUTH...THE MONSOON TROUGH IS ALONG 10N EXTENDING FROM NORTHERN COLOMBIA WESTWARD INTO THE EAST PACIFIC REGION. SCATTERED SHOWERS AND ISOLATED TSTMS ARE OCCURRING WITHIN 120 NM EITHER SIDE OF THE AXIS...INCLUDING PORTIONS OF PANANA AND COSTA RICA THIS EVENING. FINALLY...E-SE TRADES CONTINUE ACROSS THE EASTERN CARIBBEAN WITH ABUNDANT LOW-LEVEL MOISTURE AS NOTED ON TOTAL PRECIPITABLE WATER IMAGERY. WIDELY SCATTERED SHOWERS ARE OCCURRING E OF 75W AND ARE PRIMARILY FOCUSED IN THE VICINITY OF A SURFACE TROUGH ANALYZED ACROSS THE SE CARIBBEAN FROM 11N63W TO 15N63W. ANOTHER SURFACE TROUGH IS ANALYZED TO THE EAST OF THE LEEWARD ISLANDS FROM 14N57W TO 19N59W...THE REMNANTS OF ERIN... AND IS PROVIDING ANOTHER SOURCE OF LOW-LEVEL MOISTURE AND SHOWERS OVER THE NEXT 24 TO 36 HOURS FOR THE EASTERN CARIBBEAN. HISPANIOLA... EARLIER EVENING CONVECTION CONTINUES TO DIMINISH WITH ONLY A FEW REMAINING ISOLATED SHOWERS OCCURRING ACROSS THE ISLAND AT THIS TIME. NORTH-NORTHWESTERLY FLOW ALOFT REMAINS OVER THE ISLAND BETWEEN AN UPPER LEVEL TROUGH TO THE NE OVER THE ATLC...AND UPPER LEVEL RIDGING TO THE WEST. PARTIAL DRYING ALOFT IS EXPECTED OVER THE NEXT 12 TO 24 HOURS...HOWEVER LOW-LEVEL MOISTURE WILL CONTINUE TO ADVECT WESTWARD WITHIN THE E-SE TRADES ACROSS THE EASTERN AND CENTRAL CARIBBEAN. THE LOW-LEVEL MOISTURE ALONG WITH PEAK DAYTIME HEATING AND INSTABILITY WILL INITIATE AFTERNOON SHOWERS AND TSTMS. ANY ACTIVITY THAT FORMS WILL LIKELY LAST INTO THE EVENING HOURS AND DIMINISH THEREAFTER. ATLANTIC OCEAN... AN UPPER LEVEL LOW IS CENTERED OVER WESTERN CUBA NEAR 23N82W THAT CONTINUES TO PRODUCE ENHANCEMENT FOR WIDELY SCATTERED SHOWERS AND ISOLATED TSTMS OCCURRING S OF 30N W OF 78W ACROSS PORTIONS OF THE SW NORTH ATLC. THIS ACTIVITY REMAINS ON THE SOUTHWESTERN PERIPHERY OF A SURFACE RIDGE ANCHORED BY A 1022 MB HIGH CENTERED OFF THE MID-ATLC COAST NEAR 37N71W. THE SURFACE HIGH IS LARGELY SUPPORTED BY A MIDDLE TO UPPER LEVEL ANTICYCLONE CENTERED NEAR 29N72W. FARTHER EAST...AN UPPER LEVEL TROUGH AXIS EXTENDS FROM 32N54W SW TO A BASE NEAR 18N67W. MID-LATITUDE MOISTURE ASSOCIATED WITH A COLD FRONTAL BOUNDARY IN THE VICINITY OF 32N54W CONTINUES TO PRODUCING ISOLATED SHOWERS N OF 28N BETWEEN 50W-62W. OTHERWISE...THE REMAINDER OF THE CENTRAL AND EASTERN ATLC IS UNDER THE INFLUENCE OF A SURFACE RIDGE ANCHORED BY A 1022 MB HIGH CENTERED SOUTH OF THE AZORES NEAR 34N26W. THE RIDGE AXIS EXTENDS SOUTHWEST FROM THE HIGH TO NEAR 25N55W. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ HUFFMAN