000 AXNT20 KNHC 211754 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 205 PM EDT TUE MAY 21 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1715 UTC. ...TROPICAL WAVES... TROPICAL WAVE EXTENDS FROM THE EQUATOR NEAR 40W TO 05N39W MOVING W AT 10 KT. EXAMINING GLOBAL MODEL POTENTIAL VORTICITY ANALYSES AT THE 315K LEVEL...A MAXIMUM IS NOTED IN THE VICINITY OF THE WAVE AXIS BETWEEN 37W-42W. IN ADDITION...A MAXIMUM IN TOTAL PRECIPITABLE WATER IS OBSERVED IN IMAGERY FROM THE EQUATOR TO 06N BETWEEN 36W-43W. A WEAK 1012 MB SURFACE LOW IS ANALYZED WEST OF THE WAVE NEAR 04N37W. AT THIS TIME ENERGY ASSOCIATED WITH THE WAVE AND THE WEAK LOW MAY BE CONSOLIDATING AND RESULT IN A RE- POSITIONING OR ADJUSTMENT OF THE WAVE AXIS AT 21/1800 UTC IF NECESSARY. ISOLATED MODERATE CONVECTION IS OCCURRING IN THE VICINITY OF THE WAVE AND LOW CENTER FROM 01N-05N BETWEEN 36W-40W. TROPICAL WAVE EXTENDS FROM 09N68W TO 16N66W MOVING W AT 10-15 KT. THE WAVE COINCIDES WITH A BROAD AREA OF MAXIMIZED TOTAL PRECIPITABLE WATER THAT CONTINUES TO PRODUCE ISOLATED SHOWERS OVER THE NE CARIBBEAN N OF 15N E OF 68W...INCLUDING PUERTO RICO AND THE LEEWARD ISLANDS. THIS CONVECTION IS LIKELY ENHANCED BY WEAK DIFFLUENT FLOW ALOFT DUE TO UPPER LEVEL WEST-SOUTHWESTERIES OVER THE FAR EASTERN CARIBBEAN. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS FROM THE AFRICAN COAST NEAR 10N14W TO 08N16W. THE INTERTROPICAL CONVERGENCE ZONE AXIS EXTENDS FROM 08N16W TO 04N20W TO 03N26W. WIDELY SCATTERED MODERATE CONVECTION IS FROM 03N-06N BETWEEN 09W-18W...AND FROM 03N-06N BETWEEN 21W- 25W...AND WITHIN 120 NM EITHER SIDE OF A LINE FROM THE EQUATOR NEAR 28W TO 04N30W TO 06N34W. ...DISCUSSION... GULF OF MEXICO... RELATIVELY DRY AIR WITHIN MIDDLE TO UPPER LEVEL NORTHWESTERLY FLOW ALOFT IS NOTED ON WATER VAPOR IMAGERY ACROSS MUCH OF THE GULF THIS AFTERNON. THIS PATTERN CONTINUES TO SUPPORT SURFACE RIDGING THAT REMAINS ANCHORED IN THE SW NORTH ATLC WHICH RESULTS IN PERSISTENT E-SE WINDS IN THE RANGE OF 10 TO 20 KT ACROSS THE BASIN. LOOKING AHEAD...OVERALL LITTLE CHANGE IS EXPECTED THROUGH LATE THURSDAY WHEN A WEAK FRONTAL BOUNDARY WILL SKIRT THE SE CONUS AND PORTIONS OF THE COASTAL NE GULF WATERS. LASTLY...OF NOTE...VISIBLE SATELLITE IMAGERY CONTINUES TO SHOW A LARGE DISPERSED AREA OF SMOKE OVER THE WESTERN GULF W OF A LINE FROM GALVESTON TEXAS TO THE NE CORNER OF THE YUCATAN PENINSULA NEAR 21N90W. THE SMOKE AND HAZY CONDITIONS ARE LARGELY DUE TO NUMEROUS AGRICULTURAL AND WILD FIRES OCCURRING OVER PORTIONS OF SOUTHERN MEXICO AND NORTHERN CENTRAL AMERICA. CARIBBEAN SEA... MIDDLE TO UPPER LEVEL NORTHWEST FLOW ALOFT IS NOTED ON WATER VAPOR IMAGERY W OF 72W ON THE EASTERN PERIPHERY OF AN ANTICYCLONIC CIRCULATION CENTERED OVER THE EASTERN PACIFIC REGION NEAR 13N91W. VISIBLE SATELLITE IMAGERY INDICATES MOSTLY CLEAR SKIES UNDER THIS UPPER LEVEL REGIME WITH E-SE TRADE WINDS PERSISTING IN THE RANGE OF 10 TO 20 KT WITH POTENTIALLY HIGHER WIND SPEEDS IN CLOSE PROXIMITY TO THE COAST OF COLOMBIA. THE ONLY EXCEPTION IS SCATTERED SHOWERS AND TSTMS ARE OCCURRING ACROSS THE SW CARIBBEAN S OF 13N AS THE MONSOON TROUGH IS ANALYZED ALONG 10N NORTH OF PANAMA AND ACROSS CENTRAL COSTA RICA. EAST OF 72W...WEST-SOUTHWESTERLY MIDDLE TO UPPER LEVEL WINDS DOMINATE AND CONTINUE TO PROVIDE AN OVERALL DIFFLUENT ENVIRONMENT THAT SUPPORTS THE CONVECTION ASSOCIATED WITH THE TROPICAL WAVE ALONG 68W IMPACTING THE EASTERN CARIBBEAN. OTHERWISE...EASTERLY TRADES ARE EXPECTED TO CONTINUE THROUGH MUCH OF THE WEEK WITH LITTLE CHANGE ON THE SYNOPTIC SCALE. HISPANIOLA... CURRENTLY WEST-NORTHWESTERLY FLOW ALOFT IS OVER HISPANIOLA WITH WATER VAPOR IMAGERY INDICATING MORE MIDDLE TO UPPER LEVEL MOISTURE THAN IN THE LAST FEW PREVIOUS DAYS. THIS MOISTURE STEMS FROM A SHORTWAVE TROUGH CENTERED OVER NORTHERN FLORIDA THAT IS PROVIDING HISPANIOLA AND THE SURROUNDING REGION WITH MORE OVERALL MOISTURE TO WORK WITH TODAY. WHILE THE OVERALL SYNOPTIC PATTERN REMAINS THE SAME AS THE PAST FEW DAYS WITH E-SE TRADES PREVAILING...THE HIGHEST PRECIPITATION CHANCES ARE EXPECTED TO OCCUR DURING THE AFTERNOON THROUGH LATE EVENING HOURS WITH PEAK DAYTIME HEATING AND INSTABILITY. WIDELY SCATTERED SHOWERS ARE EXPECTED TO INITIATE OVER INLAND AREAS THIS AFTERNOON. AS PREVIOUSLY MENTIONED IN THE CARIBBEAN SEA SECTION...LITTLE CHANGE IS EXPECTED OVER THE NEXT FEW DAYS SYNOPTICALLY... HOWEVER...A TROPICAL WAVE WILL PASS TO THE SOUTH OVER THE SOUTHERN HALF OF THE CARIBBEAN RESULTING IN INCREASED LOW-LEVEL MOISTURE AND HIGHER PROBABILITY OF PRECIPITATION DURING THE AFTERNOON AND EVENING HOURS. ATLANTIC OCEAN... A MIDDLE TO UPPER LEVEL SHORTWAVE TROUGH IS LOCATED OVER NORTHERN FLORIDA CENTERED NEAR 29N82W AND CONTINUES TO BE SLOW TO MOVE INTO THE SW NORTH ATLC REGION BRINGING WITH IT INCREASED CLOUDINESS AND PRECIPITATION THIS AFTERNOON. CURRENTLY WIDELY SCATTERED SHOWERS AND TSTMS ARE OCCURRING N OF 22N BETWEEN 73W- 81W...INCLUDING PORTIONS OF THE FLORIDA PENINSULA. THIS ACTIVITY IS OCCURRING ON THE WESTERN PERIPHERY OF A SURFACE RIDGE ANCHORED BY A 1025 MB HIGH CENTERED EAST OF BERMUDA NEAR 32N59W. FARTHER EAST...A NORTHWEST NORTH ATLC UPPER LEVEL TROUGH IS CENTERED NORTH OF THE AREA NEAR 45N49W THAT LEADS TO BROAD UPPER LEVEL TROUGHING ACROSS THE CENTRAL ATLC BETWEEN 38W-60W AND SUPPORTS A COLD FRONT THAT ENTERS THE DISCUSSION AREA NEAR 32N45W. THE COLD FRONT EXTENDS SW TO 27N54W TO 27N61W AND ALSO EXHIBITS A PRE-FRONTAL SURFACE TROUGH EXTENDING FROM THE COLD FRONT NEAR 31N46W TO 24N49W. ISOLATED SHOWERS ARE OCCURRING WITHIN 90 NM EITHER SIDE OF THE COLD FRONT AND WITHIN 45 NM EITHER SIDE OF THE SURFACE TROUGH. THE REMAINDER OF THE EASTERN ATLC IS UNDER THE INFLUENCE OF A SURFACE RIDGE ANCHORED BY A 1035 MB HIGH CENTERED NORTH OF THE AZORES NEAR 48N27W. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ HUFFMAN