000 AXNT20 KNHC 212346 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 805 PM EDT MON OCT 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 2315 UTC. ...SPECIAL FEATURES... TROPICAL STORM LORENZO IS CENTERED NEAR 28.9N 54.9W AT 21/2100 UTC OR ABOUT 550 NM ESE OF BERMUDA MOVING NNE AT 6 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 1008 MB. MAXIMUM SUSTAINED WIND SPEED IS 35 KT WITH GUSTS TO 45 KT. SCATTERED MODERATE CONVECTION IS FROM 27N-31N BETWEEN 51W-54W. SEE LATEST NHC FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMAT3/WTNT23 KNHC FOR MORE DETAILS. ...TROPICAL WAVES... TROPICAL WAVE EXTENDS FROM 07N40W TO 15N43W MOVING W AT 15 KT. THE WAVE REMAINS EMBEDDED WITHIN THE ITCZ AND ALSO WITHIN VERY BROAD AND WEAK SURFACE TO 700 MB TROUGHING BETWEEN 40W-45W. MOST ENERGY FROM THE WAVE HAS BECOME MORE DIFFUSE OVER THE LAST 24 HOURS DUE TO UPPER LEVEL WESTERLIES TO THE NORTH ON THE SOUTHERN PERIPHERY OF AN UPPER LEVEL LOW CENTERED NEAR 21N40W. VERY DRY AIR ALOFT IS NOTED N OF 12N IN THE VICINITY OF THE WAVE THUS ANY SIGNIFICANT DEEP CONVECTION WITH THE WAVE IS LIMITED AT THIS TIME. ISOLATED MODERATE CONVECTION IS FROM 07N-12N BETWEEN 38W- 44W. TROPICAL WAVE EXTENDS FROM 10N73W TO 17N71W MOVING W AT 15 KT. THE WAVE CONTINUES TO BE SOMEWHAT DIFFICULT TO TRACK HOWEVER GLOBAL MODEL DATA INDICATES BROAD LOW-LEVEL TROUGHING ACROSS THE CENTRAL CARIBBEAN SEA THIS EVENING. NO SIGNIFICANT DEEP CONVECTION IS NOTED IN THE VICINITY OF THE WAVE AXIS AT THIS TIME. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS FROM THE AFRICAN COAST NEAR 12N16W TO 09N23W TO 06N29W. THE INTERTROPICAL CONVERGENCE ZONE AXIS EXTENDS FROM 06N29W TO 05N31W TO 07N40W TO 09N53W. ASIDE FROM THE CONVECTION ASSOCIATED WITH THE TROPICAL WAVE ALONG 42W... WIDELY SCATTERED MODERATE CONVECTION IS FROM 01N-07N BETWEEN 19W- 31W...AND FROM 09N-12N BETWEEN 48W-55W. ...DISCUSSION... GULF OF MEXICO... MIDDLE TO UPPER LEVEL SOUTHWESTERLY FLOW ALOFT IS NOTED ON WATER VAPOR IMAGERY THIS EVENING OVER THE GULF BETWEEN LONGWAVE TROUGHING OVER THE CENTRAL CONUS AND AN UPPER LEVEL ANTICYCLONE CENTERED OVER THE BAHAMAS NEAR 25N75W. WHILE STRONGER UPPER LEVEL DYNAMICS ASSOCIATED WITH THE TROUGH REMAIN OVER THE TEXAS AND OKLAHOMA PANHANDLES AS WELL AS NEW MEXICO...A STATIONARY FRONT IS ANALYZED FROM THE FLORIDA PENINSULA NEAR 29N82W W-SW TO 27N88W WHERE THE FRONT BECOMES WARM TO NEAR BROWNSVILLE TEXAS NEAR 26N97W. THE STATIONARY FRONT IS FAIRLY PRECIPITATION-FREE THIS EVENING...HOWEVER AS THE WARM FRONT SLOWLY CONTINUES TO LIFT NORTHWARD MULTI-LAYERED CLOUDINESS INCREASES ACROSS THE WESTERN GULF W OF 88W WITH SCATTERED SHOWERS AND ISOLATED TSTMS OCCURRING N OF 21N WEST OF A LINE FROM 21N92W TO THE FLORIDA PANHANDLE NEAR 30N85W. THE STRONGEST CONVECTION IS CLOSELY ASSOCIATED WITH THE WARM FRONTAL BOUNDARY IN THE VICINITY OF 26N94W. THROUGH THE OVERNIGHT HOURS INTO INTO EARLY TUESDAY THE NEXT COLD FRONT IS FORECAST TO EMERGE OFF THE TEXAS AND LOUISIANA GULF COAST SHIFTING WINDS NORTHERLY THEN NORTHEASTERLY INTO WEDNESDAY AS THE COLD FRONT CONTINUES SWEEPING ACROSS THE BASIN. CARIBBEAN SEA... AN UPPER LEVEL ANTICYCLONIC CIRCULATION IS CENTERED OVER THE WESTERN CARIBBEAN NEAR 13N78W AN IS PROVIDING FOR AN OVERALL DIFFLUENT ENVIRONMENT S OF 16N W OF 74W. WITH LOW-LEVEL MOISTURE CONVERGENCE MAXIMIZING AS WELL OVER THE SW CARIBBEAN...SCATTERED SHOWERS AND TSTMS ARE OCCURRING S OF 18N W OF A LINE FROM 18N84W TO THE NORTHERN COLOMBIA COAST NEAR 11N74W...INCLUDING INLAND PORTIONS OF NICARAGUA AND EASTERN HONDURAS. CLOSE PROXIMITY OF THE MONSOON TROUGH AXIS ALONG 10N IS ALSO ENHANCING CONVECTION OCCURRING ACROSS PANAMA AND COSTA RICA. FARTHER EAST...A TROPICAL WAVE IS ANALYZED ALONG 72W WITH NO SIGNIFICANT CONVECTION OCCURRING IN THE VICINITY OF THE WAVE AXIS AT THIS TIME. FINALLY...A MIDDLE TO UPPER LEVEL LOW IS CENTERED NORTH OF PUERTO RICO NEAR 21N66W AND IS PROVIDING A FAVORABLE UPPER LEVEL DIFFLUENT ATMOSPHERE ON THE EASTERN AND SOUTHEASTERN PERIPHERY OF THE UPPER LEVEL LOW. MOIST SOUTHWESTERLY UPPER LEVEL FLOW ALOFT IS FUELING SCATTERED SHOWERS AND WIDELY SCATTERED TSTMS ACROSS THE EASTERN CARIBBEAN THIS EVENING E OF 67W. THE STRONGEST CONVECTION REMAINS ACROSS THE NORTHERN LEEWARD ISLANDS IN THE VICINITY OF 18N63W. HISPANIOLA... CURRENTLY A FEW ISOLATED SHOWERS ARE NOTED ACROSS THE SOUTHERN COAST OF THE ISLAND BUT THESE ARE EXPECTED TO DIMINISH WITH THE LOSS OF DAYTIME HEATING. WATER VAPOR IMAGERY INDICATES A RELATIVELY DRY AND STABLE AIRMASS ALOFT WHICH WILL PROVIDE FOR MOSTLY CLEAR SKIES AND FAIR CONDITIONS OVERNIGHT INTO EARLY TUESDAY. HISPANIOLA LIES ON THE SOUTHWESTERN PERIPHERY OF A MIDDLE TO UPPER LEVEL LOW CENTERED NEAR 21N66W AND THIS LOW IS EXPECTED TO SLOWLY DRIFT SOUTHWEST THROUGH TUESDAY. MIDDLE TO UPPER LEVEL MOISTURE AND CLOUDINESS IS EXPECTED TO GRADUALLY FILTER IN ACROSS THE ISLAND ON TUESDAY WITH A HIGHER POTENTIAL FOR AFTERNOON AND EVENING ISOLATED SHOWERS AND TSTMS. ATLANTIC OCEAN... SOUTHWEST UPPER LEVEL FLOW IS NOTED ON WATER VAPOR IMAGERY OVER A PORTION OF THE SW NORTH ATLC BETWEEN UPPER LEVEL TROUGHING OVER THE CENTRAL CONUS AND AN ANTICYCLONIC CIRCULATION CENTERED OVER THE BAHAMAS NEAR 25N75W. MOISTURE PRIMARILY REMAINS TO THE NORTH OF A COLD FRONT ANALYZED FROM 32N68W TO 31N75W WHERE IT BECOMES STATIONARY TO THE FLORIDA PENINSULA NEAR CAPE CANAVERAL. ISOLATED SHOWERS ARE OCCURRING WITHIN 180 NM NORTH OF THE FRONT. TO THE SOUTHEAST OVER THE REMAINDER OF THE SW NORTH ATLC...A MIDDLE TO UPPER LEVEL LOW IS CENTERED NORTH OF PUERTO RICO NEAR 21N66W THAT SUPPORTS A LARGE AREA OF MIDDLE TO UPPER LEVEL DIFFLUENCE SE AND E OF THE UPPER LEVEL LOW GENERATING SCATTERED SHOWERS AND WIDELY SCATTERED TSTMS FROM 17N-25N BETWEEN 58W-68W. TO THE NORTHEAST OF THIS CONVECTION...TROPICAL STORM LORENZO IS CENTERED IN THE VICINITY OF 29N55W AND CONTINUES TO TRACK NORTH- NORTHEAST. OTHERWISE...ACROSS THE CENTRAL AND EASTERN ATLC...A SURFACE RIDGE REMAINS DOMINATE ANCHORED BY A 1019 MB HIGH CENTERED NEAR 28N46W. FAIR WEATHER CONDITIONS STRETCH FROM THIS HIGH CENTER EASTWARD TO THE CANARY ISLANDS. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ HUFFMAN