000 AXNT20 KNHC 082348 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 805 PM EDT TUE OCT 08 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 WAVE EXTENDS FROM 10N26W TO 17N25W MOVING W-NW AT 10-15 KT. A 1010 MB LOW IS CENTERED AT THE SOUTHERN EXTENT OF THE WAVE AXIS AND REMAINS EMBEDDED WITHIN A BROAD MONSOONAL GYRE FROM 08N- 15N BETWEEN 20W-32W. THE ENTIRE SYSTEM IS LOCATED BENEATH THE WESTERN PERIPHERY OF AN UPPER LEVEL ANTICYCLONIC CIRCULATION CENTERED OVER THE EASTERN TROPICAL ATLC NEAR 16N24W THAT IS PROVIDING AN OVERALL FAVORABLE UPPER LEVEL DIFFLUENT ENVIRONMENT. SCATTERED MODERATE CONVECTION IS FROM 10N-14N BETWEEN 26W-30W...WITH ISOLATED MODERATE CONVECTION ELSEWHERE FROM 06N-14N BETWEEN 20W-30W. ...TROPICAL WAVES... TROPICAL WAVE EXTENDS FROM 13N41W TO 21N42W MOVING W AT 10-15 KT. TO THE WEST OF THE WAVE AXIS AN UPPER LEVEL LOW IS CENTERED NEAR 21N44W THAT IS PROVIDING INCREASED SOUTHWESTERLY UPPER LEVEL SHEAR TO THE WAVE. EXAMINING TOTAL PRECIPITABLE WATER IMAGERY...THE MOISTURE FIELD ASSOCIATED WITH THE WAVE CONTINUES TO STRETCH POLEWARD WITH ENERGY LIKELY FRACTURING NORTHWARD. WITH THE SHEAR IN PLACE...ISOLATED MODERATE CONVECTION IS OCCURRING WELL TO THE EAST OF THE WAVE AXIS FROM 12N-24N BETWEEN 33W-39W. TROPICAL WAVE EXTENDS FROM 11N71W TO 18N69W MOVING W AT 10 KT. PLENTY OF MOISTURE IS NOTED ON WATER VAPOR IMAGERY ACROSS THE EASTERN CARIBBEAN SEA AS THE WAVE REMAINS BENEATH MOIST SOUTHWESTERLY FLOW EAST OF AN UPPER LEVEL TROUGH AXIS EXTENDING FROM 22N69W SW TO 13N77W. LOW-LEVEL MOISTURE CONVERGENCE IS MAXIMIZED EAST OF THE TROPICAL WAVE WITH SCATTERED MODERATE CONVECTION FROM 12N-22N BETWEEN 59W-71W. THIS CONVECTION IS LIKELY ENHANCED DUE TO THE UPPER LEVEL DIFFLUENCE GENERATED FROM THE UPPER LEVEL TROUGHING. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH AXIS EXTENDS FROM THE AFRICAN COAST NEAR 13N17W TO 10N26W TO 11N32W. THE INTERTROPICAL CONVERGENCE ZONE AXIS EXTENDS FROM 11N32W TO 12N42W TO 11N52W. BESIDES THE CONVECTION ASSOCIATED WITH THE TROPICAL WAVES...WIDELY SCATTERED MODERATE CONVECTION IS FROM 04N-12N BETWEEN 10W-20W. ...DISCUSSION... GULF OF MEXICO... A MIDDLE TO UPPER LEVEL TROUGH EXTENDS FROM OVER THE CAROLINAS NEAR 34N79W SW TO A BASE OVER THE WESTERN GULF NEAR 23N93W THAT SUPPORTS A 1009 MB LOW CENTERED OFFSHORE OF JACKSONVILLE FLORIDA NEAR 30N81W. A COLD FRONT EXTENDS SW FROM THE LOW CENTER ACROSS THE SOUTHERN FLORIDA PENINSULA TO 26N82W TO THE YUCATAN PENINSULA COAST NEAR 21N89W THEN TO 18N94W IN THE SW GULF WATERS. WIDELY SCATTERED SHOWERS AND ISOLATED TSTMS ARE OCCURRING WITHIN 120 NM EITHER SIDE OF THE COLD FRONT AND AN AREA S OF 21N W OF 94W. A SECONDARY SURFACE TROUGH IS ANALYZED FROM THE LOW CENTER ACROSS THE NORTHERN FLORIDA PENINSULA TO 28N85W DENOTING A MORE SIGNIFICANT DEWPOINT DEPRESSION AND THUS A DRIER AIRMASS MOVING IN BEHIND THE FRONT. OTHERWISE...THE REMAINDER OF THE GULF IS UNDER THE INFLUENCE OF A SURFACE RIDGE ANCHORED OVER THE MIDDLE AND LOWER MISSISSIPPI RIVER VALLEY TO THE NORTH AND A 1021 MB HIGH CENTERED OVER EASTERN MEXICO NEAR 22N99W. CLEAR SKIES AND FAIR CONDITIONS PREVAIL ON LIGHT NORTHERLY WINDS IN THE RANGE OF 10 TO 15 KT GENERALLY NW OF A LINE FROM 30N85W TO 21N97W. CARIBBEAN SEA... AN UPPER LEVEL TROUGH AXIS SPLITS THE CARIBBEAN BASIN IN HALF WITH THE TROUGH AXIS EXTENDING FROM OVER THE SW NORTH ATLC NEAR 24N69W SW TO A BASE OVER THE SW CARIBBEAN NEAR 12N78W. TO THE WEST OF THE AXIS...WATER VAPOR IMAGERY INDICATES DRY AND STABLE NORTH-NORTHEASTERLY WINDS ALOFT. WITH THE APPROACH OF A COLD FRONT MOVING SE ACROSS THE SE GULF OF MEXICO...THE ATMOSPHERE MOISTENS CLOSER TO THE YUCATAN PENINSULA AND AREAS IN THE VICINITY OF THE YUCATAN CHANNEL WITH WIDELY SCATTERED SHOWERS AND ISOLATED TSTMS OCCURRING WEST OF A LINE FROM 22N85W TO 10N78W. THIS AREA INCLUDES THE GULF OF HONDURAS...AND INLAND PORTIONS OF CENTRAL AMERICA THIS EVENING. LIKELY AIDING THE CONVECTION IN THE SW CARIBBEAN IS THE CLOSE PROXIMITY OF THE MONSOON TROUGH AXIS ANALYZED ALONG 09N/10N BETWEEN NORTHERN COLOMBIA AND COSTA RICA. TO THE EAST OF THE UPPER LEVEL TROUGH AXIS...AN UPPER LEVEL ANTICYCLONIC CIRCULATION IS CENTERED OVER THE EASTERN CARIBBEAN NEAR 13N66W. THE OVERALL DIFFLUENT ENVIRONMENT EAST OF THE TROUGH AXIS ALONG WITH LOW-LEVEL MOISTURE CONVERGENCE AIDED BY THE PRESENCE OF A TROPICAL WAVE ALONG 70W IS GENERATING SCATTERED SHOWERS AND WIDELY SCATTERED TSTMS FROM 12N-23N BETWEEN 59W-71W. HISPANIOLA... CURRENTLY SCATTERED SHOWERS AND TSTMS ARE OCCURRING ACROSS PORTIONS OF THE DOMINICAN REPUBLIC AND THIS CONVECTION IS LIKELY ENHANCED DUE TO A TROPICAL WAVE PASSING TO THE SOUTH ALONG 70W AND AN UPPER LEVEL TROUGH AXIS THAT EXTENDS FROM OVER THE SW NORTH ATLC TO OVER THE WESTERN PORTION OF THE ISLAND THIS EVENING. ATMOSPHERIC MOISTURE AND CONVECTION INCREASE TO THE EAST AND AS THE UPPER LEVEL TROUGH IS FORECAST TO REMAIN FAIRLY STATIONARY OVER THE NEXT 24 HOURS...ISOLATED SHOWERS AND TSTMS ARE EXPECTED TO PERSIST THROUGH THE OVERNIGHT HOURS WITH AN INCREASE IN AREAL COVERAGE WEDNESDAY AFTERNOON AND EVENING AS PEAK HEATING AND INSTABILITY MAX OUT DURING THOSE HOURS. ATLANTIC OCEAN... A MIDDLE TO UPPER LEVEL LOW IS CENTERED OVER THE CAROLINAS NEAR 34N79W THAT SUPPORTS A 1009 MB LOW CENTERED OFFSHORE OF JACKSONVILLE FLORIDA NEAR 30N80W. A STATIONARY FRONT EXTENDS NE FROM THE LOW TO BEYOND 32N78W AND A COLD FRONT EXTENDS SOUTH- SOUTHWEST FROM THE LOW TO 26N82W AND INTO THE SE GULF OF MEXICO. ISOLATED SHOWERS AND TSTMS ARE OCCURRING N OF 25N W OF 72W ACROSS MOST OF THE SW NORTH ATLC. FARTHER EAST...AN UPPER LEVEL LOW IS NOTED ON WATER VAPOR IMAGERY CENTERED NEAR 25N68W THAT SUPPORTS A WEAK 1013 MB LOW CENTERED NEAR 30N68W AND A SURFACE TROUGH EXTENDING E-SE FROM THE LOW TO 26N62W. WHILE NO NOTABLE SURFACE FEATURE IS ASSOCIATED WITH THE UPPER LEVEL LOW...PLENTY OF MIDDLE TO UPPER LEVEL DIFFLUENCE BETWEEN 55W-68W IS GENERATING A LARGE AREA OF SCATTERED SHOWERS AND TSTMS FROM 18N- 31N BETWEEN 59W-66W. FINALLY...A DEEP LAYERED UPPER LEVEL LOW IS NOTED ON WATER VAPOR IMAGERY CENTERED NEAR 43N39W THAT SUPPORTS A COLD FRONT THAT SKIRTS THE CENTRAL ATLC DISCUSSION WATERS FROM 32N34W TO29N40W TO 28N47W. ISOLATED SHOWERS ARE OCCURRING WITHIN 120 NM EITHER SIDE OF THE BOUNDARY. 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