Severe Storm Outlook Narrative (AC)
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000
ACUS11 KWNS 211721
SWOMCD
SPC MCD 211720
NYZ000-PAZ000-MDZ000-WVZ000-OHZ000-211915-

MESOSCALE DISCUSSION 1753
NWS STORM PREDICTION CENTER NORMAN OK
1220 PM CDT SUN SEP 21 2014

AREAS AFFECTED...PORTIONS OF ERN OH...WRN PA/NY...NRN WV...FAR WRN
MD

CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY

VALID 211720Z - 211915Z

PROBABILITY OF WATCH ISSUANCE...20 PERCENT

SUMMARY...AN INCREASE IN THUNDERSTORM COVERAGE IS EXPECTED THROUGH
THIS AFTERNOON. THE PRIMARY SEVERE THREAT WILL BE ISOLATED DAMAGING
WINDS. A WATCH IS NOT CURRENTLY ANTICIPATED...HOWEVER CONVECTIVE
TRENDS WILL CONTINUE TO BE MONITORED.

DISCUSSION...LATEST VISIBLE IMAGERY/RADAR TRENDS SHOW STRENGTHENING
UPDRAFTS/ISOLATED SHOWERS DEVELOPING FROM WESTERN NEW YORK SOUTHWARD
TO EASTERN OHIO/NORTHWEST PENNSYLVANIA AHEAD OF A COLD FRONT.
EARLIER PASSAGE OF A LINE OF SHOWERS HAS RESULTED IN ADDITIONAL
MOISTENING OF BOUNDARY LAYER BUT ALSO EXTENSIVE CLOUD COVER ACROSS
DISCUSSION AREA. STILL...DIURNAL HEATING IN THE PRESENCE OF MOSTLY
LOWER 60S DEW POINTS WILL LIKELY RESULT IN A CORRIDOR OF MLCAPE
BETWEEN 500 AND 1000 J/KG BY MID AFTERNOON. POCKETS OF SOMEWHAT
HIGHER INSTABILITY ARE POSSIBLE...WITH AREAL EXTENT TEMPERED BY
CLOUD COVER AND ABSENCE OF STEEPER LAPSE RATES. AS HEIGHT FALLS
ASSOCIATED WITH AMPLIFYING UPPER TROUGH OVER LOWER MICHIGAN DEVELOP
EASTWARD OVER THE AREA...ONE OR MORE LINES OF THUNDERSTORMS WILL
LIKELY DEVELOP DURING THE AFTERNOON. STRENGTHENING WIND FIELDS WILL
RESULT IN 40-50 KTS OF EFFECTIVE SHEAR ORIENTED LARGELY PARALLEL TO
THE SURFACE FRONT. THE ENVIRONMENT WILL FAVOR LOCALIZED
STRONG/SEVERE WIND GUSTS ASSOCIATED WITH FAST-MOVING STORMS AS THE
PRIMARY SEVERE THREAT. A WATCH IS NOT CURRENTLY ANTICIPATED GIVEN
THE EXPECTED ISOLATED NATURE OF THE THREAT...HOWEVER CONVECTIVE
TRENDS WILL CONTINUE TO BE MONITORED.

..BUNTING/CARBIN.. 09/21/2014

...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...

ATTN...WFO...BTV...ALY...BGM...BUF...CTP...LWX...PBZ...RLX...
CLE...

LAT...LON   42707896 42947878 43287838 43537797 43617698 43717643
            44217597 44527533 44197494 43237552 42197644 41527727
            39807878 39197940 39068009 39098089 39158162 39398214
            39848202 40868096 41878013 42197951 42707896



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