Severe Storm Outlook Narrative (AC)
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000
ACUS11 KWNS 300707
SWOMCD
SPC MCD 300707
GAZ000-TNZ000-ALZ000-MSZ000-300800-

MESOSCALE DISCUSSION 1853
NWS STORM PREDICTION CENTER NORMAN OK
0107 AM CST WED NOV 30 2016

AREAS AFFECTED...FAR EAST-CENTRAL MS...PARTS OF NORTHERN AL...SOUTHERN
MIDDLE TN...EXTREME NORTHWESTERN GA

CONCERNING...TORNADO WATCH 508...509...510

VALID 300707Z - 300800Z

THE SEVERE WEATHER THREAT FOR TORNADO WATCH 508...509...510 CONTINUES.

SUMMARY...THE GREATEST SUPERCELL-TORNADO RISK WILL PROBABLY BE
CONFINED TO MAINLY NORTHERN PORTIONS OF AL FOR AT LEAST THE NEXT 2
HOURS.  A GRADUAL AND OVERALL LESSENING IN THE BACKGROUND POTENTIAL
FOR EF2+ TORNADOES IS FORECAST.

DISCUSSION...06 UTC SUBJECTIVE SURFACE ANALYSIS SHOWS A PLUME OF
RICH LOW-LEVEL MOISTURE --CHARACTERIZED BY 65-68 DEG F DEWPOINTS--
FROM EAST-CENTRAL MS NORTHEASTWARD INTO NORTHERN AL.  THE 06 UTC JAN
RAOB REMAINS MODERATELY UNSTABLE WITH AROUND 1500 J/KG MLCAPE BUT
THE VEERING OF LOW-LEVEL WINDS HAS REDUCED THE SIZE OF THE HODOGRAPH
COMPARED TO THE 03 UTC RAOB.  A SLIGHTLY LARGER HODOGRAPH WAS
OBSERVED WITH THE 06 UTC BMX RAOB /250-300 M2 PER S2 SRH/ WITH THE
STRONGER H85 FLOW LOCATED CURRENTLY OVER NORTHERN AL.  YET...WEAKER
BUOYANCY WAS SAMPLED BY THE BMX RAOB /750 J PER KG MLCAPE/.

THERE IS REASONABLE CONFIDENCE IN THE NOTION OF THE GREATEST TORNADO
RISK BEING ASSOCIATED WITH THE DISCRETE WARM-SECTOR SUPERCELLS
ONGOING NEAR THE AL/MS BORDER AND EXTENDING NORTHEASTWARD NEAR THE
TN/GA BORDER.  YET...AN APPRECIABLE RISK FOR A TORNADO OR TWO MAY
ACCOMPANY SUPERCELLS EMBEDDED WITHIN A BAND OF STORMS LOCATED OVER
NORTHERN AL...ESPECIALLY IF THE ANCHORING UPDRAFT CAN BE PRONE TO
LESS-DISRUPTIVE OUTFLOW FROM ANCILLARY CONVECTION.

FARTHER SOUTH AND SOUTHWEST ACROSS EAST-CENTRAL MS AND WEST-CENTRAL
AL...LOW-LEVEL CONFLUENCE BANDS ARE STILL EVIDENT IN RADAR IMAGERY.
HOWEVER...IT APPEARS THE LACK OF SURFACE HEATING AND A STRONGER
THETA-E INFLUX ARE ACTING TO LARGELY SQUELCH THE DEVELOPMENT OF FREE
WARM-SECTOR INITIATION AND ADDITIONAL SUPERCELLS AHEAD OF THE BROKEN
SQUALL LINE LOCATED FROM NORTHERN AL SOUTHWESTWARD THROUGH
SOUTHWESTERN MS.  THIS MAY BE IMPLYING THE TORNADO RISK WILL
GRADUALLY BECOME MORE LOCALIZED GOING FORWARD TONIGHT OUTSIDE OF THE
DISCUSSION AREA.

..SMITH.. 11/30/2016

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

ATTN...WFO...MRX...FFC...OHX...BMX...HUN...JAN...

LAT...LON   34898459 33078839 33238845 34218758 35218616 35298476
            34898459



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