Severe Storm Outlook Narrative (AC)
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000
ACUS11 KWNS 281610
SWOMCD
SPC MCD 281610
LAZ000-TXZ000-281815-

MESOSCALE DISCUSSION 1827
NWS STORM PREDICTION CENTER NORMAN OK
1010 AM CST MON NOV 28 2016

AREAS AFFECTED...SOUTHEAST TEXAS AND INTO WESTERN AND SOUTHERN
LOUISIANA

CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE

VALID 281610Z - 281815Z

PROBABILITY OF WATCH ISSUANCE...60 PERCENT

SUMMARY...CONVECTION -- NOW INCLUDING ISOLATED/EMBEDDED
THUNDERSTORMS -- CONTINUES TO GRADUALLY INCREASE ACROSS PORTIONS OF
EASTERN TEXAS AND WESTERN LOUISIANA IN THE VICINITY OF THE SABINE
RIVER VALLEY.  AN ASSOCIATED/VERY SLOW RAMP-UP IN SEVERE/TORNADO
RISK MAY WARRANT WATCH ISSUANCE IN THE NEXT 1-2 HOURS.

DISCUSSION...LATEST SURFACE ANALYSIS SHOWS A COLD FRONT ADVANCING
INTO EASTERN TEXAS AT THIS TIME...WHILE A WARM FRONT LIFTS
NORTHEASTWARD ACROSS LOUISIANA AND THE ARKLATEX REGION.  WITHIN THE
WARM SECTOR...A BAND OF CONFLUENCE IS INDICATED NEAR THE SABINE
RIVER...WITH CONVECTION INCREASING ALONG IN THE VICINITY OF THIS
BOUNDARY.  INCREASING SOUTHERLY FLOW WITHIN THE WARM SECTOR
CONTINUES TO ADVECT UPPER 60S TO LOW 70S SURFACE DEWPOINTS ONSHORE...
WITH MIXED-LAYER CAPE ACROSS THE DISCUSSION AREA NOW IN THE 250 TO
750 J/KG RANGE (PER OBJECTIVE ANALYSIS) AS A RESULT.

THOUGH LIMITED POTENTIAL FOR HEATING (OWING TO THE ONGOING
PRECIPITATION AND ASSOCIATED CLOUD COVER) SHOULD TEMPER ADDITIONAL
DESTABILIZATION (AND THUS DEGREE OF SEVERE RISK)...ANY THERMODYNAMIC
WEAKNESS IS OFFSET TO SOME DEGREE BY VERY STRONG/VEERING FLOW WITH
HEIGHT RESULTING IN VERY FAVORABLE SHEAR.  THE LATEST LAKE CHARLES
VWP REVEALS SOUTHERLY BOUNDARY-LAYER FLOW VEERING AND INCREASING
STEADILY THROUGH THE LOWER AND MIDDLE TROPOSPHERE...TO WEST-SOUTHWEST
AT 80 KT NEAR 500 MB...ALONG WITH SURFACE TO 1 KM SHEAR OF 40 KT.
GIVEN THIS DEGREE OF SHEAR...SUSTAINED UPDRAFTS WILL LIKELY ACQUIRE
ROTATION...AND THUS THE RISK FOR LOCALLY DAMAGING WINDS AND HAIL...
ALONG WITH ISOLATED TORNADOES...SHOULD EVOLVE AS STRONGER STORMS
BECOME MORE NUMEROUS WITH TIME.

..GOSS/THOMPSON.. 11/28/2016

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

ATTN...WFO...JAN...LIX...LCH...SHV...HGX...

LAT...LON   30009153 29519180 29419235 29609340 29379447 28889518
            29039536 30219495 31149428 32619384 32229270 30869151
            30009153




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