Severe Storm Outlook Narrative (AC)
Issued by NWS

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ACUS02 KWNS 231727
SWODY2
SPC AC 231726

DAY 2 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1226 PM CDT WED APR 23 2014

VALID 241200Z - 251200Z

...THERE IS A SLGT RISK OF SVR TSTMS ACROSS SOUTHEAST MO...MUCH OF
AR AND INTO WRN TN...AND INTO NWRN MS AND NRN LA...

...SUMMARY...
SCATTERED STRONG TO SEVERE STORMS ARE EXPECTED TO FORM ALONG A
CORRIDOR FROM NORTHERN LOUISIANA INTO SOUTHEAST MISSOURI...AND THEN
SPREAD EAST TOWARD WESTERN TENNESSEE AND NORTHWEST MISSISSIPPI INTO
THE EVENING THURSDAY.  LOCALLY DAMAGING WINDS AND HAIL WILL BE THE
PRIMARY THREATS WITH THIS ACTIVITY.

...SYNOPSIS...
A STRONG MID- AND UPPER-LEVEL TROUGH -- COMPRISED OF PHASED PIECES
OF NRN- AND SRN-STREAM ENERGY -- WILL CROSS THE CENTRAL U.S. THIS
PERIOD.  THE SRN FEATURE WITHIN THIS TROUGH IN PARTICULAR WILL BE A
FOCUS WITH RESPECT TO THE CONVECTIVE/SEVERE FORECAST FOR THE DAY 2
PERIOD...AS IT SHIFTS OUT OF THE PLAINS AND CROSSES THE LOWER MO/MID
MS VALLEY REGION THROUGH THE AFTERNOON AND EVENING HOURS.

AT THE SURFACE...LOW PRESSURE IS FORECAST TO SHIFT EWD ACROSS THE
IA/MO REGION THROUGH THE AFTERNOON...AND THEN THE MIDWEST STATES
DURING THE EVENING AND OVERNIGHT.  AS THIS OCCURS...A TRAILING COLD
FRONT WILL MOVE EWD ACROSS THE LOWER MO/MID MS VALLEYS AND SEWD
ACROSS AR/TX/LA THROUGH SUNSET.  THIS BOUNDARY WILL FOCUS A ZONE OF
SHOWERS AND THUNDERSTORMS -- WITH INTENSITY/SEVERE RISK PEAKING
DIURNALLY ACROSS AR AND VICINITY.

...SERN MO/WRN TN SWWD INTO NRN LA...
A MOISTENING AIRMASS IS PROGGED AHEAD OF THE ADVANCING COLD
FRONT...AS SLY BOUNDARY-LAYER WINDS ADVECT LOW 60S DEWPOINTS ACROSS
AR AND INTO SERN MO.  HOWEVER...DIURNAL HEATING IS FORECAST TO BE
HINDERED BY ONGOING PRECIPITATION AND ASSOCIATED CLOUD COVER...WHICH
SHOULD BE SPREADING EWD TOWARD/INTO THE SLIGHT RISK AREA EARLY IN
THE PERIOD.  AS A RESULT...ONLY MARGINAL DESTABILIZATION IS FORECAST
-- PARTICULARLY INTO CENTRAL AND NRN AR AND ADJACENT SERN MO WHERE
STRONGEST FLOW ALOFT /ON THE SRN FRINGE OF THE UPPER VORT MAX/ IS
PROGGED TO EXIST.

THAT BEING SAID...THE STRENGTH OF THE SYSTEM AND ASSOCIATED
STRONG/COMPACT JET STREAK IS SUGGESTIVE OF SEVERE RISK DESPITE THE
ANTICIPATED MARGINAL THERMODYNAMIC ENVIRONMENT.  THOUGH SHEAR WOULD
SUPPORT ROTATING STORMS...IT APPEARS THAT A LINEAR MODE WILL BE
FAVORED AND THUS DAMAGING WINDS SHOULD BE THE PRIMARY SEVERE RISK.
A TORNADO OR TWO...HOWEVER...CANNOT BE RULED OUT -- EITHER WITHIN
THE BROADER CONVECTIVE LINE OR WITH ANY ISOLATED STORM AHEAD OF THE
LINE.  SEVERE-SIZED HAIL WOULD APPEAR TO BE MOST LIKELY ACROSS THE
SRN HALF OF THE OUTLOOK...WHERE SOMEWHAT GREATER DESTABILIZATION
POTENTIAL IS EVIDENT.

GIVEN THE MARGINAL THERMODYNAMICS ANTICIPATED...STORMS SHOULD SHOW A
FAIRLY STRONG DIURNAL PEAK IN INTENSITY...WITH WEAKENING CONVECTION
AND THUS DIMINISHING SEVERE RISK LIKELY BY EVENING AS THE FRONT
MOVES E OF THE MS VALLEY.

..GOSS.. 04/23/2014



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