Severe Storm Outlook Narrative (AC)
Issued by NWS

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ACUS01 KWNS 241957
SWODY1
SPC AC 241955

DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0255 PM CDT THU APR 24 2014

VALID 242000Z - 251200Z

...THERE IS A SLGT RISK OF SVR TSTMS FROM ERN OK/CENTRAL AND SRN
MO/AR/NRN LA EWD ACROSS THE MID MS/LOWER OH/TN VALLEYS...

...SUMMARY...
SCATTERED STRONG TO SEVERE THUNDERSTORMS ARE EXPECTED FROM CENTRAL
AND SOUTHERN MISSOURI THROUGH ARKANSAS INTO NORTHERN LOUISIANA THIS
AFTERNOON...WITH THE ACTIVITY THEN SPREADING EAST INTO PARTS OF THE
LOWER OHIO...LOWER TENNESSEE...AND LOWER MISSISSIPPI VALLEYS THIS
EVENING THROUGH EARLY FRIDAY.  DAMAGING WINDS AND LARGE HAIL WILL BE
THE PRIMARY THREATS.

...DISCUSSION...
PRIOR FORECAST REASONING REMAINS VALID...WITH LITTLE IN THE WAY OF
APPRECIABLE CHANGES NEEDED THIS UPDATE.  THE SLIGHT RISK HAS BEEN
EXPANDED NWD IN CENTRAL MO -- IN CONJUNCTION WITH NEWLY ISSUED WW
0089.  OTHERWISE...NO MAJOR CHANGES ARE BEING IMPLEMENTED ATTM...AS
THE RISK FOR LOCALLY DAMAGING WINDS AND LARGE HAIL EXPECTED TO
SPREAD EASTWARD FROM MO/ERN OK/AR/NRN LA THIS AFTERNOON INTO SRN
IL/WRN KY/WRN TN/NRN MS/NWRN AL OVERNIGHT.

..GOSS.. 04/24/2014

.PREV DISCUSSION... /ISSUED 1130 AM CDT THU APR 24 2014/

...SYNOPTIC SETUP...
PROGRESSIVE...MODERATELY AMPLIFIED PATTERN WILL PERSIST OVER THE LWR
48 THROUGH FRI...DOWNSTREAM FROM BROAD...AMPLIFYING TROUGH IN THE NE
PACIFIC. SHORTWAVE TROUGH THAT CROSSED THE SWRN U.S. YESTERDAY IS
NOW OVER NW OK. THE COMPACT...FAIRLY POTENT SYSTEM SHOULD CONTINUE
GENERALLY ENE INTO MO/NRN AR THIS EVE...AND INTO IND/CNTRL KY EARLY
FRI...AS IT ASSUMES A SLIGHT NEGATIVE TILT.

ELONGATED SFC LOW NOW OVER ERN KS/NE OK...LARGELY AN EWD-DISPLACED
LEE TROUGH...SHOULD CONSOLIDATE AND DEEPEN OVER CNTRL MO LATER
TODAY...AND OVER CNTRL PORTIONS OF IL AND IND TNGT/EARLY FRI...AS
UPR VORT OVERTAKES THE CIRCULATION AND ASSOCIATED COLD FRONT
TRAILING SW INTO E TX. THE COLD FRONT...AND STRENGTHENING CONFLUENCE
AXES TO ITS EAST...WILL SERVE TO FOCUS LOW-LVL UPLIFT AND POTENTIAL
SVR TSTM DEVELOPMENT LATER TODAY THROUGH TNGT IN MOISTENING LOW-LVL
ENVIRONMENT OVER SRN MO...AR...AND PERHAPS NE TX EWD INTO PARTS OF
THE LWR OH...LWR TN...AND LWR MS VLYS.

...OZARKS/ARKLATEX EWD INTO THE LWR OH...LWR TN...AND LWR MS VLYS
TODAY THROUGH TNGT...
A CONCENTRATED BAND OF STRONG DCVA/LARGE-SCALE ASCENT WILL TRACK E
ACROSS MUCH OF AR AND MO TODAY...AND THE LWR OH AND TN VLYS TNGT...
AHEAD OF PROGRESSIVE OK UPR VORT. AT THE SAME TIME...ASSOCIATED BAND
OF 40-60 KT 700-500 MB FLOW WILL OVERSPREAD THE REGION...CREATING A
WIND ENVIRONMENT QUITE FAVORABLE FOR SVR STORMS/SUPERCELLS. MOISTURE
INITIALLY WILL BE SOMEWHAT LIMITED...ESPECIALLY E OF THE
OZARKS/OUACHITAS. BUT MOISTURE WILL INCREASE NWD THROUGH THE LWR MS
VLY LATER TODAY INTO TNGT...AND LIKELY WILL BECOME SUFFICIENT FOR
SVR STORMS...ONE OR TWO OF WHICH COULD YIELD A TORNADO IN ADDITION
TO LARGE HAIL/DMGG WIND.

LOW-LVL MOIST AXIS AHEAD OF COLD FRONT ATTM EXTENDS FROM E CNTRL TX
NNE INTO ERN OK/SE KS/SW MO/WRN AR. STORMS SHOULD CONTINUE TO FORM
WITHIN THIS CORRIDOR...BOTH ALONG AND AHEAD OF FRONT...THROUGH THE
AFTN AS DCVA AND MODEST SFC HEATING FURTHER DESTABILIZE REGION  /REF
MCD 392/. STEEP MID-LVL LAPSE RATES AND STRENGTHENING /30-40 KT/
SWLY DEEP SHEAR MAY SUPPORT A FEW STORMS WITH SVR HAIL AND WIND. A
TORNADO CANNOT BE RULED OUT...ESPECIALLY IN FAR ERN OK AND AR LATER
TODAY...WHERE WIND PROFILES SHOULD EXHIBIT THE MAXIMUM DEEP VEERING
AMIDST SFC DEWPOINTS IN THE UPR 50S TO LOW 60S F.

FARTHER E...OTHER TSTMS ARE EXPECTED TO FORM/INTENSIFY ALONG AND
AHEAD OF PRE-FRONTAL CONFLUENCE AXIS NOW OVER WRN AR. STRONG SFC
HEATING WILL OCCUR AHEAD OF THIS AXIS OVER SE MO...ERN AR...AND NRN
LA EWD INTO WRN KY...WRN TN...AND NRN MS THROUGH THE AFTN...WHERE
/ESPECIALLY LATER TODAY INTO TNGT/ VEERING AND STRENGTHENING 850 MB
WINDS WILL SUBSTANTIALLY INCREASE MOISTURE INFLOW ACROSS REGION.
COUPLED WITH STRENGTHENING DEEP SHEAR /500 MB FLOW INCREASING TO AOA
50 KTS/...SETUP COULD YIELD A SIZABLE N-S SQLN. EMBEDDED SUPERCELLS
AND SUSTAINED CIRCULATIONS IN THE LINE COULD PRODUCE A COUPLE
TORNADOES IN ADDITION TO DMGG WIND AND SVR HAIL. THIS ACTIVITY MAY
REACH AS FAR E AS NW AL...MIDDLE TN...AND CNTRL KY EARLY FRI.



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