Severe Storm Outlook Narrative (AC)
Issued by NWS

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000
ACUS02 KWNS 291715
SWODY2
SPC AC 291714

DAY 2 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1214 PM CDT FRI APR 29 2016

VALID 301200Z - 011200Z

...THERE IS A SLGT RISK OF SVR TSTMS FROM THE SABINE/LOWER
MISSISSIPPI RIVER VALLEYS INTO THE MID MS/LOWER OH RIVER VALLEY...

...THERE IS A MRGL RISK OF SVR TSTMS IMMEDIATELY SURROUNDING THE
SLIGHT RISK AREA...

...THERE IS A MRGL RISK OF SVR TSTMS ACROSS THE WRN CAROLINAS INTO
NRN GA...

...SUMMARY...
STRONG TO SEVERE THUNDERSTORMS ARE POSSIBLE ACROSS THE MID
MISSISSIPPI VALLEY SATURDAY WITH MORE ISOLATED ACTIVITY EXPECTED
ACROSS THE LOWER MISSISSIPPI VALLEY AND SOUTHEASTERN TEXAS. A FEW
STRONG STORMS ARE ALSO POSSIBLE ACROSS THE SOUTHERN APPALACHIANS.

...SYNOPSIS...
WITH AN UPPER LOW STATIONARY OVER THE CNTRL PLAINS...A SHORTWAVE
TROUGH WILL ROTATE NEWD FROM THE ARKLATEX TOWARD THE MS
VALLEY...LOSING AMPLITUDE ALONG WITH GRADUALLY WEAKENING WIND FIELDS
ALOFT. AT THE SURFACE...LOW PRESSURE WILL BE CENTERED OVER ERN KS
SAT MORNING WITH A WEAK SFC TROUGH EXTENDING SWD INTO ERN TX. THIS
LOW WILL FILL DURING THE DAY AS IT SHIFTS EWD ALONG I-70 WITH SRN
PORTION LINGERING INTO THE LOWER MS VALLEY. MEANWHILE...A WARM FRONT
WILL LIFT NWD ACROSS THE MID MS/OH VALLEYS DURING THE DAY WITH EARLY
DAY STORMS LIKELY.

SUBSTANTIAL MOISTURE WILL REMAIN FROM ERN TX INTO THE CNTRL GULF
COAST STATES WITH UPPER 60S TO LOWER 70S F DEWPOINTS...MAINTAINED BY
CONTINUED SLY LOW-LEVEL FLOW. WSWLY FLOW ALOFT WILL REMAIN STRONG
ENOUGH TO SUPPORT SEVERE STORMS WITH HAIL AND WIND POSSIBLE ACROSS
THE WARM SECTOR...ALBEIT WITH WEAK LIFT.

...MID MS VALLEY INTO THE LOWER OH VALLEY...
SCATTERED THUNDERSTORMS ASSOCIATED WITH A 50 KT LOW LEVEL JET AND
STRONG WARM ADVECTION WILL BE ONGOING ACROSS MUCH OF AR...MO...AND
IL. LIFT IN THIS REGION WILL ALSO BE ENHANCED BY HEIGHT FALLS AND
COOLING ALOFT WITH THE WEAKENING SHORTWAVE TROUGH. SOME WIND AND
HAIL THREAT MAY ACCOMPANY SOME OF THIS ACTIVITY...ESPECIALLY WITH
CELLS NEAR THE SFC WARM FRONT LATER IN THE DAY WHEN INSTABILITY WILL
BE GREATER. COLD TEMPERATURES ALOFT AND MODESTLY VEERING WIND
PROFILES SUGGEST A FEW SUPERCELLS WILL BE POSSIBLE. AN ISOLATED
TORNADO CANNOT BE RULED OUT ACROSS THE LOWER OH VALLEY GIVEN PROPER
STORM MODE AND FAVORABLE LOW-LEVEL SHEAR NEAR THE WARM FRONT AND/OR
ANY OUTFLOW BOUNDARIES.

...LOWER MS VALLEY INTO THE SABINE RIVER VALLEY...
STORMS SHOULD BE ONGOING EARLY ACROSS AR...AND PERHAPS THE SABINE
RIVER VALLEY WITH ANY SEVERE THREAT LIKELY WANING AS THE UPPER
TROUGHS EXITS TO THE NE. THESE EARLY STORMS MAY PRODUCE AN OUTFLOW
BOUNDARY ACROSS SRN AR/NRN MS WHICH COULD SERVE AS A FOCUS FOR
ADDITIONAL AFTERNOON SEVERE STORMS. STRONG INSTABILITY WILL
MATERIALIZE WITH HEATING AND DESPITE SOMEWHAT NEUTRAL TO SLIGHTLY
RISING HEIGHTS ALOFT BEHIND THE SHORTWAVE TROUGH....WEAK SFC
CONVERGENCE SHOULD YIELD AT LEAST ISOLATED SEVERE STORMS CAPABLE OF
LARGE HAIL...PERHAPS VERY LARGE. ISOLATED LARGE HAIL STORMS ARE
EXPECTED TO EXTEND SWWD TOWARD HOUSTON AS WELL WITH ONLY WEAK SFC
CONVERGENCE.

...NRN GA...WRN CAROLINAS...
LOW-LEVEL WINDS WILL GRADUALLY INCREASE AND BACK AS THE UPPER RIDGE
BREAKS DOWN. THIS WILL ALLOW LOWER 60S F DEWPOINTS TO SURGE BACK
NWWD BEHIND THE RETREATING FRONT WITH COOL/STABLE AIR TO THE N.
STRONG HEATING AND CONVERGENCE ON THIS BOUNDARY MAY RESULT IN A FEW
STRONG STORMS CAPABLE OF MARGINALLY SEVERE HAIL. ALSO AIDING IN THE
SEVERE THREAT IS LIKELY CELLULAR STORM MODE WITH VEERING WINDS WITH
HEIGHT IN THE LOWER 3 KM. A BRIEF/WEAK TORNADO CANNOT BE RULED OUT
SHOULD CELLS TRACK EWD ALONG THE BOUNDARY.

..JEWELL.. 04/29/2016

$$



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