Severe Storm Outlook Narrative (AC)
Issued by NWS

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ACUS48 KWNS 310855
SWOD48
SPC AC 310853

DAY 4-8 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0353 AM CDT TUE MAY 31 2016

VALID 031200Z - 081200Z

...DISCUSSION...
THE MAIN FOCUS FOR SEVERE WEATHER THROUGH THE MEDIUM-RANGE PERIOD
APPEARS TO RESIDE NEAR /DAY 4/ AND E /DAY 5 AND BEYOND/ OF THE MS
VALLEY...AS UPPER TROUGHING SHIFTS INTO AND THEN EXPANDS OVER THE
ERN HALF OF THE COUNTRY.  HOWEVER...THE AMPLITUDE/EVOLUTION OF THE
EVOLVING TROUGH IS HANDLED DIFFERENTLY BY THE ECMWF VS. THE
GFS...AND AS SUCH TIMING OF THE ADVANCE OF AN ASSOCIATED SURFACE LOW
AND COLD FRONT ACROSS THE ERN U.S. IS ALSO UNCERTAIN.

THE MAIN RISK DAY 4 /FRI. 6-3/ APPEARS TO BE FOCUSED OVER THE UPPER
OH VALLEY...AS THE UPPER SHORT-WAVE TROUGH AND ASSOCIATED SURFACE
LOW SHIFT ACROSS MN AND INTO WI DURING THE AFTERNOON/EVENING.
HOWEVER...WITH EARLIER/ONGOING CONVECTION EXPECTED WITHIN A ZONE OF
WARM ADVECTION AHEAD OF THE LOW...IT APPEARS THAT DESTABILIZATION
ACROSS THE MN/WI REGION DURING THE AFTERNOON MAY BE HINDERED.  AS
SUCH...WILL REFRAIN FROM INTRODUCTION OF A 15% RISK AREA ACROSS THE
UPPER MS VALLEY AREA ATTM.

DAY 5...THE SURFACE LOW/FRONT IS PROGGED TO SHIFT SLOWLY
EWD...THOUGH IT APPEARS ATTM THAT INSTABILITY WILL LIKELY BE LIMITED
AHEAD OF THE LOW AND ASSOCIATED COLD FRONT.

LATER IN THE PERIOD...AS THE TROUGH EXPANDS INTO THE ERN U.S. BUT
WITH UNCERTAINTY REGARDING ITS EVOLUTION INCREASING...NO AREAL
HIGHLIGHTS WILL BE INCLUDED THIS FORECAST.

..GOSS.. 05/31/2016



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