Severe Storm Outlook Narrative (AC)
Issued by NWS

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ACUS02 KWNS 310449
SWODY2
SPC AC 310448

DAY 2 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1148 PM CDT SAT AUG 30 2014

VALID 011200Z - 021200Z

...THERE IS A SLGT RISK OF SVR TSTMS FROM THE UPPER GREAT LAKES TO
SERN KS...

...SUMMARY...
ISOLATED SEVERE THUNDERSTORMS MAY DEVELOP ALONG A WEAK COLD FRONT
FROM PORTIONS OF THE UPPER GREAT LAKES...SOUTHWEST ACROSS ILLINOIS
AND MISSOURI INTO SOUTHEAST KANSAS.  DAMAGING WINDS AND LARGE HAIL
MAY BE NOTED WITH THE STRONGEST STORMS.

...UPPER GREAT LAKES TO SERN KS...

SIGNIFICANT MID-LEVEL HEIGHT FALLS...ON THE ORDER OF 30-60M...WILL
OVERSPREAD THE UPPER GREAT LAKES EARLY IN THE PERIOD...PRIMARILY IN
RESPONSE TO LEAD SHORT-WAVE TROUGH THAT WILL EJECT INTO ONTARIO BY
LATE AFTERNOON.  ASSOCIATED COLD FRONT IS EXPECTED TO EXTEND FROM
THE ARROWHEAD OF MN...SSWWD ACROSS CNTRL IA INTO CNTRL KS AT
DAYBREAK...ADVANCING TO A POSITION FROM THE U.P. OF MI...ACROSS SERN
IA INTO SERN KS BY LATE AFTERNOON.  FRONTAL CONVECTION WILL LIKELY
BE ONGOING AT THE BEGINNING OF THE PERIOD...ENHANCED IN LARGE PART
BY ASCENT AHEAD OF SHORT WAVE.  WHILE GUSTY WINDS AND ISOLATED LARGE
HAIL MAY BE NOTED WITH EARLY MORNING ACTIVITY...MORE SIGNIFICANT
CONVECTION IS POSSIBLE LATER IN THE DAY.

STRONGEST BOUNDARY-LAYER HEATING SHOULD BE NOTED ACROSS KS/SWRN MO
WHERE SFC TEMPERATURES WILL WARM INTO THE 90S.  AS A
RESULT...INSTABILITY IS EXPECTED TO BE GREATEST ALONG TRAILING
PORTIONS OF THE FRONT WHERE SBCAPE SHOULD BE ON THE ORDER OF 3000
J/KG.  EVEN SO...MODEST INSTABILITY IS EXPECTED TO DEVELOP ACROSS
THE MID MS VALLEY INTO THE UPPER GREAT LAKES DESPITE THE FRONTAL
CONVECTIVE DEBRIS AND SCT PRECIPITATION.  ALTHOUGH FORECAST LAPSE
RATES ARE NOT EXPECTED TO BE THAT STEEP...STRONG MID-LEVEL SPEED MAX
IS FORECAST TO DEVELOP WITHIN THE BASE OF THE TROUGH FROM NERN KS
INTO SWRN WI.  THIS SHOULD ENHANCE ORGANIZATIONAL POTENTIAL OF
FRONTAL CONVECTION.  ALTHOUGH FORECAST BULK SHEAR FAVORS
SUPERCELLS...CONVECTIVE MODE MAY BE MORE LINEAR IN NATURE DUE TO
EXPECTED FORCING NEAR THE COLD FRONT.  LARGE HAIL AND DAMAGING WINDS
ARE THE PRIMARY SEVERE THREATS.  FRONTAL CONVECTION SHOULD GRADUALLY
SPREAD DOWNSTREAM INTO THE LOWER OH VALLEY DURING THE OVERNIGHT
HOURS.

..DARROW.. 08/31/2014



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