DAY1SVR: Day 1 Convective Outlook

ACUS01 KWNS 250100
SWODY1
SPC AC 250058

DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0758 PM CDT SAT AUG 24 2013

VALID 250100Z - 251200Z

...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF ERN ND AND NRN
MN...

...ERN ND/NRN MN...
AN UPPER HIGH ALOFT WILL REMAIN CENTERED OVER MO INTO ERN KS...WITH
THE E-W EXPANSE OF THIS HIGH EXTENDING FROM THE OH VALLEY AND SRN
APPALACHIANS TO THE SRN ROCKIES. WATER VAPOR IMAGERY SHOWED A
MIDLEVEL SHORTWAVE TROUGH...CURRENTLY MOVING ENEWD THROUGH SERN
MANITOBA/NWRN MN...WITH THIS FEATURE EXPECTED TO PROGRESS EWD ALONG
THE INTERNATIONAL BORDER...REACHING WRN LAKE SUPERIOR AND ADJACENT
ONTARIO REGION BY 12Z SUNDAY. WEAK HEIGHT FALLS EXPECTED ACROSS NRN
MN THIS FORECAST PERIOD AND SUBSEQUENT RESPONSE BY THE MASS FIELDS
WITH A STRENGTHENING SWLY LLJ EXTENDING FROM ERN SD TO NRN MN AND
THE UPPER GREAT LAKES WILL RESULT IN AN INCREASE IN LOW LEVEL WAA.

THESE FACTORS COMBINED WITH STEEP MIDLEVEL LAPSE RATES /PER 00Z
SOUNDINGS OVER THE DAKOTAS AND MN/ SPREADING EWD AND DPVA PER THE
AFOREMENTIONED IMPULSE AND SOME INFLUENCE FROM AN UPSTREAM TROUGH
MOVING ACROSS ND TONIGHT WILL SUPPORT ADDITIONAL STORMS...MAINLY
OVER NRN MN. HOWEVER...SOME POTENTIAL FOR STORM DEVELOPMENT WILL
REMAIN ACROSS ERN ND WITHIN ZONE OF LOW LEVEL CONVERGENCE ALONG A
WIND SHIFT...WHICH EARLY THIS EVENING EXTENDED FROM FAR NWRN MN
THROUGH ERN ND TO NORTH CENTRAL-WRN SD. THUS...THIS OUTLOOK WILL
MAINTAIN A SLIGHT RISK OVER ERN ND...WITH AN EXPANSION EWD SOME OVER
NORTH CENTRAL/NERN MN. THE LAST SEVERAL RUNS OF THE HRRR AND SOME
MEMBERS OF THE SREF FAVOR THE POTENTIAL FOR A BOW /ATTENDANT WIND
THREAT/ TO SPREAD ACROSS NRN MN THIS EVENING...WITH SOME THREAT
EXTENDING ESEWD INTO THE UPPER GREAT LAKES /5 PERCENT SVR WIND/HAIL
POTENTIAL/. RESIDUAL MODERATE INSTABILITY AND DEEP LAYER WINDS/SHEAR
BECOMING UNIDIRECTIONAL AS THE LLJ VEERS TO WLY TONIGHT SHOULD FAVOR
LINES/BOWING SEGMENTS...MAINLY ACROSS THE SLIGHT RISK AREA IN NRN
MN.

...LOWER CO RIVER VALLEY THROUGH UT TO THE NRN ROCKIES...
A FEW LINGERING STRONG TO POTENTIALLY SVR WIND GUSTS REMAIN POSSIBLE
ACROSS THESE AREAS...ESPECIALLY WHERE POCKETS OF MODERATE
INSTABILITY PERSIST. HOWEVER...RECENT CAPPI IMAGERY AND LIGHTNING
DATA SUGGESTED A DIMINISHING TREND IN STRONGER/SUSTAINED UPDRAFTS.
THE COMBINATION OF CONVECTIVE OVERTURNING AND/OR THE ONSET OF
BOUNDARY LAYER COOLING/STABILIZATION SHOULD MAINTAIN THIS DECREASE
IN SVR WEATHER POTENTIAL.

..PETERS.. 08/25/2013

+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-
To unsubscribe from WX-STORM send e-mail to LISTSERV@LISTSERV.ILLINOIS.EDU with
"unsub wx-storm" in the body of your message. For more information write cnovy@cox.net.