Severe Storm Outlook Narrative (AC)
Issued by NWS

Current Version | Previous Version | Graphics & Text | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
000
ACUS11 KWNS 231426
SWOMCD
SPC MCD 231425
MNZ000-SDZ000-NDZ000-231700-

MESOSCALE DISCUSSION 1368
NWS STORM PREDICTION CENTER NORMAN OK
0925 AM CDT SAT JUL 23 2016

AREAS AFFECTED...PORTIONS OF CNTRL/ERN ND...NERN SD...WRN MN

CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE

VALID 231425Z - 231700Z

PROBABILITY OF WATCH ISSUANCE...40 PERCENT

SUMMARY...CONVECTION SPREADING ACROSS PARTS OF CNTRL ND WILL HAVE
THE POTENTIAL TO EXPAND IN COVERAGE AND INCREASE IN INTENSITY
THROUGH THE LATE MORNING/EARLY AFTERNOON AS IT SPREADS EWD. WITH A
POSSIBLE INCREASE IN THE SVR-TSTM POTENTIAL...IT IS POSSIBLE THAT
THIS COULD WARRANT WW ISSUANCE DURING THE NEXT FEW HOURS.

DISCUSSION...CONVECTION HAS RECENTLY SHOWN SIGNS OF INTENSIFICATION
AND QUASI-LINEAR ORGANIZATION ACROSS PARTS OF CNTRL ND WITHIN A
PLUME OF DCVA -- PRECEDING A MID-LEVEL SHORTWAVE TROUGH CROSSING
SASKATCHEWAN AND MONTANA PER WATER-VAPOR IMAGERY. THIS ACTIVITY WILL
CONTINUE SPREADING GENERALLY EWD THROUGH THE MORNING HOURS AND
PERHAPS INTO THE EARLY AFTERNOON...AMIDST RELATIVELY RICH LOW-LEVEL
MOISTURE -- E.G. SFC DEWPOINTS IN THE MIDDLE 60S TO LOWER 70S. GIVEN
MODERATELY STEEP MID-LEVEL LAPSE RATES SAMPLED BY THE 12Z BIS
RAOB...AMPLE ELEVATED BUOYANCY IS IN PLACE AMIDST 30-45 KT OF
EFFECTIVE SHEAR.

IT IS POSSIBLE THAT IT WILL TAKE ONLY MODEST DIURNAL DIABATIC SFC
HEATING FOR CONVECTION TO BE MAINTAINED/FURTHER INCREASE IN
INTENSITY AS IT SPREADS EWD...WITH SWD DEVELOPMENT ALSO POSSIBLE.
HOWEVER...WIDESPREAD/RELATIVELY DENSE CLOUD CANOPIES -- WITH ONLY
LIMITED AREAL COVERAGE OF MORE TRANSLUCENT CLOUDS -- SHOULD STUNT
DIURNAL LOSSES OF BOUNDARY-LAYER STATIC STABILITY. AS SUCH...THERE
IS CONSIDERABLE UNCERTAINTY REGARDING THE PROPENSITY FOR DOWNDRAFTS
TO REACH THE SFC IN SUPPORT OF SVR WIND GUSTS. NEVERTHELESS...THE
BUOYANCY/VERTICAL-SHEAR PARAMETER SPACE WILL SUPPORT SOME SVR
WIND/HAIL RISK DURING THE NEXT FEW HOURS. SEASONABLY STRONG H5
HEIGHT FALLS -- AROUND 40-60 GEOPOTENTIAL METERS PER 12 HOURS --
ACROSS THE N-CNTRL CONUS SUGGEST THAT BACKGROUND LARGE-SCALE ASCENT
WILL BE PRESENT FOR ENHANCED CONVECTIVE COVERAGE.

..COHEN/WEISS.. 07/23/2016

...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...

ATTN...WFO...FGF...ABR...BIS...

LAT...LON   46689984 47529911 47889750 47559642 46919600 45979624
            45779785 45999964 46689984




USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.