Severe Storm Outlook Narrative (AC)
Issued by NWS

Home | Current Version | Previous Version | Text Only | 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 290049
SWOMCD
SPC MCD 290049
IAZ000-MNZ000-SDZ000-NEZ000-290215-

MESOSCALE DISCUSSION 1632
NWS STORM PREDICTION CENTER NORMAN OK
0749 PM CDT THU AUG 28 2014

AREAS AFFECTED...EXTREME PORTIONS OF SERN SD...NERN NEB AND NWRN IA

CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY

VALID 290049Z - 290215Z

PROBABILITY OF WATCH ISSUANCE...5 PERCENT

SUMMARY...A BRIEF TORNADO CANNOT BE RULED OUT ACROSS FAR SERN SD AND
POTENTIALLY INTO PORTIONS OF ADJACENT NERN NEB AND NWRN IA THROUGH
ABOUT 02Z.  GIVEN AN OVERALL MARGINAL THREAT AND LIMITED
SPATIOTEMPORAL RISK AREA...A WATCH IS NOT WARRANTED THIS EVENING.

DISCUSSION...EARLY EVENING SURFACE ANALYSES SHOWED A WARM FRONT OR
QUASI-STATIONARY BOUNDARY EXTENDING NEWD FROM AN AREA OF LOW
PRESSURE LOCATED OVER CENTRAL NEB INTO FAR SERN SD /BON HOMME AND
YANKTON COUNTIES/ AND THEN EWD THROUGH LINCOLN COUNTY SD AND EXTREME
NRN IA NEAR THE MN BORDER.  MEANWHILE...ADDITIONAL STORMS WERE
TENDING TO BECOME QUICKLY UNDERCUT BY AN OUTFLOW-ENHANCED EWD-MOVING
BOUNDARY FROM NEAR AND NORTH OF THE NEB SURFACE LOW NEAR MITCHELL
SD.  A MARGINAL SEVERE WEATHER THREAT BE FOCUSED INVOF THE
QUASI-STATIONARY BOUNDARY IN FAR SERN SD WHERE OBJECTIVE ANALYSES
INDICATED A CONCENTRATED CORRIDOR OF SURFACE VORTICITY AND 0-3 KM
MLCAPE OF 100-125 J/KG...ENHANCING THE POTENTIAL FOR LOW-LEVEL
STRETCHING AND TORNADO POTENTIAL.  MODEST DEEP-LAYER SHEAR WILL
CONTINUE TO LIMIT STORM ORGANIZATION AND THE NEED FOR A WATCH.
EVENTUAL STABILIZATION OF THE BOUNDARY LAYER WITH THE LOSS OF
DAYTIME HEATING IS EXPECTED TO RESULT IN A DIMINISHING TREND OF THIS
LOW TORNADO PROBABILITY.

..PETERS/EDWARDS.. 08/29/2014

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

ATTN...WFO...FSD...OAX...LBF...

LAT...LON   42719849 43319761 43529652 43369594 42969612 42739725
            42279854 42369873 42719849




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