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
000
ACUS11 KWNS 132018
SWOMCD
SPC MCD 132018
SDZ000-NEZ000-KSZ000-132215-

Mesoscale Discussion 1488
NWS Storm Prediction Center Norman OK
0318 PM CDT Sun Aug 13 2017

Areas affected...Much of central Nebraska...south central South
Dakota...northwest Kansas

Concerning...Severe potential...Watch likely

Valid 132018Z - 132215Z

Probability of Watch Issuance...80 percent

SUMMARY...A cluster of storms capable of very large hail and
damaging winds is expected to form over the next several hours over
north central Nebraska, shifting southward with time. Other storms
are possible into South Dakota with hail.

DISCUSSION...Strong heating continues across much of western and
central NE south of a front/wind shift. Meanwhile, extensive low
clouds persist over eastern NE into southeast SD, but gradual
erosion from the south/west continues.

Strong instability is in place from south central SD southward
across NE and into KS, with steep lapse rates aloft. Ample northwest
flow aloft exists with a low-amplitude shortwave trough. Hodographs
are further being lengthened by 20 kt southerly 850 mb flow.

Rapid TCU formation is now underway near the wind shift across NE,
with storm initiation expected over the next hour. Conditions will
favor right-moving supercells capable of very large hail, as well as
damaging winds. A brief tornado cannot be ruled out with any
supercells across NE initially prior to any cell/outflow mergers.

..Jewell/Guyer.. 08/13/2017

...Please see www.spc.noaa.gov for graphic product...

ATTN...WFO...FSD...OAX...GID...LBF...UNR...GLD...

LAT...LON   40459913 40139940 39829993 39800047 39960091 40410156
            41180177 41460164 41930149 42270088 42889999 43349943
            43759896 43779881 43729826 43429806 43059810 42369847
            41479882 40789902 40459913




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