Severe Thunderstorm Warning 238, NWS Hastings, NE

Area Forecast Discussion
National Weather Service Hastings NE
139 AM CDT Sun Aug 27 2017

.SHORT TERM...(Today and tonight)
Issued at 138 AM CDT Sun Aug 27 2017

Aloft: NW flow will become almost due N tonight as a ridge and
large subtropical high lodges over the Wrn USA with a trof over
the E. WV imagery shows a shortwave trof over the Dakota's. The
tail end of this trof will cross the CWA today.

Surface: A very subtle cool front was dropping S thru Neb. It
should be into Nrn KS by midday and to near I-70 by sunset. High
pres will then build over the rgn tonight.

At 06Z a couple strong-svr tstms were in progress over the
Sandhills and rgnl 88D mosaic and IR satellite shows tstms have
been increasing over the last 3 hrs. Models are in excellent
agreement that these storms will cont SSE into the CWA thru the
rest of the overnight hrs and into Sun AM.

RAP mesoanalysis indicates 2000-3000 J/kg of MUCAPE. With low-lvl
easterlies...deep layer shear is very strong (exceeding 40 kts).
We have already seen an elevated supercell. SPC is monitoring the
rgn for a possible svr tstm watch. The main question is will these
storms maintain their potency as they drop SSE overnight.

Given impending tstms...plan to keep this product short.

Tstms exit the CWA probably by midday. Late afternoon
redevelopment is unlikely as the front will be S into KS.

Main fcst concerns for today is how much debris cloudiness will
linger behind the tstms?

Also concerned about patchy fog potential late Sun night into Mon
AM.

.LONG TERM...(Monday through Saturday)
Issued at 138 AM CDT Sun Aug 27 2017

Dry and quiet wx in NNW or NW flow as a ridge dominates over the
Wrn USA with a trof in the E. Slightly cooler than normal temps
Mon-Tue...then near normal Wed-Fri. Possibly a little above normal
Sat. This week will cont the incredibly comfortable pattern that
has dominates since late July.

&&

.AVIATION...(For the 06Z KGRI/KEAR TAFS through 06Z Monday)
Issued at 1230 AM CDT Sun Aug 27 2017

Significant Wx: Brief IFR TSRAs possible until 15Z.

Overnight: VFR multi-layered clds as sct shwrs/tstms are
developing and/or moving in. There could be a period of IFR VSBYs
in +TSRA but there isn't enough certainty to include in the TAFs
yet. Winds will be lgt from the E-SE except near TSRAs which could
produce G40KT. Confidence: Low

Sun: TSRAs could linger into the AM hrs...then probably with
decreasing clouds. However...it is very uncertain how much
cloudiness will remain in the wake of any storms...but a period of
MVFR CIGs is possible. NE-ENE winds around 10 kts. Confidence: Low

Sun Eve: VFR with a few altocu possible around 9K ft. Winds
becoming lgt/vrbl. There may be some fog issues after 06Z. Further
assessment will be necessary for the 12Z TAFs. Confidence: Medium

&&

.GID WATCHES/WARNINGS/ADVISORIES...
NE...None.
KS...None.
&&

SHORT TERM...Kelley
LONG TERM...Kelley
AVIATION...Kelley

Hazardous Weather Outlook...UPDATED
National Weather Service Hastings NE
200 AM CDT Sun Aug 27 2017

KSZ005>007-017>019-NEZ039>041-046>049-060>064-072>077-082>087-
280700-
Phillips-Smith-Jewell-Rooks-Osborne-Mitchell-Valley-Greeley-Nance-
Sherman-Howard-Merrick-Polk-Dawson-Buffalo-Hall-Hamilton-York-
Gosper-Phelps-Kearney-Adams-Clay-Fillmore-Furnas-Harlan-Franklin-
Webster-Nuckolls-Thayer-
200 AM CDT Sun Aug 27 2017

This Hazardous Weather Outlook is for south central Nebraska and
portions of north central Kansas.

.DAY ONE...Rest of Tonight.

Scattered thunderstorms are likely and some storms could be
severe. The main threat will be hail up to 2 inches in diameter...
but isolated pockets of damaging winds could also occur.

.DAYS TWO THROUGH SEVEN...Sunday through Friday.

Scattered thunderstorms will continue into Sunday morning but
should exit the area by early afternoon. Some of these storms
could be severe...with hail up to the size of golf balls the main
threat.

.SPOTTER INFORMATION STATEMENT...

Spotters...please relay reports of hail and wind damage to the
National Weather Service.

&&

More information may be obtained at the following web page:
   https://www.weather.gov/hastings

Kelley