Area Forecast Discussion
Issued by NWS Hastings, NE

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FXUS63 KGID 260922

Area Forecast Discussion
National Weather Service Hastings NE
422 AM CDT Fri May 26 2017

.SHORT TERM...(Today and tonight)
Issued at 355 AM CDT Fri May 26 2017

A few light showers or sprinkles behind last nights convection are
lingering across the local area this morning. Expect this activity
to rapidly diminish over the next hour or two and for dry
conditions to prevail across the local area through the daytime
hours. In addition...with clearing skies and seasonable
temperatures forecast...expect a fairly nice afternoon across the
local area...although it could be a bit breezy as northerly winds
behind a weak frontal boundary invade the local area.

For tonight...the local area remains in a marginal or slight risk
for severe weather from the storm prediction center. With only
modest shear and very marginal instability in place across the
region...convection overnight is a bit in question...and will be
largely driven by an upper level disturbance riding in from the
west. With fairly good agreement in models tracking this wave
across the local area after midnight...could not ignore the
potential for storms overnight...and continued with likely
coverage across the local area through the very early morning
hours Saturday.

While overall...models are in fair agreement tracking a cluster
of storms across the local area after midnight...some models -
including the 00Z WRF...have little to no capped
chances at 70% which seemed reasonable considering differing
solutions and fairly marginal instability in place to work with.
Given the set-up...if storms do develop - as expected - and track
across the local area...more than likely strong winds associated
with the passing squall will be the biggest threat for severe
weather during the late night hours tonight.

.LONG TERM...(Saturday through Thursday)
Issued at 355 AM CDT Fri May 26 2017

Aloft: The shortwave trof referenced above will approach the CWA
Sat and then cross the CWA Sat night. Cyclonic NW flow will then
prevail thru Wed. The low currently over the Canadian Prairies
will become blocked invof Hudson Bay. Svrl vort max will orbit
around this low...providing a couple reinforcing shots of cooler
air. The EC/EC ens mean and the 00Z/25 GEFS Reforecast agree on
deamplification Thu with slackening/ weak flow.

Surface: The cool front currently crossing the CWA will be well to
the E and S Sat...extending from WI-MO-OK. Wrn USA high pres will be
building into the CWA. A subtle cool front will move thru Sun night
into Mon followed by weakening Canadian high pres that will drop
into the Plns Tue. The cool front will become stationary just W of
the CWA but begin to drift back E as a warm front Tue night into Wed
as high pres departs to the E. The warm front will cont to lift to
the N and E Thu putting the CWA in the warm sector.

Temps: Much cooler than normal (by roughly 10F) then near or
slightly cooler than normal Sun-Thu.

Rain: Clusters of multicell tstms should be on-going over parts of
the CWA at dawn Sat. Some hvy downpours are likely where they occur.

Thereafter the fcst is littered with low chances of shwrs/tstms
mainly based on the GFS which is aggressive in dumping QPF in every
single time period. It is probably overdone given minimal or
marginal moisture. the week progresses return flow S of
the front will gradually allow moisture to advect N and increase.
The CWA will be on the Nrn fringe of this moisture and the resultant
instability. Upslope flow into the higher terrain to the W along
with weak convergence near the front should allow for some tstm
development. With a lack of forcing aloft though...any tstms will be
very isolated/spotty. Would not expect tstm coverage to increase
until Wed night and Thu as the low-lvl jet gets involved.

No big svr wx threats are envisioned.


.AVIATION...(For the 06Z KGRI/KEAR TAFS through 06Z Friday)
Issued at 1235 AM CDT Fri May 26 2017

VFR conditions will prevail through the period with clearing skies
overnight and generally light and variable winds. Expect
increasing northerly winds during the late morning hours as a
reinforcing cold front sinks across the terminals bringing back
northerly winds through the afternoon hours as this frontal
boundary sinks into Kansas. Late in the day could see some
increasing mid/upper level cloud cover ahead of convection rolling
off the high plains...but think any precipitation and any
potentially reduced CIGS/VSBYS will come beyond the current valid
periods of the TAFS.




LONG TERM...Kelley
AVIATION...Rossi is the U.S. government's official web portal to all federal, state and local government web resources and services.