Forecast Discussions mentioning any of "ACARS" "MDCRS" "AIRCRAFT" "TAMDAR" "AMDAR" "WVSS" received at GSD on 01/03/20

AREA FORECAST DISCUSSION

National Weather Service Hastings NE

 621 PM CST Thu Jan 2 2020

.SHORT TERM...(Now through Friday)
Issued at 1219 PM CST Thu Jan 2 2020

Aloft: Aircraft winds along with WV imagery and RAP tropopause
analyses indicated a deep trof from the Nrn Plns to Nrn MX...with
a moderate-amplitude ridge over the Ern USA and a high-amplitude
ridge off the W Coast. The trof will slowly migrate acrs NEB/KS
tonight into Fri morning...and it will be E of the CWA by 18Z/Fri.
This will shift winds from W to NW. A shrtwv trof currently over
AB will dive SE into the Nrn Plns tomorrow and strengthen.

Surface: 992 mb low pres was near Lk Superior. The wk cool front
associated with this low moved thru the CWA this morning...and wk
1009 mb high pres was over NEB. This high will be overtaken by a
stronger 1020 mb high rapidly sliding down the lee side of the
Rckys tonight and tomorrow. Meanwhile...a small/wk low pres sys
will form over the Nrn Plns and the sfc low will be near MSP by
00Z/Sat.

This afternoon: Variable sky. Highs will range from 40-47F with
about 40F in the Tri-Cities. Some occasional gustiness will add a
chill in the air at times. Otherwise...a pretty nice day where sun
prevails.

Tonight: Variable sky. Clear at times...then partly-mostly cldy
after 06Z as some 5-10K ft clds streak SE acrs the CWA. Another
relatively mild night with lows in the 20s.

Fri: Mostly sunny. Blustery...espcly E of Hwy 183. NW winds will
gust up to 30 kt. The GFS is even more aggressive with G35 kt psbl
due to its stronger low-lvl winds. NAM isn`t as aggressive...but
be aware that winds could be a tad higher than we`re currently
advertising...if the GFS is right.

Near normal temps with highs 32-42F from N-S. Around 35F in the
Tri-Cities.

.LONG TERM...(Friday night through Thursday)
Issued at 1219 PM CST Thu Jan 2 2020

Aloft: The flow will remain progressive and low-amplitude thru
next Thu...but there will be a trend toward increased amplitude
mid-next week. The ridge currently off the W coast will move E and
deamplify as it crosses the Plns Sat. A wk shrtwv trof will
follow Sat night. Another trof will move in from the Pac and cross
the rgn Mon. This trof is fcst to amplify some...espcly as it
heads E Mon-Tue. A moderate-amplitude ridge will arrive over the
plns Wed...with another more significant trof fcst to envelop the
Wrn USA.

Surface: The cool front associated with the MN low (see above)
will sink thru NEB/KS Fri night. A strong low will form over AB
Sat. The burst of downslope flow will induce warm frontogenesis.
This front will cross the CWA Sat afternoon. The CWA will not be
in the warm sector long as the cool front will move thru Sat
night...as the sfc low heads E acrs Srn Canada. High pres arrives
Sun. A stronger cold front will cross the CWA Mon night or Tue...
but the core of the coldest air will miss and stay E of the rgn.
The next low pres sys to affect the rgn is slated for next Thu.

Temps: cont to average slightly warmer than normal by a few degs.

Precip: Nothing of significance...and little of insignificance.
Just an outside chance for some light flurries centered around Fri
night and then flurries or sprinkles Mon. Neither of these are in
the fcst yet due to mdl uncertainty...but may need to be added.

Arctic Cold and the Pattern: Temps have averaged much warmer than
normal since mid Nov. Temps typically swing back-and-forth
between warmer and colder than normal on 30-60 day cycles. So we
are nearing the end of this warm cycle. We have been seeing high-
confidence signals in the ensembles that a pattern change is
coming. We`ve seen multiple runs of the EC/GFS/CMC/JMA (Japanese)
ensembles and the the CFS mdl that the PNA pattern will become
strongly negative which is a high-amplitude ridge over the E Pac
and trof over the Wrn USA. This allows Arctic air to drain into
the Wrn USA and Cntrl/Nrn Plns.

So believe much colder wx is on the way...espcly as we get past
Jan 10th.

&&

.AVIATION...(For the 00Z KGRI/KEAR TAFS through 00Z Friday)
Issued at 557 PM CST Thu Jan 2 2020

The primary aviation issue will continue to center around the
strong low level wind shear expected late tonight developing
around 10Z and persisting through mid morning.

Ceilings and visibility should remain VFR throughout the period.
We do expect increasing clouds late tonight then clearing out
again by mid morning with mostly sunny skies throughout much of
Friday.

The wind will be gusty by late Friday morning and remain gusty out
of the west northwest. Some gusts could reach to around 35 mph.

&&

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

$$

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