Forecast Discussions mentioning any of "ACARS" "MDCRS" "AIRCRAFT" "TAMDAR" "AMDAR" "WVSS" received at GSD on 06/15/19

Area Forecast Discussion

National Weather Service Hastings NE

 644 PM CDT Fri Jun 14 2019

.SHORT TERM...(This evening through Saturday)
Issued at 331 PM CDT Fri Jun 14 2019

Aloft: Aircraft obs/WV imgry and RAP tropopause analyses showed
WNW flow over the CONUS with a rdg just off the W coast and a trof
along the E coast. A weak trof extended from MT-UT-Srn CA. This
trof will cont mvg ESE and cross NEB/KS tomorrow.

Surface: High pres was over the SE USA while a wavy front
extended acrs the Nrn USA to low pres over Srn SA. A wk cool front
extended SW from this low thru the Nrn Rckys. This low will mv
into ND by 12Z/Sat to near ABR by 00Z/Sun. As this occurs the wk
cool front will mv into NEB/KS tomorrow and dissipate. This front
will hv no effect other than to shift winds from S to NW.

Rest of this aftn: M/sunny over N-cntrl KS. P/sunny over S-cntrl
NEB as there are extensive patches of thick cirrostratus overhead
...plus a few stratocu.

Tonight: The aprchg trof will aid in initiating sct tstms over
the high plns of WY/CO once again this afternoon. The 12Z/HREF
indicates the most aggressive tstm dvlpmt will be over Wrn KS.
These storms should grow upscale into an MCS that mvs E...mostly
along and S of I-70. However...sct tstms will be psbl N of this
complex...all the way up to I-80. Interestingly...the 09Z/SREF
suggests higher rain probs over S-cntrl NEB than KS.

So basically we`re expecting isold-sct tstms mainly before
midnight then dcrsg clds toward dawn. There are a cpl HRRR
ensemble members that keep a few tstms going after midnight over
S-cntrl NEB.

These storms will be mvg into an corridor of mdt instability with
SREF MUCAPE 2000-3000 J/kg. Deep lyr shr will be 25-30 kt. With
the aprchg trof...this environment will be supportive of
tstms...some of which could be svr. Gvn that tstms will dvlp in
the deeply-mixed air to the W...the storms will be outflow
dominant and quickly form cold pools that will result in multicell
convective mode and the greatest potential for svr downburst
winds. Hail will be a secondary threat.

Sat: Probably dry and partly cldy. I do hv a very low 20% POP
from late morning thru afternoon just in case an isold tstm pops
up per the few mdls that output some QPF. There really isn`t much
lift/forcing.

SREF MLCAPE is fcst to range from 1500-3500 J/kg from NW-SE acrs
the CWA. Deep lyr shr will be 30-35 kt. So if something does dvlp
it could be svr...but the chance is very low that anything
actually forms.

.LONG TERM...(Saturday night through Friday)
Issued at 331 PM CDT Fri Jun 14 2019

Aloft: The last 2 runs of global mdls and the EC ens mean are in
good agreement that WNW flow will cont thru Wed before
transitioning to SW flow. The longwave flow will retrograde during
this time period as the low currently near the Aleutians is fcst
to mv thru SW Canada into the Nrn Rckys by next Thu-Fri.

Surface: A cool front will cross the CWA Sun followed by wk high
pres. Wk Canadian high pres will then take over Mon. It is fcst to
slide into the upr Midwest Tue. This means 3 days of upslope low-
lvl flow. A low pres will mv into SW Canada Wed with a warm front
dvlpg from MT-CO. This front will mv thru here Wed night...putting
the CWA into the warm sector of a deep low over the Canadian
Prairies. The associated cool front is then slated to mv thru
NEB/KS Fri.

Temps: Heights/thicknesses will average below normal resulting in
a continuation of very comfortable early summer wx (more
springlike than summerlike). Temps will be cooler than normal Sun-
Wed...with one day (probably Tue) much cooler than normal. Most
mdls are fcstg that parts of the CWA could see temps jammed in the
60s Tue. Our fcst is not indicating that yet...but it`s within
the realm of possibility.

Rain: Sct tstms will dvlp daily ovr the high plains of WY/CO and
the NEB panhandle. Some of these storms will survive and mv E into
the CWA. Tue into Tue night appears to be the best chance for
widespread rain.

&&

.AVIATION...(For the 00Z KGRI/KEAR TAFS through 00Z Saturday)
Issued at 625 PM CDT Fri Jun 14 2019

SHRAs and TSRAs are expected to develop across the area over the
next couple of hours and transition east overnight. Expect CIGS to
lower to near MVFR levels with this activity for a period of time,
although due to uncertainty in timing left a SCT 3KFT deck in the
TAFs for now and will amend as necessary based on CU development.
Otherwise, activity should come to an end before daybreak with
VFR conditions and winds shifting and becoming more westerly by
early afternoon when additional small chances for thunderstorms
will be possible - albeit very low probability.

&&

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

$$

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