Forecast Discussion
NWS Omaha/Valley, NE

786
FXUS63 KOAX 171729
AFDOAX

Area Forecast Discussion
National Weather Service Omaha/Valley NE
1229 PM CDT Wed Sep 17 2025

.KEY MESSAGES...

- Scattered off-and-on storms are expected across the entire
  area today. The best chance for widespread rain is this
  morning, but scattered storms will linger into the afternoon
  as well. There is a small chance for one or two severe storms.

- Another round of thunderstorms is expected on Thursday. Severe
  weather is once again unlikely.

- Cooler temperatures for the mid-to-late week in the 70s, with
  80s returning this weekend into early next week.

&&

.DISCUSSION...
Issued at 130 AM CDT Wed Sep 17 2025

A broad upper trough with multiple embedded vorticity maxima was
drifting every so slowly across the central and northern Plains
early this morning. It is worth noting that one of the embedded
short wave vort maximums was lifting northeast toward central
Nebraska. Two separate waves currently centered over northern
Colorado and the Yellowstone region will rotate around each
other over the next couple of days as they slowly drift east.

Current weather through this afternoon will be driven by this
first short wave trough and a frontal boundary draped across the
region. Early this morning, the front has been modified
significantly by convective outflow but generally stretches from
northwest KS into south central NE, and then up toward the SD/IA
state line. The low level jet this morning in advance of the
wave has been sufficiently strong to support continued
convective development, both along and north of the effective
front as well as in parts of the warm sector. Most Unstable CAPE
of 1000 J/kg is common across the area while deep layer shear is
not particularly impressive. Those MU parcels are weakly or even
uncapped, hence the scattered development. While there were a
few stronger updrafts this evening, instability has waned a bit
and believe it will be difficult for storms to become severe
from this point forward. The exception may be a linear segment
crossing through south central NE which may be capable of
producing some wind if it can force some momentum to the
surface. Forecast soundings and CAPE profiles ahead of this
system seem to favor elevated convection with weakening
instability as it progresses east, but can`t totally rule out
some wind.

As the day progresses and the center of the wave approaches,
there are indications in model guidance of some destabilization
around mid afternoon which may reinvigorate convection (although
the bulk of it may be east of the forecast area), and may also
provide a focused zone for additional development near the
center of the short wave. Hodographs in this area have a fair
amount of low level shear and turning. Would call this a highly
conditional scenario for a few severe storms, based largely on
the existence of surface based instability on the higher end of
the envelope of guidance...but if strong updrafts develop near
the upper circulation, shear profiles may favor some
organization with hail or even a non-zero tornado potential.
Again...highly conditional.

The abundance of model guidance is surprisingly consistent in
the predominant circulation tracking into north central NE or SD
by Thursday morning and lifting north while the Yellowstone vort
rotates around the south side and ejects into eastern Nebraska
Thursday into early Friday. Right now, it looks like slightly
drier air will cover much of the area tonight into the first
part of Thursday, with the exception perhaps being in the
southeast part of the forecast area where showers or storms may
track through. Later Thursday into Thursday evening then looks
like another better chance for scattered thunderstorms.
Intensity of the storms will lie in the details of daytime
heating, but could again see a few strong ones. Scattered
showers or a storm may continue into Friday over the eastern
areas, but will finally see a weather pattern change by the
weekend. Much of the weekend looks to be dry, but with a few
low-end chances for rain. Better rain chances return when a fast
moving short wave crosses the northern Plains on Monday. This
system will be followed by a period of upper ridging.

&&

.AVIATION /18Z TAFS THROUGH 18Z THURSDAY/...
Issued at 1221 PM CDT Wed Sep 17 2025

Showers and isolated thunderstorms continue to lift towards the
northeast early this afternoon. Ongoing rainfall will slowly
weaken and end early this afternoon. OFK is nearest the
approaching low pressure system resulting in lower MVFR
ceilings currently. Elsewhere, VFR conditions are expected to
remain prevailing. Winds are generally light and southeasterly,
but these gradually veer throughout the day. Additional
afternoon and evening scattered showers and isolated
thunderstorms may develop, but confidence is low (10-40%). With
low confidence and scattered coverage of this activity, will
not mention in the TAF at this time. Fog may develop during the
morning hours between 10-14Z, but this is towards the end of the
forecast and confidence remains low. Will continue to monitor
for later TAF forecasts.

&&

.OAX WATCHES/WARNINGS/ADVISORIES...
NE...None.
IA...None.

&&

$$

DISCUSSION...Barjenbruch/Petersen
AVIATION...Chehak

NWS OAX Office Area Forecast Discussion

Forecast Discussion
NWS Hastings, NE

328
FXUS63 KGID 171740
AFDGID

Area Forecast Discussion
National Weather Service Hastings NE
1240 PM CDT Wed Sep 17 2025

.KEY MESSAGES...

- Cooler temperatures for the remainder of the work week with
  off and on isolated to scattered showers and thunderstorms.

- Organized severe weather is not expected, but a few strong
  storms with small hail, gusty winds, and heavy downpours will
  be possible south/southeast of the Tri-Cities late this
  afternoon and into the evening.

- Mainly dry and warmer (widespread 80s) for the weekend, though
  chances for showers and thunderstorms aren`t completely zero.

- Near to above normal temperatures favored to continue through
  next week with no signs of significant/sustained cool-down
  anytime soon.

&&

.DISCUSSION...
Issued at 435 AM CDT Wed Sep 17 2025

Thunderstorms have been on a distinct downward trend over the
past 1-2 hours, in both intensity and coverage, as outflow from
last evening`s strong makes quick progress well SE of the area.
Water vapor imagery suggests a narrow zone of large scale
subsidence should ease into the area from the W/SW this morning.
However, isolated to scattered showers and weak thunderstorms
could percolate off and on just about anywhere through late
around midday thanks to modest low level warm aid advection
from a veering low level jet. Additional weak perturbations
emanating from the broader upper trough over the central
Rockies could also provide sufficient lift for new development.
Anything we see this morning won`t be nearly as strong or
widespread as what we saw late last evening.

By late afternoon, expect at least SOME clearing to work it`s
way into the area - particularly into areas from the Tri-Cities,
W and SW. Latest hi-res guidance has come around to the idea
that the primary instability axis will setup a bit further S
than expected 24 hrs ago, so appears the greatest potential for
organized convection during the late aftn-eve will be across
central into eastern KS along and S of I-70. Nonetheless,
appears some potential will still linger further N into our
area, though this will probably be predicated on actually seeing
some of that aforementioned W to E clearing. CAMs generally
depict the area from York to Superior to Osborne and points S
and E from there as having the best chance for this aftn/eve
development. IF the clearing materializes, then lingering
seasonably rich low level moisture and modest ~25kt deep layer
shear could support a few pulsey strong storms and small hail.
Lack of stronger shear and better mid level lapse rates should
preclude anything real organized in our forecast area. Clouds
and recycled rain-cooler air should keep temps a solid 10-15 deg
cooler than yesterday.

Primary upper trough will only SLOWLY edge eastward over the
next few days...so will continue to see off and on, mainly
isolated to widely scattered, shower and thunderstorm chances
through the end of the work week. With that said, overall trend
has been for generally lesser coverage and lower chances than
anticipated 24-48 hours ago. This appears to be due, in part,
by a more notable mid level dry slot. It`s becoming increasingly
probable that geographically we`ll be split between the primary
deformation/wrap-around moisture to the N, and the greatest low
level moisture/instability to the S/SE. Still favor at least
20-30 PoPs for the daytime Thu, but it just seems activity will
favor more of and "heating of the day/popcorn" type variety and
limited coverage. Some of the experimental NSSL CAMs also
indicate some potential for narrow lines/waves of convection
associated with MCVs/vort lobes to rotate through the area W to
E during the overnight hours...but confidence on specific
timing, placement, and coverage is LOW. Being on the backside of
the upper low to the N will continue to favor mostly 70s for
highs on Thursday. Same general pattern continues into Friday
but with even slimmer (though still non-zero) rain chances.

Weakening/departing upper trough will allow for rebounding
temperatures over the weekend with highs returning into the 80s
each day. In fact, Sunday could be quite warm and humid again
with favored warm spots perhaps making a run into the low 90s.
Despite some shortwave ridging, I`m hesitant to say the weekend
will remain completely dry as I just don`t trust the somewhat
"dirty" zonal to NW upper flow. Various models indicate as least
one or two weak shortwaves moving through over the weekend, but
my confidence on exactly when and where is NOT high. Just kind
of one of those patterns where we`ll have to keep an eye on
potential for PoPs to incr.

Deterministic and ensemble guidance are in rough agreement of
another upper trough sometime early next week, but vary widely
on the overall magnitude. This trough will be of Pacific origin,
so don`t expect an overly strong cold front with it, which
should favor a continuation of mostly near to above normal
temperatures next week.

&&

.AVIATION /18Z TAFS THROUGH 18Z THURSDAY/...
Issued at 1235 PM CDT Wed Sep 17 2025

For KGRI/KEAR Airports:

Showers with a possible thunderstorm are expected across the
area this afternoon. Ceilings are expected to improve by this
evening but may drop again by 06z. Some light fog is also
possible tonight. There is uncertainty with regard to how low
ceilings and/or visibilities will drop tonight. Winds will
generally range from the southwest to northwest.

&&

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

&&

$$

DISCUSSION...Thies
AVIATION...Schuldt

NWS GID Office Area Forecast Discussion