810
FXUS63 KGID 210819
AFDGID

Area Forecast Discussion
National Weather Service Hastings NE
319 AM CDT Fri Aug 21 2026

.KEY MESSAGES...

- Isolated to scattered storms (possibly some severe), are
  expected to move through the area during the daytime today
  (mainly 11am to 4pm).

- Another round of strong to severe storms may redevelop this
  evening into tonight (roughly 10pm to 2am).

- The daytime of Saturday should remain dry, but weakening
  showers/storms arrive from the west late Saturday night into
  Sunday morning.

&&

.UPDATE...
Issued at 318 AM CDT Fri Aug 21 2026

The main concern in the near term is the potential for multiple
rounds of storms today into tonight. Unfortunately, confidence
in exact details remain quite uncertain due to high variability
in the CAMs.

Recent satellite depicts a slowly increasing area of midlevel
clouds over western Nebraska into southwest South Dakota in
association with weak warm-air advection. CAMs generally favor
this to continue to develop through the morning hours.
Unfortunately, there is not much agreement on the spatial
coverage, intensity, or exact timing. The 00Z HRRR depicted a
relatively robust line of storms in the 11am to 3pm timeframe,
but the 06Z run has backed off on this considerably. IF storms
develop, convective parameters would support large hail and
damaging wind.

The potential for severe convection late this evening into
tonight largely depends on how things play out during the
daytime today. Unsurprisingly, the 00Z HRRR is much more
reserved with evening development as the daytime convection
would help stabilize a large portion of the area. Of course, the
06Z run has "flipped the script," with the decreased daytime
coverage resulting in more widespread and intense thunderstorms
late in the evening and overnight.

After any lingering showers/storms depart the area Saturday
morning, the rest of the daytime looks to be dry and pleasant.
Chances for thunderstorms return late Saturday night into
Sunday morning as convection rolls out of Colorado/Wyoming. That
said, this is likely to be on a weakening trend as it
approaches the area in the 1-3am timeframe.

&&

.DISCUSSION...
Issued at 128 PM CDT Thu Aug 20 2026

TODAY
Weak convergence amid the NW flow aloft will allow for clear
skies and highs to increase into the 80s-low 90s this afternoon.
Within this flow aloft is a shortwave disturbance along the
MN/Canadian border, supporting a weak surface low and a weak cold
front stretched across the Dakotas. This front is expected to
move southward, potentially forcing some isolated thunderstorms
into central Nebraska after 4PM, suggested by earlier model
guidance. However, it is uncertain how far the cold front will
make it given the marginal upper-level support. In fact, recent
HRRR and RRFS guidance hast this front stalling out in Northern
Nebraska, keeping thunderstorm chances limited to North of I80.
Should a thunderstorm form, CAPE values around 2000-2500 J/kg
and shear in excess of 40 kts could allow some strong to severe
storms, with main hazards being golf ball sized hail and strong
wind gusts of 60+ MPH. While a few thunderstorms are possible,
most of the area will remain dry this evening.

TOMORROW (Friday)
While not overly confident, there is a chance of
fog tomorrow morning, mainly for the eastern half of the area, with
ample low-level moisture and weak surface winds. However, model
guidance is not as aggressive with this fog as they were this
morning. The main uncertainty is the coverage of these evening
storms and if skies are able to clear for sufficient radiative
cooling. Additionally, showers/thunderstorms are possible
(15-25%) for the NE portions of the area tomorrow morning
between 3-8AM due to some weak WAA advection at 850 mb. A few of
these may be on the strong to severe side. Tomorrow afternoon
is expected to be clear and dry, allowing highs to peak in the
upper 80s to mid 90s.

Additional thunderstorms are possible tomorrow during the evening to
overnight hours. Recent model guidance suggests isolated
thunderstorm development to the North-Northwest of the area around 6-
8PM, congealing into a complex somewhere over the area. Some of
these storms may be strong to severe, as models are indicating 2500+
J/kg of SBCAPE and 45+ kt of 0-6km shear. However, the location and
timing of this thunderstorm development remains uncertain.

SATURDAY AND BEYOND
As the upper level ridge continues to expand
across the intermountain west, mostly dry conditions are
expected Saturday, with highs in the 80s. However, the chance
for showers/thunderstorms returns Saturday night into Sunday
morning as a weak shortwave emerges from the NW flow aloft.
Additional off and on showers/thunderstorms are possible into
early next week as a broader trough approaches from the West.

&&

.AVIATION /06Z TAFS THROUGH 06Z SATURDAY/...
Issued at 1158 PM CDT Thu Aug 20 2026

For KGRI/KEAR Airports:

Scattered thunderstorms possible throughout TAF period, most
likely during the morning hours after sunrise, and in the late
evening hours after sunset. Primarily VFR conditions are
expected throughout the TAF period outside of any thunderstorms.
There remains considerable spread within model guidance about
timing and location of storms throughout the TAF period. Models
overall favor two different waves of storms, one 12-20z and
another after 00z. It is plausible sub-VFR conditions could
develop in storms but given overall uncertainty, sub-VFR
conditions were omitted from the TAF at this time. Winds will be
light and variable overnight, becoming largely southeasterly
Friday afternoon.

&&

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

&&

$$

UPDATE...Mangels
DISCUSSION...Scott
AVIATION...Davis