888
FXUS63 KGID 190555
AFDGID

Area Forecast Discussion
National Weather Service Hastings NE
1255 AM CDT Thu Jun 19 2025

...Aviation Update...

.KEY MESSAGES...

- There is a low chance (5-15%) for a few thunderstorms to
  develop over western parts of the area Thursday afternoon. IF
  these develop a couple could produce marginally severe
  hail/wind.

- Dangerous heat arrives Friday and lasts through the weekend.
  Fortunately breezy southerly winds will provide some relief
  for outdoor activities.

- After the warm/dry stretch, thunderstorm chances return early
  next week (especially Monday night into Tuesday).

&&

.DISCUSSION...
Issued at 256 PM CDT Wed Jun 18 2025

Scattered cumulus persists over much of the area as of mid
afternoon, but near term models and satellite trends are not
supportive of this developing any further. Most, if not all, of
the area is expected to remain dry through this evening and
tonight.

On Thursday, upper-level ridging begins to build over the area,
and southerly winds are expected to increase (gusts 25-30
MPH) during the afternoon. This should allow the entire area to
reach the 90s...and southwestern zones could approach 100
degrees. Most models are dry for Thursday afternoon and evening,
but a couple HREF members (NSSL WRF and Fv3) are developing
some high-based convection in response to the strong diurnal
heating. IF these storms manage to develop, MLCAPE up to 3000
J/kg and deep layer shear around 40kt would support an
isolated/marginal severe threat.

Friday through the weekend, the primary concern is heat as
ridging slowly shifts eastward and an upper low pushes into the
Pacific NW. Daytime high temperatures in the upper 90s and low
100s are expected each day. Dewpoints will not be overly high as
breezy south winds (gusts 35-45 MPH) mix out the low level
moisture, but heat index values are still expected to peak in
the 100-110 degree range each day. Overnight lows are also
expected to be solidly within record-setting territory. The
latest NBM has Grand Island only dipping to 80 degrees Satudray
and Sunday mornings. This would break the daily records (78
Saturday...75 Sunday) and would be the warmest low temperature
since July of 1980!

The "bright side" is that the aforementioned winds will make
outdoor activities feel a bit more conformable (although
dehydration and heat-related illnesses are still possible).
Saturday is anticipated to be the warmest day of the stretch,
and the approaching system COULD provide some relief to
northwestern parts of the area Sunday afternoon. All of that
being said, an Extreme Heat Watch is in effect for all of our
Nebraska counties.

Thunderstorm chances then return to the area Sunday night and
continue into early next week as the upper low ejects over the
northern Plains. PoPs are already quite high (50-80%), with
northwestern parts of the area most favored to see beneficial
rains in the wake of our heat wave.

&&

.AVIATION /06Z TAFS THROUGH 06Z FRIDAY/...
Issued at 1254 AM CDT Thu Jun 19 2025

For KGRI/KEAR Airports:
- General overview:
With ONE possible (but low-probability) exception, confidence
is high in VFR ceiling/visibility and rain/thunderstorm-free
conditions throughout...with increasing southerly surface winds
and the onset of low level wind shear (LLWS) Thursday evening
being the primary issues.

- Low probability for evening thunderstorms:
Although not reflected in current TAFS due to the probability of
occurrence deemed only around 20%, there is an outside chance
that mainly the 01-04Z time frame COULD feature thunderstorms at
least in the general area. IF storms manage to develop, they
could potentially be severe. Again, omitting for now due to low-
confidence in occurrence, but this will need monitored.

- Wind details:
- Surface winds:
Light southerly breezes early this morning will steadily
increase during the day, with sustained speeds at-or-above 12KT
by around 15Z and then the overall-strongest speeds established
by 20Z and beyond...sustained around 20KT/gusts 25-30KT. There
will very little drop-off in these speeds even beyond sunset.

- Low level wind shear (LLWS):
Despite the already-breezy surface winds, a strong south-
southwesterly low-level jet will ramp up Thursday evening, with
speeds at roughly 1,500 ft. AGL reaching around 45KT between
02-06Z. The net result is roughly 30KT of shear magnitude
between the surface and this level...strong enough for formal
TAF inclusion.

&&

.GID WATCHES/WARNINGS/ADVISORIES...
NE...Extreme Heat Watch from Friday morning through Sunday evening
     for NEZ039>041-046>049-060>064-072>077-082>087.
KS...None.

&&

$$

DISCUSSION...Mangels
AVIATION...Pfannkuch