768
FXUS63 KGID 030620
AFDGID

Area Forecast Discussion
National Weather Service Hastings NE
120 AM CDT Wed Sep 3 2025

...Aviation Update...

.KEY MESSAGES...

- A cold frontal passage early Wednesday could stir up a few
  storms, a few of which could become strong to severe between
  mainly 4-9PM. The best overall potential lies towards north
  central Kansas and southeast Nebraska.

- Some concentration of smoke could sink down to the surface behind
  the front Wednesday afternoon.

- Another more reinforced cold front will cool temperatures
  Friday with highs in the mid 60s to low 70s with lows in the
  mid 40s to low 50s overnight Friday.

- A few minor precipitation chances (15-25%) lie Thursday night
  into Friday morning and again Sunday night into Monday.

&&

.DISCUSSION...
Issued at 422 PM CDT Tue Sep 2 2025


Synopsis...


The upper-level jet is expected to amplify with meridional flow
keeping the synoptic pattern fairly active across the next several
days. Troughing across the eastern half of the U.S. sets up
northwest flow across the area tonight. The main feature that will
impact the weather here locally will be from the effects of a
southward sagging upper-level low that will center itself just north
of the Great lakes starting Wednesday night. At the surface, a cold
front will initially pass through the area Wednesday morning and
will be reinforced Friday from a few passing shortwave troughs
embedded in the flow. Another shortwave trough currently residing off
the Pacific coast awaits in the wings for its queue to cross over into
the Central U.S. next week. These fronts and shortwave disturbances
will bring a few precipitation chances to the area on Wednesday,
Thursday night into Friday morning and again Sunday night into
Monday.


Tonight...


Clearing skies today has allowed temperatures to quickly reach the
70s with a few areas approaching the low 80s where the sun was able
to unravel sooner in the day. Light and sometimes variable winds
will continue through the night with lows projected in the mid 50s
to low 60s. An out of the blue shower/storm would not be a complete
surprise, though flip-floping model guidance has not brought us any
insight worth grasping at. A few cumulus across the sandhills this
afternoon as well as at least one isolated shower in northern
Nebraska suggest that the potential is there, though a majority of
the area should still remain precip free.


Wednesday...


As mentioned in the synopsis, a front will steer a north to south
temperature gradient Wednesday with highs in the low to mid 70s for
areas around and north of I-80 and with highs in the upper 70s to
mid 80s for places south of I-80. Besides the front`s impact on
temperatures, a few scattered storms/showers in the morning could
approach from the north. The biggest short-term forecast change in
the last 24 hours has been the uptick in our PoPs, primarly in the
afternoon hours for north central Kansas. Precipitation chances start
near 15% around the Tri-Cities area and gradually increase up to 35%
heading away and towards the north and east of this area for the
morning hours.

The better storm potential for Wednesday actually falls in the
afternoon for primarily our eastern to southeastern Nebraska and
north central Kansas areas. Storms, potentially strong to severe,
will likely develop somewhere along the front in southeastern
Nebraska to northeastern Kansas between mainly 4-9PM. The big
question that keeps pops limited to a degree (no greater than 35%) is
answering when these storms are to fire. The sooner in the afternoon
that storms develop, the better the chance is for these storms to
impact a few of our southeastern areas (mainly southeast Nebraska
and north central Kansas).

The front acting as a lifting mechanism should help storms take
advantage of elevated instability (1,500-2,000J of CAPE) with
increasing mid-level lapse rates (7-8C/km) from mid-level cold air
advection. Around 35-45kts of deep layer shear with dewpoints in the
low to mid 60s should be just enough to support storm
intensification. A marginal risk of severe weather currently resides
across a few portions of our Kansas areas. Large hail up to the size
of quarters and thunderstorm wind gusts near 60MPH may be possible.
It is important to emphasize that the storm potential will be highly
reliant on where the front lies when storms initiate. Current high-res
model guidance does not develop storms until after the front has
left the area, though we know that the potential for storms forming
earlier is by all means a possibility (reflected in our somewhat
generous PoPs).

Air quality is the final factor that will be watched Wednesday
afternoon as the northwesterlies aloft drag in some elevated smoke
that could partially sink down to the surface behind the front. The
HRRR and RRFS both show some, though limited, concentrations
eventually reaching the surface Wednesday afternoon.


Thursday and Beyond...


Lows Thursday morning will fall down to the mid 40s to mid 50s with
a rapid warmup in store for the afternoon. Highs will be expected to
rebound to the mid 70s to upper 80s. Winds may temporarily swing
towards the southwest before returning northerly overnight. A second
and more pronounced shortwave trough embedded within the mid-to-upper
level flow should eject yet another jet max over the area. This
disturbance should trigger a secondary and likely more robust cold
front. This more pronounced cold and dry air advection pattern will
lower highs and dewpoints for Friday. Highs in response will drop
around 10-15 degree into the mid 60s to low 70s with dewpoints only
in the mid 40s to low 50s. The coolest temperatures of the next 7
days is slated to fall Friday night with lows, beyond a few kansas
areas, in the mid to upper 40s. In addition to the cooldown friday,
a 10-25% chance for storms follows the front Thursday night into
Friday morning with the best potential concentrated towards the
south and east.

The rest of the forecast period should offer highs generally in the
70s with lows mainly in the 50s. The previously mentioned shortwave
disturbance in the synopsis section will become a wildcard for the
forecast next week. The timing and strength of the shortwave will
highly influence the direction that temperatures move as well as
when the best precipitation chances will lie. As of now, our best
guess for when the next widespread storm chances will come lie
Sunday night and Monday (15-25% chances).

&&

.AVIATION /06Z TAFS THROUGH 06Z THURSDAY/...
Issued at 119 AM CDT Wed Sep 3 2025

For KGRI/KEAR Airports:
- General overview:
High confidence in VFR ceiling/visibility and precipitation-free
conditions through the majority of the period. However, a few
spotty showers cannot be ruled out during the day Wednesday, and
of greater concern are: 1) The possibility for at least a few
hours of MVFR ceiling Wednesday afternoon...2) The possibility
for smoke from Canada fires to reduce visibility to at least
low-end VFR (perhaps MVFR?) by Wednesday evening. Winds will
not be a significant issue, but a directional shift to
northeasterly-then-northerly will occur during the day behind a
passing cold front, with several hours of gusts at least 15-20KT
likely.

- Ceiling/visibility/precipitation details:
Very high confidence in VFR and precipitation-free weather these
first 6+ hours this morning, with only a smattering of passing
mid-level clouds. Getting into the daytime hours, a
passing/isolated shower cannot be ruled out at almost any point,
and although have hinted at this with a generic "vicinity
shower" (VCSH) group for part of the day, nothing appears worthy
of a PROB30 (or greater coverage) at this time. The first main
"question mark" arrives mainly 18-00Z, during which time at
least a low-end VFR ceiling appears likely as lower stratus
arrives, and an MVFR ceiling is certainly possible (especially
21-00Z). Considered introducing a TEMPO for MVFR ceiling
potential, but with this still beyond the first 12 hours will
simply "hint" at it with SCT015 mention. By around 00Z any MVFR
ceiling potential should be departing off to the south-southwest
of both KGRI/KEAR, but by then the next potential concern
arrives in the form of some degree of reduced visibility from
Canada wildfire smoke. Based on current obs upstream over ND, at
least low-end VFR visibility is a decent bet and MVFR is
certainly possible. For now have introduced "6SM FU" to get the
ball rolling.

- Wind details:
Early this morning winds will remain light (mainly 6KT or less)
as direction gradually shifts from southwesterly to westerly
ahead of an approaching cold front. The leading edges of this
front will arrive by mid-late morning, with direction initially
turning northeasterly before turning more "true" northerly by
mid-late afternoon. Although not overly-strong, several hours of
sustained speeds at least 10-13KT/gusts 15-20KT appear
likely...before easing up by sunset and beyond.

&&

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

&&

$$

DISCUSSION...Stump
AVIATION...Pfannkuch