Grand Island, Nebraska 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

437
FXUS63 KGID 150014
AFDGID

Area Forecast Discussion
National Weather Service Hastings NE
714 PM CDT Wed May 14 2025

...Aviation Update...

.KEY MESSAGES...

- Potential for at least isolated thunderstorms will continue as
  we get into the evening hours...with the best chances mainly
  affecting roughly the NWrn third of the forecast area. There
  will be the potential for severe weather with any storms that
  make it this far south...large hail/damaging winds are the
  main threat, but an isolate tornado is not out of the
  question.

- Some showers/storms could linger into the morning hours on
  Thursday, with things drying out with time. Though drier with
  time, expecting a gusty day. WNW winds gusting 35-45 MPH are
  expected...the strongest speeds expected across the northern
  half of the forecast area.

- Friday-Saturday are currently dry, with preciptiation chances
  picking back up Sunday on through Tuesday. Still plenty of
  details to iron out, but potential for some strong-severe
  storms at time point in that Sun-Tue timeframe is not out of
  the question.

&&

.DISCUSSION...
Issued at 437 PM CDT Wed May 14 2025

Currently...

So far it`s been a quiet, but breezy/windy day across the
forecast area...some uncertainty still lingers with whether it
stays totally quiet through the rest of the afternoon. Looking
aloft, upper air and satellite data showing the main shortwave
disturbance of interest for the short term forecast continuing
to swing east- northeast through CO...which will eventually be
moving onto the Plains. At the surface, are of low pressure
currently sits over portions of west-central KS...a dryline
separating dewpoints in the 30s-40s from the 60s lies SSEward
through south central KS, with a fairly stationary warm front
extending north through the Sandhills into western SD. Winds
have been solidly southeasterly area-wide today, with gusts
mainly in the 25-30 MPH range. Also a notable trend through the
day has been dewpoints, with a nose of mid-60s creeping further
north into southern portions of the forecast area...folks
probably noting it feels more humid than in recent days. Hasn`t
been any big surprises as far as temperatures go...mid-
afternoon temps are mainly mid-upper 80s, with a few spots
sitting right near 90.

This evening on through Friday...

Million dollar question the rest of this afternoon and into this
evening how much-if any thunderstorm activity actually impacts
the forecast area...and even at this point still have some
differences between models. Already seeing some scattered
thunderstorm development over portions of the Sandhills along
that surface boundary, also where cooler mid-level temps are
currently set up. Expect that as that mid-upper level shortwave
moves further east into the area the rest of this
afternoon/evening, activity will expand in coverage...with some
lingering uncertainty how much those mid-level temps/capping
will hinder the southward extent of activity. Most models keep
all but far NWrn portions of the forecast area on the dry
side...a few try developing activity further south through the
heart of the area. Because most models support the overall drier
solution...PoPs for most are no more than 20-30 percent, with
locations south of a Geneva-PHG line dry. Do have 40- 60 percent
chances for areas along/NW of roughly a LXN-Genoa line, didn`t
go higher due to the expected overall coverage of any activity.

Now that all being said, if any storms do make their way into
the forecast area, especially through the evening
hours...they`ll be setting up/moving into an environment with
dewpoints solidly in the 60s, with the SPC Meso page currently
showing a solid axis of MLCAPE of 2500-3000 j/kg running SE-NW
into the forecast area...which models show sticking around for
several more hours, gradually shifting northeast with time.
Anything that can develop on the southern end likely won`t have
much interference from other activity...and with models showing
that SErly sfc-low level flow remaining, that lower level
directional shear would bring an elevated threat for a
tornado...thus the 5 percent Tornado probability from the SPC
Day 1 Outlooks. Otherwise...the strongest storms would be
capable of hail around golf ball size (possibly larger) and 60+
MPH wind gusts.

NNW portions of the forecast area could be impacted by a couple
rounds of thunderstorm activity...the first late today/this
evening tied closer to the stationary boundary currently
draped through the region...the second later this
evening/tonight tied to the main mid- upper level system and
accompanying sfc cold front. Models show the cold being roughly
halfway through the forecast area around midnight...with gusty
WNW winds area-wide by sunrise. Gusts exceeding 40 MPH with the
initial push of the front are not out of the question...settling
down a bit in the pre-dawn hours.

During the daytime hours on Thursday, models are in pretty good
agreement showing a more stacked mid-upper level low gradually
sliding through the Dakotas...and kept some low end
preciptiation chances across northern portions of the forecast
area (north of I-80) through the morning hours...but expecting
a dry afternoon. Though drying out with time...Thursday
continues to look like a gusty day, with west-northwest winds
sustained around 25-30 MPH expected area-wide. Gusts around
40-45 MPH are also possible, mainly across the northern half of
the area/roughly I-80 and north. High temps for the day are a
touch cooler, with low-mid 70s in the NW to right around 80 in
the SSE. Behind tonight`s cold front passage, a drier airmass
brings in dewpoints in the 30s-40s...so the threat of near-
critical to at least briefly critical fire weather conditions
remains. The lowest relative humidity values are mainly
along/south state line. Didn`t go with any formal fire
headlines...as fuels across KS are not favorable for fire
growth, and it`s currently an overall narrow area of NE that
hits critical levels for a brief period. Midnight crew will have
another round of model data to further adjust things to see if
a headline is warranted.

The dry but gusty conditions look to continue on into
Friday...as the main upper level system and tighter sfc
pattern continues to gradually slide further away from the
forecast area. Highs are fairly similar to Thursday, but a
couple degrees cooler...and winds are more NWrly, with sustained
speeds mainly in the 20-25 MPH range.

This weekend into the start of the new week...

Upper level ridging sliding east across the Plains looks to keep
the start of the weekend dry...with precip chances creeping
back in for Sunday on into Mon/Tue. Models are in decent
agreement showing the next notable upper level system digging
south across the western CONUS as the weekend passes...with the
next chances on Sunday tied to the first of potentially a few
lobes of lift to swing through the region. Plenty of details to
iron out in the coming days as far as timing/location goes of
these systems...but at least the potential for strong-severe
storms at some point in that Sun-Tue time frame looks possible.

&&

.AVIATION /00Z TAFS THROUGH 00Z FRIDAY/...
Issued at 714 PM CDT Wed May 14 2025

For KGRI/KEAR Airports:
- General overview:
High confidence VFR ceiling/visibility and
precipitation/thunderstorm-free conditions through the vast
majority of the period, with moderately-strong winds being the
primary concern behind a passing cold front. That being said,
there is at least a 2-hour "window of opportunity" for
thunderstorms later this evening, and about a 4-hour window for
potential MVFR ceiling late tonight-early Thurs morning.

- Ceiling/visibility/thunderstorm potential:
Starting off this evening, both KGRI/KEAR are 50+ miles south
and east of ongoing storms in the general area, with only
scattered VFR cumulus overhead. This is expected to remain the
case until 04-06Z, during which time the potential exists for a
quick moving thunderstorm threat (either isolated or part of a
more linear complex) to swing through from generally west-to-
east. With confidence in this scenario still less than 50/50,
have maintained PROB30 groups, but now targeting just that
2-hour window. IF thunderstorms arrive they could be strong to
marginally severe, capable of producing at least small hail but
probably more so erratic wind gusts at least 25-40KT.

Later in the night into early Thurs AM, there is an increasing
signal for roughly a 4-hour period of MVFR ceiling, and have
introduced this (at least for now) centered 08-12Z. Getting
into Thursday daytime, VFR should return with scattered clouds
mainly no lower than 3-5K ft.

- Winds:
Nearly the entire period will be moderately-windy. Starting off
these first several hours, southeast winds will continue
sustained 15-20KT/gusts around 25KT. Mainly 04-06Z, wind
speeds/directions will briefly vary considerably ahead of an
approaching cold front. Then, by 06Z (give or take an hour) this
front (possibly augmented by convective outflow) will have fully
charged through, with westerly winds then prevailing through the
remainder of the period. The overall-strongest westerlies will
occur Thursday daytime (sustained speeds around 25KT/gusts at
least 30-35KT.

&&

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

&&

$$

DISCUSSION...ADP
AVIATION...Pfannkuch