357
FXUS63 KGID 152147
AFDGID

Area Forecast Discussion
National Weather Service Hastings NE
447 PM CDT Sun Sep 15 2024

.KEY MESSAGES...

- Late tonight into Monday morning will bring another chance
  (20-40 percent) for at least scattered showers/storms...mainly
  for areas along/east of HWY 281. This activity is not expected
  to be severe. Monday night into Tuesday may bring a repeat,
  with 20 percent chances for preciptiation across most of the
  forecast area.

- Tuesday night on through the rest of the week, models showing
  an upper level pattern developing that would be more favorable
  for preciptiation chances across the forecast area. The first
  widespread chances (50-70 percent) come late Tuesday night in
  to Wednesday...then again late in the day Friday through the
  weekend (40-60 percent).

- For Monday and Tuesday, both days are expected to have
  continued gusty south-southeasterly winds. The strongest
  speeds are expected on Tuesday, especially across areas west
  of HWY 281, where gusts around 40 MPH (or more) are not out
  of the question.

&&

.DISCUSSION...
Issued at 436 PM CDT Sun Sep 15 2024

Currently...

Overall been a dry end to the weekend across the forecast area.
Upper air and satellite data showing continued weaker
southwesterly flow across the region...set up between a blocked
pattern over the eastern CONUS and an area of low pressure
digging its way south over the West Coast. Had a few spotty
showers/weak storms early this morning meandering around the
region...but they didn`t last too long. At the surface, it`s
been a breezy day, with gusty southeasterly winds driven by
troughing extending through the High Plains into TX, and high
pressure over much of the Midwest and north central/northeastern
CONUS. Gusts around 25 MPH have been fairly widespread this
afternoon. No notable surprises with temperatures, 3PM obs for
most locations are in the mid-upper 80s.

Tonight through the day on Tuesday...

This time frame for most locations will likely be dry, but there
are some low precipitation chances still in the
forecast...overall confidence just isn`t overly high even being
this close in time.

Expecting this evening and much of the overnight hours tonight
to be dry, but models are showing some isolated/scattered
activity developing sometime around 09Z (confidence in timing
isn`t high). This activity looks to be focus along some
generally weaker mid- level convergence/eastern edge of an
increased lower-level jet...potentially expanding in coverage
along a north-south corridor closer to/after sunrise. Hi-res
models have kept this corridor fairly narrow, but have varied
with its exact location...is it closer to HWY 281 or HWY 81?
With some uncertainty in the location...kept preciptiation
chances topped out in the 30-40 percent range closer to the HWY
14 corridor (middle ground between 281 and 81), with a sharp
drop-off in chances west of HWY 281. Another area of uncertainty
is with the timing of the end of this activity...which is
currently expected to wane with time during the first half of
the day while gradually shifting just a bit east. Current
forecast carries chances through 18Z, a few models suggest it
could linger a little longer. Otherwise, increased cloud cover
across central/easter areas late tonight into Monday morning,
which should diminish during the afternoon. Expecting another
breezy day for Monday, with models showing the potential it`s
bit more than today with a tighter pressure gradient. Winds
remain south- southeasterly...sustained speeds in the western
half of the forecast area of 20-25 MPH/gusts of 30-35 MPH not
out of the question, areas in the east closer to HWY 81 look to
be a little closer to what we are seeing today with gusts around
25 MPH.

Late Monday night into Tuesday morning may bring similar
conditions to what happened this morning and what is expected
tonight-Mon morning...another potential round of at least
scattered showers/storms. By the time Monday evening arrives,
models show that large western CONUS upper level low having
shifted a bit east into the central CA/NV border area, with
continued southwesterly flow across the Central Plains. Can`t
rule out a weak shortwave disturbance moving through the area
out ahead of that main low, and potential will be there for
forcing along the edge of a low-level jet being in the area as
well. At this point kept precipitation chances on the low side
at 20 percent, but they are pretty widespread across the
forecast area. Again there is some question in the timing...but
kept chances confined to the pre-18Z time frame, then dry
through the afternoon. Sounding a bit like a broken record...the
gusty winds also look to continue on into Tuesday, a could be a
touch higher than Monday thanks to the tighter pressure
gradient. South-southeast winds will again be strongest in the
western half, where gusts closer to 40 MPH are expected.

At this point, for both Monday and Tuesday, currently not
expecting any of these thunderstorms to be severe...while
models keep sufficient instability around the region, deeper
layer shear is pretty low. As far as temperatures go, both days
are similar in the mid-80s for most spots.

Tuesday night on through the rest of the week...

Persistent western CONUS low pressure/troughing looks to keep
the potential for a more active pattern around through the
rest of the week...bringing some much-welcomed precipitation
chances.

The first bout of more widespread chances arrives late Tuesday
night into Wednesday. Models showing the first upper low
shifting northeast from NV up into the Northern Rockies by early
Wednesday morning, with the southward trailing trough axis
swinging on through the Plains. Though the forecast does have
chances creeping into the west during the evening hours, models
are in pretty good agreement showing this being more of a
midnight-and-after timing. Currently, the highest, most
widespread preciptiation chances chances are in the 06-12Z time
frame....with most location`s chances in the 50-60 percent
range, and 70 percent across roughly the northwestern quarter of
the area. Post-sunrise, best chances are quickly focused
along/east of HWY 281, then end by early afternoon (some
uncertainties with that exact end time).

Precipitation chances for Wednesday night on through at least
Thursday night are lower (20-30 percent) and could be more
spotty in nature...as the region looks to be sitting between
the upper level low moving to our north Tues-Wed AM and the next
that will be working its way east toward the Rockies. Can`t
rule out more subtle shortwave disturbances moving through the
region...confidence just not overly high during this timeframe.

Later in the day on Friday and on through the weekend...weather
across the forecast area will be driven by that next upper level
low crossing the Plains. Because of some uncertainties with the
exact track and timing...preciptiation chances at this point
are in the 40- 50 percent for much of the area, with some
smaller area of 60 percent scattered in there. Timing-
wise...current forecast already has widespread 40-50 percent
chances Friday afternoon, wouldn`t be surprised if things
overall slow down as we get closer (it is only Sunday after
all)...think it`ll be more of a weekend event, but we`ll see how
models trend this week. If the models do hang on to a track
bringing that low through the heart of the Central Plains, that
could bring beneficial, measurable rain much of the area.

&&

.AVIATION /18Z TAFS THROUGH 18Z MONDAY/...
Issued at 1215 PM CDT Sun Sep 15 2024

For KGRI/KEAR Airports:

VFR conditions are currently forecast for this TAF period, and
the forecast also remains dry, though there is some uncertainty
in that during the morning hours on Monday...especially for
KGRI. Models showing some morning activity developing across
eastern portions of the area, and most keep it just east of
KGRI. Otherwise, though increased clouds are expected, at this
point expecting them to remain VFR. Gusty south-southeasterly
winds continue this afternoon, with gusts around 25
MPH...diminishing this evening and overnight. The final few
hours of this period will have southerly winds increasing once
again, with gusts around 25-30 MPH possible.

&&

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

&&

$$

DISCUSSION...ADP
AVIATION...ADP