468
FXUS63 KGID 262216
AFDGID

Area Forecast Discussion
National Weather Service Hastings NE
516 PM CDT Fri Apr 26 2024

.KEY MESSAGES...

- Ongoing lingering shower/storm activity will continue into the
  early-mid evening hours, but is expected to end for most areas
  by midnight, with the rest of the overnight hours dry.

- The break from thunderstorm chances is short-lived, with the
  next round expected to develop mid-afternoon Saturday along an
  northward pushing warm front. Large hail/damaging winds are
  the main threat, but cannot rule out the threat for tornadoes.

- The next main upper low moves through the area on Sunday,
  keeping precipitation chances in the forecast. While the SPC
  Day 3 risk areas are currently focused east of the forecast
  area, any slowdown of the system and accompanying surface
  boundaries would bring that risk back west into our area.

&&

.DISCUSSION...
Issued at 510 PM CDT Fri Apr 26 2024

Currently through tonight...

Been a very busy day today, mainly from late morning on through
mid-afternoon, as a strong low pressure system sliding east
through the Central Plains drove the development of
thunderstorms along a northward arcing warm front. The strongest
storms extended from northern Buffalo County northeastward into
Greeley County, and a few tornadoes did touch down. Damage
survey is ongoing and will continue into tomorrow. Late this
afternoon, the main focusing surface features have shifted just
to the east of the forecast area, but scattered thunderstorms
continue as the upper low continues to cross the region. Can`t
rule out some of these storms being on the strong side through
this evening, but better instability/shear parameters are also
focused east, so additional severe weather is not anticipated.

Activity is expected to wane in coverage/intensity as we get
further into the evening hours, with models in pretty good
agreement drying things out after midnight. At the surface,
expecting winds to also taper off, as the pattern influence
transitions from the departing low to the east and another
gradually deepening to our southwest. Overnight lows tonight are
expected to drop into the 40s.

Saturday and Sunday...

Unfortunately, the break from thunderstorm chances coming in
tonight is a short-lived one, lasting only into the morning
and early morning hours on Saturday. At 12Z Saturday, models
show the forecast area sitting under upper level shortwave
ridging, set up between the system driving today`s weather
(which will have moved into the western Great Lakes/MN area) and
the next low pressure system, which is expected to be in the
Four Corners region. Also start of the day between areas of
surface low pressure, keeping winds on the lighter side. Through
the day, the main upper low sill continue pushing east, ending
up over eastern CO by early evening. In response to this next
approaching upper low, surface low pressure is expected to
deepen over southeastern CO, resulting in a strengthening of the
eastward extending warm front...which by midday models show
being anywhere from across our southern forecast area counties
to closer to I-70. Through the afternoon hours, this warm front
is expected to lift north...with some uncertainty with just how
far north it gets by mid-late afternoon, but could be roughly
along the NE/KS state line. Today`s system isn`t bringing a
strong cold front through the area to `clean things out`
(instability/dewpoints) for Saturday...current dewpoints are
still mid-50s for much of the area, so areas especially
along/south of that warm front will have sufficient instability
to work with, and deeper layer shear remains strong...so severe
weather will again be a concern. The southeastern 1/3rd of the
forecast area is included in the SPC Day 2 Enhanced Risk, with
the Slight Risk northward roughly to a Arapahoe-Osceola line.
All modes of severe weather will be a concern, mainly from mid-
afternoon through the evening hours.

Shower/thunderstorm chances continue on into Sunday, as the main
upper level low looks to push northeast...models showing the
general path going through eastern CO/western KS/western NE.
The current SPC Day 3 risk areas are just off to the east of the
forecast area...but similar to today`s system, we`ll be at the
mercy of the timing of the upper low and accompanying surface
features. Any slow down and strong/severe storm concern will
increase.

Monday and beyond...

Honestly, spent little time on this time frame. Dry conditions
are expected to settle in late Sunday night into Monday, as we
sit in the wake of this weekend system. Further into the work
week, models showing an overall zonal pattern with periodic
shortwave disturbances, so precipitation chances return Tuesday-
Thursday. Forecast highs through the new work week are in the
60s-70s.

&&

.AVIATION /12Z TAFS THROUGH 12Z SATURDAY/...
Issued at 712 AM CDT Fri Apr 26 2024

UP FRONT NOTE REGARDING KEAR:
Will continue taking KEAR TAF with "AMD NOT SKED" (amendments
not scheduled) until routine weather observation transmission is
restored there.

- General overview for KGRI/KEAR:
This is a somewhat complex period, as a strong low pressure
system passes through the region from southwest to northeast,
accompanied by several aviation concerns including: sub-VFR
ceilings and visibility, showers and thunderstorms, breezy to
moderately-windy winds and a gradual directional shift from
east-southeasterly, to southerly, to southwesterly, to westerly
and eventually northwesterly.

- Ceiling/visibility/rainfall/thunderstorm details:
Starting off right away this morning, these first few hours will
feature the overall lowest ceilings and visibility of the
period, with LIFR ceiling and IFR/MVFR visibility prevailing in
light fog (and probably some drizzle). By late morning and into
the early afternoon, ceiling is expected to gradually improve to
MVFR and then low-end VFR, with VFR then expected to prevail
through the remainder of the period.

As for rain shower/thunderstorm potential, at least spotty
(generally isolated to perhaps scattered) coverage of convection
is likely especially during the 15-00Z time frame, and this is
being handled with generic "vicinity thunderstorm" (VCTS) groups
as confidence in any particular prevailing time frame is low.
Odds favor any thunderstorms being non-severe, but a brief
period of hail cannot be ruled out.

- Wind details (not accounting for any convective influences):
For the majority of the first 18 hours, sustained speeds will
average 15-25KT/gusts 20-30KT, with sustained speeds easing
under 15KT by around 03/04Z, and then the lightest winds of the
period (under 10KT) prevailing after 08/09Z. Direction-wise,
passing low pressure will result in a gradual/general shift from
east-southeasterly this morning, to southerly mid-morning to
early afternoon, to southwesterly mid afternoon, to westerly
late afternoon-evening and eventually northwesterly late
tonight.

&&

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

&&

$$

DISCUSSION...ADP
AVIATION...Pfannkuch