074
FXUS63 KGID 260954
AFDGID

Area Forecast Discussion
National Weather Service Hastings NE
454 AM CDT Sun May 26 2024

.KEY MESSAGES...

- Isolated showers and thunderstorms may redevelop late this
  afternoon and into the evening, but organized severe weather
  is not expected.

- Otherwise dry and fairly pleasant rest of the holiday weekend
  with highs in the mid 70s to lower 80s. Monday will be on the
  breezy side, esp. N of I-80 with afternoon gusts near 30 MPH.

- Most areas will remain dry and mild Tuesday and probably even
  most of Wednesday, with any low end precipitation chances
  confined to far SW/S portions of the forecast area.

- Potentially active pattern returns Wednesday night into
  Thursday and continues into at least Friday-Saturday. This
  could be our next chance for organized severe weather, but
  it`s just too far out to determine any details.

&&

.DISCUSSION...
Issued at 445 AM CDT Sun May 26 2024

Today:
I think the main forecast message for today is that models have
generally trended toward lesser coverage of showers and
thunderstorms, and a more narrow window for which they`ll be
possible. Guidance has trended more subsident and drier in the
low levels, both of which should prove to be more hostile to
convective initiation attempts within a very steep low level
lapse rate environment. As a result, forecast soundings now
maintain non-zero amounts of CINH and indicate potential for a
lot of dry air entrainment. Still can`t rule out something
isolated popping up anytime after 19-20Z, but appears the
"greatest chances" (still only 30-40%) today will come from
activity that develops over the higher terrain of the Black
Hills region then moves SE. This activity will be "up against
the clock" in terms of a quickly cooling BL after 00Z, but think
portions of south central Neb. will probably get at least
something between 21Z-03Z. Severe weather not really anticipated
with this stuff due to weak instability AND shear...though some
of the recent HRRR runs bring some gusty winds (40-50 MPH?) with
the dying shwrs/storms this eve, which seems plausible given the
amount of dry air in the low to mid levels. Outside of this
fairly low end rain potential, should be a fairly nice day -
through perhaps a bit brzy - given widespread highs in the mid
70s to low 80s. Any shwr/storm chcs quickly fade after 03Z.

Memorial Day - Wednesday:
Looks like we could string at least a few mostly dry/quiet days
with pleasant temperatures/humidity together for the start of
the week. Mon will be brzy in the afternoon, esp. N of I-80
where gusts incr to around 30 MPH, but otherwise pleasant with
highs in the mid 70s to lower 80s. It`s more of the same
temperature-wise for Tue and Wed, and dew points look to remain
seasonably low and comfortable in the 40s to low/mid 50s. Winds
will be light on Tue, but then become brzy out of the SE for Wed
with afternoon gusts around 25-30 MPH. There are some low- end
(mainly 20-30%) shower/thunderstorm chcs that return as early as
Tue and continue off and on into Wed, mainly for areas SW of the
Tri-Cities. However, think the greater chances will remain S and
SW of the forecast area where there will be better combination
of low to mid level warm air advection/isentropic ascent and
weak elevated instability.

Wednesday Night - Saturday
Models are in decent agreement that an upper ridge axis from SW
TX into the Dakotas will begin to break down Wed. PM into Thu
and allow for a series of low amplitude upper disturbances to
move through the region in zonal to SW flow. This should lead to
a gradually more active pattern once again. Models initially
suggest a pretty good setup for daily High Plains convection as
the primary instability axis remains W of the area. This
activity would then try to move eastward into some variation of
a nightly LLJ but then outrun the better moisture/instability.
As such, agree with NBM that W half of the CWA will have higher
chances (40-60%) for pcpn vs E half (20-40%), at least Wed night
into Thu. Models suggest a stronger shortwave should progress E
out of the N Rockies and onto the central/northern Plains later
in the week, generally sometime in the Thu night to Sat time
frame. This should help advect/shift the instability axis and
associated EML plume further E, as well, perhaps leading to an
increase in severe weather potential, esp. with any SEward
moving cold front Fri or Sat. Obviously, timing and mesoscale
details will be important - both of which can`t be nailed down
this far out. Regardless of the severe weather potential, latest
EPS has this as our next decent rain producer as it`s already
showing 50-70% chances for at least 0.5" in this time frame, and
20-40% for more than 1". Not bad for days 5-7 in which there are
undoubtedly timing differences amongst the members. Should see
at least a day or two of more stable conditions before ensembles
return instability back into the region early the following
week. Outside of perhaps a 1-2 day "cool down" Fri-Sat,
temperatures look to remain on the comfortable to seasonably
warm side in the mid 70s to upper 80s.


&&

.AVIATION /06Z TAFS THROUGH 06Z MONDAY/...
Issued at 120 AM CDT Sun May 26 2024

MVFR VSBYs and/or CIGs possible this morning.

Convection has shifted well E/SE of both terminals early this
morning, and dry conditions and at least a brief period of
clearing is forecast. This clearing could actually help support
some stratus and/or fog as winds remain fairly light over wet
ground from recent rainfall. No real signs of this forming just
yet elsewhere in the region, and model guidance is mixed, so
confidence on this actually panning out is fairly low. As an
inverted sfc trough passes next few hours, winds will shift from
Erly to N/NWrly by sunrise.

NWrly flow 5-15kt expected for the daytime Sunday, along with at
least SCT CU and iso showers/storms for the aftn. Models have
varied substantially with coverage and location of activity
today, so didn`t go anything more than VCSH for now. Hvy
downpours and brief reductions in flt cat is possible with the
heaviest cells. Otherwise, would expect a CU field to develop by
midday around 2-3K ft, then rise to 3-5K ft by late aftn. This
activity will be diurnally driven and weaken around sunset,
along with the NW winds. Confidence: Low to medium.

&&

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

&&

$$

DISCUSSION...Thies
AVIATION...Thies