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000
FXUS63 KGID 211713
AFDGID

Area Forecast Discussion
National Weather Service Hastings NE
1213 PM CDT Sun Apr 21 2024

.KEY MESSAGES...

- Generally warmer, more seasonable temperatures for the next
  week, with at least mid 60s to 70s each day. Overall-warmest
  day is currently forecast to be Monday with highs in the mid
  70s to lower 80s.

- Pattern tends to become more active, especially mid-late week
  and into the weekend. The next chance (30-60%) for scattered
  showers/storms comes Monday eve-night.

- Severe thunderstorms will be possible (~20% chance) for at
  least portions of the area on Thu, and perhaps beyond into
  Fri-Sun.

- Near critical fire weather conditions are possible (40-70%
  chance) Tuesday afternoon due to combination of gusty N winds
  and relative humidity values in the low-mid 20s.

&&

.DISCUSSION...
Issued at 405 AM CDT Sun Apr 21 2024

Surface and upper ridging should bring quiet and sunny
conditions to the region today, and despite the seasonably cool
temps near 60F, the sunshine and relatively lgt winds should
make for a fairly pleasant afternoon. Return flow sets up
overnight as the sfc high shifts SE and lee troughing develops
in response to shortwave moving from the N Rockies into N
Plains. This trough will force a relatively weak/Pacific cold
front through the area Mon aftn/eve, but not before temperatures
spike into the mid 70s to lower 80s within environment of deep
mixing and SWrly low level flow. Can`t rule out a brief bout of
near critical fire wx conditions for mainly Furnas Co Mon aftn,
but worst/most widespread dip in RH should focus over W KS.

The next chance for scat showers/storms will come Mon eve-night
as low level jet ramps up to 45-50kt and impinges on the
gradually southward sinking front. Effective wind shear, steep
mid-level lapse rates, and seasonably low freezing levels
suggest a non-zero chc for at least small (dime-nickel) size
hail in strongest cores. However, still appears as though
instability will be the limiting factor thanks to limited
moisture (PWATs <1"), with even the most robust MUCAPE progs
generally less than 1k J/kg. Appears greatest chcs for the
scat coverage will be between roughly I-80 and Hwy 36 corridors,
though at least low end chcs (20-30%) exist everywhere.

Whatever develops Mon night should shift well E/SE by dawn Tue
AM, setting the stage for a dry and mostly sunny daytime. High temps
will fall back a bit into the mid 60s to lower 70s, but the main
sensible weather story for the day will be the breezy N winds
gusting 25-35 MPH, low relative humidity (RH) into the 20-25%
range, and resultant near critical fire wx. RHs have trended a
couple percentage points lower over the past 24 hrs, and if this
trend continues can`t rule the need for some fire headlines Tue
PM. At least the good news, though, is that recent moisture has
really kicked the greenup of the cool season grasses over the
past couple of weeks. Tue night is a bit tricky in that some
guidance brings next bout of elevated warm air advection and
shower chcs, in which the cloud cover could help limit frost
potential amidst lows in the mid to upper 30s. However, if this
activity does not pan out, then may need one more round of Frost
headlines, esp. N/NE of the Tri-Cities.

A much more active pattern appears on track to develop for the
end of the week and continue into next weekend. Models are in
decent agreement with large scale features (incoming upper
trough, SW mid-upper level flow and opening NW Gulf of Mexico
for moisture return), though as usual for day 5+, pertinent low
level details remain a bit uncertain which will be key in
determining overall severe weather potential.

Appears deterministic models, and their associated ensemble
guidance, are coming into line showing a general pattern
conducive of multiple rounds of strong-severe convection over
broad swaths of the central U.S. over at least a 3-4 day
stretch, perhaps longer. This is evident by the decent
agreement in broad western U.S. upper troughing, SE U.S. upper
ridging, and resultant seasonably strong SWrly mid-upper flow
atop a destabilizing and increasingly moist airmass. Furthermore,
appears the western Gulf of Mexico will open up and begin to
modify the S Plains airmass as early as late Tue-Wed, and remain
"open for business" through at least next weekend. While it`s
next to impossible to accurately predict individual shortwave
troughs at this time, general model consensus is that these
waves will be strong enough to provide decent mid level speed
maxima/deep layer shear, but not too strong to drive the primary
effective front/baroclinic zone into the Gulf/Deep South. With
that said, seems like the most probable scenario at this time is
that highest severe risk will tend to focus S/SE of the local
area, reinforced by the idea of repeated rounds of convection.
So it`s possible that we could avoid the worst of the severe
weather while still receiving much needed moisture from the more
stable, northern portions of potential multiple MCSs. This is
evident by ensemble progs of positive moisture anomalies, but
only modest probabilities for more than 1k J/kg of CAPE (esp.
beyond Thu night). Newly issued SPC Day 4-8 outlook remains
largely unchanged, with Slight Risk-level probabilities over our
KS zones on Day 5 Thu, then a larger risk area that is mostly
E/SE on Day 6 Fri. A resurgence of instability is possible over
the weekend, but predictability is just too low at this time.

Exact temperatures will be largely determined by rain/cloud
coverage, but in general, would expect mostly above normal lows
(which are generally upper 30s to mid 40s) and highs within ~10
deg + or - of normal (which are 60s to low 70s).

&&

.AVIATION /18Z TAFS THROUGH 18Z MONDAY/...
Issued at 1206 PM CDT Sun Apr 21 2024

Dry weather with VFR conditions are forecast for this TAF
period, with increasing cloud cover during the latter half of
the period mainly confined to the upper levels. A surface ridge
axis sliding across the region will bring overall light winds to
the terminal sites this afternoon, variable for a bit then
turning more southwesterly. This evening, winds are expected to
turn southerly, remaining that way through the overnight hours.
Even though winds look to become more gusty in nature, models
continue to show the potential for LLWS at both sites roughly a
couple hours either side of sunrise. Final few hours of the
period continue those gusty winds, turning a bit more south-
southwesterly.

&&

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

&&

$$

DISCUSSION...Thies
AVIATION...ADP