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000
FXUS63 KGID 201027
AFDGID

Area Forecast Discussion
National Weather Service Hastings NE
527 AM CDT Sat Apr 20 2024

.KEY MESSAGES...

- Cool and cloudy again today with 20-50% chance for light
  rain/snow through the daytime hours, mainly SW of the Tri-
  Cities. <20% chance for total moisture >0.10".

- Another round of near to below freezing temperatures tonight.
  50-90% chance along/N of state line, 20-60% chance for N KS.
  Additional frost/freeze headlines are likely tonight-Sun AM.

- Nicer weather returns for Sunday afternoon. Generally near to
  above normal temperatures for the upcoming work week with
  mainly 60s and 70s for highs, and lows mostly above mid 30s.

- Rain chances return Mon PM (20-50% chance). Fairly active
  pattern mid to late week with overall greatest chances coming
  Wed night through Thu night (40-60%). The storms on Thu will
  need to be monitored for severe potential, esp. across KS.

&&

.DISCUSSION...
Issued at 515 AM CDT Sat Apr 20 2024

No major changes to the forecast this cycle.

Still looking at another cool and cloudy day today thanks to
weak upper disturbance and lift from RER of upper jet streak.
Best combination of lift and deeper moisture will focus SW of
the Tri-Cities today, particularly for areas from around
Cambridge to Phillipsburg where chances peak at around 50%.
However, even these areas will likely only receive very light
amounts as latest NBM gives <20% chance for total moisture more
than a tenth of a inch. Highs will likely be limited to upper
40s to lower 50s thanks to the persistent cloud cover, but at
least the Nrly winds will be fairly light at 5-15 MPH. See no
reason to adjust ongoing Freeze Warning as clouds have
stabilized temps along and S of the state line. Further N, some
clearing overnight allowed temps to fall further into the 30s
and even upper 20s, and areas N of I-80 are still clear and
could fall further into mid 20s by dawn.

Model consensus is for gradually clearing skies tonight, esp.
after midnight, for all but perhaps far W/SW zones. Fairly lgt
winds brought about by sfc ridging, along with dew points in the
20s, should allow for a more widespread freeze Sat night into
Sun AM. Plan once again is to allow ongoing headline to expire
and let day shift reissue for tonight, likely further S to at
least the state line. KS zones, esp further S tier, may be able
to get by with a Frost Advisory, though the 20s dew points could
keep even this on the limited side. High temps Sun aftn will
still likely be below normal in the upper 50s to lower 60s, but
it will feel pretty nice given copious sunshine and only lgt
SWrly winds around 5-10 MPH. Strengthening return S flow will
not only keep low temps above freezing Sun night, but also lead
to warmer highs on Mon in the 70s, perhaps even low 80s far SW.

Next decent chance (up to ~50%) will come with a cold front Mon
eve into overnight. Severe weather is not expected at this time,
but a few strong storms with small hail can`t be ruled out given
MUCAPE expected to rise to around 500 J/kg amidst strong
effective deep layer shear values in excess of 40kt and freezing
levels only 8-9k ft. Will also see some lift from 40-50kt LLJ
that at least briefly noses into the area 00Z-06Z before
shifting E/SE. Should be dry by Tue AM with brzy N winds working
to keep highs a bit cooler in the 60s to near 70F. Return flow
could lead to some low end pcpn chcs Tue night into Wed, but
otherwise expect highs in the 60s to low 70s and brzy SE winds.

Thunderstorm chances increase (30-50%) Wed night into Thu AM
with even stronger LLJ/warm/moisture advection in response to an
upper trough shifting E over the Four Corners region. High
temperatures on Thursday are expected to be a little warmer than
Wed, especially over KS zones, thanks to closer proximity to
potential surface warm front. Exact timing of shortwave ejection
onto the Plains, and location of pertinent sfc features such as
sfc low and associated fronts...remains a bit uncertain and
will be key to determining overall severe storm potential.
General consensus is that highest rain/storm chances will come
Thu eve/night (50-60%) with primary upper shortwave and
incipient warm air/moisture advection and convergence on nose of
LLJ. Consensus also suggests that best instability could be
confined to S Plains into KS, E of the dry line and S of the
warm front, where deep layer shear will be in excess of 40kt and
more than sufficient for severe convection. It will take some
time for airmass recovery over the NW Gulf of Mexico thanks to
early week frontal passage, so moisture return could be a bit
delayed - which also supports greater risk over KS than NE.
However, a slower ejection of the upper shortwave, which is
certainly possible if overall amplitude increases (as latest
deterministic EC hints at), could allow for more time for
moisture return, and even bring severe weather potential further
N and on Fri into play. As it stands now, appears the sfc low
will progress far enough E to keep greatest severe weather
potential over mid to lower MO Valley on Fri. This general
evolution is displayed well in the latest SPC Day 6 and Day 7
outlooks, though as we saw earlier this week, adjustments are
certainly possible as we get closer. Temps look to decline a
bit into next weekend behind the departing storm system.


&&

.AVIATION /06Z TAFS THROUGH 06Z SUNDAY/...
Issued at 1222 AM CDT Sat Apr 20 2024

VFR expected through the period. SCT to BKN mid to high clds
should fill back in by around mid morning...with CIGs gradually
lowering from 12-15k ft to 7-10k ft. Added some VCSH for EAR
during the aftn, but this shouldn`t be much more than some
sprinkles or very light showers. Cld cover is forecast to thin
out and dissipate between 02Z and 06Z Sun. Wind speeds will
generally be around 6-10kt through the period. Direction will
start off Nrly then gradually back to NWrly this aftn, then Wrly
late Sat eve. Confidence: High.

&&

.GID WATCHES/WARNINGS/ADVISORIES...
NE...Freeze Warning until 8 AM CDT this morning for NEZ039>041-
     046>049-060>064-072>077.
KS...None.

&&

$$

DISCUSSION...Thies
AVIATION...Thies