727
FXUS63 KGID 020929
AFDGID

Area Forecast Discussion
National Weather Service Hastings NE
429 AM CDT Tue Jul 2 2024

.KEY MESSAGES...

- Another upper level disturbance and surface frontal boundary
  are expected slide through the area today into this evening,
  bringing additional thunderstorm chances. While much of the
  forecast area will have the potential for strong to marginally
  severe storms, mainly this afternoon/evening, the overall best
  chances look to be along/south of a line from Geneva to
  Phillipsburg.

- Wednesday evening and overnight will bring another chance for
  strong to severe storms to the area, with the best chances
  being mainly along/west of HWY 183.

- Storm chances linger into the morning/early afternoon hours on
  Thursday/Independence Day, but the forecast dries out for the
  evening/fireworks time.

- Dry forecast continues on into Friday/Friday night, with
  periodic storm chances returning this weekend into early next
  week. Overall confidence in the timing/location of those
  chances isn`t the highest at this point.

&&

.DISCUSSION...
Issued at 423 AM CDT Tue Jul 2 2024

Currently on into tonight...

Upper air and satellite data show the area continuing to sit
under southwesterly flow early this morning, set up between
broader troughing extending south-southwest out of central
Canada and ridging extending northeastward from the TX/OK/LA/AR
border area. An embedded shortwave disturbance and a surface
warm frontal boundary sparked off thunderstorm activity late
Monday afternoon...and while the coverage/intensity has
diminished during the overnight hours, a swath of scattered
showers and weak storms continues early this morning. Lift along
the convergence zone of a 40-50+ kt low level jet is aiding in
keeping this activity going, which is and looks to remain mainly
south of I-80 the rest of this morning. At the surface, the
forecast area sits in a weaker regime, north of the more
pronounced warm/stationary front running through central into
northeast KS...resulting in light/variable winds for the
majority of locations. Satellite imagery also showing most of
the central/southern portions of the forecast area under mostly
cloudy skies with mid-upper level cloud cover...with the
northwest third or so with areas of mostly clear skies, but
spots of low level stratus sinking south. The opportunity to
cool more than other areas with less cloud cover, light winds
and recent rains has resulted in some patchy fog...which will
remain a concern through the rest of the early morning hours.
Spots with visibilities under one mile will be possible.

Looking to the rest of today into this evening, the main concern
remains with thunderstorm chances. Models showing another upper
level shortwave disturbance will be making its way east out of
the Rockies and onto the Plains today...and with lift ramping
back up with its arrival, hard to completely rule out
preciptiation for any particular place during the 12-00Z time
frame today. In general most models show continued weakening of
the ongoing activity early this morning...but show the potential
for at least scattered activity to pick back up by mid-late
morning. Though the current surface pattern is weak across the
forecast area currently, models showing with the arrival of that
upper level wave, a more organized cool front will start to
push southeast through the area...providing another focus for
thunderstorm development.

Big question is with the progress the front makes through the
day. Even with this activity that we had come through last
evening through tonight, it wasn`t a system that `cleared out`
the area of instability like some systems can...so while any
storms that develop esp. this afternoon/early evening will have
instability/shear sufficient for strong to at least marginally
severe storms to be a concern, locations along/south of that
boundary will have more juice to work with. The majority of the
forecast area is included in the SPC Day 1 Marginal Risk area,
with the Slight/Enhanced areas just to our south...as a decent
share of models show the front making enough southward progress
to push the greater threat out. But...some models showing it
being a closer call whether the front can get out of the
forecast area before those stronger storms develop...it`ll be
close. Locations roughly along/south of a Geneva-Phillipsburg
look to have the better chances of seeing any severe storms with
any frontal slow down...something to watch during the day.

Outside of precipitation chances, trended highs down a touch with
expected partly to at times mostly cloud skies and precip
potential...with upper 70s-low 80s for most of our Neb counties,
and mid 80s-low 90s near/south of the NE-KS state line, which
will be ahead of the front longer into the day. Heat index
values near 100 are still possible, mainly across portions of
Jewell, Mitchell, and Osborne counties.

Later into the evening/overnight, the better precipitation
chances push further south into KS...and while did keep a
sliver of low chance (20 percent) PoPs in far southern portions
of the forecast area, it`s possible the entire area will be dry
as we get closer to/after midnight.

Wednesday and Thursday/Independence Day...

Confidence in Wednesday`s forecast, mainly with preciptiation
chances, is not overly high. Expecting generally zonal flow to
be in place in the upper levels to start the day...with the
potential for some at least scattered activity to work its way
into far southern portions of the forecast area, as a weak
shortwave disturbance slides east across KS. Have those
precipitation chances currently confined to
Rooks/Osborne/Mitchell to start the day...some models say that
could be expanded a touch north, others say it`ll be dry...so
already some questions to start off the day. Precipitation
chances remain low throughout the rest of the day (20 percent or
less), and focus during the afternoon turns to the High Plains.
Expecting winds to start the day on the light/variable side,
turning more solidly southerly through the day...as surface low
pressure deepens over the High Plains and a more notable frontal
boundary develops ahead of an approaching upper level shortwave
disturbance. By mid-afternoon, thunderstorms are expected to
develop along this boundary, then the question becomes how it
evolves as it pushes east into the evening/overnight hours.
There are some notable differences between models with just how
much activity actually develops out west, and what actually
makes it this far east. At this point, NBM/forecast
precipitation chances are on the more optimistic side of
activity pushing east, and chances are anywhere from 50-80
percent through the Wed night-Thur AM time frame. Roughly the
western third of the forecast area is included in the SPC Day 2
Slight Risk area...with the remainder of the area in the
Marginal Risk area. While models show sufficient deeper layer
shear in place area-wide...the axis of better instability is
focused along/outside of the western edge of the forecast area.
Hail/damaging winds would be the primary threats.

Precipitation chances continue on into the day on
Thursday/Independence Day as another, stronger upper level
system moves through the Northern/Central Plains. Current
models show the best chances coming during the first half of the
day, perhaps into the early afternoon...but do have activity
clearing the area by mid-late afternoon...with the evening and
fireworks activities looking dry.

As mentioned above, winds on Wednesday turn back to the south
with time, with speeds anywhere from 10-15 MPH in the east to
15-20 MPH in the west. Highs on Wednesday are in the mid-80s
area-wide. On Thursday, with that stronger system passing to our
north, a surface cool front sinks south through the area,
ushering in northwesterly winds, which may be on the breezy side
around 15-20 MPH through the afternoon...before diminishing for
the evening/overnight hours. Highs on Thursday are forecast to
be in the mid 70s-near 80 across most of our Neb counties, with
mid-80s across KS.

Friday on into early next week...

For the end of the week into early next week, between the upper
level system that passes to our north on Thursday digging a bit
further south with time and high pressure/ridging becoming more
established over the western CONUS, our pattern turns to more
northwesterly flow. The dry forecast Thursday evening continues
on into Friday/Friday night and at least into the first half of
the day on Saturday. Another upper level low pressure system
looks to slide southeast out Canada into the Dakotas later in
the day Saturday into Saturday night, bringing the next
precipitation chances. Additional periodic low chances (20
percent) continue on into Sunday and Monday, but confidence in
timing/location drops the further out in time we go. As far as
temperatures go, Friday is fairly similar to Thursday with mid
70s-mid 80s, with the upcoming weekend highs solidly in the 80s
to around 90 in spots.

&&

.AVIATION /06Z TAFS THROUGH 06Z WEDNESDAY/...
Issued at 1220 AM CDT Tue Jul 2 2024

For KGRI/KEAR Airports:

Can`t rule out some isolated showers/storms in the vicinity of
the terminal areas over the next few hours, kept a VC mention
going, with better chances pushing further southeast with time.
Later tonight, models showing the potential for lower level
stratus to move into the area, and could see some reductions in
visibility. Currently have IFR conditions developing, will see
how models/upstream obs trend, LIFR conditions are not out of
the question. Should see improvement in visibility/ceilings
through the day, with VFR conditions this afternoon, but there
will be another chance for scattered preciptiation to push
through the area. With confidence in exact placement of activity
a little low, kept precip mention as VC at this point. As far as
winds go, expecting mainly light/variable winds tonight, with a
frontal boundary eventually sinking south and ushering in
northerly winds by mid-morning. Generally speeds look to be
around 10-15 MPH, but a few gusts closer to 20 MPH this
afternoon will be possible.

&&

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

&&

$$

DISCUSSION...ADP
AVIATION...ADP