043
FXUS63 KGID 031112
AFDGID

Area Forecast Discussion
National Weather Service Hastings NE
612 AM CDT Wed Jul 3 2024

.KEY MESSAGES...

- A few isolated to scattered showers/non-severe storms may make
  their way into portions of the area through the first half of
  the day, mainly along/south of I-80.

- Better chances for thunderstorms come in two rounds this
  evening and overnight. The first, tied to a complex sliding
  southeast this evening, will have the best potential for
  strong-severe storms, especially west of Highway 281 in
  Nebraska as well as across north central KS. Large hail and
  damaging wind gusts look to be the primary threats.

- The second round of storms later tonight, tied to the arrival
  of the main upper level system, is expected to arrive closer
  to/after roughly 3 AM. While some stronger storms will be
  possible, the overall threat for severe weather should be
  diminished.

- Storm chances will continue on into the day on
  Thursday/Independence Day, but are expected to end by mid-late
  afternoon...with the evening/fireworks activities expected to
  be dry.

&&

.DISCUSSION...
Issued at 423 AM CDT Wed Jul 3 2024

Currently...

Been an overall quiet night so far across the forecast area,
with mostly clear skies. Looking aloft, upper air and
satellite data showing west-southwesterly flow in place across
the region...set up between broad troughing spread across much
of Canada and high pressure centered over the Gulf Coast region.
At the surface, weak high pressure settled across the area is
keeping winds light/variable, with frontal boundaries located
both to the SE and NNW of the forecast area. Though it`s been
dry overnight (which many locations needed after recent heavy
rains)...an area of scattered showers and thunderstorms is
currently extending from east central CO southeastward into
south central KS. This activity is being driven by increased
lower level warm air advection/convergence and more subtle
forcing aloft...and has ever so gradually drifting north with
time. Expecting mid-upper level cloud cover to increase through
the rest of the early morning hours...but some models still
showing the potential for some spotty fog. The mostly clear
skies and light winds have allowed temps to drop into the 50s in
some location across south central NE as of 3AM...with lower
across north central KS.

Today into Thursday/Independence Day...

Looking at the daytime hours today...models continue to show
some differences with this ongoing activity to our southwest,
and how much makes it far enough north to affect our forecast
area. The overall best chances look to remain over portions of
KS closer to/south of I-70, but kept some 30-40 percent chances
across our KS counties in the 12-18Z time frame. One change was
to add some 20 percent chances further north, spread through
counties along I-80...not great chances for measurable precip,
but hi-res models showing the potential for at least isolated
activity to push east through the morning. Not expecting any
severe weather with any of this activity.

Through the day, models continue to show the next upper level
disturbance to impact our area sliding southeast out of western
Canada and through the Nrn Rockies. Ahead of this disturbance,
expecting surface low pressure to deepen over the High Plains,
while the area of high pressure pushes to our east. As a result,
the current light/variable winds will be switching to the SSE
with time, and while speeds won`t have an significant increase
(10-20 MPH from east to west), gusts closer to 20 MPH will be
possible this afternoon, mainly for areas west of HWY 281. By
mid-late afternoon, a surface frontal boundary become more well
defined over western Nebraska...with thunderstorms expected to
fire along it as that upper level disturbances moves in. The big
question the becomes...what will the impact be on our forecast
area? Unfortunately there are still some notable differences
between models with just how well things hold together as the
complex push southeast. Different runs of different models have
gone back and forth between activity diminishing notably before
getting here to a mature MCS having little trouble moving
in...so hard to have a high amount of confidence.

Forecast reflective more of the models showing an MCS moving
into western portions of the forecast area early this
evening...but its strength as it makes eastward progress is in
question, as models continue to show the main axis of better
instability (lower level and elevated) bring more focused over
western NE/KS, perhaps into western portions of the forecast
area. Deeper layer shear remains sufficient for strong to severe
storms to be a concern, it`ll just be a matter of instability
present...which its return northward through the day today could
be inhibited by the convection that will be crossing KS. There
are a number of `gonna have to see how things evolve` details
with the forecast for later today/this evening. Roughly the
western half of the forecast area remains in the SPC Slight Risk
area...with the rest of the area in the Marginal Risk area.
Large hail, damaging winds, heavy rain look to be the primary
concerns.

Another complicating factor in the forecast as we get into the
overnight hours is that we may end up getting two separate
rounds of activity moving through the area, with a little bit of
a lull in between. The first, discussed above, is tied to that
sfc frontal boundary and developing MCS...the second is tied to
the mid-upper level trough axis of the main system itself.
Activity with its arrival into western portions of the area
looks to be closer to the 09-12Z time frame. Think the potential
for severe weather would be diminished with the arrival second
round.

These precip chances then spread east/continue on
into the daytime hours on Thursday, with models showing the
upper level system evolving into a closed low as it slides
east across SD. Timing between models hasn`t changed
significantly...still looking at the main precipitation chances
being through the first half of the day, pushing east of the
forecast area by mid-afternoon. At this point the better chances
for any severe weather look to focus east of the forecast area.
Have the late afternoon/evening/fireworks hours dry area-wide.
Outside of the precipitation chances, this upper level system
will push a cool front through the area...ushering in
potentially breezy northwesterly winds, which should diminish in
the evening. Following high temperatures today expected to be
in the low-mid 80s, highs for Thursday look to be in the mid
70s-near 80 from north to south across our Neb. counties, with
low-mid 80s across our KS counties.

Friday on into the new work week...

Models remain in good agreement showing a pattern change by the
time the end of the week rolls around, at 12Z Friday showing
the upper level low over MN/WI with its southward extending
trough axis, while a ridge axis extends north along the West
Coast. This more northwesterly upper flow looks to remain in
place through the end of this 7-day forecast period...with the
main concern then being any potential shortwave disturbances
passing southeast through the Plains. At this point models are
in ok agreement with the on Friday being dry, and while
evening/overnight hours are currently dry in the forecast, will
have to see how models trend with the timing of a couple of
waves looking to move into the region. Forecast currently
focuses the better chances on Sat/Sun, drying back out Mon/Tue.
Hard to have a high degree of confidence in the timing/path of
these disturbances the further out in time you go.

As far as temperatures go, upper 70s-mid 80s are forecast for
Friday, with mid 80s-low 90s on Sat and 70s/80s for Sunday...but
how the timing of any precipitation chances end up panning out
could throw a wrench in those weekend highs. Mainly 80s
currently forecast for Mon/Tue. Normal highs for this time of
year are mid 80s north to right around 90 in the south.

&&

.AVIATION /12Z TAFS THROUGH 12Z THURSDAY/...
Issued at 607 AM CDT Wed Jul 3 2024

For KGRI/KEAR Airports:

Can`t rule out some patchy fog in the area early this morning,
but the better potential for sub-VFR conditions looks to be in
the final few hours of this period, which has MVFR ceilings.
There will be some isolated to scattered showers/storms moving
through this morning, but confidence in any impact at the
terminals was low enough at this time to keep out any
mention...better chances will be to the south. Better chances
for storms arrive mid-late evening then again toward the end of
the period, and a VCTS mention both times. Light/variable winds
early this morning turn more southerly with time, with speeds
increasing to around 15 MPH. A few gusts closer to 20 MPH are
not out of the question this afternoon, especially at KEAR.
Light/variable winds return later this evening/overnight.

&&

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

&&

$$

DISCUSSION...ADP
AVIATION...ADP