647
FXUS63 KDDC 062045
AFDDDC

Area Forecast Discussion
National Weather Service Dodge City KS
345 PM CDT Thu Jun 6 2024

.KEY MESSAGES...

- First 100-degree heat forecast across far southwest Kansas
  tomorrow. (50-60% probability of exceedance 100+ degrees for
  Liberal, Elkhart, Johnson, Hugoton, Ulysses)

- Scattered early Friday morning showers and thunderstorms
  mainly between Ark River and Oklahoma line, followed by
  another chance of storms later in the afternoon and Friday
  Night. Marginal Risk (1 of 5) of severe weather

- Increased likelihood of large thunderstorm system Saturday
  Night with POPs increased to 60% for much of the southwest
  Kansas region.

&&

.SHORT TERM /THROUGH FRIDAY/...
Issued at 342 PM CDT Thu Jun 6 2024

This afternoon, water vapor loop and RAP analysis showed a broad
ridge of high pressure extending across much of the western and
central CONUS, which was allowing temperatures to really heat up
across the Southwest and into New Mexico. Roswell, NM was baking in
104F heat as of 1950Z. This heat will make a run on much of our
forecast area tomorrow. In the meantime, a cold front passage
earlier this morning kept our temperatures at bay across southwest
Kansas, but mid to upper 80s were observed from the Ark River south
to the Oklahoma line.

The front to our south will stall out and return north as a warm
from tonight/early Friday morning. The frontal zone in the 800-700mb
layer will likely provide enough upward vertical motion due to
increased warm frontogenesis in the 09-15Z time frame. The
convection allowing models (CAMs) are not too excited about early
Friday morning storms, but the NAM12 and GFS20 (non-CAM models) are
more aggressive with their QPF development along the 800-700mb
frontal zone across the southern third of our forecast area (mainly
along/south of the Ark River). The HRRR runs do show some signal in
its Composite Reflectivity, but the HRRR model does not have very
aggressive thunderstorm development. We will keep 20-30 POPs going
early in the morning given the aforementioned frontogenetic forcing
for ascent, but leaning more toward just widely scattered non-severe
convection at this point.

Later in the day Friday, a dryline will develop with temperatures
really warming up along/west of the dryline. There is strong
consensus among all models, including short term CAMs, of at least a
quarter to a third of the forecast area (far southwest Kansas)
reaching 100 degrees in the mid-late afternoon before any
thunderstorms develop. So, official forecast highs will be 100 or
101 for areas like Liberal, Elkhart, Hugoton, Johnson, and Ulysses.
Elsewhere east of the dryline, temperatures will likely top out in
the lower to mid 90s.

Later in the afternoon and evening Friday, the focus will shift to
renewed surface-based thunderstorm development. All models show
thunderstorm activity developing and/or moving into western Kansas.
The question then comes down into the details. How much of the
thunderstorm activity will be what moves in from Colorado vs. how
much of our activity in southwest Kansas will be from pristine
development along the trough axis/dryline to the east of the
Colorado line. Colorado storms will initially develop in drier air
where convective temperature is reached first (i.e. 0-3km AGL lapse
rates becoming dry adiabatic). Regardless, we will not be looking at
a significant severe weather event as the main forcing for ascent
and greater deep layer wind shear will be up across Nebraska, so the
SPC Day Two Marginal Risk (Level 1 of 5) is a good forecast at this
point. The likelihood of a nocturnal mesoscale convective system
(MCS) sweeping across our southwest Kansas region is rather low with
the main MCS signal well to our northeast.

&&

.LONG TERM /FRIDAY NIGHT THROUGH THURSDAY/...
Issued at 342 PM CDT Thu Jun 6 2024

Over the past several forecast cycles, the best signal for the most
numerous thunderstorm activity across west central/southwest Kansas
has been the Saturday Night period. This thinking has not changed,
and in fact there is now growing confidence in a fairly robust MCS
or two tracking across much of western/central Kansas Saturday
Night. For this reason, the Saturday Night period POPs have been
increased to "Likely" 55+ percent across nearly the entire forecast
area with the exception of our eastern counties.

A significant Saturday Night MCS will almost assuredly have impacts
on Sunday`s sensible weather. For this reason, Sunday`s forecast is
less confident, but low level moisture will be around and almost all
models show low level winds in a favorable east/southeast upslope
direction with mid to upper 60s dewpoints pulling back west into
southwest Kansas. The 64-thousand dollar question, though, is how
worked over the boundary layer will be and will there be enough
recovery for another MCS Sunday evening/night. The best forecast is
that the axis of best MCS probability Sunday Night will be a bit
farther south than where Saturday Night`s MCS will be.

After Sunday Night, the pattern becomes complicated with an upper
low likely off the coast of southern California/Baja and the main
polar jet well to the north along the Canada line. Eventually, the
cutoff upper level low will eject northeast across the Intermountain
West/Rockies, but there is a lot of model difference in the
evolution of this going into mid to late next week.

&&

.AVIATION /18Z TAFS THROUGH 18Z FRIDAY/...
Issued at 1147 AM CDT Thu Jun 6 2024

A cold front resulted in northeast winds at the onset of this
TAF period, averaging 18 to 22 knots sustained at GCK, DDC, and
HYS. Winds will gradually decrease in speed through the
afternoon as the pressure gradient relaxes. By early evening,
easterly winds will range 7 to 10 knots, remaining at that speed
and direction much of the night. We expect overnight showers and
widely scattered thunderstorms to develop in the 09-14Z time
frame across portions of southwest Kansas, however the
probability of impact at specific terminals is still too low
(30% or less) to include in any of the TAFs for this issuance,
however following synoptic TAFs may be including mention of
thunder at any or all of LBL, GCK, DDC terminals if confidence
increases as we get closer to that time frame.

&&

.DDC WATCHES/WARNINGS/ADVISORIES...
None.

&&

$$

SHORT TERM...Umscheid
LONG TERM...Umscheid
AVIATION...Umscheid