332
FXUS63 KLBF 180819
AFDLBF

Area Forecast Discussion
National Weather Service North Platte NE
319 AM CDT Tue Jun 18 2024

.KEY MESSAGES...

- A Marginal Risk of severe thunderstorms this afternoon along
  the eastern edges of the CWA, mainly along a line east of
  western Frontier County to southwestern Custer County to
  Garfield, Wheeler and southwestern Boyd counties.

- High temperatures nearly 10 to 20 degrees below seasonal
  average are expected Wednesday in the wake of a cold front.

- An active pattern keeps chances of showers and thunderstorms
  through the end of the week. At this time, the severe
  potential is uncertain.

&&

.SYNOPSIS...
Issued at 317 AM CDT Tue Jun 18 2024

Upper air analysis and satellite imagery place an upper level trough
over the western United States, with the trough axis through Utah
and Arizona. Western Nebraska sits just to the east of the eastern
edge of the trough, in an area supportive of divergence aloft. Early
this morning, storms are noted over the Dakotas under areas of
greatest divergence aloft. At the surface, a low pressure system is
observed over western Nebraska early this morning, with a warm front
extended across southern South Dakota, and a cold front trailing to
the southwest across north central Colorado.

&&

.SHORT TERM /THROUGH WEDNESDAY NIGHT/...
Issued at 317 AM CDT Tue Jun 18 2024

The low pressure system over western Nebraska early this morning
will continue tracking eastward. As the low tracks to the northeast,
the cold front will track across the region this morning, which will
help diminish the gusty winds observed overnight. The cold front
will be the focus for severe weather potential later this afternoon,
though the more active severe weather appears to be well east of the
region, focused more over eastern Nebraska. Given the proximity to
the cold front, the Storm Prediction Center has placed portions of
the region in a Marginal Risk (level 1 of 5) for severe weather this
afternoon. This area is roughly along and east of a line from
western Frontier County to southwestern Custer County to Garfield,
Wheeler and southwestern Boyd counties. Latest CAM guidance suggests
the best potential for precipitation this afternoon will be over the
portions of north central Nebraska in the Marginal Risk. Although
there is a Marginal Risk across the region, the severe weather
threat is very conditional on storms being able to initiate this
afternoon. Forecast soundings from the CAMs show quite a robust cap,
meaning any storms that could potentially form will more than likely
be elevated in nature. The main severe weather concerns would be for
large hail and strong thunderstorm winds, but again, conditional on
storms initiating west of the cold front.

Otherwise, the cold frontal passage this morning will keep things
more on the mild side this afternoon, with temperatures climbing
into the 70s across most of the region, with a few spots breaking 80
degrees. As the cold front pushes east, it is eventually expected to
stall around Iowa and Missouri. As the front stalls, clouds continue
to back build over the region, providing building cloud cover
throughout the afternoon and overnight. Overnight and through
Wednesday night, another round of showers and thunderstorms is
expected to form and track across the region. At this time the
severe weather threat is low.

Of note for Wednesday, is the cool post frontal environment settling
over the region. Temperatures are only expected to climb into the
60s across most of the region, with perhaps a few areas breaking 70
degrees. These temperatures are below our seasonal average by around
10 to 20 degrees. As stated above, there will also be another chance
for precipitation during this cooler period Wednesday into Wednesday
night. While the cooler temperatures will limit any severe weather
concern, it could be a catalyst for efficient rain production for
showers and locally heavy rain. At this time, the best potential for
locally heavy rain appears to be areas east of Highway 83.

&&

.LONG TERM /THURSDAY THROUGH MONDAY/...
Issued at 317 AM CDT Tue Jun 18 2024

The upper level pattern remains fairly supportive of rain through
the end of the week. The upper level trough remains fairly
stationary over the western United States through the end of the
week. Guidance suggests the potential for a few small shortwaves to
potentially eject out of the main trough, which could be a catalyst
for showers and thunderstorms through the end of the week.

By Friday afternoon, the trough is expected to begin lifting and
tracking to the northeast. This leads to upper level ridging
beginning to set up later in the weekend into early next week. As
the upper level ridging settles in, temperatures are expected to
begin climbing back to seasonal averages starting Friday and through
the weekend, returning back to above average early next week. Timing
and exact values will continue to be refined in further forecasts,
but for now, expecting a return to warmer and drier conditions early
next week.

&&

.AVIATION /06Z TAFS THROUGH 06Z WEDNESDAY/...
Issued at 105 AM CDT Tue Jun 18 2024

The primary concern this TAF period will be strong southerly
winds gusting at or above 40kt along with low level wind shear
through the first part of the valid period. A cold front will
push through TAF sites toward daybreak and push the axis of the
low level jet eastward, shifting winds to the northwest and ending
the low level wind shear. While winds behind the front will
still be gusty for a while, speeds will gradually relax behind
the front through the afternoon.

Flight conditions will be VFR except for a couple of hours
either side of the frontal passage as a band of clouds moves
through with the front. KVTN will see CIGs on the lower side of
MVFR but the best potential for IFR is just to the north in
South Dakota. KLBF will be on the low side of VFR with
probabilistic guidance indicating only a 30 percent chance for
sub-VFR conditions. Will monitor sky trends closely and amend
if needed before the new TAF issuance at 12Z.

There may be some widely scattered showers with the frontal
passage, along with potential for some diurnal convection later
this afternoon. However indications are that the coverage will
be quite sparse so will maintain dry conditions this valid
period and amend if trends in radar or surface observations
begin to favor more coverage of precipitation.

&&

.LBF WATCHES/WARNINGS/ADVISORIES...
None.

&&

$$

SYNOPSIS...Richie
SHORT TERM...Richie
LONG TERM...Richie
AVIATION...MBS