338
FXUS63 KGLD 040832
AFDGLD

Area Forecast Discussion
National Weather Service Goodland KS
232 AM MDT Fri Jul 4 2025

.KEY MESSAGES...

- Scattered storms today and tonight with a marginal risk for
  wind gusts up to 60 mph and locally heavy rainfall of 1-2".

- On and off thunderstorm chances continue through the weekend
  into next week.

- Remaining mild throughout with highs around the low 90s.

&&

.UPDATE...
Issued at 230 AM MDT Fri Jul 4 2025

Shortwave trough over western Colorado early this morning will
lift northeast today with a slight negative tilt. Widely
scattered showers and isolated thunderstorms this morning will
become more numerous this afternoon as the shortwave approaches.
The environment will be weakly to moderately unstable with HREF
mean showing up to 2000 j/kg of SBCAPE and surface-500mb shear
of around 20 kts. CAMs have mostly retreated from a line of
storms to more scattered coverage, with best chances east of
Highway 25 this afternoon and evening. Wind still looks to be
the primary severe risk, but only near any stronger updrafts
that manage to develop which will be more isolated in nature due
to lack of shear. Locally heavy rainfall will also be a
concern, with 3-hour PMM showing some medium probabilities
(50-70%) of 1-2" in the Nebraska/Kansas border area this
afternoon, then east of Highway 25 this evening, which could
possibly lead to some localized nuisance type flooding. Tonight,
better storm chances generally shift east, but still expect
some scattered activity further west with the upper trough slow
to move out. In fact, latest HRRR and NAMnest both suggesting a
cluster of storms will develop in western Nebraska and dive
southeast late this evening or overnight. If that were to occur,
might see more of an organized wind threat.

&&

.SHORT TERM /THROUGH SATURDAY/...
Issued at 1116 AM MDT Thu Jul 3 2025

Rest of today...

Breezy day across the Plains. Remnant shortwave vortex lifting NE
over the 4-corners region ahead of a set of trof axes and attendant
shortwaves ejecting E through the N Pacific jet. Enhancement of the
SW to NE pressure gradient throughout the atmospheric column along
with the gradual deepening of a lee cyclone immediately E of the
Rockies. Increasing S winds drawing N deep sub-tropical moisture,
notably from FWD / OUN where 12z soundings exhibit a near-saturated
column with +2 inch precipitable waters. Low to mid level moisture
continually advecting N, as can be seen via visible satellite, ever
so slightly cooling the column. With daytime mixing well up to 5-10
kft along with expected midday to afternoon scattered cumulus, we
should be a degree or two cooler than yesterdays highs, forecast
today around the low 90s. Surface dewpoints maintained around 60
should keep minimum relative humidity above 30 percent. The main
impact today will be gusty S winds. Mix down of faster momentum with
deep layer mixing should yield sustained winds around 15 to 20 mph
with gusts around 25 mph, as high as around 35 mph possible.

Tonight...

Increasing low clouds. With surface temperatures cooling resulting
in the boundary layer decoupling it`ll still remain breezy at the
surface. But stronger winds aloft will continue to advect moisture N
and subsequently pooling beneath the anticipated inversion we will
likely see the development of low stratus into the morning hours.
With the S winds and developing cloud deck, the blanket across the
region should keep lows mild with values around the mid 60s.

Friday into Friday night...

Line of storms forecast to sweep through the forecast area beginning
around midday going into evening. Main threats will be locally heavy
rainfall along with strong to damaging winds with gusts possibly as
high as 70 mph.

Synoptically, remnant shortwave energy ejects from the Rockies into
the N Plains. Enhancement of low-mid level S winds, sub-tropical
moisture is usurped N. While better surface cyclone development is
progged across the N Plains beneath the RRQ of H3 jet, a trailing
cold front SW towards a triple point low to the lee of the Rockies
will be the focus for midday into afternoon convection. A series of
trof axes through the broader SW to NE cyclonic flow will be the
forcing mechanisms that will touch of the forecast line of thunder-
storms, given more confidence in outcomes per convective allowing
models.

Yet some uncertainty. For one, how quickly we break out from morning
low stratus and begin destabilizing prior. This yields implications
for how much instability can be generated. A consensus of convective
allowing models have upwards of 2k J/kg potentially maxing above 3k
J/kg. Secondly, the timing of synoptic features initiating potential
storm development. It is entirely possible that things could kick
off earlier than expected. Third, deep layer bulk shear that will
maintain updraft maintenance. For certain the sweeping cold front
will provide the lift. Yet overall shear looks weak to marginal. Yet
right-moving storm motions and mean layer winds have an orthogonal
component to the front, and should storms perhaps create their own
local environment with an enhancement to the wind profile, perhaps
with some eye on the anticipated triple-point low in E CO, then it
is possible to see strong to damaging wind gusts behind the expected
line of storms possibly as high as 70 mph.

What is certain is that there will be plenty of deep layer moisture
with precipitable waters 1.5 - 2.0 inches across the region and with
freezing levels up around 16 kft and H85 dewpoints around +16-17C
there are certainly indications of an environment supportive of
precipitation efficiency with any storms that develop. But the push
of additional energy through the N Pacific jet should make the line
progressive across our region such that flooding is not so much a
concern. Can`t rule out an isolated impact if it happens to rain
well enough in the right spot. Expect someone is going to come out
with over an inch of precipitation when all is said and done.

Right now expecting the line of storms to be out of the area as late
as midnight behind which NW winds prevail and conditions clear. As
we clear out and winds become light we should be able to bottom out
to lows around the low 60s.

&&

.LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/...
Issued at 138 PM MDT Wed Jul 2 2025

Not much change to overall forecast thinking. A wash, rinse, repeat
pattern. The maintenance of the monsoonal high over the 4-corners
region will invoke upslope flow across our area towards the front
range of the Rockies. With any shortwave energy riding along the
N-periphery of the monsoonal high, diving cyclonically E/SE across
the region which will likely seen a maintenance of heat and humidity
with the S flow, we should see the development of thunderstorms
that could pose potential threats of wind, hail and locally heavy
rain. But confidence with regards to specifics remain low at this
time. So, overall, on and off afternoon into evening thunderstorm
chances with highs around 90 and lows around 60 with breezy S winds
prevailing.

&&

.AVIATION /06Z TAFS THROUGH 06Z SATURDAY/...
Issued at 1048 PM MDT Thu Jul 3 2025

Moisture is forecast to increase across the area overnight
which as a result will increase clouds across the area with an
increasing signal for low stratus developing for each terminal.
Do think there is a potential for some showers and perhaps a low
(15-20%) chance for a rogue lightning strike starting at KGLD
around 12Z and 17Z. Due to weak CAPE confidence is not there to
put any thunder/lightning mention in the TAF at this time. The
main question is how long will the stratus hold on as this will
affect the coverage for afternoon and evening storms so will
introduce a PROB30 for each site for afternoon/evening storms. A
moist airmass is in place so if a storm where to impact a
terminal visibilities have a high probability of falling to IFR
conditions or even perhaps lower. Another round of storms is
possible towards the latter portion of the period but may be a
little dependent on how the afternoon convection pans out so
will hold off for now for this TAF period.

&&

.GLD WATCHES/WARNINGS/ADVISORIES...
KS...None.
CO...None.
NE...None.

&&

$$

UPDATE...024
SHORT TERM...Sipprell
LONG TERM...Sipprell
AVIATION...Trigg