535
FXUS63 KGLD 030405
AFDGLD

Area Forecast Discussion
National Weather Service Goodland KS
1005 PM MDT Thu May 2 2024

.KEY MESSAGES...

- Cold front late Friday afternoon and Friday evening will
  result in a line of thunderstorms moving through the area with
  a marginal risk of severe storms. The main hazards will be
  potentially widespread strong winds along and behind the front
  as well as blowing dust. There are lower risks for hail and
  perhaps a brief tornado along the front.

- Fire weather concerns return Monday through Thursday for
  various parts of the forecast area.

- Thunderstorms, a few of which may become strong to possibly
  severe, will be possible Monday afternoon/evening.

&&

.SHORT TERM /THROUGH SUNDAY NIGHT/...
Issued at 130 PM MDT Thu May 2 2024

Surface high pressure in control today with northwest winds
gusting up to 30 mph in the early afternoon and continuing to
slowly diminish as the pressure gradient relaxes. Tonight, a
weak shortwave trough moving out of Colorado may produce a few
isolated light rain showers, mainly in Colorado. Mean QPF
amounts are a few hundredths of an inch across northwest Yuma
County, less elsewhere. Low temperatures will range from the
upper 30s to lower 40s.

Friday will be mostly sunny and dry in the morning then
increasing clouds with a chance for showers and thunderstorms in
western areas during the afternoon. Shortwave trough moving
through the northern plains will send a cold front racing down
the plains in the late afternoon hours and through the evening.
Models suggest a line of thunderstorms will develop along the
front. Instability is fairly limited, topping out around 500-800
j/kg, but deep layer shear remains strong at around 50 kts.
While can`t discount a low end risk for hail or even a brief
tornado with the sharp frontal boundary, main hazards Friday
evening will be strong winds and perhaps blowing dust. Low
level lapse rates are not particularly favorable behind the
front, but there is a narrow corridor of more favorable rates
just ahead of it. Rainfall last night in many areas will be
working against the blowing dust potential. Given all the
variables confidence in blowing dust is medium at best, but
confidence in wind is high. HREF probabilities show about 20-30%
of members with gusts of over 50 mph centered around 03z with
the front. Some local gusts could be higher with convective
enhancement. The line of storms should be moving out of the
western counties by 06z and eastern counties by 09z. HREF mean
precipitation amounts are generally around a quarter to a half
an inch, with 90th percentile amounts of up to 1". Low
temperatures will range from the lower 30s in northeast Colorado
to the middle 40s in north central Kansas.

Saturday will be mostly sunny and dry during the day with highs
in the low to mid 60s. Flow aloft will transition to southwest
ahead of a system entering the Pacific coast, with northeast to
easterly winds at the surface. A shortwave trough coming out of
New Mexico ahead of the system will bring a chance for showers
and isolated thunderstorms to areas south of Interstate 70
Saturday night. SBCAPE and MUCAPE are more or less zero with
weak shear, so no severe storms are expected. 12-hour mean
precipitation amounts are less than a tenth of an inch by early
Sunday morning. Low temperatures will be in the low to mid 40s.

Southwest flow continues on Sunday with possible weak embedded
waves. At the surface will see increasing southeast winds,
breezy to windy by the afternoon with mostly cloudy skies. Might
see a few scattered light showers through the day, but best
chances will be in the morning with any lingering showers from
Saturday night. There is some minimal SBCAPE available in the
afternoon (100-200 j/kg) so an isolated thunderstorm is
possible, but severe storms not expected. High temperatures
optimistically forecast to be in the upper 60s to lower 70s, but
would not be surprised if they were a bit cooler. The low
chances for showers and isolated thunderstorms continues into
Sunday night as upper heights continue to fall ahead of the main
trough axis approaching the central Rockies by that time. Low
temperatures will range from the upper 40s to middle 50s.

&&

.LONG TERM /MONDAY THROUGH THURSDAY/...
Issued at 207 PM MDT Thu May 2 2024

The forecast period starts out with southwest flow over the Tri-
State area Monday morning.  An upper trough will be centered due
north of the Four Corners region.  Models have come into less
agreement from yesterday over the potential track of our next storm
system through the day on Monday.  The GFS now brings the track
further south into northwestern Kansas and extreme southwestern
Nebraska, before bringing it north into Nebraska and central South
Dakota. The ECMWF brings the system northeast across the
Bighorn Mountains (Wyoming) and into the West River region of
the Dakotas. A dryline is expected to move across the CWA during
the daytime hours on Monday. Right now, there is not a lot of
CAPE (SB <1000 J/kg) to work with as the system comes through,
but will want to continue to monitor things over the next few
days as we get closer to the event and things come into a little
better focus. Monday afternoon, there is a chance for some fire
weather concerns across the southwestern portion of the area.
Minimum relative humidity values are expected to fall into the
teens with wind gusts above the 25 MPH threshold.

Tuesday and Wednesday, a broad upper trough moves into the Tri-State
region, putting us under southwest flow.  Expect high temperatures
to be primarily in the 70s, although a few 60s cannot be entirely
ruled out in eastern Colorado.  Tuesday afternoon, there will be a
chance for some fire weather conditions, primarily in the
southwestern portion of the area.  Minimum relative humidity values
will fall into the teens and wind gusts are expected to reach 25 MPH
in areas.

Thursday brings a pattern transition as the trough progresses
eastward and we come under northerly to northwest flow.

&&

.AVIATION /06Z TAFS THROUGH 06Z SATURDAY/...
Issued at 1005 PM MDT Thu May 2 2024

KGLD...VFR conditions are expected through about 01z. A
southeast wind under 10kts at taf issuance will veer to the
south at similar speeds by 12z. From 13z-00z, southerly winds
gusting up to 40kts are expected. After 01z, sub VFR cigs and
vis are anticipated as showers and thunderstorms move through,
associated with a cold front. Northerly winds gusting up to
40kts or so are expected both due to the strong 3 hour pressure
rises behind the front and from the expected convection. Gusts
could be higher.

KMCK...VFR conditions are expected through about 01z. A light
and variable wind is expected from taf issuance through 13z.
From 14z-00z, southerly winds gusting up to 35kts are expected.
After 01z, winds shift to the north, gusting up to 40kts as a
cold front and strong 3 hour pressure rises move through. Sub
VFR cigs and vis are anticipated due to showers and
thunderstorms moving through.

&&

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

&&

$$

SHORT TERM...BV
LONG TERM...Wekesser
AVIATION...99