009
FXUS63 KGLD 030848
AFDGLD

Area Forecast Discussion
National Weather Service Goodland KS
248 AM MDT Fri May 3 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 most
  of the Tri-State area, but favor along and south of I-70.

- 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 FRIDAY/...
Issued at 243 AM MDT Fri May 3 2024

For the long term period, active weather is possible Monday with
generally average temperatures and daily precipitation chances
through the week.

Sunday is forecast to have an upper low/trough push into the Western
CONUS and move towards the Four Corners region. Meanwhile, moisture
is forecast to stream in from the south near the surface as a
surface low develops along the Front Range while additional moisture
moves in over the mountains. This could lead to a fairly cloudy day
where temperatures will cap in the 60`s, though any area with sun
for a couple of hours should reach the 70`s, especially near and
west of the Colorado border. Showers and a few storms could develop
with all the moisture in the area, but the severe threat should be
near zero with instability still forecast to be fairly low with
MUCAPE generally near or less than 500 J/KG.

Sunday night through Monday is when conditions are forecast to get
more interesting as the upper low moves near and over the area along
with the surface low. One the first things to watch will be the
winds. With the speed of the upper trough and how deep it could get,
the pressure gradient and height gradients could get fairly strong
and allow winds to exceed 30 mph and gusts exceed 55 mph starting as
soon as Sunday evening. However, confidence is currently only around
40% as ensembles show a fairly high spread in 500mb tracks and
progression. This in turn also affects the surface low and it`s
progression. One of the main things that could keep the winds on the
lower side is that some of the ensembles are pulling the trough
north. This would shift the stronger gradients more towards Nebraska
and the Dakotas. Our winds would still strengthen above 20 mph with
gusts above 35 mph, but high wind criteria warnings would become
unlikely. The chances for the high winds then increase the further
south the track of the main surface low goes (farthest south looks
to be around the Southern KS border). In either scenario, low
temperatures Sunday night will likely stay in the 50`s with the
moisture, cloud cover, and increased winds over the area.

For Monday, conditions are fairly variable given the surface low has
solutions with tracks that go through the area during the day or hug
the KS/CO border along with tracks that are north of the area and
south of the area (I am referring to the deepest part of the surface
low). In scenarios where the low moves through the area and is to
the east during the day, moisture would lower across the area,
increasing critical fire weather chances and lowering storm and
severe storm potential. In solutions where the low and front stay
over or near the area, critical fire weather conditions become less
likely while storm and severe storm chances increase. Winds
approaching high wind warning criteria become more likely as well.
Would could be of particular concern is if the low is south of the
area and the warm front is draped across the area. We then begin to
face scenarios similar to recent events with a warm front and a
dryline/cold front acting as storm genesis points. High temperatures
are forecast to be in the 60`s behind the system and in the 70`s and
maybe low 80`s ahead of the system. Monday night remains just as
varied with conditions ranging from calming and dry, to stormy with
high winds. Currently, don`t have a good inclination towards any one
scenario so have gone with a more neutral forecast and am waiting
for better consensus in guidance and maybe better sampling of the
system (since it is still offshore).

Tuesday and Wednesday look to be more "average day" with near
average temperatures in the 60`s and 70`s and some small chances for
precipitation as the upper pattern is forecast to turn more to a
broad trough with the initial disturbance pushing east while the
trough as a whole spins over the Northern Plains. Will need to watch
for critical conditions south of I-70 with the drier air over the
area dropping RH into the teens.

For the end of the work week, currently forecasting near average
conditions in a broad trough pattern. Guidance is split on whether
the upper trough just pushes off to the east or if a small low
splits off and retrogrades west. In either case, there is the
possibility of another front if the trough is strong enough as it
pushes off to the east, though there may not be much moisture
available for storms to work with.

&&

.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...KAK
AVIATION...99