576
FXUS63 KGLD 141621
AFDGLD

Area Forecast Discussion
National Weather Service Goodland KS
1021 AM MDT Fri Jun 14 2024

.KEY MESSAGES...

- Thunderstorms will develop in northeast Colorado by mid
  afternoon, reaching the Colorado and Kansas border area by 6
  PM MT, and sweeping across the rest of the area this evening.
  The primary hazard will be destructive winds in excess of 60
  mph and locally up to 90 mph. Some large hail may accompany
  initial storm development in the afternoon and early evening,
  as well as a tornado or two, before merging into clusters.
  Locally heavy rainfall will also be possible as well as flash
  flooding.

- There is a marginal risk for a severe storm or two Saturday
  afternoon and early evening in northwest Kansas east of a
  Norton to Leoti line. Stronger storms will be capable of hail
  up to quarter size and wind gusts in excess of 60 mph.

- Return of triple digit heat expected on Sunday.

&&

.SHORT TERM /THROUGH SUNDAY NIGHT/...
Issued at 145 AM MDT Fri Jun 14 2024

Overnight showers and isolated thunderstorms appear to be the
result of a weak shortwave trough topping the ridge axis. This
activity will continue through this morning as the wave moves
east. May see a break in the precipitation from late morning
through mid afternoon, then convection develops in Colorado
21-22z with the next, and much stronger, shortwave moving out
of the Rockies. Storms reach the Colorado-Kansas border area
around 00z and then sweep through the forecast area Friday
evening. The environment will be moderately unstable, ensemble
mean values running around 2000-2500 j/kg with some pockets in
excess of 3000 j/kg, and deep layer shear of 30-40 kts. CAMs
suggest two possible clusters developing, one in northeast
Colorado that moves northeast into Nebraska, and more of a
linear cluster that moves across northwest Kansas this evening.
Either cluster will be capable of producing wind gusts in excess
of 60 mph, with some of the model output showing gusts of up to
90 mph possible. The potential for destructive winds will be the
main hazard. In addition, large hail may accompany initial
discrete supercells that form before merging into a cluster, as
well as a tornado or two. Finally, heavy rainfall and flash
flooding will become a concern into the evening hours, with 90th
percentile QPF of 2-3 inches from Yuma County, Colorado,
eastward into the Kansas and Nebraska border area. Higher
percentile QPF amounts further south are generally around 1 inch
with the faster moving linear cluster, except in the Greeley and
Wichita county areas where it is around 2 inches. The severe
threat should end by 06z and precipitation ending by around 09z.
High temperatures will be in the upper 80s and lows tonight in
the 60s.

The upper trough axis slowly moves through the area on Saturday,
ending up near the eastern zones Saturday afternoon, with a weak
reflection at the surface. Scattered afternoon thunderstorms
will develop with best chances east of a Norton to Leoti line in
northwest Kansas with weak convergence along the surface trough.
The environment will only be marginally conducive to severe
storms, with instability topping off at around 1500 j/kg and
deep layer shear of around 20-25 kts. Cannot completely rule out
an isolated low-end severe storm or two, but overall severe
threat is low. Storms should move out relatively early Saturday
evening as the trough pushes east. High temperatures will be in
the lower 90s and lows Saturday night in the 60s.

On Sunday, will have a weak southwesterly flow aloft and a warm
front surging northward at the surface. The front will herald
the return of extreme heat, with highs back into the upper 90s
and lower 100s. Assuming the surface front stays north of the
area as the models indicate, in central Nebraska, will only see
slight chances for showers and thunderstorms Sunday night with a
weak shortwave moving through the flow. However, if the front is
further south, precipitation chances may be higher, particularly
in southwest Nebraska. Low temperatures Sunday night will be
in the 60s and 70s.

&&

.LONG TERM /MONDAY THROUGH THURSDAY/...
Issued at 242 AM MDT Fri Jun 14 2024

For the long term, we are looking at the potential for showers and
thunderstorms almost daily next week. On Monday the area will be
caught between patterns with SW flow aloft as an upper low moves
over the Pacific Northwest and an upper high sits along the
Carolina Coast. Shortwaves traveling across the Rockies will
help strengthen a surface low expected to sit over NE Colorado.
So far, Monday seems to be dry for the Tri-State Area with ~15%
confidence and PoPs for storms to impact our northeast corner.
There are some fire weather concerns for Monday afternoon as
highs reach the 90s to around 100s. The main area of concern for
near critical to critical fire weather conditions is over the
western half of Cheyenne County, CO and potentially southwest
Kit Carson County where RH values could fall into the mid teens.
Southerly winds may gust up to 35 mph in the aforementioned
area while the remainder of the area could see gusts up to 40
mph. Overnight lows could fall into the upper 50s to lower 70s.

On Tuesday we begin to see an increase in rain/storm chances as a
cold front moves across the area during the latter half of the
day. Another cold front is expected to move over the area on
Thursday as the shortwaves continue to move over the region. The
best time frame for any showers and storms will be during the
afternoon and evening hours Tuesday through Thursday.
Temperatures on Tuesday will be in the 80s to mid 90s for highs
and the 50s to lower 60s overnight. Wednesday will have even
cooler highs thanks to the frontal passage with highs in the mid
70 to lower 80s and lows in the 50s to lower 60s. Thursday will
be similar to the prior day with highs in the upper 70s to
lower 80s and overnight lows in the 60s.

&&

.AVIATION /18Z TAFS THROUGH 18Z SATURDAY/...
Issued at 1015 AM MDT Fri Jun 14 2024

For KGLD, VFR conditions through 00z Saturday, then a MVFR/VFR
mix through 06z as rw/trw are expected. 4-6sm visibility
reduction in rain, with ceilings down to OVC025 at times. VFR
after 06z Saturday. Winds, mainly south-southeast 10-15kts.
Gusts to 25kts through 00z. Winds briefly go to southwest
15-25kts from 00z-03z. LLWS 03z-06z Saturday 200@40kts.

For KMCK, mainly VFR conditions at this time. The threat for
storms after 00z Saturday could bring in MVFR conditions from
03z-06z. VCTS possible through at least 02z-06z. Winds, south-
southeast 10-15kts. Gusts to 25kts through 02z Saturday. LLWS
02z-06z Saturday 210@60kts.

&&

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

&&

$$

SHORT TERM...024
LONG TERM...KMK
AVIATION...JN