712
FXUS63 KGLD 020824
AFDGLD

Area Forecast Discussion
National Weather Service Goodland KS
224 AM MDT Thu May 2 2024

.KEY MESSAGES...

- Scattered thunderstorms are anticipated to develop over
  portions of northeast CO and northwest KS Friday afternoon.
  Severe storms capable of producing damaging winds are
  possible, mainly late Fri aft/eve, when storms may increase in
  coverage and track SE toward southwestern and south-central KS.

&&

.UPDATE...
Issued at 1250 AM MDT Thu May 2 2024

As of 1235 AM MDT (0635 UTC).. appreciable convection has
exited the NWS Goodland county warning area. Additional
development is not anticipated. As a result, Severe Thunderstorm
Watch 174 has been cancelled.

&&

.SHORT TERM /THROUGH SATURDAY NIGHT/...
Issued at 200 PM MDT Wed May 1 2024

Most of the area remains cloudy and cool this afternoon, with
some clearing noted on satellite across southern and western
portions. A warm front was surging northward across southwest
Kansas, and at 19z was roughly along a Garden City to Jetmore
line. Meanwhile, a cold front was moving out of the Colorado
Front Range in response to an upper level shortwave trough.

Not much has changed from previous thinking. The warm front to
the south has a chance of reaching southern Logan and Gove
counties by later this afternoon, which would potentially put
them in the warm sector which is very unstable. Latest RAP
analysis shows up to 3000 j/kg in that area with bulk shear
values of up to 60 kts. In fact, latest runs of the HRRR and RAP
show initiation occurring by 21-23z around the Lake Scott area.
Any discrete supercell in that location would be capable of
producing large hail, damaging winds and perhaps a tornado.
Those storms seem to fade by 02-03z, and attention turns to the
northwest where more widespread convection will be getting
underway in response to the upper dynamics and surface cold
front. While storms may initially be surface based, expecting
mostly elevated storms this evening across much of northwest
Kansas and southwest Nebraska. MUCAPE values will be around
1500-2500 j/kg and shear values around 60 kts. So elevated
supercells will certainly be possible, capable of producing
large to very large hail and perhaps a few isolated damaging
wind gusts. This risk will move east through the late evening
hours and spill into the overnight hours in far eastern areas
like Norton and Graham counties, finally exiting to the east by
07-09z. There will also be a risk of excessive rainfall in the
northeast part of the area, particularly from McCook to Oberlin
and Norton, where mean rainfall amounts are around 1 inch and
90th-95th percentile rainfall amounts are in the 1 to 2 inch
range. Low temperatures will range from the upper 30s in
Colorado to the middle 40s in north central Kansas.

Thursday will be breezy in the morning, then diminishing winds,
mostly sunny and mild in the afternoon with highs in the 60s. A
weak shortwave trough comes out of Colorado in the afternoon and
evening hours bringing a chance for scattered showers and
perhaps an isolated thunderstorm through the evening and
overnight, with best chances in northeast Colorado. Low
temperatures will range from the upper 30s to lower 40s.

The pattern does not change much on Friday. Another shortwave
trough moves out of the Rockies in the afternoon, a bit stronger
than the one on Thursday, with increasing chances for showers
and thunderstorms with the associated surface cold front.
Showers and storms will be likely by Friday night as the front
moves through the area. Surface based instability will be rather
limited, generally under 1000 j/kg is forecast ahead of the
front, but deep layer shear values will be 40-50 kts. Those
parameters may be sufficient for a few severe storms capable of
producing hail up to quarter size and gust winds. Instability
rapidly decreases after about 03z as the front races southeast,
probably ending the severe threat. High temperatures will be in
the upper 60s to lower 70s and lows Friday night ranging from
the lower 30s in northeast Colorado to the middle 40s in north
central Kansas.

&&

.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
Issued at 217 AM MDT Thu May 2 2024

Saturday morning the area is under west-southwesterly flow aloft
with upper level ridging now centered over the Intermountain West
and the next low pressure system off the coast of the Pacific
Northwest. After a mostly dry day Saturday with high pressure moving
across, weak waves will then move through the flow in the Saturday
evening-Sunday timeframe and may trigger a few showers and
thunderstorms (~20-30% chance). Sunday afternoon-evening the upper
low progresses across the Great Basin. Breezy to windy conditions
are expected Sunday into Monday due to the tightening gradient
between high pressure moving off to the east and a developing low in
the lee of the Rockies. Current forecast calls for gusts to around
30-40 mph. Into the first part of the work week, winds of this
magnitude may create critical fire weather conditions, mainly
focused across west and southwest portions of the area where
relative humidity is forecast to drop into the 10-20% range. Also
expecting showers and thunderstorms for parts of the area on Monday.
Some uncertainty remains in position of the surface low which would
influence severe potential. If any part of the CWA would be favored
to see strong to severe storm potential, expecting it`d be
across the eastern 1/3 to 1/2 of the area where CAPE values to
around 1000-2000 J/kg coincide with better moisture and ample
shear. Current confidence is low as the latest guidance has
trended the surface low farther east, and the severe potential
for our CWA hinges on its timing/ placement. Will continue to
monitor as guidance comes in better alignment. SPC`s current Day
6 (Monday) 15% risk is east of the area, from southwest
NE/eastern half of KS/central OK.

Tuesday-Wednesday may again have potential for portions of the area
(mainly west and southwest) reaching near-critical to critical fire
weather conditions with RH forecast in the teens and winds gusting
25-35 Tuesday and to around 25 mph Wednesday.

For temperatures, highs are forecast generally in the 60s for
Saturday before undergoing a warming trend into the 70s to low 80s
by the start of the work week, ever so slightly cooler Wednesday-
Thursday. For low temperatures, expecting low-mid 40s Sunday
morning, into the upper 40s to middle 50s Monday morning, and
upper 30s to mid-upper 40s Tuesday, Wednesday, Thursday
mornings.

&&

.AVIATION /06Z TAFS THROUGH 06Z FRIDAY/...
Issued at 1104 PM MDT Wed May 1 2024

IFR conditions expected due to storms and/or low ceilings
through sunrise over KMCK and KGLD. KMCK may be impacted from
~05Z-08Z by thunderstorms moving at least within the vicinity of
the terminal. Thunderstorm wind gusts up to 60 mph would be the
main hazard; however, confidence in severe storms impacting the
terminal are low to medium. Low ceilings will persist through
the overnight hours as the storm system moves east out of the
West-Central High Plains. Ceilings are expected to improve to
VFR from west to east over both terminals early beginning ~11Z
for KGLD and ~15Z for KMCK.

&&

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

&&

$$

UPDATE...BV
SHORT TERM...024
LONG TERM...CC
AVIATION...KMK