291
FXUS63 KGLD 102246
AFDGLD

Area Forecast Discussion
National Weather Service Goodland KS
446 PM MDT Mon Aug 10 2026

.KEY MESSAGES...

- Air temperatures nearing 100-105F are forecast through
  Tuesday. Heat indices may approach/briefly meet 105F along
  and east of Highway 83 in Kansas.

- Repeat of yesterday with the storm activity this
  afternoon/evening; straight- line wind gusts being the
  primary threat.

- Storm chances continue daily the next few days.

&&

.UPDATE...
Issued at 349 PM MDT Mon Aug 10 2026

In collaboration with SPC, have issued a severe thunderstorm
watch for the west half of the forecast area through 11 PM MT.
Confidence for severe wind production falls as storms move out
of CO, but the question is how far east will the severe wind
threat extend.

Latest hourly models are suggesting a cluster of storms move
into the forecast area from the north, similar to last night.
Moderate confidence if that will happen. If it does Red Willow
County may need to be added to the watch.

&&

.SHORT TERM /THROUGH TUESDAY NIGHT/...
Issued at 1139 AM MDT Mon Aug 10 2026

Upper air analysis shows the ridge over the Four Corners Region
becoming more flat than yesterday.  Water vapor imagery shows a
corridor of moisture extending west from the forecast area toward
the mountains; cloud cover is increasing in this corridor.

This afternoon the cloud cover should persist into the mid afternoon
before clearing some.  There may be a couple hour clearing in the
clouds before the next round of storms move in from the west. The
lingering cloud cover may allow temperatures to be a few degrees
cooler than what is forecast.  Meanwhile the line of storms should
move into the forecast area around 5 PM. The environment looks very
similar to yesterday, high cloud bases low level jet (LLJ) nose
forming to the south late afternoon, and an upper level short wave
trough moving in this evening.  Dew points continue to be higher
going north in the forecast area, and deep layer shear slightly
increases northward too.  Main threat will be wind gusts up to 70
MPH with any storms.

This evening the upper level short wave trough continues moving
eastward across the forecast area, filling as it exits CO. Meanwhile
the LLJ nose will move northward.  This added source for convergence
should cause storm coverage to increase, or atleast remain the same
as the storm wave trough fills.  A secondary effect will be the LLJ
nose limiting how far east the storm activity will go.  With the
short wave trough filling, am not expecting storm activity to
continue much past the LLJ nose during the evening.  Where the LLJ
nose sets up will determine the eastward extent of the storm
activity.  Storm activity should end before midnight.

There may be a rather narrow window for large hail to occur this
evening.  As the storm activity moves east the deep layer shear will
weaken as the winds decline with the ridge strengthening.  The large
hail threat should decline as the deep layer shear weakens.  Am
thinking the hail should be quarter size at largest.

Model ensembles focus the severe wind threat over CO, with the wind
threat declining as storms exit CO.  This seems reasonable given the
upper level short wave trough weakening as it moves eastward with
the ridge strengthening.  The high end value for wind gusts is 70
MPH, with the mean value being around 40 MPH

Models did a poor job with the timing of the storm activity
yesterday and last night.  Given the same environment, confidence is
moderate that the current timing will be accurate.  If the same
trend continues from yesterday, the storms will move in one to two
hours later than what is forecast.

Tuesday will be similar to today.  The ridge will remain unchanged
and possibly intensify slightly more.  Meanwhile another upper level
short wave trough will move in from the west during the late
afternoon/early evening.  The model data differs regarding how
strong this trough will be; if it will only extend over the
southwest part of the forecast area or if it will extend over all of
Eastern CO. Current model guidance is favoring the short wave trough
only being over the far southwest part of the forecast area. However
the data yesterday did kept the short wave trough shallow enough to
not even move into the forecast area.  Straight-line winds will
continue to be the threat with any storms that form.

Highs for Tuesday afternoon will be a few degrees warmer than today.
The heat index values are forecast to briefly reach 105F for
locations east of Highway 83.  Currently am not anticipating needing
an advisory as the heat has been communicated other ways already.

&&

.LONG TERM /WEDNESDAY THROUGH MONDAY/...
Issued at 230 PM MDT Mon Aug 10 2026

Wednesday is looking to be our final day of unseasonably warm
temperatures for the county warning area (CWA). High temperatures
are forecast in the 90s to 100s Wednesday. Winds will overall be
light, but afternoon gusts around 25 mph are possible for the
northwest CWA. After Wednesday, our region is forecast to
transition to a weak ridging pattern aloft with ensembles showing a
persistent surface low setting up somewhere in western Kansas. This
will start a much needed cooling trend for the CWA. High
temperatures are forecast in the 80s to 90s for Thursday. The
cooling trend continues through the weekend with high temperatures
forecast in the 70s to 80s Friday through Monday.

Starting Wednesday afternoon and continuing through the end of the
forecast period, chances for precipitation are plentiful throughout
the entire CWA. Currently, the the Storm Prediction Center (SPC) has
our CWA outlooked for varying degrees of severe weather potential
with the northern CWA being the highest at a slight risk of severe
weather for Wednesday. Model soundings are showing less than 1000
J/kg of CAPE, 0-6 km shear around 30-40 knots and strong low to mid
level lapse rates. Main hazards are expected to be large hail and
severe winds if storms are able to form. Where the best chances for
severe weather to occur will ultimately be dependent on where
in western Kansas the surface low sets up. If the low sets up a
bit further south, severe weather coverage could increase south
of I-70. Model soundings are also showing precipitable water
values above 1 inch throughout the CWA. Heavy rainfall and
flooding potential will be a concern for any storms that form,
regardless of severity. Slow moving storms and any training
storms will have the highest potential for flooding.

Thursday through at least Sunday, chances for showers and
thunderstorms continue for the area due to multiple rounds of
embedded shortwaves passing through the region. The late afternoons
and evenings will be our best chances for precipitation each day with
PoPs maxing out around 80% for the western CWA and decreasing
further east. With multiple days of widespread precipitation in the
forecast, flooding potential will need to be monitored.

&&

.AVIATION /18Z TAFS THROUGH 18Z WEDNESDAY/...
Issued at 430 PM MDT Mon Aug 10 2026

VFR conditions forecast for the TAFs. Storm timing continues to
be the focus for the TAFs. Timing should be fairly
representative for KGLD based on the storms to the west. KMCK is
a bit more tricky for timing as this is based on storms that
have yet to form. Did include a mention of wind gusts for both
sites given the environment and what happened yesterday.

There still looks to be a potential for fog at KMCK. So far the
fog potential is northeast of the site, so will keep the
visibility at VFR for now.

&&

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

&&

$$

UPDATE...JTL
SHORT TERM...JTL
LONG TERM...Rhoades
AVIATION...JTL