423
FXUS63 KGLD 131822
AFDGLD

Area Forecast Discussion
National Weather Service Goodland KS
1222 PM MDT Thu Jun 13 2024

.KEY MESSAGES...

- Hot temperatures persist across the area today, mainly south
  of I-70 where highs will reach the upper 90s to lower 100s.

- Scattered storms will develop in northeast Colorado and south
  of Interstate 70 in northwest Kansas this afternoon. A few
  storms will be capable of producing hail up to quarter size
  and damaging wind gusts through the evening.

- More widespread severe weather is anticipated Friday afternoon
  and evening. Storms will develop in Colorado during the
  afternoon and move through the remainder of the area Friday
  night. Some of these storms will be capable of producing large
  hail, damaging winds and a few tornadoes. Locally heavy
  rainfall and flash flooding will also be possible.

- Return of triple digit heat expected on Sunday.

&&

.UPDATE...
Issued at 1037 AM MDT Thu Jun 13 2024

With the passage of a weak frontal boundary through the area
this morning, have opted to decrease forecasted highs by a few
degrees area-wide. Still looking for areas south of I-70 to be
warmest for today.

&&

.SHORT TERM /THROUGH FRIDAY NIGHT/...
Issued at 215 AM MDT Thu Jun 13 2024

Shallow cold front moves through the area this morning then
stalls in Colorado and along/just south of Highway 96 in Kansas.
Shortwave trough will come over the ridge axis with convective
initiation occurring in the 20-22z time frame along the front.
The environment will be weakly unstable with around 30 kts of
deep layer shear. Moisture will be somewhat limited and storms
high based, posing primarily a risk for severe wind gusts as
they drift eastward this evening. Other storms may develop in
the post frontal upslope regime as far west as the the Front
Range. These storms will be in a highly sheared environment and
a supercell or two is possible, potentially impacting Colorado
counties in the evening with a large hail/high wind/brief
tornado risk. Showers and thunderstorms wind down by 06z. High
temperatures today will barely be impacted by the so-called cold
front, ranging from the lower 90s in southwest Nebraska to the
lower 100s south of Interstate 70. Lows tonight will be in the
60s.

For Friday, a few morning showers or isolated thunderstorms are
possible, but better chances will hold off until Friday
afternoon. The ridge axis will move east with a fairly strong
shortwave trough coming out of Colorado behind it. Expect to see
a rapid increase in coverage in Colorado by late afternoon and
overspreading the remainder of the area Friday evening. Models
forecast moderate to strong instability to develop, 25000-3500
j/kg, and deep layer shear of 30-40 kts. Given the strong lift
from the shortwave and these environmental parameters, severe
thunderstorms seem likely, with very large hail, damaging winds
and a few tornadoes possible. CAMs show a couple of clusters
developing Friday evening, one lifting northeast into Nebraska
and another moving east across northwest Kansas. Heavy rainfall
will also be possible, with mean precipitation amounts for the
event ranging from around a half in Colorado to around 1 inch in
southwest Nebraska. 90th percentile QPF is between 2 and 3
inches in southwest Nebraska and along the Kansas and Nebraska
border area with the northern cluster of storms, as well as
generally south of Highway 40 in northwest Kansas with the
second cluster. Severe and flooding threats should end by around
06z with just lingering showers and isolated thunderstorms
overnight. High temperatures will be in the upper 80s to lower
90s and lows Friday night ranging from the upper 50s to middle
60s.

The shortwave trough axis will be slowly moving across the area
Saturday morning and be located in eastern forecast area by the
afternoon and time of peak heating. Scattered showers and
thunderstorms will develop in weak instability and weak shear
during the afternoon, with best chances in the east where there
will also be some surface convergence near a trough/diffuse dry
line. Cannot completely discount a marginal risk for a severe
storm or two in those eastern areas during the afternoon, but
overall risk seems fairly low for severe storms. Additional
rainfall amounts on Saturday are up to a quarter of an inch in
eastern areas (Norton to Leoti) and up to a tenth of an inch in
western areas. Precipitation winds down and moves east fairly
early Saturday evening. High temperatures will be in the lower
90s and lows in the 60s.

&&

.LONG TERM /SATURDAY THROUGH THURSDAY/...
Issued at 1221 PM MDT Thu Jun 13 2024

Saturday we will see the leftovers over the upper-level low move
through and out of the area. This could sparks up some showers and
lower end storms. The greatest potential hazard would be if this
precipitation moved over areas that had been rained on the previous
couple of day, creating a flooding risk.

Sunday, the low will clear the area and we will be under weak
southwesterly flow aloft. This will give us about a 15-20% daily
chance of precipitation due to shortwaves in the evenings, but
nothing highly organized is expected until the weak flow is
disrupted, likely Tuesday afternoon. Around this time, the pressure
gradient tightens up as the low over the NW CONUS pushes farther
inland. This would work to amplify any disturbances and increase
chances for PoPs. By mid-next week, we could see the low moving into
the Great Plains and sending a cold front through the region. This
would spark up some storms and start cooling temperatures down some.

High temperatures until mid-next week look to be in the low 90s to
low 100s. After the cold front moves through, after Tuesday, we will
likely only warm into the 80s and low 90s. Overnight temperatures
will follow a similar pattern and drop into the 60s to low 70s each
night, save for Sunday night. Sunday night, additional cloud cover
and fairly strong winds from the south are expected to keep
temperatures in the mid 60s to mid 70s. Gusts overnight could get up
to 30 kts. Behind the cold front, lows will cool down into the mid
50s to low 60s.

&&

.AVIATION /18Z TAFS THROUGH 18Z FRIDAY/...
Issued at 1000 AM MDT Thu Jun 13 2024

For KGLD, looking for mainly VFR conditions through much of the
forecast period. MVFR ceilings probable from 13z Friday onward.
Also, scattered thunderstorms are also possible this evening.
With confidence on timing/placement of any storms low, will
leave off mentioning and update later in the forecast. Winds,
north 10-15kts through 20z, then east-northeast 10-20kts. From
13z Friday onward, east-southeast around 10kts.

For KMCK, VFR conditions expected through the forecast period.
Winds, northerly 15-25kts through 20z before shifting
northeast. From 00z-14z Friday, northeast around 10kts then
shifting to the southeast thereafter.

&&

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

&&

$$

UPDATE...JN
SHORT TERM...JN
LONG TERM...CA
AVIATION...JN