744
FXUS63 KGLD 162000
AFDGLD

Area Forecast Discussion
National Weather Service Goodland KS
200 PM MDT Mon Sep 16 2024

.KEY MESSAGES...

- Warm and windy conditions are forecast for today and Tuesday
  with highs generally around 90. Winds are forecast to gust to
  30-40 mph today and 35-50 mph tomorrow.

- Storms are possible during the afternoon/evening hours today
  and tomorrow, though tomorrow has the better chance (40-80%).
  Severe weather is possible tomorrow with gusts up to 65 mph
  possible.

- Rain chances and cooler temperatures next weekend.

&&

.SHORT TERM /THROUGH THURSDAY NIGHT/...
Issued at 308 AM MDT Mon Sep 16 2024

The short term forecast remains active with strong winds the next
two days and chances for storms.

Early morning storms continue to impact eastern portions of the
area, largely driven by the presence of low/mid level moisture and
lower level convergence cause by the LLJ. Storms have been sub-
severe and the increase in winds saw earlier this evening has not
been occurring so the jet does not appear to be mixing down as
efficiently. These storms should leave the area around or shortly
before sunrise.

For the morning and early afternoon hours, skies are forecast to
initially clear off underneath southwest flow aloft and allow
temperatures to warm around 90. Meanwhile, the upper low/trough over
the Western CONUS is forecast to begin shifting slightly to the
east. This will tighten the height gradients over the area and allow
winds to strengthen to around 30 kts in the 850-700mb layer. With
the heating and mixing through the day, this will allow for surface
wind gusts up to 35-40 mph through the day.

Later in the afternoon and during the evening, the area will have
another chance for storms with lower pressure along the Front Range
creating a convergence zone along the Palmer divide as the southwest
flow brings in some mid-level moisture from the southwest. The low
level jet is forecast to develop again during the evening hours and
help carry storm chances east across the area. Coverage is currently
forecast to be isolated to scattered with the overall lack of
forcing and drier air in the lower levels. But similar to recent
days, will need to keep an eye for how much the jet enhances storm
development and maintenance. Storms should generally remain sub-
severe with gusts generally below 50 mph, but a storm or two could
produce a gust up to 60 mph. I`m more worried about a scenario
similar to yesterday evening where the jet may briefly mix down
before the inversion fully sets up. In short, expect another windy
evening. The rest of the night will see storm activity slowly taper
off and lows drop into the 60`s while winds remain somewhat elevated
around 15-20 mph as the upper trough moves closer to the area.

Tuesday, the upper low is forecast to move through the Rockies. This
will continue to tighten the height gradients with winds around 40
kts possible in the 850-700mb level. With clear skies to start,
ample mixing should occur and allow for surface wind gusts around 35
to 50 mph through the day. Temperatures are forecast to warm to
around 90 again no warm air advection as the system nears.
Widespread/concentrated blowing dust is not expected as local
research suggests the winds are just weak enough with 2km lapse
rates to steep to contain any dust. However, any recently plowed
field or source region for dust may see localized visibility
reductions.

Later Tuesday afternoon and into the evening, the upper trough and
surface low pressure system are forecast to swing through the area.
With the upper southwest flow bringing in moisture and the brief
southeasterly surface flow forecast to bring in some moisture,
storms are expected to fire up along the Palmer Divide and then
track east through the area. As long as storms don`t gust out and
surface winds ahead of the line of storms maintain a more
southeasterly orientation, there should be enough moisture and lift
to have decent storms move through as a line or multiple clusters.
This will give the area a good chance for rain with POPs generally
in the 40-80% range. Severe storms will be possible more with the
earlier storms in Eastern Colorado and counties just to the east
when there is a higher chance of storms being organized or discreet.
Overall instability is forecast to be marginal (MUCAPE around 1500
J/KG) with effective shear low to generally unidirectional winds.
However, the overall strong flow and roughly linear mode will make
it possible to see a few gusts to 65-70 mph. As a side note,
previous events have shown that winds tend to be sub-severe when the
overall surface flow is strong until near or after sunset. In short,
a chance for marginally severe storms moving across the area is
possible.

Tuesday night should see storms exit the area around or shortly
after 2-3am central time. As the upper trough continues to lift
north, the surface gradient is forecast to weaken as the main low
pressure center lifts north as well. As long as the inversion sets
up, the stronger winds aloft should also decouple through the night
and allow winds to lower getting close to sunrise. This should allow
for lows in the 50`s for any locales that have storms clear out
earlier in the night.

&&

.LONG TERM /FRIDAY THROUGH MONDAY/...
Issued at 200 PM MDT Mon Sep 16 2024

Upper low in the Four Corners to start the period on Friday will
move into the central Rockies on Saturday and into the central
plains on Sunday. Northwest flow will then follow for early
next week on the back side of the system as it lifts into the
northern plains.

Precipitation chances Friday through Sunday will be the primary
forecast concern. Will start with southwest flow on Friday ahead
of the main system. Embedded waves and a frontal boundary will
combine for scattered showers and storms. Best moisture and
instability look to stay just southeast of the area, with more
of a dry southwest flow further north. If that holds, severe
chances will be low due to limited instability, though wind may
still be a concern with the high based storms. Cold front moves
through Friday night through Saturday morning (the usual timing
differences in the models), but by mid day Saturday should see a
post frontal regime across the area with breezy northeast winds.
Main upper low will move out of the Rockies Saturday afternoon
or Saturday night, accompanied by good chances for
rain/isolated thunderstorms. Severe storms not expected due to
the cooler/stable conditions. However, some signals in the
models for locally heavy rainfall, but exactly where the best
chances will occur uncertain due to the model differences in
track, strength and timing of the system. Precipitation chances
may linger well into Sunday depending on how fast the system
lifts out. A dry northwest flow will follow on Monday.

Temperatures remain above normal on Friday with upper 80s to
lower 90s. Quite a large range in temperatures in the models
for Saturday through Monday, with the ECMWF slower/warmer
overall compared to the wetter/cooler GFS solution. The blended
forecast essentially yields temperatures near normal, with highs
in the 70s to lower 80s and lows in the 40s and 50s.

&&

.AVIATION /18Z TAFS THROUGH 18Z TUESDAY/...
Issued at 1050 AM MDT Mon Sep 16 2024

KGLD...VFR conditions are expected through the period. Southerly
winds gusting to 35kts are anticipated from taf issuance through
sunset, subsiding a bit but still gusty overnight through
sunrise Tuesday morning. Southerly winds quickly increase after
sunrise with gusts up to 35kts. Presently, showers/thunderstorms
will be possible near/over the terminal in the 23z-01z
timeframe. The primary hazard will be strong wind gusts,
potentially severe, along with blowing dust that could produce
significant reductions in visibility. Should this occur, sub VFR
cigs and vis would be likely.

KMCK...VFR conditions are expected through the period. Southerly
winds gusting up to 35kts are anticipated from taf issuance
through sunset with winds subsiding some through sunrise Tuesday
morning. Southerly winds quickly increase after sunrise with
gusts up to 35kts. Presently, showers/thunderstorms will be
possible near/over the terminal in the 01z-02z timeframe with
gusty outflow winds the primary hazard.

&&

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

&&

$$

SHORT TERM...KAK
LONG TERM...024
AVIATION...99