758
FXUS63 KGLD 070905
AFDGLD

Area Forecast Discussion
National Weather Service Goodland KS
305 AM MDT Fri Jun 7 2024

.KEY MESSAGES...

- Severe weather is possible this afternoon and evening with
  hail up to two inches, wind gusts up to 70 mph, and maybe a
  tornado possible. Overall storm chances are around 50%. Severe
  weather is expected to be more isolated to scattered, not
  widespread across the area.

- Active weather pattern continues Saturday through Monday with
  similar trend of storms moving in from the west during the
  afternoon/evening.

- Potential break in the active weather pattern mid week.

&&

.SHORT TERM /THROUGH SATURDAY NIGHT/...
Issued at 301 AM MDT Fri Jun 7 2024

Current observations show a broad ridge over much of the Western and
Central CONUS. Near the surface, radar is showing a few showers
starting to develop as the southeasterly flow has advected moisture
into the area. These showers are forecast to last through much of
the early morning hours and move across the area. Severe weather is
unlikely with low instability (MUCPAE generally below 1000-1500 J/KG
) and a lack of forcing. A few thunderstorms should also mix in with
the stronger updrafts.

For the remainder of the day, the upper ridge is forecast to slowly
deamplify as a broad trough, low slides in the Northern Plains.
However, the southerly to southwesterly flow the area will get
during the day will increase temperatures quite a bit with highs
generally forecast to reach the mid to upper 90`s. A few locales
south of I-70 could see 100, but the moisture advection may keep
everything just below 100. Skies are forecast to be mostly sunny.

This afternoon and evening, the upper trough moving through the
Northern Plains is forecast to help pull and deepen the surface low
pressure over the Front Range. The low is forecast to broaden and
move over the area by the late afternoon hours. As it does, it is
forecast to pull drier air in from the west. Though it may be too
late to prevent storm development with most of the area forecast to
still see dewpoints in the 50`s and 60`s. Instead, it looks like the
key to how and where storms develop will be how quickly the low
pushes east and how broad it gets. The slower the low advances east
and the deeper it gets, the more storms the area will see and the
severe chances would increase. However, the current forecast calls
for the low to move over the area relatively quickly and broaden out
which would limit the amount of surface convergence available to
help generate storms as well as weaken the shear. Storms could be
further hampered if too much dry air in the mid levels moves in from
the west and either has storms entrain dry air or enhances a cap.

So for the current forecast, have storms generally firing up around
3pm MT in Eastern Colorado and moving east fairly quickly. The
further east storms go, the more likely they would be to be severe
with hail up to two inches, wind gusts up to 70 mph, and maybe a
tornado. Overall storm chances would be around 50% with coverage
forecast to be scattered so widespread severe weather across the
area is unlikely. In a more worst case scenario, we would maintain
midlevel moisture across the area with some low-level dry air
advection. This would lead to loaded gun soundings and allow for
much stronger storms. Chance of this looks to only be 10% so it is
more of a remote possibility.

Tonight, there could be another round of storms on the wrap around
side of the surface low and along some shortwave energy. If storms
fired ahead of this round, the environment may be worked over and
allow for a limited wind gust and Quasi Linear Convective System
(QLCS) tornado threat. If not, then both threats would be a bit
higher and would mainly affect areas north of Highway 36. the
current chance for this batch is around 30%. Once the storms move
off or dissipate, mostly cloudy skies are forecast to linger with
lows in the 50`s and 60`s.

Tomorrow, the upper trough and lows over the Norther Plains and
Canada is forecast to broaden out and creep a bit further south.
With this, the area is forecast to go to more zonal flow and have
the lower pressure push south of the area. With some cooler
air/higher surface pressure moving in, temperatures are forecast to
be cooler in the 70`s and 80`s. Cloud cover could also linger
through the day and keep temperatures a few degrees cooler than
forecast, but breaks in the clouds during the day is more likely.

For the afternoon and evening, storms are forecast to develop along
the higher terrain in Eastern Colorado as mid level moisture advects
into the area. Storms are forecast to cluster fairly quickly and
move off to the east, dissipating as they go along. The key to watch
for will be if any supercells develop or get embedded in the
cluster. In that case, initial supercells may be capable of
producing large to very large hail. As time goes on, they would
transition to a heavy rain and flooding threat given the right mover
motion is forecast to be to the southeast and slower than the main
line.

The evening and overnight hours are forecast to see storms dissipate
as low pressure moves further from the area and instability
decreases. Mostly cloudy skies are forecast to linger again with
lows in the 50`s and 60`s.

&&

.LONG TERM /SUNDAY THROUGH THURSDAY/...
Issued at 230 AM MDT Fri Jun 7 2024

Sun-Mon: A WNW-ESE elongated upper level low over the Canadian
Prairies (Alberta, Saskatchewan, Manitoba) will play a
significant role with regard to the evolution of the upper level
pattern over the Northern and Central Plains late this weekend
and early next week -- as one might infer from recent /00Z/
operational runs of the GFS/ECMWF. The GFS suggests that this
feature will slowly dig SSE through the Northern Plains (Sun)
into the Central MS River Valley (Mon) -- a cooler/wetter
pattern for the Tri-State area. The ECMWF, on the other hand,
suggests that this feature will stall in Canada, leaving a
modest upper level ridge in place over the Central Plains -- a
warmer/drier pattern for the Tri-State area. With the above in
mind.. confidence in sensible weather conditions is well below
average. Steering the forecast toward climatology appears to be
the most prudent course of action at this time.

Tue-Fri: Long range guidance continues to indicate that the
main belt of mid-latitude westerlies (and majority of
progressive shortwave energy) will be relegated to higher
latitudes.. over the Pacific Northwest, northern Rockies,
Dakotas and Upper Great Lakes (40-50N).. and that a stagnant
flow pattern will prevail at lower latitudes, over the Desert
Southwest, 4-Corners, central-southern Rockies and Central-
Southern Plains.. where several waves may be trapped /cut-off/
within. If the Tri-State area is indeed situated on the far
southern fringe of the westerlies, one would expect seasonable
conditions (i.e. climatology). It should be noted that increased
pattern complexity -- e.g. the presence of one or several cut-
off waves invof the southern Pacific Coast, Desert Southwest,
4-Corners, Southern Plains and/or Gulf Coast -- drastically
reduces forecast confidence.. especially at this range.

&&

.AVIATION /06Z TAFS THROUGH 06Z SATURDAY/...
Issued at 1038 PM MDT Thu Jun 6 2024

VAD wind profiler at KGLD shows LLWS potential increasing along
with support from RAP and GFS forecast soundings so will include
for each terminal overnight. Confidence has continued to
increase in -tsra to impact the GLD terminal so have added in a
tempo for this. Southerly winds then continue through the day
before another chance of storms moves across the area. Overall
coverage continues to remain murky so have opted to go with
VCTS as any storms look to be isolated to scattered, severe
weather may be possible as well. Winds then turn to the north
behind the storms through the end of the period.

&&

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

&&

$$

SHORT TERM...KAK
LONG TERM...BV
AVIATION...Trigg