502
FXUS63 KGLD 291117
AFDGLD

Area Forecast Discussion
National Weather Service Goodland KS
517 AM MDT Sat Jun 29 2024

.KEY MESSAGES...

- Cold front passage today leads to cooler temperatures.

- Cold front early Sunday morning retreats as a warm front with
  showers and storms; heavy to torrential rain possible.

- Daily chances for storms continues Sunday through the next
  week.

- Triple digit temperatures Monday.

&&

.SHORT TERM /THROUGH SUNDAY NIGHT/...
Issued at 306 AM MDT Sat Jun 29 2024

Convection ongoing mainly south of I-70 is being aided by the LLJ
does look to continue through around sunrise. No hazards are
currently anticipated other than heavy rainfall and some gusty
winds around 40 mph. Storms have been precipitation loaded,
causing some locales to see torrential rainfall with KDP values
in excess of 10. Currently watching a front move into the area
from the north and will move south through the morning hours.
RAP has been consistently showing a transient period of fog,
locally dense is possible followed by stratus behind the front
so have added in a quick moving area of fog that is currently
forecast to be out of the area (Greeley, Wichita counties) by
late morning. Cooler temperatures in the 80s are currently
forecasted across the entire area today. RAP has been showing
some 700-500 mb moisture moving into SE portions of the area
which may support some quick pop up showers this afternoon which
given the lack of any forcing will be quick in duration and not
amount to more than a hundredth or two of precipitation at
best. Due to spotty nature of this signal thus far have silent
pops in the forecast.

Tonight, the cold front looks to retreat back north as a warm front.
Some subtle 700mb forcing along the leading edge of the front
looks to develop scattered to numerous storms along the front.
Increasing lapse rates as well overnight may support some hail
threat with the strongest storms but due to the overall lack of
CAPE and meager shear think nickel sized hail would be the max
hail size. Very heavy to torrential rain looks to occur as well
as winds will become southeasterly allowing a strong amount of
moisture return to move into the area.

Sunday morning, the atmosphere stabilizes in a widespread area of
stratus and perhaps some localized fog. Currently leading towards
stratus as winds will be above 10 mph. Soundings look to be very
saturated throughout the profile with the exception of some drier
air around the 700 mb level which looks to create light rain or just
drizzle throughout the majority of the day for those east of Highway
27 and south of I70. RAP surface and 850mb RH values look to remain
nearly saturated throughout the duration of the day which
should help keep the stratus thick and temperatures cool as a
result. Have begun the trend of lowering temperatures across
the east down into the mid to upper 70s. There may be some
breaks in the clouds during the late afternoon/early evening
hours which would let the temperature rise some. If these breaks
don`t happen then highs may need to be lowered even more,
interestingly enough the NAM is still keeping highs across the
east only in the mid 60s. Some record coldest high temperatures
may be in jeopardy if the stratus does indeed hold thick.

There does continue to be some variations of where the western
periphery of the stratus deck will lie; those that are not in
stratus will continue to see the strong moisture advection move
into the area as a surface high across the southern Plain/SW
Kansas begins to redevelop. A developing trough across the
Inter-Mountain west will lead to a tight gradient developing
which may end up being the stratus line. A 700 mb shortwave off
of the Rockies looks to develop showers and storms off of the
Front Range and looks to move towards the Colorado Plains. Wind
shear will be supportive of some organization of storms
especially the further west towards the Front Range you go,
however there may be a narrow plume of better instabilty across
eastern Colorado where storms may become more intense as they
ride around the surface high. So the main question for coverage
will be how amplified will the surface high be. A more amplified
high would lead to more subsidence leading to less storms, less
amplified would lead to more storms.

&&

.LONG TERM /MONDAY THROUGH FRIDAY/...
Issued at 354 AM MDT Sat Jun 29 2024

Another somewhat active period is in store next week with almost
daily chances for showers and storms across the Tri-State area.  An
omega pattern is expected to remain over the CONUS through midweek
with an upper high sitting over the Southeast and portions of the
Southern Plains. The Tri-State area will be caught in between the
trough over the Northwest CONUS and the aforementioned high. The
trough will eventually flatten the ridge to confine it over the
Southern CONUS while the trough axis slowly moves over the High
Plains Wednesday and Thursday. The ECMWF stalls the trough over the
region a bit longer, but I`m leaning more towards the GFS which only
stall for a day. Another area of high pressure is expected to
develop over the Southwest CONUS Friday, extending north to the
Canadian border by Saturday. Monday through Wednesday, shortwave
disturbances will travel across the Central High Plains that will
interact with a surface trough along the Front Range and help boost
precipitation chances for the area.

On Monday a warm front is expected to set up along to just east of
Hwy 83. East of the front will be the preferred area for convection
with the GFS and NAM showing an axis of 1500-2000 J/kg of Surface
Based CAPE. Up to 1500 J/kg of CAPE are possible west of the front
which will help make showers and storms possible for the
remainder of the area. A cold front will move over the area late
Monday into Tuesday. Dry conditions are anticipated for much of
the day Tuesday, with showers and storm chances increasing to
around 45-50% during the evening to overnight hours. Showers and
storm chances could continue throughout the day Wednesday while
another surface low sets up over the forecast area Thursday
morning. During the day on Thursday, we should be mostly dry
with chances returning (low to medium confidence) during the
evening hours. Friday has the lowest confidence and chances for
precipitation given the uncertainty for how fast the upper
trough moves through and the high develops over the Western
CONUS.

Monday is expected to be the hottest day of the week with highs in
the mid 90s to lower 100s. Heat indices up to 104 degrees are
possible Monday afternoon, so we will continue to monitor for any
Heat Advisory potential, especially east of Highway 25. Monday night
lows are forecast to be in the 60s to mid 70s. With the frontal
passage, temperatures should be slightly cooler Tuesday with highs
in the upper 80s to 90s and overnight lows in the 60s. Wednesday
should be even better with highs in the upper 80s to around 90
degrees and lows in the upper 50s to mid 60s. Thursday starts to
warm back up with similar temperatures to Tuesday with Friday
potentially having a similar temperature forecast to Wednesday.

&&

.AVIATION /12Z TAFS THROUGH 12Z SUNDAY/...
Issued at 512 AM MDT Sat Jun 29 2024

Stratus is rapidly developing along/in wake of a passing cold
front with mainly MVFR ceilings being seen with some isolated
IFR especially on the western portion of the area. Some patchy
fog is also possible due to the recently saturated boundary
layer; although some uncertainty on coverage of fog due to dew
point depressions in excess of 5 degrees in spots and and wind
around 10 knots.

Stratus will end north to south throughout the morning along
with the wind slowly becoming more easterly. The cold front will
retreat north tonight as a warm front bringing storm potential
back, some dry air may be in place across KGLD so will leave
VCTS for now. A little more doubt in the northern extent of the
storms tonight so will leave KMCK dry for now. Strong signal
for stratus returning towards the end or just after the end of
this TAF period.

&&

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

&&

$$

SHORT TERM...Trigg
LONG TERM...KMK
AVIATION...Trigg