097
FXUS63 KGLD 311151
AFDGLD

Area Forecast Discussion
National Weather Service Goodland KS
551 AM MDT Fri May 31 2024

.KEY MESSAGES...

- Strong to severe storms remain forecast for both today and
  Saturday. Storms will generally form in Eastern Colorado
  during the afternoon and evening hours and move east. Flooding
  remains a concern with heavy rainfall the last few days and
  more heavy rain possible.

- Much warmer with 20%-40% chances for thunderstorms Sunday
  through Tuesday. Sunday could see severe storms. Highs in the
  80s and 90s.


- Generally drier Wednesday and Thursday with highs in the 80s.

&&

.SHORT TERM /THROUGH SATURDAY NIGHT/...
Issued at 248 AM MDT Fri May 31 2024

The short term pattern is forecast to remain much of the same with
mostly zonal flow aloft over the area. Henceforth, daily chances for
storms and near average temperatures are forecast for today and
tomorrow.

As of 2am, there were two lines present across the area around
Highway 83 and in Eastern Colorado. A third line may develop as the
two outflow boundaries are nearing each other. This may cause storms
to persist through the early morning hours and maybe even a little
past sunrise for Eastern portions of the area. The forecast will
hinge on what happens with these storms as the additional moisture
in the air column (along with near surface flow advecting moisture
in from the east) could keep the area cloud covered and keep
temperatures in the 70`s. Otherwise, areas that see sun for most of
the day could warm to around 80. The other thing to watch with these
early storms is for outflow boundaries to kick out which could spark
storms through the day, especially with the low level moisture
present. So currently have a 20% chance for storms through the day
in NW Kansas and SW Nebraska as any boundary could spark a storm.
Storms would be unlikely to be severe during the morning and early
afternoon, but the chance isn`t zero.

The higher chance for storms is this evening as storms are forecast
to develop in the higher terrain of Eastern Colorado and move east
into the area. The setup is pretty similar to last evening, however
surface winds may be a bit more from the south and contribute to
higher effective shear for the area. This would increase the threat
for large hail up to two inches at least initially until storms move
off to the east and potentially cluster. Even with the larger hail
possible, most hail would likely be below 1.5 inches with lots of it
and heavy rain possible. A few wind gusts to 65 mph are also
possible, but chances look similar to last evening which is low.
Storms are forecast to slowly move southeast and exit the area
within a few hours of midnight.

Tomorrow, some of the forecast will depend on how long storms linger
tonight. If storms don`t linger and there aren`t boundaries moving
through the area, Saturday should see partly cloudy skies through
the day. Highs would warm into the low to mid 80`s. The afternoon
and evening hours would then bring another chance for storms with a
similar scenario of storms forming over Eastern Colorado and moving
east. There could be a few additional isolated to scattered storms
ahead of the main line as instability is forecast to be greater with
the warmer temperatures and moisture availability remaining roughly
the same. With instability forecast to be higher and effective shear
also forecast to be higher, storms could produce larger hail
(potentially greater than 2") and survive enough to move across the
entire area. Wind gusts to 70 mph and a tornado or two could be
possible (though tornado parameters continue to look weak in the
forecast). As with the previous days, heavy rain and flooding will
be a concern for most of the area given recent heavy rains.

&&

.LONG TERM /SUNDAY THROUGH THURSDAY/...
Issued at 248 AM MDT Fri May 31 2024

For Sunday through Tuesday, the upper flow continues to be forecast
to be mostly zonal, though some slight ridging followed by a low
amplitude trough is forecast for Sunday. The slight ridging Sunday
and the development of a low pressure center north of the area is
forecast to switch our lower level flow to out of the southwest.
This would help bring in some warmer and drier air into the area.
That being said, the drier air looks to be confined to Eastern
Colorado (if it moves in at all) with surface dewpoints remaining in
the 50`s and 60`s for the rest of the area. With high temperatures
forecast to reach the low 90`s and maybe even the mid 90`s, Eastern
Colorado could see RH drop into the mid teens. Critical fire weather
conditions for that area would be a concern, but the recent rains
will likely limit any potential for rapid fire growth. Storms would
then develop where the moisture remains and track east across the
area along with the upper trough. Severe weather would be likely
with these storms. Monday and Tuesday are forecast to be a tad
cooler, though still near 90 with storm chances both days. However,
moisture availability may begin to lower with will lower storm and
severe chances, though Tuesday may be aided by another upper trough
and surface low.

Wednesday and Thursday are currently forecast to see ridging develop
over the area. There is some uncertainty with where the ridge axis
would be and if an upper low forecast to be over the Great Lakes can
deepen and dig west. As long as the ridge begins to influence the
area, warmer temperatures, drier air, and lower storm chances would
become more likely.

&&

.AVIATION /12Z TAFS THROUGH 12Z SATURDAY/...
Issued at 528 AM MDT Fri May 31 2024

For KGLD... VFR conditions are forecast through the period,
though will have to watch for some lower ceilings this morning.
The storms should have prevented ceilings from lowering, but
earlier guidance was suggesting a period of ceilings around
500ft. Otherwise, storms are possible from 22-04Z, but most
likely around 00Z. Storms could be severe with large hail and
wind gusts to 70 mph. The rest of the night is forecast to have
VFR conditions and relatively light southeasterly winds.

For KMCK... VFR conditions are forecast through the period, will
need to watch for lowering ceilings and a brief round of showers
through the morning hours. Then this afternoon/evening, storms
are possible from 21-06Z with the most likely time around 00Z.
Once the storms pass, VFR conditions with light southeasterly
winds are forecast.

&&

.HYDROLOGY...
Issued at 528 AM MDT Fri May 31 2024

Still have concerns with flooding through the weekend. Multiple
advisories and a few warnings were sent out last night as most
of the area received another 1 to 4 inches of rain. Compounding
this with the multiple inches of rain received the prior days
have left parts of the area with 50-75% soil saturation, leaving
them more prone to flooding.

The potential help the next few days is that the forecast
soundings have downshear vectors around 40-45 kts which is much
faster than the previous days and would require more efficient
storms to produce more than two inches. Will have to watch for
storms clustering and training over areas as this would offset
the faster motion. So far the chances aren`t watch worthy, but
the flooding threat continues.

&&

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

&&

$$

SHORT TERM...KAK
LONG TERM...KAK
AVIATION...KAK
HYDROLOGY...KAK