159
FXUS63 KGLD 140801
AFDGLD

Area Forecast Discussion
National Weather Service Goodland KS
201 AM MDT Wed Aug 14 2024

.KEY MESSAGES...

- Another round of strong to severe storms this evening
  currently favoring north of I-70; all hazards are possible,
  including flooding.

- The weekend and early next week are forecast to see lower
  precipitation chances and high temperatures return into the
  90`s and maybe the 100`s.

&&

.SHORT TERM /THROUGH FRIDAY NIGHT/...
Issued at 1159 AM MDT Tue Aug 13 2024

Dense cloud cover is persisting throughout most of the Tri-
State area, but southwesterly winds are slowly clearing it out.
Central portions of the CWA can expect some direct sunlight in
the afternoon, but the far northeastern CWA will likely remain
cloudy all day.

Jumping right into the severe thunderstorm threat today, it
appears we will have two separate forcing mechanisms firing off
the storms that will eventually merge into one. Nearly all CAMs
are showing a very similar development this evening with timing
and specific parameters being slightly different between the
models. As a result, confidence is fairly high regarding the
early storm track.

The area that looks to fire off first will be in the
south-central or southwestern CWA, starting around 0-1Z. The
850mb LLJ looks to spark a few (2-5) isolated storms that will
move to the northeast. Looking at 16Z HRRR and 12Z NAMNEST
sounding for the south-central CWA at 2Z, all hazards will be
possible. Effective inflow layer, 0-1 km, and 0-3km shear are
around 25 kts and EBWD is around 45 kts. PWATS are 1.5+ inches
and MLCAPE is around 2650 J/kg. If these storms are able to form
free of any competing updrafts and not cluster together, hail
up to 2 inches would be possible, as would a tornado or two.
The hail threat will be severely limited by the 16,000-18,000
foot moist melting layer, but that increases the potential for
torrential rainfall. Storm motion looks to be around 35+ kts
and these look to be isolated cells or clusters, so the threat
for training storms causing flash flooding is low. These storms
will likely (90% confidence) be ingested by the the second wave
of storms from the east around 4Z.

The second wave of storms will be more widespread and look to
form to the west of the CWA and move east-northeast into the
CWA. These storms will be forced by a lee low ejecting off of
the Rockies. These storms will be in more of a linear
formation. These storms look to enter the western CWA around
1-2Z, absorb the first storms around 4Z, and proceed across the
northern half of the CWA. The storms look to last all night, but
the best time for severe weather to occur from this second wave
will be between 3-7Z. As far as hazards, 70 MPH winds, 1 inch
hail, and a brief QLCS tornado will all be possible. A sounding
from the 16Z HRRR and 12Z NAMNEST in northern Yuma county for 3Z
show around 1,600 J/kg of MLCAPE, PWATS near 1.6 inches, and
EBWD around 30 kts. 0-3 shear looks to be around 20-25 kts from
the south, which is nearly parallel to the orientation of the
storm, lowering confidence on the QLCS tornado potential. The
motion of these storms is concerning for flooding reasons. While
the system as a whole will be progressing to the east-
northeast, the downshear motion will be from the southwest, the
orientation of the line itself. This causes a setup for training
storms to occur, potentially leading to flash flooding. Much
like the first wave of storms, the melting height looks to be
above 15,000 feet and very moist, allowing very efficient hail
melting and warm weather precipitation processes to occur,
increasing the potential for flooding.

Following the storms, the winds are expected to be light and
variable, which will allow fog to form, much like the past few
days. Currently, the northeastern 1/3 of the CWA looks to get
to worst fog, likely dropping down to less than a mile of
visibility. This fog will limit overnight cooling and keep
temperatures in the 60s across the CWA.

Tomorrow morning, as stratus and fog linger throughout much of
the CWA, a mid-level ridge will begin moving into the area.
This will work to lift the fog and stratus from west to east
throughout the day. High temperatures will warm into the upper
80s.

Tomorrow afternoon and early evening, another shortwave will
eject off the Rockies and give us another wave of storms across
the CWA. We could see some severe weather with these storms,
with wind being the primary threat and hail as a secondary
threat. Storms look to enter the northwestern CWA around 0Z and
move southeast through the CWA, exiting around 14Z. Low
temperatures tomorrow night look to cool into the mid 50s to
lower 60s.

&&

.LONG TERM /SATURDAY THROUGH TUESDAY/...
Issued at 159 AM MDT Wed Aug 14 2024

The long term continues to look warmer and a bit drier with an upper
ridge still forecast to be over the area for most of the period.
With the ridge over the area, 850mb temps are forecast to rise into
the upper 20`s, if not the lower 30`s celsius. This would support
temperatures in the 90`s and lower 100`s with cloud cover over the
area looking less likely in the newest guidance. These temperatures
would likely linger through Mon/Tues with no major change in the
forecast pattern hinted at. We`ll still need to watch for daily
storm chances, though chances should be fairly low (<20%) and any
severe potential remain isolated and/or unorganized.

Going into the mid-week, there`s a split in what the upper pattern
does. Some guidance suggests that the upper ridge will remain with
an omega pattern over the CONUS, keeping us in a hot and relatively
dry pattern. Temperatures could reach the mid 100`s if the ridge
amplifies as much as some ensemble members suggest. Other members
are suggesting that an upper low near the Great Lakes region would
swing through the Plains, similar to a few events in the past few
weeks and months. In this scenario, temperatures would be cooler
with highs in the 80`s likely, or even cooler if persistent cloud
cover returned. We could also see an organized severe event Tues/Wed
in this scenario along with overall higher precipitation
chances.

&&

.AVIATION /06Z TAFS THROUGH 06Z THURSDAY/...
Issued at 1110 PM MDT Tue Aug 13 2024

MCS is currently moving across KMCK where showers and storms
look to continue through the next few hours along with a
gradually decreasing severe threat. As this moves out will need
to watch for stratus and fog through at least mid morning if not
perhaps longer. As for KGLD a hit or miss shower or storms
remains possible through 11Z but with a very low severe threat.
Low stratus is already developing with LIFR potential increasing
as well. A little more skeptical on fog potential for KGLD as
winds look to turn more westerly so didnt get to aggressive with
the fog.

&&

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

&&

$$

SHORT TERM...CA
LONG TERM...KAK
AVIATION...Trigg