080
FXUS63 KGLD 152131
AFDGLD

Area Forecast Discussion
National Weather Service Goodland KS
331 PM MDT Sat Aug 15 2026

.KEY MESSAGES...

- Severe storms are possible this evening with large hail likely
  around an inch and wind gusts up to 70 mph.

- A Flood Watch has been issued for Cheyenne (CO), Wallace,
  Logan, Gove, Greeley and Wichita counties through Sunday
  morning. The potential for another cluster or two of storms
  moving over areas that have seen 1-3 inches of rain each of
  the prior nights has resulted in a heightened risk of
  flooding and possibly flash flooding.

- Severe storms are possible again Sunday, albeit with a lower
  chance of occurring. The main risk area would be Eastern
  Colorado while the main threat would be wind gusts up to 60
  mph and large hail. Flash flooding could be a concern
  depending on how much rain falls on Saturday.

- More seasonable temperatures through the weekend and into
  Monday.

&&

.SHORT TERM /THROUGH MONDAY NIGHT/...
Issued at 1215 PM MDT Sat Aug 15 2026

Saturday, high pressure sets up across the eastern southern Plains
which sets up for a nice surge of monsoonal moisture for the area.
Focus is on another shortwave within the mid level flow which will
again be the source for shower and storms development starting
across Colorado. Similar to previous days, a few areas of storms are
forecast to develop. The first is the typical convection off of the
Front Range that will again be driven by a shortwave within the
flow. The second however looks to be along a cold front from the
north during the evening hours. For zones one and two  zones, do
also have concerns for capping which may lead to storms waning in
intensity or even fully dying out. A 3rd area is also seen across
portions of the area as well. Confidence is a bit higher in the 1st
and 3rd areas based on the past couple days. Currently am thinking
that the 3rd area will be the dominant area of rainfall again
as it is fueled by the jet. The difference for the day is that
the jet is progged to be a little bit further to the east than
the past few days. For the severe weather potential, each of
these zones will have the potential for wind gusts of 60-70 mph,
large hail may be possible as well but confidence has really
decreased in that threat. Eastern Colorado may have the higher
potential for hail and damaging winds but the last few days
convection has really struggled once it enters our forecast
area. I do have the same concern again today especially with
the current cloud cover in place as temperatures have not be
able to warm up very much. The 700mb jet seems to have had the
biggest influence with severe winds the past few nights which
the 12Z HREF MAX wind gust also suggests the same thing again as
well for later this evening. With the continued cloud cover in
place for the day, my confidence in severe weather occurring has
decreased quite a bit as lapse rates should remain lower which
is currently being realized in the 18Z SPC Mesoanalysis page.

With the recent heavy rainfall of 1-3 inches over the past
couple nights for counties along and south of Highway 40 have
concern that flooding may be become a bit more common overnight with
the next cluster and having the higher confidence that it will
develop have opted to issue a Flood Watch through Sunday morning.
Cheyenne county Colorado was the difficult county to decide on as
only their southern and southeast portions of the area saw the
heaviest rain but with the potential that the same area could get
impacted by the first and third cluster opted to include them in
watch.

There is a scenario, where all three clusters survive into the
area along with some overlapping of them which could lead to
some flooding north of the Flood Watch or more serious flooding
within the Flood Watch. Confidence in this scenario is only
5-10%, so not anywhere near high enough confidence currently to
go broader with the Flood Watch. There is also a worst case
scenario with less than 5% confidence that storms stall out with
multiple outflow boundaries in the area which would have the
potential to lead to a considerable flooding situation for
somewhere in the forecast area. This is supportive by around 5
GEFS members and have also been seeing the potential the past
few days, but the signal has not been consistent at all. All in
all this forecast is currently a low confidence but could
potentially have higher impacts.

Sunday, high pressure broadens out across the souther Plains which
blocks our moisture into place. Cloud cover is forecast to remain
thick through most if not all of the day helping keep temperatures
in the upper 70s to mid 80s. Yet another shortwave is forecast to
move off of the Rockies. Severe weather may be possible again but
similar to today not impressive as we may not be able to warm up
enough for storms to sustain themselves and may not even develop in
the first place. Should storms develop they would favor eastern
Colorado. If we are able to warm up enough then more isolated to
widely scattered development could be possible across NW Kansas.
Wind gusts up to 60 mph would be the mos likely hazard.

Monday, our region is forecast to be in a mostly zonal upper-level
flow with some subtle ridging developing across the northern
Rockies.  Guidance suggests that showers and storms may again
develop along a boundary on the northern end of an expanding
high pressure over the southern Plains. There may be a low risk
of severe weather with damaging winds currently appearing to the
primary hazard. High temperatures for the day are forecast in
the mid 80s across the area.

&&

.LONG TERM /TUESDAY THROUGH SATURDAY/...
Issued at 1215 PM MDT Sat Aug 15 2026

Starting the extended period Tuesday, high pressure is forecast to
continue to slightly extend northward across the area. The further
north the high pressure can go then the warmer temperatures will be.
Current forecast has temperatures returning to the mid to upper
90s, but if the high pressure can remain a little further south
then highs in the upper 80s to low 90s would be common. The
position of high will also dictate precipation chances as well.
With the current forecast being on the warmer end this does
decrease our precipitation chances as guidance indicates that a
shortwave will develop on the northern periphery of the high.
If storms were to develop, they would turn severe with damaging
winds the main threat as they form a cluster and move to the
southeast. Currently should storms develop the northern and
eastern portions of the area would be favored.

Wednesday, has a similar pattern but is more dictate by the
development of a ridge across the western CONUS. Again guidance
indicates another shortwave within the flow which could move into
the area and possibly entire most if not the entire forecast area.
Current guidance indicates that shear is a little better around
35- 40 knots which could support a damaging wind and perhaps
even large hail threat if storms don`t grow upscale too quickly.
Those two days will need to be continued to be monitored.

Thursday, through the end of the forecast period indicates that
another strong ridge will develop across the western CONUS as warm
temperatures in the low to mid 90s return. The amplitude of the
ridge will dictate how warm it gets and if precipitation
chances occur as we may continue to reside on the eastern side
of said ridge.

&&

.AVIATION /00Z TAFS THROUGH 00Z SUNDAY/...
Issued at 327 PM MDT Sat Aug 15 2026

Watching the potential for showers and storms to move into the
area this evening. Guidance again has differences on start times
of potential rainfall so opted for a broad PROB30. Remain aware
for potential AMD`s as timing better presents itself. Should a
storm move over a terminal am currently anticipating a period of
MVFR visibilities and ceilings to occur. After storms move out
similar to previous mornings patchy fog with minor visibility
reductions and stratus to occur. Winds for the day Sunday are
forecast to remain light after the fog and stratus dissipates.

&&

.HYDROLOGY...
Issued at 1215 PM MDT Sat Aug 15 2026

With the recent heavy rainfall of 1-3 inches over the past couple
nights for counties along and south of Highway 40 have concern that
flooding may be become a bit more common overnight with the next
cluster and having the higher confidence that it will develop have
opted to issue a Flood Watch through Sunday morning. Cheyenne county
Colorado was the difficult county to decide on as only their
southern and southeast portions of the area saw the heaviest rain
but with the potential that the same area could get impacted by the
first and third cluster opted to include them in watch. I included
Logan and Gove counties due to the further east 700mb jet which
indicates to me that perhaps guidance isn`t bringing the heaviest
rain potential as far east as it should. The past few nights with a
similar jet magnitude wise, albeit further west has been the most
impressive in the heaviest rainfall and the continuous rainfall.
Rainfall rates of at least 1.5 to 2.5 inches per hour again seems
reasonable given the same setup as the previous days.

There is definitely lower confidence than what I would like to
have at this time in the way that this event will pan out due to
the multiple clusters of storms and the potential for outflows
to completely disrupt environments. This is my theory as to why
Hi-RES guidance has been struggling with overall evolutions and
coverage which can be seen looking at various total QPF outputs
which shows swaths of heavy rain going in varying directions at
the 12Z Sunday time period. The one thing that all of them do
agree with though is within the swaths of heaviest rain
additional 2-4 inches with isolated up to 6 inches of rain is
possible overnight across the watch area. Some guidance also
indicates very slow Corfidi vectors around 10-15 knots which
would indicate some training potential as well.

There is a scenario, where all three clusters survive into the
area along with some overlapping of them which could lead to
some flooding north of the Flood Watch or more serious flooding
within the Flood Watch. Confidence in this scenario is only
5-10%, so not anywhere near high enough confidence currently to
go broader with the Flood Watch. There is also a worst case
scenario with less than 5% confidence that storms stall out with
multiple outflow boundaries in the area which would have the
potential to lead to a considerable flooding situation for
somewhere in the forecast area. This is supportive by around 5
GEFS members and have also been seeing the potential the past
few days, but the signal has not been consistent at all. All in
all this forecast is currently a low confidence but could
potentially have higher impacts.

&&

.GLD WATCHES/WARNINGS/ADVISORIES...
KS...Flood Watch through late tonight for KSZ027>029-041-042.
CO...Flood Watch through late tonight for COZ092.
NE...None.

&&

$$

SHORT TERM...Trigg
LONG TERM...Trigg
AVIATION...Trigg
HYDROLOGY...Trigg