-- Discussion containing changed information from previous version are highlighted. --
897
FXUS63 KGLD 130040
AFDGLD

Area Forecast Discussion
National Weather Service Goodland KS
640 PM MDT Sun May 12 2024

.KEY MESSAGES...

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- Another round of showers/thunderstorms Tuesday through
  Thursday with a Marginal Risk of excessive rainfall
  Wednesday/Wednesday night.

- Much lower chances (20%-30%) for precipitation Friday and
  Saturday with afternoon temperatures in the upper 70s to lower
  80s.
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&&

.SHORT TERM /THROUGH MONDAY NIGHT/...
Issued at 123 PM MDT Sun May 12 2024

This afternoon and evening will have more widespread precipitation,
stronger storms, as a low pressure system is moving over the CWA.
Since last night, the 850 mb LLJ has been moving more moisture into
the region and now that the surface low is in the CWA, wrap-around
precipitation is occurring and will continue into the night. CAPE
still seems moderate with 1,000-1,500 J/kg and little CIN to hold it
back. Shear is fairly weak, with 0-6km shear less than 25 kts across
nearly all of the CWA. 0-3 CAPE is one of the most impressive
parameters for the afternoon with soundings showing 50-150 J/kg
ahead of the first wave of precipitation. This setup makes
landspouts possible in the early stages of the event. Model guidance
is having a difficult time resolving exact placement for any
boundaries early this afternoon, but the area most likely for a
boundary to set-up will in a north/south orientation and within
about 50 miles of the CO/KS border throughout our CWA. This boundary
would serve as a focal point for any landspout formation.

As the storms mature and the event progress (around 21-3Z time
frame), hail will become more of a threat. As the low moves to the
eastern side of the CWA, shear will slightly increase (5-15 kts) and
more moisture will wrap into the CWA, giving us a higher threat for
severe hail. With the weaker shear and warm, moist lower levels,
heavy rain could become an issue, causing some concern for flooding
potential, mainly southeastern CWA. However, due to little rainfall
over the previous week and the types of storm formation expected,
there is about 15% confidence flooding would occur. More information
can be found in the Hydro section below.

The storms will look to grow to the south as the entire system moves
to the east. CAMs are showing 2-3 bands of rain forming in the
northwestern CWA before moving across the CWA. The western storms
will be moving quicker than the storms over the eastern CWA. By 6Z,
majority of the storms should have moved out of the area, but
lingering showers through 12-18Z Monday is possible in the far
eastern CWA.

As the storms begin clearing out, northwesterly winds will pick up,
gusts up around 20-25 kts by tomorrow afternoon are expected. Also,
as the storms move out overnight, the skies will begin to clear up
again from west to east. This will let low temperatures in the west
cool into the lower 40s while locations in the east will stay in the
50s tonight. Tomorrow looks to be mostly clear, and despite
northerly winds, high temperatures look to warm into the mid 70s.
The mostly clear skies will continue overnight tomorrow and
temperatures across the entire Tri-State area will cool into the
40s.

&&

.LONG TERM /TUESDAY THROUGH SUNDAY/...
Issued at 116 PM MDT Sun May 12 2024

Westerly to northwesterly flow will be in place over the area
Tuesday as an upper level trough dives southeast across the Bighorns
and into portions of Colorado.  Afternoon high temperatures will
range from the upper 70s to mid-80s, about 10 degrees above normal
in some locations.  Ahead of the advancing trough, there will be a
potential for showers and thunderstorms across portions of the Tri-
State area.  Right now, the best chances for shower/storm activity
appears to be Tuesday afternoon for areas along and north of
Interstate 70 (50-70% chance).  Precipitation chances will decrease
west to east across the area Tuesday evening into the overnight
hours.

Wednesday and Thursday, the upper trough crosses into eastern
Nebraska and western Colorado.  Temperatures will be slightly cooler
both days as a weak cold front moves through the region and cool air
filters in.  High temperatures will be in the low to mid-70s both
days.  There will be a chance for showers and thunderstorms both
days as this system moves through the region.

Friday and into to the weekend, we are looking at the potential for
a warm up.  Uncertainty remains as the pattern becomes more active.
Models show split slow becoming more pronounced Thursday and into
the weekend. The northern split extends from West Coast to East
Coast, with the upper trough exiting the region to the east. Heading
into Friday and the weekend, models diverge significantly, with the
GFS bringing a ridge over the area.  The ECMWF brings an upper
trough over the region for that period of time.  There is a non-zero
chance for a few isolated showers and storms during this time,
however, confidence in this solution is extremely low for the time
being.

&&

.AVIATION /00Z TAFS THROUGH 00Z TUESDAY/...
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Issued at 600 PM MDT Sun May 12 2024

A period of sub-VFR ceilings is possible at the MCK terminal
early Monday morning, otherwise.. VFR conditions are anticipated
to prevail through the TAF period at both terminals. Winds will
remain light and variable overnight.. becoming northerly at
10-15 knots Monday morning.
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&&

.HYDROLOGY...
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Issued at 123 PM MDT Sun May 12 2024

The 850 mb LLJ over the past 12 hours has moved ample moisture
into central Kansas and the surface low passing over the CWA as
this is being written is wrapping around this moisture into the
heart of the CWA. PWATS are currently about 1 inch to the east
of the low and about 2/3 to 4/5 of an inch to the west of the
low. As the evening progresses, PWATS are expected to increase.
Mid and Low level RH values will also increase as the column
becomes more saturated. MUCAPE looks to range around 500-1,000
J/kg, LCL-EL wind around 20 kts, and Corfidi up/downshear shear
vectors are about 10/15 kts respectively. These parameters lead
to about 70% confidence that heavy rain will occur, but with a
lack of organized shear, confidence lowers that these cells will
last very long.

Antecedent conditions are also not favorable for flooding to
occur. Nearly all of the CWA has seen less than 1 inch of rain
over the past 48 hours, so the ground is ready to soak up the
rain. There was a narrow area in northern Wichita county that
did receive a little over an inch of rain yesterday, so if a
storm could sit over that area for an hour or so, flooding
concerns would increase. As mentioned above, general confidence
in flooding today is about 15%. This would be localized flooding
widespread flooding is not expected.

There will be another chance of excessive rainfall Tue/Wed, but
that flooding risk will depend heavily on how well the area
dries out tomorrow.
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&&

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

&&

$$

SHORT TERM...CA
LONG TERM...Wekesser
AVIATION...Vincent
HYDROLOGY...CA