573
FXUS63 KGLD 122305
AFDGLD

Area Forecast Discussion
National Weather Service Goodland KS
505 PM MDT Mon Aug 12 2024

.KEY MESSAGES...

- Dense fog may return late tonight behind the rain.

- Low confidence for severe weather occurring during the late
  afternoon/evening over the southwest quadrant of the forecast
  area.

- Flood watch issued for East Central CO for tonight.

- Potential for stronger storms Tuesday evening over the
  northwest quadrant of the forecast area.

- Rain chances continue through most of the week and
  temperatures gradually warm.

&&

.SHORT TERM /THROUGH TUESDAY NIGHT/...
Issued at 232 PM MDT Mon Aug 12 2024

Latest upper air analysis shows the ridge still centered over the
Desert Southwest.  Rounding the ridge are smaller scale troughs. The
short wave trough that will aid in storm development this afternoon
is currently moving across Wyoming.  Meanwhile cloud cover remains in
place over much of the forecast area.  This should cause a
stabilizing factor regarding storm development later today.

For the rest of today storm activity has already started over the
western part of the forecast area.  Here the environment will be
unstable. However the environment becomes more stable toward the
CO/KS border.  Where this transition to a stable environment is will
depend on where the cloud cover has had a chance to linger the
longest.

Tonight storm activity should begin to move into the forecast area
ahead of the upper level short wave trough that has been approaching
from the west.  Latest data indicates the instability should decline
toward the KS/CO border, but where exactly that occurs depends on
the westward extent of the cloud cover today.  Best assessment is
the environment become more stable east of the first column of KS
counties.  Deep layer shear will be around 35 kts and instability
will be around 2000 j/kg for MLCAPE. The limiting factor will be the
lower shear, which is half of what it was yesterday.  Also, the
storms look to be in more of a cluster due to the mean flow being
from a southerly direction; parallel to the mountains and dry line
the storms will be forming off of.  Since the storms will be in a
group, and the shear is on the low end of the spectrum, am expecting
the hail to be on the low end of the severe spectrum.  The cloud
bases will be rather low so the threat for severe wind gusts is on
the low side unless the storms form a line.  Once the storm activity
moves into KS the severe threat should decline if it doesn`t already.

On a side note, confidence is on the low side for severe weather to
occur.  The shear is rather weak and storms are favored to cluster
together.  The timing for storms moving into the forecast area is
also not very helpful either since this will be after peak heating,
which will lessen storm intensity.

During the latter half of the evening and through the rest of the
night a rather large area of rainfall should progress east across
the forecast area.  The GEFS and ECMWF ensembles do not agree with
the placement of the best chance for rainfall, but both have rather
high percentages for rainfall to occur.  Even the HREF is showing
higher percentages for rainfall tonight.  Based the current flood
watch on where the highest rainfall amounts would be from the HREF
data.  Confidence for flooding declines as the storms move east due
to the storms moving faster as they progress east of CO later in the
night.

Tuesday morning there may be storm activity ongoing over the eastern
half of the forecast area as the upper level short wave trough
slowly moves eastward.  This activity should be east of the forecast
area before late morning.  Fog may form behind the rain.

Clouds should clear through the morning, allowing temperatures to be
warmer than today.  Later in the afternoon another round of storm
activity will approach from the west, but not move into the forecast
area until the evening.

Tuesday night storm activity will move into the forecast area from
the west.  This short wave trough will be more potent than the one
for tonight.  Model data has the updraft for any potential storm
being stronger than what may occur today.  As such, am thinking this
storm activity will be of greater intensity than today.  The favored
track is over the northwest quadrant of the forecast area.  The
later arrival may serve to squelch storm intensity though.
Additional strong storms may also form as the compact short wave
trough moves over the northwest part of the forecast area during the
evening.  These elevated storms are supported by the NAM soundings
for that time period, which gives confidence to the soundings being
representative.  The storms should track north of the forecast area
during the overnight hours.

&&

.LONG TERM /WEDNESDAY THROUGH MONDAY/...
Issued at 208 PM MDT Mon Aug 12 2024

The long-term will start off with a high pressure system in the
ARK-LA-TX area extending a ridge through the mid-Mississippi River
Valley. In the Pacific Northwest, a trough will be cutting into the
CONUS, with a loose axis extending down into western New Mexico. As
the week progresses, another high near Baja California will slowly
move over the Southern CONUS. These three features will allow for a
moderately active pattern to persist through the period by forcing
the 250mb jet to be southwesterly then northwesterly, and keeping
the jet core near the CWA until about Sunday.

Wednesday evening, we look to have the 700mb trough axis move
through the area. This will give us enough forcing to have a low-end
chance at severe thunderstorms. Wind and hail would be the biggest
threat as these storms will be elevated from the low-level
southwesterly flow throughout the day. Storms look to begin in the
mid afternoon and last until around midnight. Temperatures look to
warm into the mid 80s to low 90s ahead of the storms and cool into
the mid 50s to low 60s that night.

Thursday, guidance is showing the ridge will slowly start working in
from the southwest. Northerly winds will keep us in the low to mid
80s. PoPs are low Thursday, but a few showers could occur in the
evening and overnight hours. Lows look to mimic Wednesday night`s
low temperatures.

Friday through Monday look similar to each other as the ridge builds
in even more. There is about a 20% chance of precipitation in the
afternoon and evening hours each day and temperatures will range
from the mid 80s to mid 90s. Low temperatures Friday night and
onward look to be in the upper 50s to low 60s.

&&

.AVIATION /00Z TAFS THROUGH 00Z THURSDAY/...
Issued at 505 PM MDT Mon Aug 12 2024

KGLD...VFR conditions are expected from taf issuance through 01z
with winds from the southeast, gusting up to 20kts at times.
From 02z-17z, sub VFR conditions are expected with winds from
the southeast up to 11kts. Highest confidence in
shower/thunderstorm activity impacting the terminal is in the
04z-08z timeframe. Primary hazard is locally heavy rainfall that
may reduce visibilities, otherwise stratus should be over the
terminal. After 18z, VFR conditions are anticipated with winds
from the southeast up to 11kts.

KMCK...VFR conditions are expected from taf issuance through 07z
with winds from the southeast up to 10kts. There is a
possibility of cigs at sub VFR range at any time. From 08z-19z,
sub VFR conditions are expected with winds from the east to
east-southeast at speeds up to 11kts. Showers/thunderstorms may
impact the terminal in the 08z-11z timeframe with locally heavy
rainfall the primary hazard. After 20z, VFR conditions are
anticipated with winds from the southeast up to 11kts.

&&

.GLD WATCHES/WARNINGS/ADVISORIES...
KS...None.
CO...Flood Watch until 3 AM MDT Tuesday for COZ090>092.
NE...None.

&&

$$

SHORT TERM...JTL
LONG TERM...CA
AVIATION...99