515
FXUS63 KGLD 160807
AFDGLD

Area Forecast Discussion
National Weather Service Goodland KS
207 AM MDT Fri Aug 16 2024

.KEY MESSAGES...

- Low chance for severe weather this morning and afternoon.

- Drier and warmer going into the weekend.

- Some uncertainty with next week`s pattern, but currently could
  favor above average temperatures to begin the week.

&&

.SHORT TERM /THROUGH SATURDAY NIGHT/...
Issued at 205 AM MDT Fri Aug 16 2024

For the short term period, the main focus is on the severe weather
threat today. While severe weather chances are low overall, they may
be a bit more impactful with chances during the morning hours and a
chance for significant severe weather this afternoon. Otherwise,
benign conditions are forecast for the rest of the period.

Current observations show an upper ridge beginning to amplify over
the Western Rockies while mid-level moisture moves over the area
from the northwest flow. Guidance is suggesting that a 700mb
shortwave is currently moving towards the area from the west. With
the ongoing showers and storms, this seems likely and will help
continue to generate showers and storms through the morning hours.
Most storms will be sub-severe, especially through sunrise with
current MUCAPE below 500 J/KG and lapse rates generally 7 C/KM
or less. Around and after sunrise, MUCAPE could increase to 1000
J/KG with effective shear around 45 kts, allowing a small
chance for a stronger storm to develop. If it holds together
long enough, hail around 1 to 1.5 inches would be possible. As
the storms move on, they will be in an environment with DCAPE
greater than 1000 J/KG, downshear vectors around 50kts and upper
cloud level winds around 50 kts. This could allow for a couple
gusts to 60-65 mph, especially if storms ride along an outflow.

Once the morning storms move on and dissipate (as the 700mb wave
dissipates), skies should clear and temperatures warm into the low
90`s with 850mb temps in the upper 20`s C. Winds should remain
relatively light around 10 mph or less with a broad pressure
gradient, though the direction may vary at times as lower pressure
tries to form in Eastern Colorado.

This afternoon, there`s an 85% chance that skies remain clear and
winds just slowly lower through the evening. However, if
temperatures become warm enough and the cap erodes, a supercell
(maybe two) could develop near the CO border near a weak surface
convergence zone. If the supercell does develop, significant severe
weather would be possible with MUCAPE around or greater than 2000
J/KG, 50-55 kts of effective shear, downshear vectors around 60kts
and upper storm winds around 70kts. Currently messaging hail up to
2.5 inches (mid level lapse rates are forecast to be around 7 C/KM)
and wind gusts up to 75 mph. The storm would move southeast through
the area through the late afternoon hours.

This evening and into tonight, skies are forecast to be clear and
winds lighten as the upper ridge axis continues to move closer to
the area. Lows are forecast to drop to around 60.

Tomorrow, sunny skies and warm temperatures in the low to mid 90`s
are forecast with the ridge axis moving more over the Eastern
Rockies and relatively dry air forecast to be over the area. There`s
still a 10% chance for a shortwave to move through and produce some
showers near the Tri-State border, but the weak forcing, broad
subsidence, and lack of moisture really keep the chances low.
Tomorrow evening and night, the low level flow is forecast to be
from the southeast which will bring moisture to the area, but likely
too late to produce storms with no forcing over the area. The
moisture increase should keep lows a bit warmer in the mid 60`s.

&&

.LONG TERM /SUNDAY THROUGH THURSDAY/...
Issued at 1220 PM MDT Thu Aug 15 2024

Both the latest GFS and ECMWF continue to show an amplified 500mb
ridge over the central Plains during the extended period. Late
afternoon/evening shortwave passages each day combined with lee-side
troughing to our west could allow for rw/trw chances w/ the focus in
the evening should they occur. While there will be a 30-40% chance
to start off on Sunday night, chances decreases to the 15-20% range
by the middle of next week. Track of the shortwaves do change by
then due to models differing in placement of ridge resulting in
either west or southwest flow aloft, combined with decent low level,
above normal warmth could allow for less storm chances due to drier
low levels. If this occurs, the better chances will be west closest
to the lee-side trough, better instability.

The latest NBM pops do continue this trend in latest updated
guidance. The latest GEFS 6-hr precip does show this as well with
best chances in the Sun-Mon timeframe.

For temps, looking for highs each day to range mainly in the 90s.
This will be dependent on cloud cover over the area. The trend could
be higher next week if precipitation does not develop. Overnight
lows will range in the lower to mid 60s each night. Some locales in
Colorado could even see the upper 50s. Again these numbers will be
dependent on cloud cover from any evening/overnight storms.

&&

.AVIATION /00Z TAFS THROUGH 00Z SATURDAY/...
Issued at 1025 PM MDT Thu Aug 15 2024

VFR conditions at both KGLD and KMCK are expected to persist
through the period. There is a chance for some showers and
storms to move through the region tonight, hence the VCTS and
TEMPO groups with showers. Coverage looks to be pretty spotty
if any storms are able to form. KMCK has the better chance at
seeing the storms impact their site, but both sites could see
some showers or storms. If a storm moves over a site,
visibilities would likely drop, but ceilings will likely remain
high. The storms will linger into the mid to late morning
tomorrow, but then clear skies are expected.

&&

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

&&

$$

SHORT TERM...KAK
LONG TERM...JN
AVIATION...CA