Area Forecast Discussion
Issued by NWS Goodland, KS

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FXUS63 KGLD 221109

Area Forecast Discussion
National Weather Service Goodland KS
509 AM MDT Tue May 22 2018

.SHORT TERM...(Today through Thursday)
Issued at 315 AM MDT Tue May 22 2018

Upper ridge axis will lift out today resulting in southwest flow
aloft by this afternoon. A couple of weak embedded shortwave
troughs will provide just enough forcing for a few isolated to
widely scattered thunderstorms to develop. Convective allowing
models highlight two possible areas: the HRRR develops storms
around 21z from Norton southwest to Garden City, while the NMM and
ARW bring a few storms off the Palmer Divide in the late afternoon
to early evening in northeast Colorado. Environment will be
unfavorable for severe storms with only 10-20kts of deep layer
shear and weak instability. Storms should dissipate by mid
evening. High temperatures will warm into the middle 80s to around
90 with proximity of the ridge.

Upper low finally lifts out of the Great Basin and into the
northern Rockies Wednesday afternoon. Local area will be on the
southern fringe of the better forcing, but models have increased
coverage of convection, especially Wednesday evening, which is
when the upper heights are falling. Instability/shear parameters
are marginally better for severe storms but still not that great.
Best shear will be over northeast Colorado where 30-40kts is
forecast, but that area will be the most stable with SBCAPE at 03z
of only around 1000 Jkg. Nonetheless, cannot rule out a severe
storm or two but overall threat seems rather low. Increased POPs a
bit for the better coverage. Temperatures warm into the upper 80s
to lower 90s for highs.

Next upper low will be approaching the California coast on
Thursday. The flow ahead of it over the central plains is weak,
with a hint of shortwave ridging. Models again showing isolated to
widely scattered storms in the afternoon/evening timeframe.
However, hard to find any forcing and coverage should be very
limited. Shear/instability parameters generally unfavorable for
severe storms. Warm temperatures continue.

.LONG TERM...(Friday through Monday)
Issued at 145 AM MDT Tue May 22 2018

Upper ridging is anticipated to move over the High Plains on Friday
as an upper low sets up on top of the west coast. The ridge persists
through the weekend, slowly progressing east ahead of the low. Most
of this timeframe will be dry for the region, but storms cannot be
ruled out at this time on any given day due to the pattern.

The upper low gradually travels eastward from the west coast to near
Utah by Monday. This next system generates shower and thunderstorm
chances for the region Sunday night, and especially on Monday.
Monday has the best coverage and chances for precipitation during
the extended period, but will need to wait to see how guidance
resolves this disturbance before putting too much stock into it.

It appears a Pacific cold front moves into the region Friday night,
but the airmass behind it will not be much cooler, with highs in the
80s to low 90s throughout the extended. Low temperatures will be in
the 50s to low 60s.


.AVIATION...(For the 12Z TAFS through 12Z Wednesday morning)
Issued at 508 AM MDT Tue May 22 2018

VFR expected at both KGLD and KMCK through the TAF period.
Isolated to widely scattered thunderstorms will develop this
afternoon and continue into the early evening, but due to the
limited coverage confidence is low in directly impacting either




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