889
FXUS63 KGLD 251901
AFDGLD

Area Forecast Discussion
National Weather Service Goodland KS
101 PM MDT Tue Jul 25 2017

.SHORT TERM...(This afternoon through Wednesday)
Issued at 1126 AM MDT Tue Jul 25 2017

17Z Water vapor imagery indicated large anticyclonic circulation
centered over south central Colorado. Morning soundings indicated
a large change in airmass qualities between KDDC and KDEN. KDEN
sounding was primarily dry with steep (greater than 8 C/km) lapse
rates off of the surface. KDDC was much more humid with PW values
of 1.29 inch and a fairly deep moist layer, but with overall poor
lapse rates between H7 and H5. At the surface, trough axis was
draped across eastern Colorado with dewpoints in the mid and upper
60s to its east and dewpoints in the 50s to the west.

Thunderstorm chances will be primary forecast concerns tonight and
tomorrow, followed by magnitude of cooldown behind cold front
Wednesday.

Various short range models show a lot of variance with respect to
how afternoon and evening thunderstorms develop. Solutions vary
from storms remaining near sfc trough to forming into large
cluster and advancing across whole CWA. Starting to see cumulus
development along trough which may shed some light on how storms
will evolve. As cold front advances south tonight and short wave
trough flattens ridge somewhat, expect storms to advance to the
east and south with best coverage mainly along and north of
Interstate 70 where large scale forcing and available instability
most in line.

Expect storms to diminish in the morning hours with the bulk of
the morning and afternoon being dry across the area. Thunderstorm
development will be heavily influenced by how much clearing and
heating can occur. Should a low stratus deck maintain itself this
will greatly diminish potential for any post frontal storms.

Overall confidence high that temps will be around 15 degrees
cooler than today in northwestern CWA, but confidence in frontal
position lower to the south so not ready to dial down temps a lot
in this area.



.LONG TERM...(Friday through Monday)
Issued at 204 AM MDT Tue Jul 25 2017

During the extended period an upper level ridge amplifies over the
Rockies creating a strong northwesterly flow aloft over the region.
The 700mb level shows significant amount of moisture over the local
area. Additionally, a series of shortwave troughs are expected to
move within this upper level flow, resulting in a chance of showers
and thunderstorms each afternoon and evening for the period.

Temperatures during the extended area anticipated to be near
normal.

&&

.AVIATION...(For the 12Z TAFS through 12Z Wednesday morning)
Issued at 408 AM MDT Tue Jul 25 2017

VFR conditions are expected at GLD and MCK through the TAF
period. Gusty south winds will develop at MCK and GLD to the east
of a surface trough positioned over eastern Colorado today.
Isolated to scattered storms will develop near this trough and
move across the region this evening. Have included a VCTS in both
GLD and MCK between 01-06Z to indicate this. Have also decreased
winds after 01Z as the night time inversion sets up leading to
LLWS after 05Z at both MCK and GLD through about 10Z.


&&

.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&

$$

SHORT TERM...JRM
LONG TERM...BW
AVIATION...SME