Area Forecast Discussion
Issued by NWS Denver/Boulder, CO

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FXUS65 KBOU 190245

Area Forecast Discussion
National Weather Service Denver/Boulder CO
845 PM MDT WED MAY 18 2016

Issued at 844 PM MDT Wed May 18 2016

There was only one brief shower on the plains north of DIA this
evening. Other than that all convection has been confined to the
mountains and foothills. The high country convection will continue
to die off with loss of daytime heating and instability, so
generally expect clearing skies overnight. The one exception may
be for some patchy fog and stratus to develop in the Elbert and
Lincoln county areas with moist southerly flow overnight.


.SHORT TERM...(This afternoon through Thursday)
Issued at 245 PM MDT Wed May 18 2016

Scattered showers and isolated t-storms have stayed over the high
terrain this afternoon due in large part to light southeast
transport winds. a moist southerly low-level flow on the plains
have kept many locations east of the I-25 urban corridor clouded
over all day. Models indicate some cape out there but also a bit
of cin to over come. So will keep showers chances below 10 percent
out there for the rest of this afternoon and early this evening...
then zero chances rest of the night. In the high country...bulk of
the t-storms/lightning strikes have remained south of I-70...but
this may change over the next few hours compliments of weak lift
and mid-level instability generated by a poorly defined shortwave
trough sweeping down from southern wyoming. Storms generated by
this disturbance likely to be of short duration and low intensity
due to their late start.

Overnight...the upper low and its bundle of moisture and weakening
large scale ascent continue to pass south of Colorado. As it moves
across New Mexico...the mean layer flow over eastern Colorado
shifts from a moist southeasterly to a drier south-southwesterly
component. This should result in gradual clearing overnight over the
plains and later over the high country. Fog not expected on
the plains tonight except perhaps in moist river bottom areas.

On Thursday...upper low and attended trough shifts east-
southeast of Colorado allowing a shortwave upper ridge and
warmer/drier air aloft to spread eastward over Colorado during the
day. 700-500 mb flow becomes zonal and 700 mb temperature over the
Front Range urban corridor warm 4.0-4.5 deg c 00z/Thu- 00z/Fri.
More sunshine and warming aloft should warm sfc temperatures 8-12
deg f. High Temperatures on the plains in the low to mid 70s back
to near average for mid May. Shower and t-storm chances lower
tomorrow with scattered pops in the high country by afternoon due
in large part to strong daytime heating. Chances on the plains
less than 10 percent with a drier environment in place.

.LONG TERM...(Thursday night through Tuesday)
Issued at 245 PM MDT Wed May 18 2016

On Friday an upper level ridge will be in place over the state
ahead of a closed low over the pacific NW. Moisture over the
mountains combined with 1500+j/kg will create enough instability
for afternoon thunderstorm development. On the plains conditions
will remain dry with the help of a lee side trough and subsequent
downsloping. Temperatures will continue to increase with highs on
Friday in the upper 70s to lower 80s.

Conditions will continue to dry as ridging moves in and drier SW
flow dominates for Saturday. Temperatures will increase with
highs in the 80s. On Sunday the upper level low weakens into an
open wave with a 90+ kt jet over western CO by Sunday night.
Increasing precipitation Sunday night into Monday with an
accompanying cold front will keep showers in the mountains until
early Monday and drop temperatures into the upper 60s. By the late
afternoon on Monday models are showing some QPF over the higher
terrain that could carry over into the Foothills overnight Monday
bringing a slight chance of showers with overnight temperatures
into the 40s. Strong UL SW flow will continue on Tuesday with a
slight chance of convection in the mountains and highs in the
upper 60s to lower 70s.


.AVIATION...(For the 00Z TAFS through 00Z Thursday evening)
Issued at 844 PM MDT Wed May 18 2016

Threat of any showers has ended this evening. VFR conditions will
persist through Thursday, although we should see isolated high
based convection and possibly gusty winds spread off the higher
terrain and toward KDEN after 00Z Friday.


.BOU Watches/Warnings/Advisories...


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