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Area forecast discussion
National Weather Service Denver/Boulder Colorado
1028 am MDT Mon Sep 23 2019

Update...
issued at 1028 am MDT Mon Sep 23 2019

Cirrus shield is pushing northeast across the forecast area, and
some of it's thick enough it could shave a degree or two off the
forecast high temperatures. Temperatures will still be several
degrees above normal with most of the plains reaching the lower
80s. Other than that, a dry day is in store with little moisture
below 400 mb.

&&

Short term...(today and tonight)
issued at 305 am MDT Mon Sep 23 2019

Colorado remains under a ridge of high pressure early
this morning, but this will be shifting east of Colorado later today
as upper level trof of low pressure digs into the Great Basin. Ahead
of the trof, expect increasing high level moisture today as the flow
turns more southwesterly. There will be a stronger 85kt jet streak
which will be spreading over the area this afternoon but airmass
will be too dry to amount to any precipitation. Precipitable
water values now are fairly low, mainly around .30" in the
mountains/nearby plains and up to half inch over the plains.
Despite the increase in high level moisture, low levels will
remain dry with dewpoints only in the 20s/30s across the plains
and only a marginal increase in precipitable water values by later
today.

Forecast soundings also look dry with no thunderstorms expected
with little or no cape available. Temperatures will warm under the
southwest flow, as 700mb temperatures rise to around +11c at
Denver. This will result in a 3c warming and equates to upper 70s
and lower 80s over the plains this afternoon.

For tonight, the upper trof splits with much of the dynamic energy
shifting south into the Desert Southwest while northern branch
approaches Colorado and some increase in westerly flow over the
mountains. Otherwise, little or no impact through tonight.

Long term...(tuesday through sunday)
issued at 305 am MDT Mon Sep 23 2019

For the extended, the upper level low will be in place over the
desert SW. The circulation will become cut off from the upper level
flow and stay in place mainly over northern baja and Southern California
through the middle of the week. This will leave Colorado in between
stronger upper level northwest flow to the north and weaker zonal flow to
the south. Weather for the region during this period will be dry
with temperatures coming in slightly above normal with highs ranging
from the mid 80s on Tuesday to the lower 70s by Friday. On
Wednesday, models show a dry cold front dropping down from Wyoming
ushering in a cooler airmass. Enhanced easterly flow across the
plains will help to bring increased clouds in addition to the more
fall-like temperatures. Late Thursday, another push of cooler air
from the north will bring temperatures back down into the lower 70s
for Friday with increased clouds. A weak shortwave will cut
across the central mountains Friday bringing enough lift to
combine with moisture ahead of the upper low for a slight chance of
showers and thunderstorms by the late afternoon.

For the weekend, the center of the upper low that was spinning over
the desert SW will finally kick out to the NE and move into the
Texas Panhandle by Saturday morning. A Lee side trough will deepen
and increase strong southerly winds over the eastern plains. A
slight chance of showers and storms will once again be possible
across the higher elevation.

&&

Aviation...(for the 18z tafs through 18z Tuesday afternoon)
issued at 1028 am MDT Mon Sep 23 2019

VFR conditions will persist with only high level clouds above 20
thousand feet. Typical diurnal wind patterns will prevail through
Tuesday, with easterly after 18z becoming southerly 02z-05z
tonight.

&&

Bou watches/warnings/advisories...
none.
&&

$$

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