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Area forecast discussion 
National Weather Service Grand Junction Colorado
1046 PM MDT Monday Jul 27 2015

issued at 810 PM MDT Monday Jul 27 2015

At 8 PM warm temperatures continued across the forecast area. The
northern towns...Vernal Craig Hayden are a few degrees cooler than
Sunday evening. The dry cool front is difficult to analyze but is
most likely draped along the Roan-Tavaputs-Flat Tops and will sag
through the I-70 corridor this evening then through the remainder
of the forecast area by Tuesday morning. Evening dewpoints were
much lower than yesterday across the forecast area. And this will
allow winds to drop off quickly with sunset in the lower
elevations. Cool temperatures are expected across the north
tonight and have updated the forecast there. Tuesday afternoon
expect about 10 degrees of cooling across the north...5 degrees
across the central zones...and little change south.


Short term...(tonight through Tuesday night)
issued at 214 PM MDT Monday Jul 27 2015

The southwest flow has strengthened early this afternoon as a
shortwave trough moves into the northern rockies...and an
associated cold front approaches our northwest corner. These winds
have mixed to the surface in the prefrontal environment...and helped
by daytime heating. The strongest winds are expected over the
northern half. But a corridor from the Grand Flat in east-central
Utah the Craig-Baggs Wyoming seems to be under the
gun so far this afternoon. Canyonlands Airport...Douglas Pass and
several RAWS sites in northwest Colorado have already reached Wind Advisory
criteria. Therefore a Wind Advisory has been issued for these
areas until 8 PM MDT. Also a red flag warning is in effect for
northwest Colorado and portions of west central Colorado. See fire weather
discussion below. The cold front is expected to reach the
northwest corner of the forecast area late this afternoon...then
proceed across northwest Colorado this evening. It appears that this
front will stall across our central portion overnight and weaken.
By late this evening winds will diminish as the air mass Delaware-
couples and the front becomes less of a player. Nighttime temperatures
should be somewhat cooler than the warm readings seen last night
especially the Post frontal air mass.

Warmer air will gradually advect back into this region during the
day on Tuesday as the center of low pressure over the northern
tier states of the contiguous US moves east. In its wake...weak
high pressure will keep winds light across the region Tuesday
night. Conditions will be somewhat breezy across the Utah/WY/co
border Tuesday afternoon...but gusts no higher than 20 to 25 miles per hour
are expected as forecast soundings are consistent on a cap in
place at about 600 to 650 mb where winds are no greater than 10
kts up the column from the surface.

Long term...(wednesday through monday)
issued at 214 PM MDT Monday Jul 27 2015

Broad high pressure over the southern tier of the US will
strengthen and its center of circulation will gradually move west
toward the Great Basin by the end of the week. As its center of
circulation situates itself just far enough east to bring
southerly flow to The Four Corners on Wednesday...available
moisture will increase as the moisture tap gets caught in the
flow. Expect an increase in activity across SW Colorado and southeast
Utah Wednesday and Thursday and potentially into the weekend as development
of showers and thunderstorms becomes more likely. Northeast Utah
and northwest Colorado are expected to remain dry over the next
week except for the isolated mountain thunderstorm which could
develop more so at the end of the week into the weekend.
Temperatures look to remain near climatology...or slightly above
toward the weekend.


Aviation...(for the 06z tafs through 06z Tuesday night)
issued at 1046 PM MDT Monday Jul 27 2015

VFR conditions will prevail the next 24 hours with no impacts to
visibility or ceilings anticipated. Wind gusts from the northwest may exceed
25 miles per hour along the Roaring Fork valley and could impact Landing
traffic at kase Tuesday afternoon.


Fire weather...
issued at 810 PM MDT Monday Jul 27 2015

The dry cool front will sag south of the I-70 corridor with sunset
and work through the southern zones by Tuesday morning. Gusty
winds will diminish quickly with sunset and humidity will quickly
recover. Therefore the warnings were allowed to expire at 8 PM.


Gjt watches/warnings/advisories...


long term...jam
fire weather...Joe

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