Area Forecast Discussion
Issued by NWS Grand Junction, CO

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FXUS65 KGJT 260550

Area Forecast Discussion
National Weather Service GRAND JUNCTION CO
1150 PM MDT Thu May 25 2017

Issued at 702 PM MDT Thu May 25 2017

Updated to remove expired Red Flag Warning headlines for today.
Will let the Red Flag Warning for today expire at 7 pm as red flag
criteria is not widespread enough to keep the warning going. Some
localized conditions are being seen but coverage is not quite
there. Relative humidities should also begin to recover over the
next hour or two as temperatures cool. The Red Flag Warning for
Friday afternoon remains in effect for Colorado Fire Weather Zones
203, 290 and 292.


.SHORT TERM...(Tonight through Friday night)
Issued at 325 PM MDT Thu May 25 2017

Currently, there is a large gradient of temperatures between
cooler air (40s and 50s) generally north of I-70 and locations
south where cooler air has not reached yet and temperatures are in
the 70s and 80s. Short term forecast models indicate cooler air
dropping a bit further south this evening but this will only bring
a minor decrease in low temperatures tonight. The energy which is
firing off precipitation across NE Utah and northern Colorado
today will move east and bring a more stable environment to the
region overnight and into Friday. Though a few showers may develop
Friday, these will be very isolated in nature and more likely
virga producing rather than any accumulation precipitation.
Available moisture begins to increase again on Friday night from
the north and west. A closed low splitting off of the parent
closed low over Saskatchewan is expected to develop over Oregon
and Idaho and push energy into NE Utah beginning Friday night,
beginning another round of showers and potentially thunderstorms
across NE Utah and NW Colorado again. There will be the
possibility for some snow showers above 9000 ft in the Flattops,
Elkhead, Park and Gore Ranges Friday night. Little accumulation (1
to 2 inches max) is expected.

.LONG TERM...(Saturday through Thursday)
Issued at 325 PM MDT Thu May 25 2017

Trough is on track to move northwest to southeast through Utah and
Colorado on Saturday afternoon, bringing an elongated piece of
energy that will allow for a decent bit of activity with PV fields
supporting this thinking. The one limiter for activity will be the
possibility of cloud bases being mid to high-level based with
PWATS only around 0.30 in to 0.40 in.

Beginning Sunday, high pressure is still on track to amplify over
the western US. Closed low developing over Baja California will
help to pump moisture into western Colorado and allow for diurnal
shower and thunderstorm activity each afternoon over the higher
terrain. Lightning will be the greatest threat next week for those
working or recreating in the mountains.


.AVIATION...(For the 06Z TAFS through 06Z Friday night)
Issued at 1150 PM MDT Thu May 25 2017

Showers will continue across the area through about 12Z Friday
with VCSH at most terminals, mainly along and south of I-70 due to
a passing boundary, with some occassional breezes due to a passing
shower, but overall light winds overnight. Skies will become
scattered to few by late Friday morning into the afternoon with
winds increasing for another breezy day ahead of another
approaching disturbance. Areas along and south of I-70 should
remain dry on Friday with showers and thunderstorms developing by
late Friday afternoon across areas north of I-70 near the


Issued at 325 PM MDT Thu May 25 2017

Ongoing Red Flag conditions in Colorado Fire Weather Zones 207
and 290 due to gusty winds and low relative humidity. Another weather
disturbance will create windy conditions and critical fire
conditions again Friday afternoon across Colorado Fire Weather
Zones 203, 290, and 292. The wind gusts are being produced because
of a tight temperature gradient between the relatively warm air
in place over the region and much cooler air to our north. Moisture
finally returns to the region for a day on Saturday when a
weather disturbance moves through and brings most locations some


CO...Red Flag Warning from noon to 7 PM MDT Friday for COZ203-290-292.



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