Area Forecast Discussion
Issued by NWS Grand Junction, CO

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000
FXUS65 KGJT 291001
AFDGJT

Area Forecast Discussion
National Weather Service GRAND JUNCTION CO
401 AM MDT Sat Apr 29 2017

.SHORT TERM...(Today through Sunday)
Issued at 401 AM MDT Sat Apr 29 2017

A deep upper level low centered over southwest Colorado this
morning will continue to sling moisture westward across our
forecast area today. Latest satellite imagery shows the low
actually wobbling back westward a bit as it continues to gather
strength. Short-term models in decent agreement with the low
eventually turning south, diving into central New Mexico this
afternoon before lifting northeast across the Texas Panhandle
tonight. Trowal signature evident in the GOER-16 data over the
past 8 hours or so with band of heavier showers pushing westward.
Latest low level water vapor imagery showing some breakage in the
connecting stream to the front range and would expect this to
disrupt our bonus snows across the western slope by mid-morning.
The exception being over the San Juans where there appears to be a
renewed push in the lower level moisture fields back westward and
also a good signal that the low is sinking slowly southward as
the models are suggesting. Flow will also be backing around to the
northeast and east after a night of deep easterlies. Fairly
widespread impacts occurring over our central and southern
mountains with icy and snowpack passes visibly on webcams that
area available.

So what does this all mean for our forecast today? Expect showers
to persist through midday, with activity decreasing a bit this
afternoon, especially along and northern of Interstate 70. Winter
weather advisories for the central and southern mountains will
continue as impacts to travel will linger until mid to late
morning when solar power will help to thaw out road surfaces. Any
additional accumulations are expect to be under 3 inches today
for the mountains with even less over the valleys. As the low
kicks out into the plains tonight flow aloft shifts to northerly
with cool and more stable conditions moving back in. Dry weather
expected on Sunday with a shot of sun expected, before another
period of unsettled weather arrives Sunday night.

Have hoisted another Freeze watch for Grand Valley, including
Palisade, Grand Junction and Fruita for tonight in addition to a
continued warning and a new watch for the Montrose and Delta
areas. Snow has been flying in the vicinity of Montrose for the
past few hours with temps locked in right at the freezing mark.
With this system lifting out tonight, would expect cloud cover to
diminish as we see more stable conditions move in with winds
decoupling. All signs that temps may be a tad bit colder than
current MOS guidance suggests. As for daytime highs, today looks a
solid 10 to 15 degrees below seasonal norms, with Sunday coming
in around 5 to 10 degrees below normal. Even with the recent
cooler weather, Grand Junction is still holding on to the 3rd
warmest start to the year through yesterday with an average
temperature of 43.8.

.LONG TERM...(Sunday night through Friday)
Issued at 401 AM MDT Sat Apr 29 2017

Latest blended model solutions suggest unsettled conditions will
continue across the northern zones with northwest flow aloft in
place. Moisture and embedded shortwave energy would be expected to
pass across the northern mountains keeping showers in the
forecast. QPF values are not all that impressive at this time, so
new snowfall amounts look to remain under highlight thresholds at
this time. Of course still some time before we get into that
pattern.

High pressure is then expected to slide in by midweek with dry and
warmer conditions from Wednesday through Friday. The ridge is
expected to break down late next week with models trending back
toward a more active period by next weekend.

Temperatures through this period will be starting off on the cool
side of normal with a nudge back above expected by midweek as the
ridge builds in from the west.

Beyond this forecast period, CPC indicating temps will be trending
toward above normal while precipitation trends toward wetter
conditions during the 8 to 14 day period.

&&

.AVIATION...(For the 12Z TAFS through 12Z Sunday morning)
Issued at 401 AM MDT Sat Apr 29 2017

A strong low pressure system centered near Durango will bring deep
easterly flow across much of western Colorado and eastern Utah
today. The winds aloft will switch to the northeast and north
after 21Z this afternoon as the low pressure system moves east of
the continental divide. Expect scattered to numerous rain and snow
showers across the area with ILS cigs continuing. Areas of
IFR/MVFR cigs and vsbys should be expected, especially in the
vicinity of showers. Mountains will be frequently obscured
through this operational period.

&&

.GJT WATCHES/WARNINGS/ADVISORIES...
CO...Freeze Watch from this evening through Sunday morning for COZ006-
     011.

     Winter Weather Advisory until noon MDT today for COZ009-010-012-
     018-019.

     Freeze Warning until 9 AM MDT this morning for COZ011.

UT...None.
&&

$$

SHORT TERM...JDC
LONG TERM...07
AVIATION...JDC



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