Area Forecast Discussion
Issued by NWS Flagstaff, AZ
FXUS65 KFGZ 120350
Area Forecast Discussion
National Weather Service Flagstaff AZ
850 PM MST Wed Jan 11 2017
.SYNOPSIS...A trough moving down the west coast will bring a
period of unsettled weather to northern Arizona through the
weekend. The greatest chances for rain and high elevation snow
will be over the northwest part of Arizona through Friday...and
most of Arizona this weekend. Fair weather is expected early next
.UPDATE...A few light showers fell today mainly from Grand Canyon
region north to the Utah border (both Grand Canyon and Page
airports reported light rain). These have since dissipated as the
shortwave responsible has moved east. Meanwhile, moderate
west/southwest flow continues ahead of a broad trough developing
over the west coast. Expect clouds to gradually increase/thicken
through the overnight hours across northwestern portions of the
forecast area with a few light showers possible by daybreak
Thursday. Forecast trends look on track with no changes needed at
.PREV DISCUSSION /300 PM MST/...Models are in good agreement
with bringing the trough currently over the Oregon coast southward
along the West Coast...and over northern Baja by Saturday.
Associated with this trough...a weak baroclinic zone (front) will
slowly sag across N. Arizona on Thursday dropping our temperatures
a bit, but more importantly serving as a focus for precipitation
Thursday and Thursday night. Lift associated with this baroclinic
zone will bring areas of rain and snow over the northwest part of
the state...with snow levels generally between 6000 and 6500 ft.
An inch or two of snow accumulations are expected over the higher
terrain of Coconino County by Friday morning.
On Saturday and Sunday...the low is forecast to move from northern
Baja into eastern New Mexico. Sufficient moisture should be tapped
to wrap rain and snow over much of Arizona, with snow levels
rising to around 7000 feet near Flagstaff to over 8000 feet near
the White Mountains as warmer air is drawn in from the south.
There is some uncertainty on the amount of rain and snow that
could result from the passage of this system as the models diverge
somewhat on Saturday...but there is the potential for over 1.0" of
precipitation over the White Mountains and high terrain of eastern
Arizona by Sunday evening.
A few lingering showers are likely over eastern Arizona on Monday
as the trough elongates and ejects to the east...with dry and
warmer weather into the middle of next week as high pressure aloft
builds into the desert southwest.
.AVIATION...For the 06Z Forecast...Local MVFR CIGS and a light
shower possible overnight across northwestern Arizona. Expect
scattered showers to develop aft 12Z Thursday lasting through the
forecast period primarily affecting areas from Prescott-Flagstaff-
Kayenta westward where local MVFR to IFR conditions will be
common. Expect southerly winds 10-20 kts. Aviation discussion not
updated for TAF amendments.
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