Scientific Forecaster Discussion
fxus65 kfgz 170438
Area forecast discussion
National Weather Service Flagstaff Arizona
938 PM MST Sat Nov 16 2019
Synopsis...expect clear skies across the area through Monday with
dry and mild weather. Rainy cool weather moves in Tuesday evening
and should continue through Friday. This system will bring snow to
the high country mostly above 8,000 ft Thursday and Friday.
Update...infrared satellite imagery this evening showed the last
of the high based clouds retreating towards New Mexico. Northern
Arizona returns to a period of clear overnight skies.
A dry trough will scrape The Four Corners region tonight and help
to increase the near-surface pressure gradient. The increased
gradient and a shift to more northerly flow will create locally
gusty north to northeast surface winds tonight into Sunday mid-day.
The winds will be strongest along and southwest of the Mogollon
Rim with some areas experiencing sustained winds of 10 - 15 mph
and gusts upwards of 20 - 25 mph.
Sunday afternoon temperatures will continue to be five to fifteen
degrees fahrenheit above normal under sunny skies.
Previous discussion /358 PM MST/...high clouds continue to move south
out of the area. Look for clear skies and mild, dry weather
Tuesday and Wednesday...the cut-off low off of baja gets picked
up by a trough descending from the Pacific northwest going into
Tuesday. The low opens into a shortwave and tracks across Arizona
Tuesday afternoon into Wednesday, pulling deep tropical moisture
up from the south. Expect mid to high clouds moving in from the
south Tuesday morning with deeper moisture and lower ceilings by
Tuesday evening. Rain showers will spread across most of northern
Arizona with an inch or more of precipitation possible in Yavapai
and western Gila counties Tuesday night through Wednesday.
Thursday and Friday...the trough from the northwest moves across
the region Thursday with the associated cooler air aloft, bringing
a wintery mix to the area mostly above 7,000 ft. Possible
scattered snow showers will continue Thursday night into Friday.
Little snow accumulation is expected below 8,000 ft from this
system. The San Francisco peaks can expect up to 20 inches of snow,
and about 15 inches in the White Mountains.
Beyond Friday...models indicate a longwave trough setting up over
the western US which could bring unsettled weather to northern
Aviation...for the 06z package...VFR conditions and generally
light winds will continue for the next 24 hours. There will be
locally gusty north to northeast winds along and southwest of a
line from kflg to ksow through 15z Sunday. Aviation discussion not
updated for taf amendments.
Fire weather...mild temperatures and dry conditions will
continue through Monday night. Winds will generally remain light.
However, locally gusty north to northeast winds are possible
tonight along and south of the Mogollon Rim.
Tuesday through Thursday...a change to wet conditions and colder
temperatures starts Tuesday afternoon, with widespread wetting rain
amounts already accumulated by mid day Wednesday. Strong south to
southwest winds possible Wednesday.