Area Forecast Discussion
Issued by NWS Flagstaff, AZ
FXUS65 KFGZ 131622
Area Forecast Discussion
National Weather Service Flagstaff AZ
922 AM MST Mon Feb 13 2017
.SYNOPSIS...Scattered showers will slowly decrease from west to
east through tonight. A second disturbance will bring a chance
for showers primarily along the Mogollon Rim Tuesday afternoon. A
drying and warming trend is then forecast through Thursday.
Another cold front is expected to bring colder temps and rain and
snow Friday through Sunday.
.UPDATE...Patchy dense fog will gradually dissipate across
northern Arizona later this morning as vertical mixing commences.
Precipitation chances will gradually diminish from west to east
through tonight as the upper low responsible for the recent
precipitation lifts into New Mexico.
Updated the forecast to indicate stratiform precipitation this
morning, transitioning to convective activity this afternoon based
off the latest hi-res model solutions.
The remaining forecast is on track. The updated products have been
.PREV DISCUSSION /242 AM MST/... This mornings water vapor loop
shows the upper low center about 150 miles south of Tucson, and
moving slowly eastward. Area radars show scattered showers and
isolated thunderstorms across southern AZ and these moving to the
N-NE. OOZ forecast model continuity is good and few changes were
made to the short term forecast.
For today, snow levels are the lowest this morning along the AZ NM
border and are around 6500-7000 feet. Areas of fog are probable
across the area as low level humidities are near or at 100
percent. Plentiful deep moisture will persist across eastern AZ
through the day with numerous showers expected near the NM state
line. Drying to commence across western parts of the state, though
a slight chance of showers is forecast for Yavapai and Coconino
The GFS/ECMWF/NAM prog a second east-west oriented wave to rotate
south over northern Arizona Tuesday. This disturbance will bring
a chance for light showers primarily to the northeast quarter of
the state and along the Mogollon Rim. Showers to taper off
Upper level ridging will then build into the southwestern US from
Tuesday night through Thursday. This will lead to a drying and
warming trend, with temperatures running about 10 degrees above
normal on Thursday. Winds aloft become southwesterly Thursday
night ahead of a broad trough moving onto the West Coast.
Friday through Sunday - Model consistency remains good regarding
a cold frontal passage late Friday through Saturday across our
area. Precipitation chances are into the likely category for much
of the area. Model QPF amounts also continue to indicate the
potential for moderate to heavy precipitation Friday night
through Saturday, with significant winter weather for the high
country. Early projections for snow levels are 6500-7500 ft Friday
night and Saturday, 5500-6500 ft Saturday night. On Sunday,
operational runs again show a cold and moist northwest flow with
another shortwave approaching or passing through the area with a
continued chance of snow and lower elevation rain. It`s too early
to give specific details regarding snow amounts and timing, so
continue to monitor the forecast through this week.
.AVIATION...For the 18Z package...Areas of fog/low ceilings and
IFR/LIFR conditions with isolated VLIFR conditions until 18Z-19Z.
After 19Z, mainly MVFR conditions with showers possible. Snow
levels will generally remain above 8000 feet MSL. A slow
improvement to VFR conditions should develop from west to east
late this afternoon and evening. Aviation discussion not updated
for TAF amendments.
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