439 
FXUS65 KFGZ 050422
AFDFGZ

Area Forecast Discussion
National Weather Service Flagstaff AZ
922 PM MST Mon Feb 4 2019

.SYNOPSIS...Moist southwest flow will keep unsettled and cool
conditions going into Tuesday. A strong cold front will move
across northern Arizona Tuesday night and Wednesday morning.
Significant accumulating snow is expected over the higher terrain
in the next 36-48 hours. Dry weather will return for Thursday and
Friday. Unsettled weather may develop again over the weekend.

&&

.DISCUSSION...Radar and satellite trends indicate rain and snow 
over portions of northern Arizona this evening. Expect 
precipitation to continue overnight, ahead of an approaching low 
currently over western Oregon. The forecast calls for between a 
trace to 3 inches of snow above 6000 feet through tomorrow 
morning, with snow continuing from Tuesday into Wednesday.

In addition, gusty winds have been observed this evening, 
strongest along and immediately downstream of the Mogollon Rim. 
Current measurements show greater than 40 mph wind gusts in Show 
Low, with a 51 mph wind gusts measured at the airport in Taylor. 
These gusty winds will continue overnight.

In terms of grid updates, did increase wind speeds using a blend
of high resolution forecast models during the evening and
overnight hours. Otherwise, the current forecast appears to be on
track and no further forecast adjustments were made.

&&

.PREV DISCUSSION /246 PM MST/...Very active weather continues
through Wednesday with a strong cold front crossing the region
Tuesday night into Wednesday morning. Winter Storm Warnings and
Advisories have been issued along the Mogollon Rim as well as the
Coconino and Kaibab Plateaus. Significant snow accumulations are
anticipated in these areas from late tonight through Wednesday
morning. Water levels remain high along and south of the Rim, but
have been slowly receding through the day.

Rain and snow showers will gradually increase through the evening
hours and overnight along and south of the Mogollon Rim. Weak CAA
will slowly drop snow levels down to between 6,000-6,500 feet by
early Tuesday morning. Widespread rain and snow showers will
continue on Tuesday as strong upslope flow persists. A strong
front associated with a very cold upper low will cross the region
Tuesday night into Wednesday morning which will bring the period
of most significant precipitation and lowering snow levels.
General snowfall amounts of 6-12 inches above 6,000 feet are
forecasted at this time through midday Wednesday. One concern
pertaining to snowfall amounts is the shallow nature of the
moisture until Tuesday evening when deeper moisture arrives with
the front. This will be something to monitor especially later
tonight and Tuesday during the daylight hours.

Additionally, gusty southwest winds will persist through the
period with the potential for blowing snow and low visibility
especially Tuesday night and Wednesday morning. Daytime
temperatures on Wednesday will struggle to get out of the mid-
upper 20s over the higher terrain with wind chills making it feel
even colder.

On top of winter weather impacts, hydrology concerns remain as
more precipitation is poised to fall over the region. While this
system will not be as wet as the system yesterday, this could
cause some additional flooding issues. Based on this and
coordination with the CBRFC, we opted to issue a Flash Flood Watch
from 11pm tonight - 5pm Wednesday afternoon for northern Gila and
Yavapai counties.

Quieter weather is on the way for Thursday and Friday with much
lighter winds. Latest long range guidance indicates a potential
return to unsettled weather over the weekend, but confidence is
low on how this will play out.

&&

.AVIATION...For the 06Z Package...Through 00Z - SHSN 
gradually increasing over higher terrain along/west of the Mogollon 
Rim, with light rain showers possible at lower elevations. Periods 
of IFR/LIFR cigs at the higher elevation terminals. After 
00Z - areas of RA and SN with snow levels falling from west to east 
to less than 5000 ft msl west of KFLG to 6000 ft to the east. Gusty 
southwest winds through the period, strongest along/east of terrain 
features where gusts to 30-40 kt likely. Aviation discussion not 
updated for TAF amendments.

&&

.FIRE WEATHER...Scattered rain and snow showers tonight, mainly over 
the Mogollon Rim and Kaibab Plateau, will increase in coverage 
Tuesday. Breezy southwest winds will persist tonight and Tuesday as 
temperatures remain below normal. Rain and snow showers continue 
Wednesday as both temperatures and southwest wind speeds decrease.

Thursday through Saturday...Drier conditions, decreased wind speeds, 
and a modest warming trend will develop Thursday and Friday. Chance 
for unsettled weather to return by Saturday.

&&

.FGZ WATCHES/WARNINGS/ADVISORIES...Winter Storm Warning until 8 AM
MST Wednesday FOR AZZ004-015-016. 

Flash Flood Watch through Wednesday afternoon FOR AZZ008-018-037-
038.

Winter Weather Advisory until 8 AM MST Wednesday FOR AZZ007.

Winter Weather Advisory from 5 PM Tuesday to 11 AM MST Wednesday 
FOR AZZ017.


&&

$$

PUBLIC...RR/TPS
AVIATION...JJ
FIRE WEATHER...NL


For Northern Arizona weather information visit
weather.gov/flagstaff