Flash Flood Warning 72, NWS Flagstaff, AZ

Area Forecast Discussion
National Weather Service Flagstaff AZ
855 PM MST Wed Dec 04 2019

.SYNOPSIS...Rain and snow showers will continue to move
across the area overnight, lingering along the Mogollon Rim and
portions of Apache county through early Thursday morning. Cool, but
drier weather arrives Thursday afternoon. After dry and seasonable
conditions Friday and Saturday, another weather system will bring
unsettled weather back the region Sunday and Monday.

&&

.DISCUSSION...A cold front is currently approaching the I-17
corridor, driven by an upper low over southern Nevada. Snow levels
have dropped a bit lower than boundary layer conditions and 700mb
temperatures would have otherwise indicated, likely due to very deep
saturation.

This front moves quickly eastward overnight as the upper low shears
through the Great Basin, with s/wv ridging quickly following on its
heels. This will bring most precipitation to an end quickly after
Midnight MST, the exception being shallow upslope showers that will
continue over the Mogollon Rim into early Thursday morning. By
Thursday afternoon, expect drying conditions, but remaining a bit
cool.

Updates already out for lower snow levels and a little accumulation
in spots above 7000 feet.

LONG TERM (Thursday night through Tuesday)...A shortwave ridge
will build over the Southwest and southern Rockies region behind
the incoming low pressure system. Drier westerly flow aloft will
accompany this ridge and limit chances of precipitation while it
is located over the Southwest through Saturday afternoon.

Temperatures will begin to warm as mid-level heights rebound
with the shortwave ridge. Daytime temperatures will increase
about ten degrees between Thursday and Saturday. The warmer
temperatures forecast Saturday will be above normal across much
of the northland.

A Pacific Northwest trough will begin to dig southwestward
Saturday afternoon. A plume of moisture off the southern
California coast could interact with this trough and bring showers
beginning Saturday evening to northern Arizona. All GEFS members
are showing chances of measurable precipitation from Saturday
overnight into Sunday evening. Chances of precipitation in this
period were increased only slightly with this forecast. This will
be a drier system, but storm total precipitation amounts will
continue to be monitored. Only slight chances for showers are
expected by the early morning hours Monday.

The operational GFS is much more progressive on this late weekend
system and moves the deep moisture out of the area faster than
the operational ECMWF. These models display about a twelve hour
difference in the timing for the final showers within southeastern
areas of the County Warning Area. This timing will continue to be
monitored, especially for eastern Arizona.

Drier air behind this frontal passage will help to clear skies
from Monday morning into the afternoon. Temperatures are forecast
to rebound slightly behind the front for Monday and Tuesday.

&&

.AVIATION...For the 06Z package...Until 18z Thursday, expect wdsprd
MVFR/local IFR conditions due to low clouds and fog. Additionally, a
band of light / moderate precipitation associated with a cold front
will move eastward through Navajo and Apache counties through 15z.
After 18z Thursday, improving ceilings and visibilities to VFR for
most of northern Arizona, lingering stratus along the Mogollon Rim
may bring local MVFR conditions. Aviation discussion not updated for
TAF amendments.

&&

.FIRE WEATHER...A quick moving low pressure system will bring
breezy southwest winds along with rain and high elevation snow
showers to the area through early Thursday. Fair weather can be
expected Thursday afternoon into Friday.

Saturday through Monday...Dry conditions can be expected for most
locations through Saturday afternoon. More widespread chances for
wetting rains return Sunday. Chances for showers decrease Monday.

&&

.FGZ WATCHES/WARNINGS/ADVISORIES...NONE.

&&

PUBLIC...Peterson/TPS
AVIATION...DL/Peterson
FIRE WEATHER...TPS/NL

For Northern Arizona weather information visit
weather.gov/flagstaff

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
944 PM MST WED DEC 4 2019

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0600 PM     FLASH FLOOD      1 SW MCGUIREVILLE       34.63N 111.82W
12/04/2019                   YAVAPAI            AZ   LAW ENFORCEMENT

            SUCCESSFUL SWIFT WATER RESCUE OCCURRED ALONG
            REAY RD DUE TO A FLASH FLOOD IN BEAVER
            CREEK. THE RESCUE WAS SUCCESSFULLY COMPLETED
            BY 1845 MST.

&&

BEP

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
953 PM MST WED DEC 4 2019

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0445 PM     FLASH FLOOD      2 SW MCGUIREVILLE       34.61N 111.84W
12/04/2019                   YAVAPAI            AZ   OTHER FEDERAL

            STREAM GAUGE (BCMA3) ON BEAVER CREEK NEAR
            MONTEZUMA CASTLE NATIONAL MONUMENT REPORTED
            A RISE OF 2.37 FEET IN ONE HOUR. THIS RISE
            IN THE STREAM HAPPENED BETWEEN 3:45 PM (2.51
            FEET) AND 4:45 PM (4.88 FEET) MST ON THE 4TH
            OF DECEMBER. THE STREAM CONTINUED TO RISE TO
            OVER 9 FEET.

&&

BEP