Flash Flood Warning 144, NWS Flagstaff, AZ

Area Forecast Discussion
National Weather Service Flagstaff AZ
433 PM MST Tue Oct 2 2018

.SYNOPSIS...Widespread showers and isolated thunderstorms will
continue across northern Arizona through this evening before
gradually tapering off. Another round of showers and thunderstorms
is expected on Wednesday afternoon and evening, especially in
western Coconino and Yavapai counties. A much colder storm system
is expected this weekend with rain and high elevation snow.

&&

.DISCUSSION...The extremely heavy rainfall amounts that were
expected over southeast Yavapai County and the eastern Mogollon
Rim have materialized today, while areas farther north and west
including Prescott and Flagstaff have seen amounts on the lower
end. The most impressive amounts so far have been from Crown King
to near Cordes and Sunset Point where 3.50" to 5.00" amounts have
been recorded. Also, along the eastern Mogollon Rim north of
Payson there has been 2.00" to 3.00" of rain since this morning.
The heaviest amounts have been in the favored upslope regions just
east of the track of the remnant tropical low-mid level
circulation. For the rest of today and tonight, the depth of
moisture over the region is expected to become more shallow,
decreasing the efficiency of rainfall. There will still be a few
hours however where additional heavy rain should continue over the
favored areas. We will keep the Flash Flood Watch going overnight
in Yavapai County and over the eastern Mogollon Rim but the watch
was cancelled farther north over most of Coconino County. With the
saturated low level air mass in place, there will also be patches
of fog through Wednesday morning.

Wednesday - a low pressure system will move onto the southern
California coast during the day and open up as it crosses southern
NV and northwest AZ Wednesday evening and overnight. Low level
moisture will remain plentiful, so cooling mid level temperatures
and large scale lift with the approaching low should produce a
round of showers and thunderstorms, espousal over Coconino and
much of Yavapai counties. Increasing deep layer wind shear will
also bring a chance of some strong to severe thunderstorms, with
hail and strong wind the main threats. Western Yavapai and NW
Coconino county are included in a slight risk area from the Storm
Prediction Center, with the marginal risk stretching farther east
through Yavapai County and along the Mogollon Rim.

Thursday and Friday - we will be in between systems with little to
no chance of rain and temperatures slightly below normal.
Saturday and Sunday - model guidance and ensembles remain in good
agreement that a deep and cold trough will move into Arizona from
the north. This is likely to bring much colder temperatures with
increasing winds and a good chance of rain and high elevation
snow. Will continue to fine tune the forecast through the week,
stay tuned for more details.

&&

.AVIATION...For the 00Z package...MVFR/IFR conditions present for
many locations through 01Z and expect overnight FG as well. SCT
showers near KPRC as the widespread rain continues to move towards
the northeast before becoming SCT overnight. Chance of thunderstorms
Wednesday that could produce gusty and erratic winds. Aviation
discussion not updated for TAF amendments.

&&

.FIRE WEATHER...Light to moderate rainfall continues through
the evening. Showers and storms again on Wednesday, with the best
chances across Yavapai and Coconino counties. Gusty southwest winds
Thursday. Cooler temperatures will persist regionwide.

.Friday through Sunday...Unsettled weather will prevail with
cooler temperatures and gusty southwest winds at times. Possible
return of precipitation on Sunday.

&&

.FGZ WATCHES/WARNINGS/ADVISORIES...Flash Flood Watch through
late tonight FOR AZZ008-016-018-037-038.

&&

PUBLIC...JJ
AVIATION...NL
FIRE WEATHER...NL

For Northern Arizona weather information visit
weather.gov/flagstaff

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
322 PM MST TUE OCT 2 2018

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

1120 AM     FLASH FLOOD      2 NNW BLACK CANYON CITY 34.09N 112.15W
10/02/2018                   YAVAPAI            AZ   PUBLIC

            RISE OF 3 FEET IN ABOUT TWO HOURS ALONG
            BLACK CANYON CREEK AT THE LOW WATER CROSSING
            OVER MAREN AVENUE IN BLACK CANYON CITY.
            RECORDED BY YCFCD STREAM GAUGE.

&&

NWS FLAGSTAFF

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
326 PM MST TUE OCT 2 2018

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

1145 AM     FLASH FLOOD      4 ESE CORDES JUNCTION   34.31N 112.05W
10/02/2018                   YAVAPAI            AZ   OTHER FEDERAL

            USGS STREAM GAUGE ALONG AGUA FRIA RIVER EAST
            OF CORDES JUNCTION RECORDED A RISE OF ABOUT
            3.5 FEET IN THREE HOURS.

&&

NWS FLAGSTAFF