Flash Flood Warning 52, NWS Flagstaff, AZ

686 
WGUS75 KFGZ 232044
FFSFGZ

Flash Flood Statement
National Weather Service Flagstaff AZ
144 PM MST SUN JUL 23 2017

AZC005-232230-
/O.CON.KFGZ.FF.W.0052.000000T0000Z-170723T2230Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Coconino-
144 PM MST SUN JUL 23 2017

...THE FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 330 PM MST FOR
COCONINO COUNTY...

At 142 PM MST, Doppler radar indicated rain intensity has decreased. 
Scattered light showers continue at this time. Up to two to three 
inches of rain has already fallen and is expected to cause flash 
flooding.

Some locations that will experience flooding include...
Williams, Dogtown Lake Campground and Kaibab Lake Campground. 

This includes the following streams and drainages...Dogtown Wash...
Sycamore Creek...West Cataract Creek...Red Lake Wash...Hell Canyon...
Cataract Creek and Johnson Creek.

This includes the following highways...
 Business Interstate 40 between mile markers 163 and 165.
 Interstate 40 between mile markers 161 and 171.
 State Route 64 between mile markers 186 and 193.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Move to higher ground now. Act quickly to protect your life.

Remain alert for flooding even in locations not receiving rain. Dry
washes, streams, and rivers can become raging killer currents in a
matter of minutes, even from distant rainfall.

&&

LAT...LON 3543 11230 3535 11211 3524 11204 3516 11219
      3536 11232

$$

MCT

035 
WGUS75 KFGZ 232221
FFSFGZ

Flash Flood Statement
National Weather Service Flagstaff AZ
321 PM MST SUN JUL 23 2017

AZC005-232230-
/O.EXP.KFGZ.FF.W.0052.000000T0000Z-170723T2230Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Coconino-
321 PM MST SUN JUL 23 2017

...THE FLASH FLOOD WARNING FOR COCONINO COUNTY WILL EXPIRE AT 330 PM
MST...

The heavy rain has ended. Flooding is no longer expected to pose a 
threat at this time. However, there could still be high water and 
flooded low water crossings. Please continue to heed any remaining 
road closures.

LAT...LON 3543 11230 3535 11211 3524 11204 3516 11219
      3536 11232

$$

MCT

Area Forecast Discussion
National Weather Service Flagstaff AZ
950 AM MST Sun Jul 23 2017

.SYNOPSIS...A Flash Flood Watch has been issued for northern
Arizona valid Sunday from noon to midnight. Heavy rainfall with
flash flooding is possible from stronger storms. Active monsoon
conditions are expected to continue Tuesday. A decrease in storm
coverage should develop starting Wednesday, especially across
western and central Arizona.

&&

.UPDATE...
We have issued flash flood watch for for all of Apache, Coconino,
Navajo, Yavapai, and northern Gila Counties valid from noon today
through midnight tonight. The cloud cover and light rain showers
that covered southern Coconino and Yavapai counties at sunrise is
decreasing, and cu development is already going south of the
Mogollon rim and over the San Franciso peaks. PW in this mornings
sounding is over an inch, with mositure increase seen in the
700-550 mb layer vs 24 hours ago. We have seen a few observed 2
inch reports from yesterday,  and expect more today given what
we've seen this morning.

&&

.PREV DISCUSSION /414 AM MST/...Expecting an active day as
abundant monsoon moisture is present over central and northern
Arizona. Model forecast soundings indicate fairly high levels of
instability along and south of the Mogollon Rim this afternoon,
with steering flow generally pushing storms slowly toward the
west/northwest. This setup would allow for a few strong to
marginally severe thunderstorms developing along the Mogollon
Rim/White Mtns and pushing slowly into northern Gila and portions
of Yavapai County later in the afternoon and evening. Also, with
the stronger storms (and/or areas with cell training), there will
be a risk of heavy rain and localized flash flooding. One thing
that could limit this possibility is ongoing cloud cover, acting
to inhibit instability and storm strength. If these clouds show a
decreasing trend later this morning, there could be a need for a
Flash Flood Watch for this  afternoon/evening from the Mogollon
Rim southward - we will monitor through the morning. Later
tonight and Monday...an inverted trough feature over southeast AZ
is forecast to move up into northern Arizona, with abundant
moisture persisting. This will turn the steering flow from the
southeast tonight and then southerly Monday. Storms could persist
into the overnight hours tonight with the help of the feature. On
Monday, forecast soundings show a nearly saturated atmosphere
through a deep layer. Rain chances are high, but the amount of
cloud cover could act to hold down instability and decrease storm
intensity, rainfall rates and flash flood potential. Stay tuned as
this part of the forecast remains uncertain and could change.

Tuesday - the inverted trough is forecast to move north of the
state, with slightly lower precipitable water values over the
region. Looking for a more typical monsoon pattern, with scattered
afternoon storms moving SW to NE.

Wednesday & Thursday - models indicating a drier air mass and
some warming in the mid levels. Not expecting storms to shut down
completely, but coverage should be isolated to scattered at best.

Friday onward - high pressure forecast to shift to our north,
allowing for easterly flow and gradual moistening. Storm chances
return to typical monsoon levels.

&&

.AVIATION...For the 18Z package...Sct to numrs shra/tsra and isold
+tsra. Most storms forming over higher terrain and moving west and
northwest. Activity will be slow to decrease tonight, transitioning
to more of a stratiform type. MVFR/IFR conditions in the strongest
storms. Aviation discussion not updated for TAF amendments.

&&

.FIRE WEATHER...Expect above normal storm activity and high relative
humidity values Sunday and Monday, as moisture continues to stream
into the district. Wetting rain chances will remain high.

Tuesday through Thursday...Chances for showers and thunderstorms
will continue, but coverage and frequency should decrease. Slightly
drier conditions near the surface will enhance the threat for gusty
outflow winds, associated with thunderstorms.

&&

.FGZ WATCHES/WARNINGS/ADVISORIES...Flash Flood Watch through this evening FOR AZZ004>018-037>040.

&&

PUBLIC...DL/JJ
AVIATION...Peterson
FIRE WEATHER...Peterson

For Northern Arizona weather information visit
weather.gov/flagstaff

Hazardous Weather Outlook
National Weather Service Flagstaff AZ
950 AM MST Sun Jul 23 2017

AZZ004>018-037>040-240415-
Kaibab Plateau-Marble and Glen Canyons-Grand Canyon Country-
Coconino Plateau-Yavapai County Mountains-
Northeast Plateaus and Mesas Hwy 264 Northward-Chinle Valley-
Chuska Mountains and Defiance Plateau-
Little Colorado River Valley in Coconino County-
Little Colorado River Valley in Navajo County-
Little Colorado River Valley in Apache County-
Western Mogollon Rim-Eastern Mogollon Rim-White Mountains-
Northern Gila County-Yavapai County Valleys and Basins-
Oak Creek and Sycamore Canyons-Black Mesa Area-
Northeast Plateaus and Mesas South of Hwy 264-
950 AM MST Sun Jul 23 2017

This hazardous weather outlook is for Apache...Coconino...
Northern Gila...Navajo...and Yavapai Counties in Northern
Arizona.

.DAY ONE...Today and Tonight

Look for another round of scattered to numerous showers and
thunderstorms this afternoon and evening. The steering flow aloft
will be weak, pushing storms slowly toward the west-northwest. A
few storms today will be capable of dropping 1 to 3 inch downpours
which could result in flash flooding. A Flash Flood Watch has been
issued for all of northern and central Arizona.

Higher instability along and south of the Mogollon Rim could also
produce a few strong to severe thunderstorms, with hail up to one
inch in diameter and strong wind gusts.

.DAYS TWO THROUGH SEVEN...Monday through Saturday

Showers and thunderstorms are likely Monday, a few possibly
producing heavy rainfall and localized flash flooding. A decrease
in storm coverage is expected midweek before increasing again by
Thursday or Friday.

.SPOTTER INFORMATION STATEMENT...

Weather spotters are encouraged to report significant weather
conditions according to standard operating procedures.

Special Weather Statement
National Weather Service Flagstaff AZ
1133 AM MST SUN JUL 23 2017

AZZ007-015-231915-
Western Mogollon Rim-Coconino Plateau-
1133 AM MST SUN JUL 23 2017

...SIGNIFICANT WEATHER ADVISORY FOR WILLIAMS AREA UNTIL 1215 PM
MST...

At 1133 AM MST, Doppler radar was tracking a strong thunderstorm over
Williams, or 29 miles west of Flagstaff. this storm was nearly
stationary.

Dime size hail and winds in excess of 40 mph will be possible with
this storm.

Locations impacted include...
Williams, Dogtown Lake Campground and Kaibab Lake Campground.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Torrential rainfall is also occurring with this storm, and may lead
to localized flooding. Do not drive your vehicle through flooded
roadways.

&&

LAT...LON 3516 11210 3519 11231 3542 11221 3533 11203
TIME...MOT...LOC 1833Z 201DEG 2KT 3525 11214

MCT

Special Weather Statement
National Weather Service Flagstaff AZ
1205 PM MST SUN JUL 23 2017

AZZ006-007-231945-
Coconino Plateau-Grand Canyon Country-
1205 PM MST SUN JUL 23 2017

...SIGNIFICANT WEATHER ADVISORY NORTH OF VALLE UNTIL 1245 PM MST...

At 1204 PM MST, Doppler radar was tracking a strong thunderstorm 8
miles north of Valle, or 24 miles southwest of Desert View at Grand
Canyon, moving northeast at 15 mph.

Dime size hail and winds in excess of 40 mph will be possible with
this storm.

This storm will remain over mainly rural areas OF Coconino County.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Torrential rainfall is also occurring with this storm, and may lead
to localized flooding. Do not drive your vehicle through flooded
roadways.

&&

LAT...LON 3565 11218 3577 11227 3597 11199 3575 11183
TIME...MOT...LOC 1904Z 238DEG 14KT 3578 11210

MCT