Severe Thunderstorm Warning 69, NWS Flagstaff, AZ

846 
WWUS55 KFGZ 042122
SVSFGZ

Severe Weather Statement
National Weather Service Flagstaff AZ
222 PM MST SAT AUG 4 2018

AZC017-042132-
/O.EXP.KFGZ.SV.W.0069.000000T0000Z-180804T2130Z/
Navajo-
222 PM MST SAT AUG 4 2018

...THE SEVERE THUNDERSTORM WARNING FOR NAVAJO COUNTY WILL EXPIRE AT
230 PM MST...
                
The storm which prompted the warning has weakened below severe
limits, and no longer pose an immediate threat to life or property.
Therefore the warning will be allowed to expire.

LAT...LON 3458 11073 3466 11075 3473 11075 3481 11067
      3477 11049
TIME...MOT...LOC 2122Z 310DEG 7KT 3467 11065 

$$

RR

Area Forecast Discussion
National Weather Service Flagstaff AZ
850 AM MST Sat Aug 4 2018

.SYNOPSIS...For the weekend, thunderstorm chances will be much
lower as a passing disturbance brings drier air to the area.
Daytime temperatures will be several degrees above normal.
Moisture will gradually return toward the middle or end of next
week, with storm chances increasing across the northland.

&&

.DISCUSSION...Observations across northern Arizona reveal dew
points are around 10 degrees below yesterday's values. In general,
dew points range from the mid-40s to mid-50s, lowest in far
northeast Arizona. In addition, this mornings's upper-air
sounding from near Flagstaff, AZ measured precipitable water of
0.69 inches, down from the 0.91 inches observed yesterday. This
decrease in moisture, along with more dry and stable mid-level air
will lead to a reduction in shower and thunderstorm activity
today.

With that said, enough lingering moisture and surface heating
is in place for at least isolated showers and thunderstorms
today. Storms are expected to form first along the Mogollon Rim
and higher terrain in Yavapai County, before slowly moving toward
the northeast around 5 to 10 mph. Little storm activity is
forecast in the mountains of far northeast Arizona as that is
where the driest air resides.

The current forecast is on track, and no updates are anticipated
at this time.

&&

.PREV DISCUSSION /424 AM MST/...As the strong ridge axis shifts to
a position near or just south of our area through Monday, a drier
air mass will affect much of northern Arizona. There will still
be some isolated to scattered afternoon and early evening storms
today, mainly focused along and just north of higher terrain.
Sunday and Monday look even drier, with most areas remaining dry
except the eastern Mogollon Rim, White Mtns and Chuska Mtns where
isolated to scattered storms continue. With strong high pressure
nearby, daytime temperatures will be 5-10 degrees above normal
each day through at least Tuesday.

By the middle and end of next week, the center of high pressure is
forecast to shift northwest of the state. This will allow for a
gradual increase in moisture, especially for southern Arizona but
with modest increases up to the Mogollon Rim and White Mtns.
Steering flow during this period is expected to be from northeast
to southwest, pushing any storms that develop along the Rim and
White Mtns into deeper moisture over Yavapai/Gila counties. North
of the Mogollon Rim, the flow doesn't look favorable for enough
moisture for anything beyond isolated storms through next week at
this point. We kept the increase in storm chances modest and
gradual due to uncertainty in moisture fields, and the
unpredictability of moist outflows sent northward from storms that
could form south of the area.

&&

.AVIATION...For the 18Z package...Mostly VFR conditions are
expected to continue over the next 24 hrs. Scattered TSRA will
develop over the White Mtns this afternoon with isolated storms
possible elsewhere. Brief MVFR/IFR and gusty winds in/near storms.
Otherwise, winds generally SW 10-20 kts. Aviation discussion not
updated for TAF amendments.

&&

.FIRE WEATHER...A warmer and drier trend will begin today with
isolated to scattered thunderstorm coverage from the Mogollon Rim
into the White Mountains. Storms on Sunday will mainly be limited to
the White Mountains region. Expect erratic outflow winds near any
showers or storms. Otherwise, breezy southwest winds will develop
during the afternoon hours.

Monday through Wednesday...Warmer and drier weather will last at
least into the early part of next week, with the possibility of
moisture increasing into central Arizona by midweek.

&&

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

&&

PUBLIC...RR/JJ
AVIATION...RR
FIRE WEATHER...MCT

For Northern Arizona weather information visit
weather.gov/flagstaff