Severe Thunderstorm Warning 25, NWS Flagstaff, AZ

Area Forecast Discussion
National Weather Service Flagstaff AZ
1000 AM MST Thu Jul 19 2018

.SYNOPSIS...Expect afternoon and evening showers and thunderstorms
through at least Saturday. The greatest coverage and highest
potential for stronger storms will be over the Mogollon Rim and
Yavapai County where areas of heavy rain could produce localized
flooding. Warmer afternoon temperatures and less storm coverage
may start on Sunday.

&&

.UPDATE...12Z sounding showed a PW of 0.74 inch...down from 1.00
yesterday morning. Very little cloud cover this morning so there
will be abundant solar heating this morning. Easterly flow up
through 5H and then southwest winds above around 3H. This could
help storms develop. We are expecting another active day today.
Making some adjustments to the POPs this evening as high
resolution models are indicating a few thunderstorm clusters
lasting and moving into the lower elevations.

&&

.PREV DISCUSSION /344 AM MST/... Cloud cover has been decreasing
since midnight across northern Arizona, though the amount of
monsoonal moisture overhead is expected to show little change
through Saturday.

So for today, expect showers and tstorms to develop across the
high terrain by late morning and spread into the valleys this
afternoon. Storm steering flow this afternoon will be very light,
thus storms will be slow moving and may produce heavy rainfall
amounts. Storms dropping south and westward off the Mogollon Rim
will be headed into tstorm capes of 1000-2000 j/kg. The GFS shows
another cyclonic mesoscale circulation late this afternoon, this
one moving into the White Mtns. Something to keep an eye out for.

For Friday and Saturday, the subtropical high pressure re-
centers near Four Corners on Friday. This puts northern Arizona
in very light south to southeast flow pattern with rich monsoon
moisture through Saturday. Expect primarily afternoon and evening
showers and thunderstorms with storms moving very slowly from
south to north. Heavy rain and flash flooding will be the main
storm threats.

From Sunday through Wednesday - Progs continue to show drier air
moving overhead above 500 mb (theta 330 surface). N0 changes were
made to this period with the idea we will see a decrease in
daytime storm coverage and fair weather overnight. Max temps up 2
to 5 degrees for this period vs today.

&&

.AVIATION...For the 18Z package...VFR conditions and mostly clear
skies this morning will transition to sct-nmrs shra/tsra with isold
+tsra by 19Z-20Z. Convective activity most wdsprd between 21Z-02Z.
Strongest storms will produce localized MVFR/IFR conditions and wind
gusts to 50kts. Aviation discussion not updated for TAF
amendments.

&&

.FIRE WEATHER...An active monsoon pattern with scattered to
numerous slow moving thunderstorms will continue today and Friday.
Heavy rain and erratic thunderstorm winds will be the main threats.
Outside of thunderstorms, winds will generally be light.

Saturday through Monday...Thunderstorm chances will continue each
day through the weekend into early next week. There is a possibility
of a slight downturn in activity sometime next week.

&&

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

&&

PUBLIC...MAS/DL
AVIATION...Peterson
FIRE WEATHER...DB

For Northern Arizona weather information visit
weather.gov/flagstaff

Special Weather Statement
National Weather Service Flagstaff AZ
1210 PM MST THU JUL 19 2018

AZZ015-192000-
Western Mogollon Rim-
1210 PM MST THU JUL 19 2018

...SIGNIFICANT WEATHER ADVISORY FOR COCONINO COUNTY UNTIL 100 PM
MST...

At 1210 PM MST, Doppler radar was tracking a strong thunderstorm over
Flagstaff Mall, or over Flagstaff. this storm was nearly stationary.

Dime size hail and winds in excess of 30 mph will be possible with
this storm.

Locations impacted include...
Flagstaff, Flagstaff Mall, Cosnino and Walnut Canyon National
Monument.

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 3515 11160 3523 11166 3528 11153 3519 11147
TIME...MOT...LOC 1910Z 231DEG 3KT 3521 11158

Special Weather Statement
National Weather Service Flagstaff AZ
1229 PM MST THU JUL 19 2018

AZZ011-192015-
Chuska Mountains and Defiance Plateau-
1229 PM MST THU JUL 19 2018

...SIGNIFICANT WEATHER ADVISORY FOR APACHE COUNTY UNTIL 115 PM MST...

At 1229 PM MST, Doppler radar was tracking a strong thunderstorm
over Window Rock. This storm was nearly stationary.

Dime size hail and winds in excess of 30 mph will be possible with
this storm.

Locations impacted include...
Fort Defiance, Window Rock and St. Michaels.

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 3554 10918 3572 10922 3581 10905 3579 10904
      3556 10905
TIME...MOT...LOC 1929Z 227DEG 8KT 3570 10907

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
1257 PM MST THU JUL 19 2018

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

1243 PM     HAIL             2 SSE FLAGSTAFF MALL    35.20N 111.56W
07/19/2018  E0.75 INCH       COCONINO           AZ   PUBLIC

            EXACT LOCATION IS AN ESTIMATE.

&&

MCT

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
136 PM MST THU JUL 19 2018

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

0126 PM     HAIL             3 S FLAGSTAFF MALL      35.18N 111.58W
07/19/2018  E1.00 INCH       COCONINO           AZ   NWS EMPLOYEE

&&

MCT