Alert archive / Arizona / Special Weather Statements in 2021

Special Weather Statement, NWS Flagstaff, AZ

July 18, 2021

NWS Flagstaff, AZ issued this special weather statement at Jul 18, 2021, 6:21 PM MST. It was in force for 24 min. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued
Jul 18, 2021, 6:21 PM MST (01:21 UTC)
Expired
Jul 18, 2021, 6:45 PM MST
In force
24 min
Issued by
NWS Flagstaff, AZ

The radar

The Flagstaff radar (KFSX), 90 km from the middle of the area, began a volume at 01:21 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

The nearest sounding before it

Phoenix, AZ (KPSR), launched 00:00Z, 1.4 hours before the alert went out and 97 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.

Skew-T log-pSkew-T log-p diagram, Phoenix, AZ at 00:00Z on 2021-07-19Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1031 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Phoenix, AZ at 00:00Z on 2021-07-19The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -20 square meters per square second.1939Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.
Mixed-layer CAPE
1031 J/kg
Mixed-layer CIN
-48 J/kg
Mixed-layer LCL
2190 m above ground
0-6 km bulk shear
25 kt
0-1 km storm-relative helicity
-20 m²/s²
0-3 km storm-relative helicity
86 m²/s²
Significant tornado parameter
0.0
Supercell composite
1.2

Open this sounding in Storm Lab

The text

As transmitted.

692 
WWUS85 KFGZ 190121
SPSFGZ

Special Weather Statement
National Weather Service Flagstaff AZ
621 PM MST Sun Jul 18 2021
 
AZZ037-190145-
Yavapai County Valleys and Basins-
621 PM MST Sun Jul 18 2021

...STRONG THUNDERSTORM ALONG INTERSTATE 17 BETWEEN CORDES LAKES AND 
BUMBLE BEE UNTIL 6:50 PM MST...

At 619 PM MST, Doppler radar was tracking a strong thunderstorm over
Cordes, or 24 miles north of New River, moving northwest at 25 mph.

Half inch hail and winds in excess of 40 mph will be possible with
this storm.

Locations impacted include...
Bumble Bee, Cordes Junction, Cordes Lakes, Cordes and Spring Valley. 
Interstate 17 from mile markers 255 to 260. 

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.

Frequent cloud to ground lightning is occurring with this storm.
Lightning can strike 10 miles away from a thunderstorm. Seek a safe
shelter inside a building or vehicle.

&&

LAT...LON 3432 11200 3416 11214 3427 11227 3439 11217
TIME...MOT...LOC 0119Z 115DEG 21KT 3427 11214 

$$

TPS

The office that day

Everything else NWS Flagstaff, AZ issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jul 18, 5:31 PM MSTFlash Flood Warning Considerable damage threatFGZGila59 min
Jul 18, 5:43 PM MSTSevere Thunderstorm WarningFGZGila, Yavapai24 min
Jul 18, 6:14 PM MSTFlash Flood Warning Considerable damage threatFGZYavapai3 hr
Jul 19, 1:48 PM MSTFlash Flood Warning Considerable damage threatFGZYavapai3 hr
Jul 19, 1:54 PM MSTSpecial Weather StatementFGZ51 min
Jul 19, 2:08 PM MSTSevere Thunderstorm WarningFGZCoconino37 min
Jul 19, 2:30 PM MSTFlash Flood Warning Considerable damage threatFGZCoconino2 hr
Jul 19, 3:07 PM MSTSpecial Weather StatementFGZ23 min
Jul 19, 3:28 PM MSTSpecial Weather StatementFGZ32 min
Jul 19, 3:37 PM MSTFlash Flood Warning Considerable damage threatFGZCoconino3 hr
Jul 19, 4:01 PM MSTFlash Flood Warning Considerable damage threatFGZNavajo3 hr
Jul 19, 4:27 PM MSTFlash Flood Warning Considerable damage threatFGZYavapai2 hr

Nearby

Special Weather Statements in Arizona, 2021Every special weather statement in 2021

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.