Alert archive / Arizona / Severe Thunderstorm Warnings in 2021
Severe Thunderstorm Warning 24, NWS Flagstaff, AZ
NWS Flagstaff, AZ issued this severe thunderstorm warning at Jul 10, 2021, 5:09 PM MST for Coconino County, Gila County, Yavapai County, Arizona. It was in force for 51 min. 1 report came from inside the area while it was in force.
The area
The outline as issued, with what was reported inside it.
The facts
- Issued
- Jul 10, 2021, 5:09 PM MST (00:09 UTC)
- Expired
- Jul 10, 2021, 6:00 PM MST
- In force
- 51 min
- Issued by
- NWS Flagstaff, AZ
- Area
- Storm-based polygon
- Hail
- 1.0 in
- Wind
- 70.0 mph
Counties Coconino County, AZ, Gila County, AZ, Yavapai County, AZ
The radar
The Flagstaff radar (KFSX), 14 km from the middle of the area, began a volume at 00:13 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.
What was reported inside it
| Time | Report | Where | Remark |
|---|---|---|---|
| Jul 10, 5:22 PM MST | HAIL 0.88 | 2 E Clints Well, AZ | PUBLIC ESTIMATED HAIL AROUND A NICKEL SIZE IN DIAMETER WITH PASSING SEVERE-WARNED THUNDERSTORMS. |
Local storm reports filed while the alert was in force, from inside its polygon or its counties.
Did it verify
Not verified. The Iowa Environmental Mesonet's Cow found no qualifying storm report inside this severe thunderstorm warning while it was in force. That is not proof nothing happened: reports are thin where few people live.
Cow counts a report within 15 km of the polygon while the warning was in force: a tornado for a tornado warning; hail of 1 inch or more, a gust of 58 mph or more or wind damage for a severe thunderstorm warning; a flash flood report for a flash flood warning.
The watch it was issued in
The SPC watch in force over the same counties when this warning went out.
| Issued | Product | Office | Lasted |
|---|---|---|---|
| Jul 10, 4:52 PM MST | Severe Thunderstorm Watch | SPC | 7 hr |
The nearest sounding before it
Flgstf/Belemont, AZ (KFGZ), launched 00:00Z, 0.2 hours before the alert went out and 82 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.
- Mixed-layer CAPE
- 105 J/kg
- Mixed-layer CIN
- -140 J/kg
- Mixed-layer LCL
- 3739 m above ground
- 0-6 km bulk shear
- 29 kt
- 0-1 km storm-relative helicity
- 23 m²/s²
- 0-3 km storm-relative helicity
- 107 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- -0.0
The text
As transmitted.
021
WUUS55 KFGZ 110009
SVRFGZ
AZC005-007-025-110100-
/O.NEW.KFGZ.SV.W.0024.210711T0009Z-210711T0100Z/
BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Flagstaff AZ
509 PM MST Sat Jul 10 2021
The National Weather Service in Flagstaff has issued a
* Severe Thunderstorm Warning for...
Gila County in east central Arizona...
Yavapai County in west central Arizona...
Coconino County in north central Arizona...
* Until 600 PM MST.
* At 509 PM MST, severe thunderstorms were located along a line
extending from 6 miles northwest of Stoneman Lake to near Forest
Lakes, moving west at 10 mph.
HAZARD...70 mph wind gusts and quarter size hail.
SOURCE...Radar indicated.
IMPACT...Hail damage to vehicles is expected. Expect considerable
tree damage. Wind damage is also likely to mobile homes,
roofs, and outbuildings.
* Locations impacted include...
Sedona, Forest Lakes, Haigler Creek, Stoneman Lake, Tonto Village,
Clints Well, Christopher Creek, Happy Jack, Kohls Ranch, Hunter
Creek, Washington Park, Mead Ranch, Forest Road 169 Campground,
Bear Flat, Upper Tonto Creek Campground, Clints Well Campground,
Ponderosa Campground, Forest Road 195 Campground, Rim Campground
and Woods Canyon Lake Campground.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
For your protection move to an interior room on the lowest floor of a
building.
Torrential rainfall is occurring with these storms, and may lead to
flash flooding. Do not drive your vehicle through flooded roadways.
&&
LAT...LON 3485 11179 3448 11145 3415 11093 3435 11078
3462 11123 3488 11147
TIME...MOT...LOC 0009Z 068DEG 8KT 3485 11159 3431 11089
HAIL...1.00IN
WIND...70MPH
$$
RRWhat forecasters said that day
The local office's own words before this severe thunderstorm warning went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.
NWS Flagstaff, AZ wrote its last area forecast discussion before this severe thunderstorm warning went out at Jul 10, 3:46 PM MST, 1 hour 23 minutes earlier.
Area forecast discussion, Jul 10, 3:46 PM MST, 1 hour 23 minutes before
Area Forecast Discussion National Weather Service Flagstaff AZ 345 PM MST Sat Jul 10 202 .SYNOPSIS...Hot weather continues this weekend, with chances of afternoon and evening showers and thunderstorms, primarily south of the I-40 corridor. More significant moisture looks to return next week, with greater chances for showers and thunderstorms across much of northern and central Arizona. && .DISCUSSION...Convection has fired off pretty much as expected, with the exception of a fairly active area that formed in central Navajo and Apache counties, that is now approaching the I-40 corridor. Activity should diminish and head into the lower deserts this evening, with clearing skies from the north. Somewhat quieter on Sunday as we lose some boundary layer moisture and remain warm aloft. This will be short-lived, as the doors are fully open to the monsoon next week. Expect active weather next week as we ramp into moderate/high monsoon levels. Flash flooding and severe hail will become more common each day. Heat peaks today, still around tomorrow, then next week will cool to more seasonable levels. && .AVIATION...For the 00Z package...Expect mainly VFR conditions for the 24 hour TAF forecast period. Sct SHRA/TSRA and ISOLD +TSRA producing brief MVFR along and south of the I-40 corridor through 03Z Sunday. Similar conditions redevelop again AFT 18Z-19Z Sunday. Sfc winds 5-15kts outside of storms. Aviation discussion not updated for TAF amendments. && .FIRE WEATHER...Scattered showers and thunderstorms are expected again on Sunday, mainly south of the I-40 corridor. Activity will increase Monday, with lowering temperatures. Tuesday through Thursday...Expect an active pattern, with scattered to numerous showers and thunderstorms each day. As a result, expect cooler temperatures and generally light winds. && .FGZ WATCHES/WARNINGS/ADVISORIES... Excessive Heat Warning until 8 PM MST Saturday for AZZ037. Excessive Heat Warning until 8 PM MST Sunday for AZZ005-006. && PUBLIC...Peterson AVIATION...Peterson FIRE WEATHER...Peterson For Northern Arizona weather information visit weather.gov/flagstaff
In the hours before
Special weather statement, Jul 10, 12:36 PM MST, 4 hours 33 minutes before
Special Weather Statement National Weather Service Flagstaff AZ 136 PM MDT Sat Jul 10 2021 AZZ011-040-102000- Chuska Mountains and Defiance Plateau- Northeast Plateaus and Mesas South of Hwy 264- 136 PM MDT Sat Jul 10 2021 ...SIGNIFICANT WEATHER ADVISORY FOR A STRONG THUNDERSTORM OVER APACHE COUNTY AND THE NAVAJO NATION UNTIL 200 PM MDT... At 134 PM MDT, Doppler radar was tracking a strong thunderstorm over Wide Ruins moving south at 20 mph. Nickel size hail and winds in excess of 40 mph will be possible with this storm. Locations impacted include... Wide Ruins and parts of US Hwy 191 between Wide Ruins and Chambers. LAT...LON 3551 10957 3550 10939 3530 10935 3533 10966 TIME...MOT...LOC 1934Z 004DEG 17KT 3543 10948 NL
Local storm report, Jul 10, 1:12 PM MST, 3 hours 57 minutes before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
112 PM MST SAT JUL 10 2021
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0707 PM HAIL 1 NW HEBER-OVERGAARD 34.43N 110.58W
07/09/2021 M1.00 INCH NAVAJO AZ PUBLIC
&&Special weather statement, Jul 10, 1:57 PM MST, 3 hours 12 minutes before
Special Weather Statement National Weather Service Flagstaff AZ 157 PM MST Sat Jul 10 2021 AZZ018-102130- Northern Gila County- 157 PM MST Sat Jul 10 2021 ...SIGNIFICANT WEATHER ADVISORY FOR A STRONG THUNDERSTORM IN GILA COUNTY INCLUDING AREAS NEAR CANYON DAY UNTIL 230 PM MST... At 156 PM MST, Doppler radar was tracking a strong thunderstorm near Fort Apache and Canyon Day, or 32 miles south of Show Low, moving west at 15 mph. Nickel size hail and winds in excess of 40 mph will be possible with this storm. Locations impacted include... Whiteriver, Fort Apache Reservation and Canyon Day. PRECAUTIONARY/PREPAREDNESS ACTIONS... 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 3380 11029 3386 11000 3367 11000 3364 11009 TIME...MOT...LOC 2056Z 077DEG 11KT 3377 11005 NL
Special weather statement, Jul 10, 2:55 PM MST, 2 hours 14 minutes before
Special Weather Statement
National Weather Service Flagstaff AZ
255 PM MST Sat Jul 10 2021
AZZ008-037-102245-
Yavapai County Valleys and Basins-Yavapai County Mountains-
255 PM MST Sat Jul 10 2021
...SIGNIFICANT WEATHER ADVISORY FOR STRONG THUNDERSTORMS IN YAVAPAI
COUNTY UNTIL 345 PM MST...
At 254 PM MST, Doppler radar was tracking strong thunderstorms along
a line extending from 6 miles west of Paulden to near Yavapai County
Fairgrounds. Movement was west at 15 mph.
Half inch hail and wind gusts up to 50 mph will be possible with
these storms.
Locations impacted include...
Chino Valley, Prescott Valley, Prescott, Prescott Airport, Williamson
Valley, Prescott Gateway Mall, Iron Springs, Yavapai Campground,
Downtown Prescott, Ponderosa Park, Indian Hill West Prescott, Oak
Knoll Village, Lynx Lake Dam, Prescott Valley Event Center and White
Spar Campground.
LAT...LON 3482 11278 3445 11247 3461 11225 3470 11241
3486 11256
TIME...MOT...LOC 2154Z 068DEG 15KT 3487 11258 3460 11232
NLThe office that day
Everything else NWS Flagstaff, AZ issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jul 10, 5:16 PM MST | Severe Thunderstorm Warning | FGZ | Apache, Coconino, Gila, Navajo | 44 min |
| Jul 10, 5:56 PM MST | Severe Thunderstorm Warning | FGZ | Gila, Yavapai | 49 min |
| Jul 10, 6:23 PM MST | Flash Flood Warning | FGZ | Gila, Navajo | 3 hr |
| Jul 10, 6:44 PM MST | Severe Thunderstorm Warning | FGZ | Gila, Yavapai | 35 min |
| Jul 11, 3:22 PM MST | Special Weather Statement | FGZ | Yavapai | 23 min |
| Jul 11, 3:35 PM MST | Severe Thunderstorm Warning | FGZ | Yavapai | 40 min |
| Jul 11, 3:49 PM MST | Severe Thunderstorm Warning | FGZ | Yavapai | 41 min |
| Jul 11, 4:25 PM MST | Severe Thunderstorm Warning | FGZ | Yavapai | 35 min |
| Jul 11, 4:46 PM MST | Severe Thunderstorm Warning | FGZ | Yavapai | 29 min |
| Jul 11, 4:58 PM MST | Severe Thunderstorm Warning | FGZ | Yavapai | 11 min |
Nearby
Severe Thunderstorm Warnings in Arizona, 2021Every severe thunderstorm warning 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.