Monsoon moisture remained in place over central Arizona which caused a thunderstorm with heavy rain over central Yavapai County.
Every event with a place to put it. Tap one for its entry below.
Deaths and injuries are direct and indirect together, as the offices filed them. Damage is property and crops in the dollars of the year, not adjusted for inflation, and only where an office estimated it.
The episode as NWS FGZ wrote it up.
Monsoon moisture remained in place over central Arizona which caused a thunderstorm with heavy rain over central Yavapai County.
The local office's own words before the first event, 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 the first event at Jul 15, 2:53 PM MST, 5 hours 37 minutes earlier.
Area Forecast Discussion National Weather Service Flagstaff AZ 253 PM MST Thu Jul 15 2021 .SYNOPSIS...Scattered to widespread coverage of showers and thunderstorms is expected across northern Arizona through the weekend. Temperatures warm a few degrees by the weekend compared to the rest of this week, along with continued storm chances. && .DISCUSSION...Afternoon thunderstorms have been slow to start in a few areas as a more stable airmass was in place this morning early on. Now, we have started to see daytime heating take over and new thunderstorms have begun firing mainly across Coconino, Yavapai, and northern Gila Counties. Hi-res guidance has really struggled with initiation of storms today in response to the stable morning air and very mesoscale processes ongoing. Expect showers and thunderstorms will continue through the afternoon before coverage begins to trend downward this evening with the loss of daytime heating. Flash flooding will continue to be possible for areas that receive any of the stronger thunderstorms this afternoon. Movement has been faster today but we have seen a few storms this afternoon producing very heavy downpours. For the weekend and into next week, we will see continued daily chances for afternoon scattered to widely scattered showers and thunderstorms each day with the best chances along and south of the high terrain. The high will begin to drift eastward over the Four Corners and strengthen. Moisture looks to remain locked in through the end of the period without much of a break. With increasingly moist antecedent conditions, localized flash flooding with continue to be a daily threat. By the end of next week, better moisture may make it all the way north of the Mogollon Rim allowing for increasing coverage of showers and storms area wide. The monsoon is in full swing! && .AVIATION...For the 00Z package...Mainly VFR conditions through the TAF period. Shower and thunderstorm activity will continue through 02-03z mainly west and south of a line from KSOW to KGCN. Near thunderstorms, local areas of MVFR ceilings and visibilities along with wind gusts above 40 mph will be possible late in the afternoon and evening. Shower and thunderstorm activity to return after 18z Fri first along the high terrain before settling into the lower elevations. Aviation discussion not updated for TAF amendments. && .FIRE WEATHER...Showers and thunderstorms will continue across northern Arizona each afternoon through the Saturday. Wetting rains and flash flooding are possible. Winds will remain light, except near thunderstorms where gusty and erratic winds are possible. Sunday through Tuesday...Scattered afternoon thunderstorms continue into the Sunday. Moisture will increase into Monday and Tuesday with increasing shower and thunderstorm chances each day. && .FGZ WATCHES/WARNINGS/ADVISORIES...NONE. && PUBLIC...ET AVIATION...ET FIRE WEATHER...ET For Northern Arizona weather information visit weather.gov/flagstaff
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
251 PM MST THU JUL 15 2021
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0500 PM FLASH FLOOD TATAHATSO WASH 36.44N 111.85W
07/14/2021 COCONINO AZ PUBLIC
A FLASH FLOOD DOWN THE TATAHATSO WASH/SLOT
CANYON. WASHED AWAY THE CAMP WHERE TWO
COMMERCIAL RAFTS WITH 30 PASSENGERS ON THE
COLORADO RIVER HAD PULLED OFF FOR THE
EVENING. ON PERSON STILL MISSING. NO
INJURIES REPORTED.
&&
DMSpecial Weather Statement National Weather Service Flagstaff AZ 455 PM MST Thu Jul 15 2021 AZZ004-005-009-039-160030- Kaibab Plateau-Black Mesa Area-Marble and Glen Canyons-Northeast Plateaus and Mesas Hwy 264 Northward- 455 PM MST Thu Jul 15 2021 ...SIGNIFICANT WEATHER ADVISORY FOR COCONINO COUNTY UNTIL 530 PM MST/630 PM MDT/... At 454 PM MST/554 PM MDT/, Doppler radar was tracking a strong thunderstorm 9 miles northwest of Bitter Springs, or 22 miles southwest of Page, moving east at 10 mph. Half inch 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 3666 11197 3682 11192 3683 11165 3658 11173 TIME...MOT...LOC 2354Z 277DEG 10KT 3672 11179 MCT
The Flagstaff radar (KFSX), 117 km away, was scanning. The volume nearest the first event began at 03:28 UTC.
1 flash flood. Local standard time, as filed.
The river gauge on Granite Creek rose 2.5 feet above base flow.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Arizona in 2021Every state in 2021This day in weather historyWarnings in Arizona, July 2021
NOAA National Centers for Environmental Information, Storm Events Database, compiled from the National Weather Service’s monthly Storm Data. Complete through 2026-06; NCEI adds each month about 75 days after it ends and revises past years a few times a year. Rebuilt 2026-09-24. Each event’s entry at NCEI: 978400.