A thunderstorm southeast of Flagstaff produce a funnel cloud.
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The episode as NWS FGZ wrote it up.
A thunderstorm southeast of Flagstaff produce a funnel cloud.
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 Aug 28, 9:10 AM MST, 3 hours earlier.
Area Forecast Discussion National Weather Service Flagstaff AZ 910 AM MST Sat Aug 28 2021 .SYNOPSIS...Hot temperatures will continue this weekend, with a chance of afternoon and evening thunderstorms mainly along and south of Interstate 40. Moisture and storm chances will increase significantly next week, with some areas of heavy rainfall possible by Tuesday and Wednesday. Temperatures will cool to below normal by the middle and end of the week. && .UPDATE...Scattered showers and thunderstorms develop along the Mogollon Rim and westward into the high terrain of Yavapai County. Storms are expected to continue through the afternoon, then dropping south off the Rim later this evening. Much of the activity will diminish afterward, with only a few lingering showers later this evening over Yavapai County. Only minor updates to expand PoP over Yavapai County for the early afternoon for latest hi-res guidance. Forecast otherwise remains on track with no changes needed. && .PREV DISCUSSION /341 AM MST/...A mid level ridge will be located over northern Arizona this weekend bringing hot afternoons, especially for the lower elevations including the Verde Valley, Page/Lake Powell area, and the Grand Canyon inner gorge where afternoon highs will exceed 100F. Use caution if planning outdoor activities in these areas. Otherwise, as the ridge slides northward there will be some east-northeast steering flow developing from the Mogollon Rim southward. This should allow the isolated to scattered afternoon thunderstorms that develop to move off the rim country into northern Gila and Yavapai counties by later in the afternoon and evening both days. Most unstable CAPE values in the 500-1000 J/kg range and weak shear point to a few strong storms with wind gusts to 40+ mph and small hail but nothing organized. Monday through mid week - the ridge is forecast to gradually weaken and shift east of the state, allowing for a more southerly flow to develop. Anomalously high values of precipitable water are forecast to enter the region from the south, aided by Hurricane Nora which is forecast by the NHC to enter the southern end of the Gulf of California by Monday afternoon and about halfway up the gulf by Wednesday afternoon. Significant surges of low level moisture up the gulf and into Arizona will be possible as early as Monday which could enhance storm activity along/south of the Mogollon Rim on Monday afternoon and evening. However, this appears most likely on Tuesday and Wednesday as very deep moisture arrives that could interact with a trough moving in off the Pacific. The threat for widespread showers and thunderstorms with heavy rain and potential flash flooding will increase during this period. The location and exact timing of the heaviest rain is still uncertain and may change over the next couple of days, so stay tuned for updates and be prepared for this big change in the weather. Some of the latest guidance suggests that the wet period could stretch into Thursday as well. Beyond that, a return to a more typical monsoon pattern is forecast. && .AVIATION...For the 18Z package...Primarily VFR conditions over the next 24 hours. Look for scattered showers and thunderstorms mainly along or south of the I-40 corridor. Wind gusts to 35 kts in the vicinity of storms. Most convective activity diminishing after 03Z. Aviation discussion not updated for TAF amendments. && .FIRE WEATHER...Expect hot weather and generally light winds today and Sunday, with a few afternoon winds gusts to 20 mph. Isolated to scattered showers and thunderstorms expected each afternoon, with most activity along and south of the I-40 corridor. Monday through Wednesday...Moisture and thunderstorm chances will increase especially by Tuesday and Wednesday when some areas of heavy rainfall are possible. Temperatures will steadily decrease through the period. && .FGZ WATCHES/WARNINGS/ADVISORIES...NONE. && PUBLIC...Humphreys/JJ AVIATION...McCollum FIRE WEATHER...JJ For Northern Arizona weather information visit weather.gov/flagstaff
The Flagstaff radar (KFSX), 79 km away, was scanning. The volume nearest the first event began at 19:07 UTC.
1 funnel cloud. Local standard time, as filed.
Pictures posted on social media showed a funnel cloud about a mile south of the Flagstaff Mall. Location estimated based on known landmarks.
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, August 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: 983710.