Monsoon moisture fueled a thunderstorm that caused wind damage.
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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 fueled a thunderstorm that caused wind damage.
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 13, 9:22 AM MST, 4 hours 30 minutes earlier.
Area Forecast Discussion National Weather Service Flagstaff AZ 922 AM MST Mon Jul 13 2020 .SYNOPSIS...Dangerously hot temperatures will continue across lower elevations of Arizona, and Excessive Heat Warnings remain in effect for much of the state below 4500 feet through this evening. Otherwise, isolated to scattered showers and thunderstorms are possible each afternoon this week, with activity primarily occurring over higher terrain. && .UPDATE...Only minor updates made to the forecast, increasing our storm coverage over NE AZ this afternoon. Otherwise, the hot, breezy forecast is in good shape, and no significant updates planned. && .PREV DISCUSSION /318 AM MST/...Hot conditions will continue for another day, today before a slight cooling trend starts tomorrow. The strong large scale ridge centered over New Mexico continues to create hot conditions for the region. Excesive heat warnings will continue across the area again through 8 pm this evening for elevations below 4500 feet Some breezy conditions will be possible this afternoon as a tightening pressure gradient aloft will allow for some breezy southwesterly winds to mix down to the surface today. This mixing will also bring in drier air, that will have the potential to limit storm formation over the next few days. Limited storm activity south of the border in Sonora is providing only a modest reinforcement of low level moisture across Arizona today, lower elevation locations in Yavapai and further south continue to show dewpoints in the 50s, with higher elevation locations seeing value closer to mid 40s. This isn't too far off from the last few morning, but when added to scouring potential of diurnal winds today, the potential for storms will begin to erode across the area starting in the western parts of Yavapai and Coconino County today. Thankfully enough moisture will remain that we are not anticipating any near critical fire conditions in most of the area despite the increase in winds. The one exception to this is in Northern Coconino county where RH values haven't climbed significantly over the past few days. This will be a point of concern as Monday afternoon progresses. Models are not in great agreement concerning how rapidly moisture is replenished across the area beginning Tuesday. Have kept a slight change of precipitation over the eastern Mogollon Rim and White Mountains for Tuesday afternoon, with more widespread coverage pushing westward along the rim on Wednesday afternoon. Confidence is low concerning this exact solution, moisture from thunderstorm complexes in Sonora could possibly speeding this process if it moves back into the region a little stronger than some model members anticipate it. Late in the week going into next weekend models are expecting enough moisture that we will see a more widespread afternoon showers and thunderstorms, of course confidence is low on exact timing and location, but chance of precipitation will generally be increase through the remainder of the week, albeit only slightly due to a low confidence. && .AVIATION...For the 18Z package...SW winds around 10-15 kts gusting 20-30 kts will develop today with scattered TSRA developing in the White Mountains and along the NM border. Isolated storms as far west as KGCN to KFLG. Brief MVFR conditions and outflow wind gusts to 40 kts possible near any storms. Aviation discussion not updated for TAF amendments. && .FIRE WEATHER...Hot temperatures today will cool to near-normal by Tuesday. Expect breezy southwest winds each day, strongest in the afternoon. Enough moisture remains for isolated to scattered storms each afternoon. Lightning and outflow winds are expected. Wednesday through Friday...Near-normal temperatures will persist. Isolated thunderstorms are possible over the high terrain each afternoon, but greatest coverage expected in eastern zones. && .FGZ WATCHES/WARNINGS/ADVISORIES...Excessive Heat Warning until 8 PM MST this evening FOR AZZ005- 006-018-037-038. && PUBLIC...BAK/Suk AVIATION...BAK FIRE WEATHER...BAK For Northern Arizona weather information visit weather.gov/flagstaff
Special Weather Statement National Weather Service Flagstaff AZ 1043 AM MST Mon Jul 13 2020 AZZ013-014-131815- Little Colorado River Valley in Navajo County-Little Colorado River Valley in Apache County- 1043 AM MST Mon Jul 13 2020 ...SIGNIFICANT WEATHER ADVISORY FOR A STRONG THUNDERSTORM 10 MILES NORTHEAST OF SNOWFLAKE UNTIL 1115 AM MST... At 1042 AM MST, Doppler radar was tracking a strong thunderstorm 10 miles northeast of Snowflake, or 27 miles north of Show Low, moving east at 5 mph. Nickel size hail and winds in excess of 40 mph will be possible with this storm. This storm will remain over mainly rural areas of Apache and Navajo Counties. 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 3450 10983 3456 10998 3468 10994 3465 10976 TIME...MOT...LOC 1742Z 289DEG 5KT 3462 10991 TM
Special Weather Statement National Weather Service Flagstaff AZ 1140 AM MST Mon Jul 13 2020 AZZ014-131915- Little Colorado River Valley in Apache County- 1140 AM MST Mon Jul 13 2020 ...SIGNIFICANT WEATHER ADVISORY FOR A STRONG THUNDERSTORM 11 MILES EAST OF LYMAN LAKE STATE PARK UNTIL 1215 PM MST... At 1139 AM MST, Doppler radar was tracking a strong thunderstorm 11 miles east of Lyman Lake State Park, or 15 miles northeast of Springerville, moving east at 10 mph. Penny size hail and wind gusts up to 50 mph will be possible with this storm. This storm will remain over mainly rural areas of Apache County. LAT...LON 3422 10929 3444 10923 3442 10905 3416 10905 TIME...MOT...LOC 1839Z 285DEG 11KT 3434 10917 TM
Special Weather Statement National Weather Service Flagstaff AZ 1258 PM MST Mon Jul 13 2020 AZZ013-040-132030- Little Colorado River Valley in Navajo County- Northeast Plateaus and Mesas South of Hwy 264- 1258 PM MST Mon Jul 13 2020 ...SIGNIFICANT WEATHER ADVISORY FOR A STRONG THUNDERSTORM 6 MILES NORTH OF HOLBROOK UNTIL 130 PM MST... At 1256 PM MST, Doppler radar was tracking a strong thunderstorm 6 miles north of Holbrook, moving east at 20 mph. Penny size hail and wind gusts up to 50 mph will be possible with this storm. Locations impacted include... Holbrook, Sun Valley and Petrified Forest National Park. LAT...LON 3492 11018 3506 11024 3516 10992 3492 10988 TIME...MOT...LOC 1956Z 256DEG 17KT 3500 11017 TM
Special Weather Statement
National Weather Service Flagstaff AZ
102 PM MST Mon Jul 13 2020
AZZ014-132030-
Little Colorado River Valley in Apache County-
102 PM MST Mon Jul 13 2020
...SIGNIFICANT WEATHER ADVISORY FOR A STRONG THUNDERSTORM 10
MILES EAST OF LYMAN LAKE STATE PARK UNTIL 130 PM MST...
At 101 PM MST, Doppler radar was tracking a strong thunderstorm 10
miles east of Lyman Lake State Park, or 14 miles north of
Springerville, moving northeast at 10 mph.
Penny size hail and wind gusts up to 50 mph will be possible with
this storm.
This storm will remain over mainly rural areas of Apache County.
LAT...LON 3421 10916 3432 10927 3445 10917 3439 10905
3431 10904
TIME...MOT...LOC 2001Z 219DEG 7KT 3433 10919
TMThe Flagstaff radar (KFSX), 140 km away, was scanning. The volume nearest the first event began at 20:50 UTC.
1 thunderstorm wind. Local standard time, as filed.
An Arizona Department of Transportation wind sensor near Petrified Forest National Park reported a peak wind gust of 64 MPH along Interstate 40.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Arizona in 2020Every state in 2020This day in weather historyWarnings in Arizona, July 2020
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: 899699.