A low pressure system stalling over the Great Basin brought windy and dry conditions to northern Arizona.
Every event with a place to put it; 3 filed by county or forecast zone are drawn at its center, in a lighter ring. 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.
A low pressure system stalling over the Great Basin brought windy and dry conditions to northern Arizona.
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 May 11, 10:20 AM MST, 2 hours 31 minutes earlier.
Area Forecast Discussion National Weather Service Flagstaff AZ 1020 AM MST Fri May 11 2018 .SYNOPSIS...A low pressure system over the Great Basin will bring windy and dry conditions to northern Arizona for several days. In addition, dangerous fire weather conditions are expected today and Saturday. Cooler temperatures are anticipated this weekend, with a slow warming trend developing early next week. && .DISCUSSION...A deep upper low will enter the northern Great Basin today and will close off through late Saturday. Relatively warm and dry air place across Arizona combined with this gradient will lead to strong winds and critical fire weather conditions just about everywhere today. Gusty winds will persist into Saturday as well, with the eastern zones likely seeing advisory level gusts and another day of critical fire weather conditions. Additionally, stronger wind gusts this afternoon may produce areas of blowing dust and/or sand, especially over central and northern sections of Navajo and Apache counties. Cooler air will move into Arizona Saturday and Sunday, due to this persistent upper low. This will drop our temperatures to a few degrees below normal. The low slowly fills and shears out next week, allowing for hght rises and a warming trend. Dry weather will continue, with breezy afternoons nearly everyday next week. These trends are covered and no updates are planned this morning. && .AVIATION...For the 18Z package...VFR conditions are expected over the next 24 hours. Local MVFR conditions will be possible for areas of blowing dust/sand, mostly northeast of the Mogollon Rim, by this afternoon. Strong SW winds of 20-30 kts, gusts 40 to near 50 kts. Winds decreasing slightly after 03Z. Aviation discussion not updated for TAF amendments. && .FIRE WEATHER...A Red Flag Warning remains in effect for all of northern Arizona for today. Southwest winds will be strongest this afternoon, with gusts 35 to 55 mph, along with very dry conditions. Saturday, southwest winds will decrease but remain strong enough to create critical fire weather conditions for the eastern portion of the area. A Red Flag Warning is in effect Saturday for portions of eastern Arizona. Sunday through Tuesday...Expect warm and dry weather Sunday through Tuesday, with breezy south to southwest winds in the afternoons and lighter winds overnight. && .FGZ WATCHES/WARNINGS/ADVISORIES... Red Flag Warning until 8 PM MST this evening for AZZ104>118-137>140. Wind Advisory until 8 PM MST this evening for AZZ004>018-037>040. Red Flag Warning from 11 AM to 8 PM MST Saturday for AZZ109>114- 116>118-139-140. && PUBLIC...Peterson AVIATION...MCT FIRE WEATHER...ET/MCT For Northern Arizona weather information visit weather.gov/flagstaff
The national radar mosaic for the moment the first event began.
3 high wind. Local standard time, as filed.
The Window Rock Airport had a peak wind gust of 59 MPH at 1251 PM MST.
The Springerville Airport reported a peak wind gust of 61 MPH at 115 PM MST.
The Flagstaff Airport ASOS reported a peak wind gust of 60 MPH at 243 PM.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Arizona in 2018Every state in 2018This day in weather historyWarnings in Arizona, May 2018
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: 748855, 748859, 748858.