A strong trough of low pressure center and cool front moved across the western United States on May 18. This brought strong winds and blowing dust to portions of 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 strong trough of low pressure center and cool front moved across the western United States on May 18. This brought strong winds and blowing dust to portions of 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 18, 2:30 AM MST, 6 hours 20 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE FLAGSTAFF AZ 230 AM MST FRI MAY 18 2012 .SYNOPSIS...A LOW PRESSURE SYSTEM MOVING ACROSS THE WESTERN UNITED STATES WILL BRING WINDY CONDITIONS TO NORTHERN ARIZONA TODAY. LIGHTER WINDS ARE EXPECTED OVER THE WEEKEND AND INTO EARLY NEXT WEEK AS HIGH PRESSURE REBUILDS OVER THE REGION. TEMPERATURES WILL REMAIN WARM THROUGH THE PERIOD BUT LOWER TO NEAR NORMAL LEVELS TODAY AND SATURDAY. && .DISCUSSION...A FAST MOVING SHORTWAVE TROUGH AND ASSOCIATED COOL FRONT WILL SWEEP ACROSS NORTHERN ARIZONA TODAY. IN ADVANCE OF THE TROUGH AXIS/FRONT STRONG FLOW WILL MOVE OVER ARIZONA ALOFT. FOLLOWING SUNRISE AND THE ONSET OF DAYTIME HEATING VERTICAL MIXING OF THE AIR MASS WILL QUICKLY BRING THESE STRONGER WINDS TO THE SURFACE. STRONG WINDS WILL THEN CONTINUE THROUGH MUCH OF THE DAY. AS THE THROUGH AXIS HEADS EASTWARD COULD SEE SOME DECREASE IN WINDS LATE IN THE DAY FROM A PRESCOTT-FLAGSTAFF-PAGE LINE NORTHWESTWARD. SOUTHWEST WINDS 20 TO 30 MPH WINDS WITH GUSTS OF 40 TO 50 MPH CAN BE EXPECTED...ESPECIALLY FROM THE MOGOLLON RIM NORTHWARD. THE WIND WILL BE STRONG ENOUGH AT TIMES FOR AREAS OF BLOWING DUST IN THE LITTLE COLORADO RIVER VALLEY AND NORTHWARD THROUGH ACROSS THE CHINLE VALLEY. IN ADDITION...JUST ENOUGH MOISTURE AND COOLER AIR ALOFT (ASSOCIATED WITH THE TROUGH AXIS) WILL COMBINE WITH DAYTIME HEATING THIS AFTERNOON AN ISOLATED SHOWER OR THUNDERSTORM NEAR THE ARIZONA/UTAH BORDER...WHICH WOULD PRODUCE EVEN STRONGER WIND GUSTS. SATURDAY THROUGH MONDAY...HIGH PRESSURE WILL BUILD BACK ACROSS THE SOUTHWEST UNITED STATES WITH WARMER TEMPERATURES AND LIGHTER WINDS EXPECTED. MODELS STILL HINTING THAT SOME MOISTURE COULD MOVE INTO FAR EASTERN ARIZONA ON MONDAY BUT THINK THE INFLUENCE OF DRY WESTERLY FLOW WILL BE TOO STRONG FOR ANYTHING MORE THAN SCATTERED HIGH BASED CUMULUS. HAVE LEFT A VERY SLIGHT CHANCE OF A SHOWER OR THUNDERSTORM FOR NOW BUT WITH WESTERLY FLOW DOMINATING THE PATTERN IF WILL BE TOUGH FOR APPRECIABLE MOISTURE TO MOVE OVER THE AREA. TUESDAY INTO THE END OF NEXT WEEK...FORECAST MODELS SHOW A SERIES OF WEATHER DISTURBANCES BRUSHING ARIZONA CULMINATING IN STRONGER TROUGHING ALONG THE WEST COAST TOWARD THE END OF THE PERIOD. THE MAIN IMPACT LOOKS TO BE INCREASING WINDS THROUGH THE PERIOD ALONG WITH A GRADUAL COOL DOWN TO NEAR NORMAL TEMPERATURES. COULD EVEN BE A SLIGHT CHANCE OF A THUNDERSTORM ALONG THE ARIZONA/UTAH BORDER FROM TIME-TO-TIME. ARIZONA COULD END UP UNDER A FAIRLY CLASSIC FIRE WEATHER PATTERN TOWARD THE END OF NEXT WEEK. SOMETHING TO KEEP AN EYE ON AS MODELS CONVERGE ON A SOLUTION OVER THE NEXT FEW DAYS. && .AVIATION...FOR THE 12Z PACKAGE...VERY FAST SW FLOW ALOFT TODAY...WITH 10000 FT MSL WINDS SW 35-45KT...BECOMING WSW AT 25-35 KT AFTER 21Z. AFTER 15Z SFC WINDS SOUTHWEST 15-30 KT TO 45KT. WIND DECREASING AFT 01Z SAT. ISOLATED HIGH BASED THUNDERSTORMS NEAR THE UT BORDER BTWN 17Z-01Z. AVIATION DISCUSSION NOT UPDATED FOR AMENDMENTS. && .FIRE WEATHER...A DRY COOL FRONT WILL MOVE ACROSS NORTHERN ARIZONA TODAY. 20 FOOT WINDS HAVE REMAINED SOUTHWESTERLY EARLY THIS MORNING WITH POOR RH RECOVERY. 20 FOOT WIND SPEEDS WILL INCREASE RAPIDLY BY MID MORNING ACROSS THE NORTHLAND AND THE START TIME OF TODAYS RED FLAG WARNING HAS BEEN ADVANCED TO 8 AM MST. ON SATURDAY...WARM AND DRY CONDITIONS CONTINUE WITH MUCH LIGHTER WEST TO NORTHWEST WIND. SUNDAY THROUGH TUESDAY...DRY CONDITIONS WILL CONTINUE WITH AFTERNOON HIGH TEMPERATURES FROM 5 TO 10 DEGREES ABOVE NORMAL. LOOK FOR LIGHT WINDS SUNDAY AND MONDAY WITH BREEZY SOUTHWESTERLIES ON TUESDAY. && .FGZ WATCHES/WARNINGS/ADVISORIES... RED FLAG WARNING FROM 8 AM TO 8 PM MST FRIDAY FOR AZZ104>118- 137>140. WIND ADVISORY FROM 10 AM TO 5 PM MST FRIDAY FOR AZZ004-006-007. && PUBLIC.........MCCOLLUM AVIATION.......DL FIRE WEATHER...DL FOR NORTHERN ARIZONA WEATHER INFORMATION VISIT WEATHER.GOV/FLAGSTAFF
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE FLAGSTAFF AZ 318 AM MST FRI MAY 18 2012 AZZ004>018-037>040-190900- KAIBAB PLATEAU-MARBLE AND GLEN CANYONS-GRAND CANYON COUNTRY- COCONINO PLATEAU-YAVAPAI COUNTY MOUNTAINS- NORTHEAST PLATEAUS AND MESAS HWY 264 NORTHWARD-CHINLE VALLEY- CHUSKA MOUNTAINS AND DEFIANCE PLATEAU- LITTLE COLORADO RIVER VALLEY IN COCONINO COUNTY- LITTLE COLORADO RIVER VALLEY IN NAVAJO COUNTY- LITTLE COLORADO RIVER VALLEY IN APACHE COUNTY- WESTERN MOGOLLON RIM-EASTERN MOGOLLON RIM-WHITE MOUNTAINS- NORTHERN GILA COUNTY-YAVAPAI COUNTY VALLEYS AND BASINS- OAK CREEK AND SYCAMORE CANYONS-BLACK MESA AREA- NORTHEAST PLATEAUS AND MESAS SOUTH OF HWY 264- 318 AM MST FRI MAY 18 2012 THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF EAST CENTRAL ARIZONA...NORTH CENTRAL ARIZONA...NORTHEAST ARIZONA AND WEST CENTRAL ARIZONA. .DAY ONE...TODAY AND TONIGHT WINDY AND DRY CONDITIONS ARE EXPECTED TODAY AS A STRONG WEATHER DISTURBANCE MOVES ACROSS THE STATE. WIND GUSTS IN EXCESS OF 40 MPH ARE EXPECTED FROM THE MOGOLLON RIM NORTHWARD BY THIS AFTERNOON. IN ADDITION...DRY AND WINDY CONDITIONS WILL BRING HIGH FIRE DANGER TO ALL OF NORTHERN ARIZONA INTO THIS EVENING. REFER TO THE FORECAST AS WELL AS RED FLAG WARNING AND WIND ADVISORY PRODUCTS FOR DETAILS. .DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY NO HAZARDOUS WEATHER IS EXPECTED.
The national radar mosaic for the moment the first event began.
2 dust storm, 1 high wind. Local standard time, as filed.
The RAWS at Houserock reported a peak wind gust of 58 MPH.
The Department of Public Safety escorted traffic through dusty areas on Interstate 40 in the Winslow area.
The Department of Public Safety escorted traffic through dusty areas on Interstate 40 in the Winslow area.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Arizona in 2012Every state in 2012This day in weather historyWarnings in Arizona, May 2012
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: 393988, 393991, 393993.