Gusty southeast winds created low visibilities for motorists along hwy 347 in Pinal County in the early hours on the morning of March 21, 2011. Later the same day, during the afternoon and evening hours, rain showers developed over Pinal county as well as northwest Maricopa and southern Gila county.
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 PSR wrote it up.
Gusty southeast winds created low visibilities for motorists along hwy 347 in Pinal County in the early hours on the morning of March 21, 2011. Later the same day, during the afternoon and evening hours, rain showers developed over Pinal county as well as northwest Maricopa and southern Gila 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 Phoenix, AZ wrote its last area forecast discussion before the first event at Mar 21, 5:25 AM MST, 4 hours 18 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE PHOENIX AZ 525 AM MST MON MAR 21 2011 .UPDATE...UPDATED AVIATION AND FIRE WEATHER DISCUSSIONS. && .SYNOPSIS... A PACIFIC STORM SYSTEM AND COLD FRONT WILL MOVE THROUGH THE REGION TODAY. A CHANCE OF SHOWERS IS EXPECTED ACROSS THE AREA THROUGH EARLY TUESDAY MORNING...ALONG WITH COOLER TEMPERATURES AND AREAS OF GUSTY WINDS. TEMPERATURES ARE EXPECTED TO GRADUALLY INCREASE DURING THE MIDDLE OF THIS COMING WEEK...WITH DRIER WEATHER EXPECTED. && .DISCUSSION... OVERNIGHT SATELLITE AND RADAR TRENDS SHOW DEEPENING LOW PRESSURE OFF THE CALIFORNIA COAST...WITH A BROAD AREA OF PRECIPITATION MOVING ACROSS SOUTHERN CALIFORNIA. LIGHT RAIN SHOWERS HAVE MADE THEIR WAY ACROSS OUR FAR WESTERN ZONES...AND ALONG THE LOWER CO RIVER VALLEY EARLY THIS MORNING. AHEAD OF THE TROUGH...A STRONG JET /115KT +/ WILL DEVELOP ACROSS ARIZONA PROVIDING THE NECESSARY UPWARD VERTICAL MOTION TO GENERATE PRECIPITATION. THE BEST CHANCE FOR VALLEY RAIN LOOKS TO BE AFTER 18Z...WITH AROUND ONE QUARTER INCH TO FOURTH TENTHS INCH EXPECTED ACROSS THE CWA...WITH HIGHER AMOUNTS TO THE NORTH AND EAST OF PHOENIX. MEANWHILE...INCREASING CLOUDS AND PRECIPITATION WILL KEEP TEMPERATURES ACROSS THE LOWER DESERTS IN THE LOW TO MID 60S...ABOUT 15 DEGREES BELOW AVERAGE FOR THIS TIME OF YEAR. WINDS WILL BE GUSTY AT TIMES...MAINLY THIS MORNING...WITH THE POTENTIAL TO BRIEFLY PRODUCE AREAS OF BLOWING DUST AHEAD OF ANY DEVELOPING SHOWERS. THE CHANCE FOR PRECIP WILL CONTINUE MAINLY EAST OF PHOENIX TONIGHT INTO VERY EARLY TUESDAY MORNING...AS A WEAK SECONDARY WAVE MOVES THROUGH THE AREA. DRIER CONDITIONS WILL DEVELOP BY TUESDAY AFTERNOON/EVENING...WITH A FEW DEG OF WARMING EXPECTED. FOR THE EXTENDED PERIOD...ECMWF AND GFS REMAIN IN GOOD AGREEMENT THROUGH ABOUT FRIDAY...INDICATING A COUPLE MORE WEAK WAVES TO PASS THROUGH THE GREATER SOUTHWEST...KEEPING TEMPS AT OR BELOW NORMAL FOR THIS TIME OF YEAR. DIFFERENCES BETWEEN THE MODELS START TO SURFACE BY SATURDAY...WITH THE ECMWF SHOWING SHORTWAVE RIDGING WHILE THE GFS HANGS ON TO GENERAL TROUGHINESS ACROSS ARIZONA AND THE GREATER SOUTHWEST. FORECAST REFLECTS A BLEND OF THE BETTER PERFORMING GUIDANCE...RESULTING IN HIGH TEMPS IN THE MID 70S /A COUPLE DEG BELOW NORMAL FOR THIS TIME OF YEAR/ BY THE LATTER PART OF THE FORECAST PERIOD. WILL HOLD ON TO MAINLY SINGLE DIGIT POPS FOR THE EXTENDED...AS THE OVERALL PATTERN CONTINUES TO LOOK A BIT UNSETTLED...AND CONFIDENCE IN THE MODELS DETERIORATES SIGNIFICANTLY THIS FAR OUT. && .AVIATION... SOUTH CENTRAL ARIZONA...INCLUDING KPHX...KIWA...AND SURROUNDING AIRFIELDS... GUSTY SOUTH-SOUTHWEST WINDS AHEAD OF COLD FRONT...UP TO 30 KTS THIS MORNING. SCT SHOWERS AND ASSOCIATED LOWER CIGS TO NEAR 6 THSD FT WILL CONTINUE UNTIL 22/02Z AT KPHX. LOW CONFIDENCE ON LLWS AT KPHX...BUT 30-40 KTS JUST ABOVE THE SFC MAY BE SUFFICIENT TO INSERT LLWS ABOUT THE TIME THE COLD FRONT PASSES THE AREA...LIKE ABOUT 18Z. INSTABILITY SHOWERS LIKELY EARLY THIS AFTERNOON...AND I EXPECT 5-6 THSD FT CIGS. VSBY POSSIBLY AS LOW AS 6 SM WITH MODERATE TO HEAVY SHOWERS INTO EARLY EVENING. PARTIAL CLEARING AFT 22/02Z WITH SCT/BKN MID CLOUDS. NORTHWEST WINDS DIMINISHING TO LESS THAN 7 KTS AFT 22/07Z. SOUTHWEST ARIZONA AND SOUTHEAST CALIFORNIA INCLUDING KIPL AND KBLH... FRONTAL BAND EXTENDED FROM KLAS TO KNYL AT 12Z...WITH SHOWERS MOVG TO THE NORTHEAST. VFR CONDITIONS TO CONTINUE...ALTHOUGH BRIEF MVFR CIGS/VSBYS MAY DEVELOP OVER HIGHER TERRAIN THIS MORNING. PARTIAL CLEARING STILL EXPECTED LATE MONDAY AFTERNOON AND EVENING HOURS. WEST WINDS OCNLY GUSTING TO 30-35 KTS TODAY. AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS. && .FIRE WEATHER... WEDNESDAY THROUGH SUNDAY... A SERIES OF PACIFIC STORM SYSTEMS WILL BRUSH BY TO THE NORTH THIS WEEK. ONE OF THE STRONGER SYSTEMS WILL BRING A SLIGHT CHANCE OF SHOWERS TO SOUTHERN GILA COUNTY FRIDAY AND SATURDAY...OTHERWISE EXPECT MOSTLY SUNNY DAYS WITH LIGHT BREEZES THIS WEEK AND INTO THE UPCOMING WEEKEND. HIGH TEMPERATURES ACROSS THE DESERTS WILL CLIMB INTO THE COMFORTABLE 70S EACH DAY. && .PSR WATCHES/WARNINGS/ADVISORIES... AZ...NONE. CA...NONE. && NATIONAL WEATHER SERVICE PHOENIX IS ON THE INTERNET AT WEATHER.GOV/PHOENIX DISCUSSION...WANEK AVIATION...SIPPLE FIRE WEATHER...SIPPLE
1 dust storm. Local standard time, as filed.
Pinal County Sheriff's Office Dispatch called to notify a visibility of 1/4 mile. Field officers also confirmed dense blowing dust along state highway 347.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Arizona in 2011Every state in 2011This day in weather historyWarnings in Arizona, March 2011
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: 290227.