Heavy rain from thunderstorms fell in the Verde Valley from Cottonwood to Sedona. There was street flooding in Cottonwood.
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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.
Heavy rain from thunderstorms fell in the Verde Valley from Cottonwood to Sedona. There was street flooding in Cottonwood.
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 23, 3:30 PM MST, 1 hour 40 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE FLAGSTAFF AZ 330 PM MST SAT MAY 23 2009 .SYNOPSIS...AN AREA OF LOW PRESSURE WILL PRODUCE SHOWERS AND THUNDERSTORMS...ALONG WITH COOL TEMPERATURES...THROUGH SUNDAY ACROSS NORTHERN ARIZONA. A GRADUAL DRYING AND WARMING TREND IS EXPECTED MEMORIAL DAY THROUGH NEXT WEEK. HOWEVER...A CHANCE OF SHOWERS WILL REMAIN EACH DAY THROUGH FRIDAY. && .DISCUSSION...SCATTERED SHOWERS AND THUNDERSTORMS HAVE DEVELOPED ACROSS MUCH OF NORTHERN ARIZONA THIS AFTERNOON. THE HEAVIEST RAIN FALL RATE OVER A GAGE WAS 0.20 INCH IN AN HOUR. 88D ESTIMATED THE HEAVIEST RAINFALL RATE OF 0.60 INCH. THIS IS ABOUT 60 PERCENT OF THE HEAVIEST RAINFALL YESTERDAY. SHOWERS AND THUNDERSTORMS WILL CONTINUE INTO THE EVENING HOURS AND THEN DECREASE AFTER DARK. AN ELONGATED AREA OF LOW PRESSURE THAT EXTENDS FROM CENTRAL NEVADA TO NEAR THE BIG BEND AREA OF TEXAS IS RESPONSIBLE FOR THE VERY MOIST AND MODERATELY UNSTABLE AIR MASS OVER ARIZONA TODAY. THIS LOW IS EXPECTED TO MOVE NORTH AND EAST OF ARIZONA BY SUNDAY. THIS WILL BRING A DOWNTURN TO THE SHOWERS AND THUNDERSTORMS ON SUNDAY. ANOTHER SHORT WAVE TROUGH IS EXPECTED TO MOVE INTO THE SOUTHWEST BY LATE MONDAY. THE MAIN PLUME OF SUBTROPICAL MOISTURE WILL HAVE SHIFTED EASTWARD BY THEN. SOME MOISTURE WILL REMAIN ACROSS THE SOUTHWEST FOR THIS SHORT WAVE TO INTERACT WITH. THE NET RESULT WILL BE A DOWNWARD TREND IN CONVECTIVE ACTIVITY BEGINNING ON SUNDAY BUT THERE WILL REMAIN A CHANCE FOR SHOWERS EACH DAY THROUGH THE WEEK. DAYTIME TEMPERATURES WILL SLOWLY WARM TO NEAR SEASONABLE READINGS BY MID WEEK. HOLIDAY TRAVELERS TO THE HIGH COUNTRY SHOULD BE PREPARED FOR COOL TEMPERATURES...RAINY CONDITIONS...AND MUDDY FOREST ROADS FOR THE NEXT FEW DAYS. && .AVIATION...FOR THE 00Z PACKAGE...EXPECT CONTINUED RAIN SHOWERS WITH EMBEDDED THUNDERSTORMS DURING THE EVENING ACROSS THE NORTHLAND. WIDESPREAD MVFR AND LOCAL IFR CONDITIONS ARE EXPECTED THROUGH 07Z THIS EVENING. A SLIGHT CHANCE (20-30 PERCENT) FOR -SHRA/-TSRA ACTIVITY WILL CONTINUE AFT 07Z...WITH AREAS MVFR AND LCL IFR CONDITIONS. SHOWERS AND THUNDERSTORMS WILL ONCE AGAIN REDEVELOP SUNDAY...WITH THE BEST CHANCES OCCURRING AFTER 18Z OVER THE HIGH TERRAIN. AVIATION DISCUSSION NOT UPDATED FOR AMENDMENTS. && .FIRE WEATHER...THE UPPER LOW WILL BE GRADUALLY MOVING OUT OF THE FORECAST AREA DURING TONIGHT AND SUNDAY...WITH SOMEWHAT DRIER AIR MOVING IN FROM THE WEST. ENOUGH MOISTURE WILL REMAIN OVER THE FORECAST AREA TO CONTINUE THE CHANCES FOR SHOWERS AND THUNDERSTORMS SUNDAY AND MONDAY. FOR TUESDAY THROUGH THURSDAY...WINDS ARE EXPECTED TO REMAIN RATHER LIGHT AND FROM A WEST TO SOUTHWEST DIRECTION. SOME DRYING WILL TAKE PLACE...BUT IT WONT BE ENOUGH TO RULE OUT A DAILY CHANCE FOR SHOWERS AND THUNDERSTORMS. RH VALUES DURING THE DAY SHOULD RANGE FROM 15-25 PERCENT. && .FGZ WATCHES/WARNINGS/ADVISORIES...NONE. && PUBLIC.....................MAS AVIATION/FIRE WEATHER......42 (LAST SHIFT AT WFO FGZ) VISIT WEATHER.GOV/FLAGSTAFF FOR NORTHERN ARIZONA WEATHER INFORMATION.
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE FLAGSTAFF AZ 700 AM MST SAT MAY 23 2009 AZZ004>018-037>040-240700- WESTERN MOGOLLON RIM-GRAND CANYON COUNTRY-YAVAPAI COUNTY MOUNTAINS- YAVAPAI COUNTY VALLEYS AND BASINS-OAK CREEK AND SYCAMORE CANYONS- MARBLE AND GLEN CANYONS-KAIBAB PLATEAU-COCONINO PLATEAU- NORTHEAST PLATEAU AND MESAS HWY 264 NORTHWARD- NORTHEAST PLATEAU AND MESAS SOUTH OF HWY 264- CHINLE VALLEY-CHUSKA MOUNTAINS AND DEFIANCE PLATEAU- BLACK MESA AREA-LITTLE COLORADO RIVER VALLEY IN COCONINO COUNTY- LITTLE COLORADO RIVER VALLEY IN NAVAJO COUNTY- LITTLE COLORADO RIVER VALLEY IN APACHE COUNTY- EASTERN MOGOLLON RIM-WHITE MOUNTAINS-NORTHERN GILA COUNTY- 700 AM MST SAT MAY 23 2009 THIS HAZARDOUS WEATHER OUTLOOK IS FOR APACHE...COCONINO...NORTHERN GILA...NAVAJO...AND YAVAPAI COUNTIES IN NORTHERN ARIZONA. .DAY ONE...TODAY AN AREA OF LOW PRESSURE AND A VERY MOIST AND MODERATELY UNSTABLE AIR MASS WILL REMAIN ACROSS ARIZONA TODAY. THE COMBINATION OF THESE INGREDIENTS WILL LEAD TO ANOTHER DAY OF WIDESPREAD SHOWERS AND THUNDERSTORMS. SOME OF THESE THUNDERSTORMS MAY PRODUCE HEAVY RAINFALL AND RESULT IN SOME LOCALIZED FLOODING. .DAYS TWO THROUGH SEVEN...SUNDAY THROUGH FRIDAY THE PROBABILITY FOR WIDESPREAD HAZARDOUS WEATHER IS LOW. .SPOTTER INFORMATION STATEMENT... WEATHER SPOTTERS ARE ENCOURAGED TO REPORT SIGNIFICANT WEATHER CONDITIONS ACCORDING TO STANDARD OPERATING PROCEDURES.
The Flagstaff radar (KFSX), 85 km away, was scanning. The volume nearest the first event began at 00:09 UTC.
1 heavy rain, 1 hail. Local standard time, as filed.
Heavy rain from a thunderstorm fell over the Cottonwood area. Rainfall rates exceeded 2.00 inches an hour in some reports. Street flooding was reported all over town by the Cottonwood Police Department.
Dime sized (3/4 inch diameter) hail was reported in south Cottonwood with very heavy rain.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Arizona in 2009Every state in 2009This day in weather historyWarnings in Arizona, May 2009
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: 175306, 175314.