A thunderstorm produce strong winds and large waves on Lake Powell.
Every event with a place to put it. 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 thunderstorm produce strong winds and large waves on Lake Powell.
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 Aug 22, 3:30 PM MST, 1 hour 15 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE FLAGSTAFF AZ 330 PM MST SAT AUG 22 2009 .SYNOPSIS...A MOIST SOUTHERLY FLOW WILL BRING SCATTERED SHOWERS AND THUNDERSTORMS ALONG WITH COOLER TEMPERATURES THIS WEEKEND. STARTING MONDAY...SOUTHWEST FLOW ALOFT BRING DRYING ALOFT ACROSS THE AREA. THIS WILL BRING A SLIGHT CHANCE OF SHOWERS AND THUNDERSTORMS AND GRADUALLY WARMING DAYTIME TEMPERATURES. && .DISCUSSION... SHOWERS AND THUNDERSTORMS COVER MUCH OF NORTHERN ARIZONA THIS AFTERNOON. LOCALLY HEAVY RAIN HAS BEEN OBSERVED...0.59 INCH IN 15 MINUTES IN COTTONWOOD FOR EXAMPLE. FORECAST MODELS CONSISTENCY REMAINS GOOD FOR THE NEXT SEVERAL DAYS. FOR TONIGHT AND SUNDAY...SOUTHERLY FLOW ALOFT TONIGHT IS FORECAST TO BECOME SOUTH SOUTHWESTERLY SUNDAY. THIS DUE TO THE EASTWARD MOVEMENT OF THE ANTICYCLONE CENTER AWAY FROM NEW MEXICO AND THE OPENING UP OF THE CUT OFF LOW NOW WEST OF SAN DIEGO. MONSOON MOISTURE WILL REMAIN OVER THE NORTHLAND AND ANOTHER DAY OF SCATTERED SHOWERS AND THUNDERSTORMS IS EXPECTED. STARTING MONDAY...PROGS SHOW THE SAN DIEGO LOW TO BEGIN MOVING INTO THE GREAT BASIN. DRYING ALOFT FROM WEST TO EAST IS SEEN IN THE CROSS SECTIONS...ALONG WITH COOLER H5 AIR MOVING INTO NORTHWESTERN AZ. THUS WILL KEEP A CHANCE OF THUNDERSTORMS GOING. FROM TUESDAY THROUGH FRIDAY...PROGS SHOW HIGH PRESSURE TO REFORM OVER THE DESERT SOUTHWEST. POPS WERE MASSAGED TO SHOW A DIURNAL TREND WITH ONLY SLIGHT CHANCES FOR AREAS ABOVE 7000 FEET AND DRY ELSEWHERE. IF CURRENT MODEL TRENDS CONTINUE...POPS MAY NEED TO BE ELIMINATED TUESDAY AND WEDNESDAY AND MAX TEMPS BUMPED UP A FEW DEGREES MORE. && .AVIATION...FOR THE 00Z PACKAGE...SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS WILL CONTINUE THROUGH AROUND 03Z...WITH DECREASING COVERAGE OVERNIGHT. MVFR CONDITIONS WITH ISOLATED IFR VISIBILITIES ARE LIKELY WITH THESE STORMS. IN ADDITION...THE STRONGEST STORMS MAY CONTAIN HAIL AND WIND GUSTS NEAR 40 KT. STORM MOTION WILL BE TOWARD THE N-NW NEAR 20 KT. SCATTERED SHOWERS AND THUNDERSTORMS WILL DEVELOP AGAIN AFTER 18Z SUNDAY. AVIATION DISCUSSION NOT UPDATED FOR AMENDMENTS. && && .FGZ WATCHES/WARNINGS/ADVISORIES...NONE. && PUBLIC..................DL AVIATION................JJ VISIT WEATHER.GOV/FLAGSTAFF FOR NORTHERN ARIZONA WEATHER INFORMATION.
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE FLAGSTAFF AZ 941 AM MST SAT AUG 22 2009 AZZ004>018-037>040-230700- 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- 941 AM MST SAT AUG 22 2009 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 MONSOON MOISTURE IS MOVING NORTHWARD INTO NORTHERN ARIZONA THIS MORNING. SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS ARE EXPECTED TODAY WEST OF A LINE FROM TUSAYAN TO ALPINE. LOCALLY HEAVY RAIN IS POSSIBLE TODAY WEST OF A LINE FROM PAGE TO PAYSON. AREAS EAST OF THE LINE FROM TUSAYAN TO ALPINE SHOULD SEE WIDELY SCATTERED SHOWERS AND THUNDERSTORMS. .DAYS TWO THROUGH SEVEN...SUNDAY THROUGH FRIDAY ON SUNDAY....SOUTHERLY FLOW WILL CONTINUE OVER ARIZONA...AND SCATTERED SHOWERS AND THUNDERSTORMS ARE EXPECTED ACROSS ALL OF NORTHERN ARIZONA. THE CHANCES WILL FOR MAINLY AFTERNOON SHOWERS AND THUNDERSTORMS WILL CONTINUE THROUGH NEXT WEEK. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION WILL NOT BE NEEDED.
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
146 PM MST SAT AUG 22 2009
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0122 PM TSTM WND GST WINSLOW 35.03N 110.71W
08/22/2009 M58 MPH NAVAJO AZ ASOS
&&
JJThe Cedar City radar (KICX), 139 km away, was scanning. The volume nearest the first event began at 23:44 UTC.
1 thunderstorm wind. Local standard time, as filed.
A thunderstorm over Lake Powell produced wind gusts to 54 MPH and waves up to 7 feet high. One houseboat and 13 other boats were swamped. Four law enforcement boats responded to 16 distress calls.
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, August 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: 189801.