Thunderstorms began late afternoon and moved West starting out near Roosevelt Lake and moving into the East Valley dumping heavy rains and picking up dust to reduce visibilities. Multiple flood advisories, airport weather warnings (lightning), severe thunderstorm warnings and a dust storm warning were issued.
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 PSR wrote it up.
Thunderstorms began late afternoon and moved West starting out near Roosevelt Lake and moving into the East Valley dumping heavy rains and picking up dust to reduce visibilities. Multiple flood advisories, airport weather warnings (lightning), severe thunderstorm warnings and a dust storm warning were issued.
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 Aug 21, 3:05 PM MST, 5 hours 40 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE PHOENIX AZ 305 PM MST SAT AUG 21 2010 .SYNOPSIS... MOISTURE WILL RETURN TO THE REGION TONIGHT AND CHANCES FOR AFTERNOON AND EVENING THUNDERSTORMS WILL INCREASE THIS WEEKEND. A CONTINUED THREAT OF SHOWERS AND THUNDERSTORMS IS EXPECTED THROUGH THE UPCOMING WEEK AS THE REGION RETURNS TO A TYPICAL MONSOON PATTERN. && .DISCUSSION... AS OF 2 PM...TEMPERATURES OVER THE CENTRAL DESERTS WERE RUNNING ABOUT 2-6 DEGREES COOLER THAN THIS TIME YESTERDAY...AS HIGH LEVEL DEBRIS CLOUDINESS COUPLED WITH INCREASED BOUNDARY LAYER HUMIDITY ACTED TO PUT A LID ON THE TEMPS. CONVECTION STARTED TO FIRE OVER THE CENTRAL AZ MOUNTAINS...AS WELL AS OVER SERN AZ WHERE BETTER CLEARING HAD TAKEN PLACE. PROGS CONTINUE TO ADVERTISE A RETURN TO A BETTER MONSOONAL FLOW PATTERN...WHICH SHOULD LEAD TO ENHANCED CHANCES FOR SHOWERS AND THUNDERSTORMS ACROSS THE CWA TONIGHT THROUGH SUNDAY NIGHT. FLOW ALOFT HAS BEEN BACKING...AND BECOMING MORE SOUTHERLY...AHEAD OF A LOW PRESSURE TROF SITUATED ALONG THE PAC NW COAST. THIS FLOW WILL BE ADVECTING DEEPER MONSOONAL MOISTURE INTO THE CWA...PWAT VALUES FROM THE 12Z PHOENIX SOUNDING WERE IN EXCESS OF 1.5 INCHES. MORNING TUS/PHX RAOBS DEPICTED A FAIR AMOUNT OF CAPE...AND WITH SURFACE DEWPOINTS IN THE 60S AT 2 PM...THERE SHOULD CERTAINLY BE SUFFICIENT CAPE TO SUPPORT A CHANCE FOR STORMS OVER THE SOUTH CENTRAL DESERTS THIS EVENING. SELY STEERING WINDS AT 15-20 KTS SHOULD BE ABLE TO ADVECT STORMS OVER THE HIGHER TERRAIN OF SERN AZ...AND MOVE THEM NORTH INTO SOUTH-CENTRAL AZ THIS EVENING. AMPLE LOW LEVEL MOISTURE WILL ALLOW OUTFLOW BOUNDARY INTERACTION TO DEVELOP ADDITIONAL STORMS TO DEVELOP AS WELL. HAVE RAISED POPS INTO THE LOW END CHANCE CATEGORY EAST OF THE LOWER CO RIVER VALLEY TONIGHT...WITH SLIGHT CHANCES EXTENDING INTO SERN CA. IR AND VAPOR IMAGERY CONTINUE TO SHOW AN INVERTED TROF MOVING WEST AND INTO THE CENTRAL GULF OF CA THIS AFTERNOON. PROGS HAVE INITIALIZED THIS FAIRLY WELL...AND FORECAST THE FEATURE TO WEAKEN AND TURN TO THE NORTH TONIGHT...WITH THE MAIN VORT MAX SLATED TO MOVE NORTHWARD THROUGH SERN CA/SWRN AZ TOMORROW. GIVEN THE COPIOUS LOW LEVEL MOISTURE THAT SHOULD BE IN PLACE OVER THE WESTERN CWA SUNDAY...WITH 850MB DEWPOINTS IN EXCESS OF 14C...THIS FEATURE SHOULD BE ABLE TO HELP ISOLATED TO SCATTERED THUNDERSTORMS DEVELOP. AS SUCH POPS HAVE BEEN RAISED OUT WEST SUNDAY/SUNDAY NIGHT INTO THE CHANCE CATEGORY OVER MUCH OF THE WESTERN CWA. FOR THE PHOENIX AREA SUNDAY WE WILL CALL FOR POPS OF JUST 20 PERCENT...FIGURING THAT CONVECTION TONIGHT WILL TAKE A BITE OUT OF THE BOUNDARY LAYER...SO TO SPEAK...AND STABILIZE THINGS A BIT. OF COURSE...HIGH TEMPS SUNDAY SHOULD BE SLIGHTLY COOLER THAN TODAY...GIVEN ALL OF THE HUMIDITY PRESENT. WE WILL CALL FOR MAX TEMPS AROUND CLIMO...WHICH MAY END UP A BIT ON THE HIGH SIDE SHOULD CONVECTION REALLY BLOSSOM TONIGHT. ON MONDAY PROGS INDICATE THAT THE UPPER HIGH WILL SHIFT A BIT TO THE SOUTH AND EAST...AS TROFFING MOVES THROUGH THE NORTHERN TIER OF STATES. FLOW WILL TURN A BIT MORE TO THE SOUTHWEST AGAIN...AND ALLOW MOISTURE TO THIN SOMEWHAT. AS SUCH...POPS WILL LOWER AND APPROACH CLIMO NUMBERS...WITH HIGH TEMPS TO CLIMB AGAIN. HOTTER DESERT LOCALES SHOULD APPROACH OR EVEN EXCEED 110 DEGREES...ESPECIALLY OVER THE SWRN AZ AND SERN CA DESERTS. AS ALWAYS...HEAT WILL CONTINUE TO BE AN ISSUE WITH THIS FORECAST PACKAGE. ON SUNDAY...DESPITE HIGH TEMPS NEAR CLIMO...HIGH SURFACE DEWPOINTS MAY ALLOW A FEW PLACES TO REACH NEAR 110 WITH THE HEAT INDEX. ON MONDAY...AS THE AIRMASS DRIES AND HIGH TEMPS CLIMB...AGAIN HEAT INDEXS MAY APPROACH 110 OVER SOUTH-CENTRAL AZ AND 115 OUT WEST. FOR BOTH DAYS...DO NOT EXPECT AREAL COVERAGE OR DURATION TO BE SUFFICIENT TO WARRANT AN EXCESSIVE HEAT WARNING...WILL ALLOW THE SPS OUTLOOK AND HWO TO COVER THINGS. TUESDAY MAY BE A DIFFERENT STORY. LATEST GFS/ECMWA REALLY START TO BUILD THE UPPER HIGH OVER THE DESERT SOUTHWEST WITH A 595DM HIGH CENTER FORMING JUST NORTH OF PHOENIX. WITH MOISTURE VALUES IN THE LOW LAYERS STILL LIMITED... THERE WILL BE POTENTIAL TO ACTUALLY REACH OR EXCEED THE MAX TEMP HEAT WARNING THRESHOLDS...AS WELL AS THE HEAT INDEX THRESHOLD. MEX MOS HAS BEEN CALLING FOR HIGHS AT PHOENIX AROUND 112 OFF AND ON OVER THE PAST SEVERAL RUNS. GFS FORECAST SOUNDINGS ALSO SHOW 3-4 DEGREES OF WARMING FROM MONDAY TO TUESDAY. ATTM...WILL CALL FOR A HIGH OF 111 AT PHOENIX...AND MENTION THE POSSIBILITY OF NEEDING AN EXCESSIVE HEAT WATCH FOR TUESDAY IN THE SPS. CONFIDENCE STILL A BIT LOW...AND WILL LET THE OUTLOOK COVER THE SITUATION. OTHERWISE...EXPECT A LOW TO MEDIUM GRADE MONSOON FORECAST FOR TUESDAY...WITH POPS MOSTLY IN THE SLIGHT CHANCE CATEGORY. STEERING FLOW WILL BE WEAK...BUT SHOULD BE FROM THE EAST OR NORTHEAST...WHICH IS A FAVORABLE DIRECTION TO BRING STORMS INTO THE CENTRAL AZ DESERTS. CONFIDENCE IN THE FORECAST FROM WEDNESDAY ONWARD IS STILL SOMEWHAT LOW...AS THE EUROPEAN AND GFS MODELS DIFFER IN THEIR RESPECTIVE POSITIONS OF THE UPPER HIGH. THE EUROPEAN WOULD INDICATE THAT A BROAD SOUTHWESTERLY FLOW AND DRY CONDITIONS WILL RETURN TO THE REGION WHILE THE GFS BRINGS A MOIST SOUTHEASTERLY FLOW BACK INTO THE AREA LATE IN THE WEEK. FOR NOW...A TREND TOWARD CLIMO LOOKS REASONABLE. BOTH MODELS HAVE BEEN STRUGGLING WITH HOW TO HANDLE THE END OF THE WEEK OVER THEIR PAST FEW RUNS AND IT MAY BE PRUDENT TO HOLD OFF ON TRENDING THE FORECAST TOO WET OR TOO DRY AT THIS POINT. && .AVIATION... SOUTH-CENTRAL ARIZONA INCLUDING KPHX AND KIWA... EXPECT THUNDERSTORMS TO FORM OVER THE MOUNTAINS NORTH...EAST AND SOUTH OF KIWA/KPHX LATE THIS AFTERNOON/EVENING. S-SELY STEERING FLOW MAINTAINS THE POTENTIAL FOR AN ISOLD THUNDERSTORM TO IMPACT KIWA AND KPHX IN ADDITION TO GUSTY OUTFLOW WINDS AND LOCALIZED BLOWING DUST...PRIMARILY AFTER 6PM/01Z SUNDAY. SOUTHEAST CALIFORNIA...SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH... GUSTY SOUTH-SOUTHEASTERLY WINDS UP TO 25KTS WILL PERPETUATE A MOIST AIRMASS OVER THE REGION THIS AFTERNOON...YIELDING A SLIGHT CHANCE OF SHOWERS AND THUNDERSTORMS STARTING THIS EVENING AND THROUGH 12Z SUNDAY MORNING...MAINLY ALONG THE LOWER COLORADO RIVER VALLEY NORTH AND EAST OF KBLH. DISCUSSION NOT UPDATED FOR AMENDED TAFS. && .FIRE WEATHER... MONDAY THROUGH FRIDAY... HIGH PRESSURE WILL BE OVER ARIZONA FOR MOST OF THE EXTENDED PERIOD RESULTING IN NEAR NORMAL TEMPERATURES. SUFFICIENT MOISTURE AND INSTABILITY WILL EXIST FOR A DAILY THREAT OF AFTERNOON AND EVENING THUNDERSTORMS GENERALLY EAST OF THE LOWER COLORADO RIVER ACROSS SOUTH-CENTRAL ARIZONA. HUMIDITY VALUES WILL DECREASE A BIT EARLY IN THE WEEK...WITH LITTLE CHANGE LATER IN THE WEEK. NO SIGNIFICANT WINDS EXPECTED. && .PSR WATCHES/WARNINGS/ADVISORIES... AZ...NONE. CA...NONE. && NATIONAL WEATHER SERVICE PHOENIX IS ON THE INTERNET AT WEATHER.GOV/PHOENIX DISCUSSION...CB/LEINS AVIATION...MEYERS FIRE WEATHER...INIGUEZ
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE PHOENIX AZ 326 AM MST SAT AUG 21 2010 AZZ022-023-027-028-221400- NORTHWEST MARICOPA COUNTY-GREATER PHOENIX AREA- SOUTHWEST MARICOPA COUNTY-NORTHWEST AND NORTH CENTRAL PINAL COUNTY- 326 AM MST SAT AUG 21 2010 THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF SOUTH-CENTRAL ARIZONA. .DAY ONE...TODAY AND TONIGHT ISOLATED SHOWERS AND THUNDERSTORMS ARE POSSIBLE THIS EVENING. ALSO...AREAS OF BLOWING DUST ALONG THE I-10 CORRIDOR ARE POSSIBLE LATE THIS AFTERNOON AND EVENING. VERY MOIST AIR WILL MOVE INTO THE REGION TODAY. WHILE THIS WILL LIKELY RESULT IN LOWER MAXIMUM AFTERNOON TEMPERATURES...HEAT INDICES WILL APPROACH 109 DEGREES THIS AFTERNOON. WHILE THESE CONDITIONS ARE JUST BELOW EXCESSIVE HEAT WARNING CRITERIA...USE CAUTION IF PLANNING OUTDOOR ACTIVITIES THIS AFTERNOON AND REMEMBER TO STAY HYDRATED. .DAYS TWO THROUGH SEVEN...SUNDAY THROUGH FRIDAY THERE IS AN INCREASING THREAT FOR SHOWERS AND THUNDERSTORMS ON SUNDAY. GUSTY WINDS...BRIEF PERIODS OF HEAVY RAIN...AREAS OF BLOWING DUST...AND CLOUD TO GROUND LIGHTNING ARE THE PRIMARY THREATS FROM ANY STORMS THAT DEVELOP. THERE IS A CONTINUED CHANCE FOR SHOWERS AND THUNDERSTORMS THROUGH MOST OF THE UPCOMING WEEK AS A MORE TYPICAL MONSOON WEATHER PATTERN DEVELOPS ACROSS THE REGION. THE HOT AND MUGGY CONDITIONS WILL PERSIST SUNDAY AND MONDAY. HEAT INDICES COULD EXCEED 110 DEGREES AROUND THE GREATER PHOENIX AREA SUNDAY AND MONDAY BUT THERE IS STILL SOME UNCERTAINTY HOW HIGH THE HEAT INDICES WILL GET. .SPOTTER INFORMATION STATEMENT... WEATHER SPOTTERS ARE ENCOURAGED TO REPORT SIGNIFICANT WEATHER CONDITIONS ACCORDING TO STANDARD OPERATING PROCEDURES. AZZ024-221400- SOUTHERN GILA COUNTY/TONTO NATIONAL FOREST FOOTHILLS- 326 AM MST SAT AUG 21 2010 THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF EAST-CENTRAL ARIZONA. .DAY ONE...TODAY AND TONIGHT SHOWERS AND THUNDERSTORMS ARE POSSIBLE TODAY. THE PRIMARY THREATS FROM ANY STORMS THAT DEVELOP ARE PERIODS OF HEAVY RAIN...CLOUD TO GROUND LIGHTNING...AND GUSTY WINDS. .DAYS TWO THROUGH SEVEN...SUNDAY THROUGH FRIDAY THERE IS A CONTINUED CHANCE FOR SHOWERS AND THUNDERSTORMS FROM SUNDAY THROUGH FRIDAY AS THE REGION RETURNS TO A MORE TYPICAL MONSOON WEATHER PATTERN. .SPOTTER INFORMATION STATEMENT... WEATHER SPOTTERS ARE ENCOURAGED TO REPORT SIGNIFICANT WEATHER CONDITIONS ACCORDING TO STANDARD OPERATING PROCEDURES. AZZ020-021-025-026-CAZ031>033-221400- LOWER COLORADO RIVER VALLEY AZ-WEST CENTRAL DESERTS- YUMA/MARTINEZ LAKE AND VICINITY-SOUTHWEST DESERTS- LOWER COLORADO RIVER VALLEY CA-RIVERSIDE COUNTY/EASTERN DESERTS- IMPERIAL COUNTY- 326 AM MST SAT AUG 21 2010 /326 AM PDT SAT AUG 21 2010/ THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF EXTREME SOUTHWEST ARIZONA...EXTREME WEST-CENTRAL ARIZONA...SOUTHWEST ARIZONA...WEST- CENTRAL ARIZONA AND EXTREME SOUTHEAST CALIFORNIA. .DAY ONE...TODAY AND TONIGHT ISOLATED SHOWERS AND THUNDERSTORMS ARE POSSIBLE TODAY AND TONIGHT. THE PRIMARY THREATS FROM ANY STORMS THAT DEVELOP ARE PERIODS OF HEAVY RAIN...CLOUD TO GROUND LIGHTNING...GUSTY WINDS...AND AREAS OF BLOWING DUST. ALSO...WARM MUGGY CONDITIONS ACROSS THE REGION COULD RESULT IN HEAT INDICES ABOVE 110 DEGREES THIS AFTERNOON. USE CAUTION IF PLANNING OUTDOOR ACTIVITIES AND REMEMBER TO STAY HYDRATED. .DAYS TWO THROUGH SEVEN...SUNDAY THROUGH FRIDAY THERE IS ALSO A SLIGHT CHANCE OF SHOWERS AND THUNDERSTORMS ON SUNDAY. IN ADDITION...THE WARM MUGGY AIR-MASS WILL REMAIN IN PLACE THROUGH MONDAY. HEAT INDICES MAY EXCEED 110 DEGREES AT TIMES SUNDAY AND MONDAY. .SPOTTER INFORMATION STATEMENT... WEATHER SPOTTERS ARE ENCOURAGED TO REPORT SIGNIFICANT WEATHER CONDITIONS ACCORDING TO STANDARD OPERATING PROCEDURES. CAZ030-221400- JOSHUA TREE NATIONAL PARK- 326 AM PDT SAT AUG 21 2010 THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF SOUTHEAST CALIFORNIA. .DAY ONE...TODAY AND TONIGHT ISOLATED SHOWERS AND THUNDERSTORMS ARE POSSIBLE TODAY. THE PRIMARY THREATS FROM ANY STORMS THAT DEVELOP ARE PERIODS OF HEAVY RAIN...GUSTY WINDS...AND CLOUD TO GROUND LIGHTNING. HOT AND MUGGY CONDITIONS ARE EXPECTED TODAY. THOSE PLANNING OUTDOOR ACTIVITIES SHOULD REMEMBER TO STAY HYDRATED. .DAYS TWO THROUGH SEVEN...SUNDAY THROUGH FRIDAY THERE IS A SLIGHT CHANCE OF SHOWERS AND THUNDERSTORMS ON SUNDAY AS WELL. IN ADDITION TO THE CHANCE OF THUNDERSTORMS...THE WARM AND MUGGY AIR-MASS WILL REMAIN ACROSS THE REGION SUNDAY AND MONDAY. .SPOTTER INFORMATION STATEMENT... WEATHER SPOTTERS ARE ENCOURAGED TO REPORT SIGNIFICANT WEATHER CONDITIONS ACCORDING TO STANDARD OPERATING PROCEDURES. NATIONAL WEATHER SERVICE PHOENIX IS ON THE INTERNET AT WEATHER.GOV/PHOENIX
SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE PHOENIX AZ 330 PM MST SAT AUG 21 2010 AZZ020>023-025>028-CAZ031>033-221200- LOWER COLORADO RIVER VALLEY AZ-WEST CENTRAL DESERTS- NORTHWEST MARICOPA COUNTY-GREATER PHOENIX AREA- YUMA/MARTINEZ LAKE AND VICINITY-SOUTHWEST DESERTS- SOUTHWEST MARICOPA COUNTY-NORTHWEST AND NORTH CENTRAL PINAL COUNTY- LOWER COLORADO RIVER VALLEY CA-RIVERSIDE COUNTY/EASTERN DESERTS- IMPERIAL COUNTY- INCLUDING THE CITIES OF...EHRENBERG...PARKER...BOUSE...QUARTZSITE... SALOME...BUCKEYE...LAKE PLEASANT...MORRISTOWN...NEW RIVER... TONOPAH...WICKENBURG...CAREFREE...CAVE CREEK...CHANDLER... FOUNTAIN HILLS...GILBERT...GLENDALE...MESA...PEORIA...PHOENIX... SCOTTSDALE...SUN CITY...TEMPE...FORTUNA FOOTHILLS...SAN LUIS... SOMERTON...YUMA...DATELAND...TACNA...WELLTON...GILA BEND... APACHE JUNCTION...CASA GRANDE...COOLIDGE...FLORENCE...BLYTHE... CHIRIACO SUMMIT...DESERT CENTER...EAGLE MOUNTAIN...BRAWLEY... CALEXICO...EL CENTRO...GLAMIS...IMPERIAL...AND THE SALTON SEA 330 PM MST SAT AUG 21 2010 /330 PM PDT SAT AUG 21 2010/ ...HOT AND MUGGY CONDITIONS TO CONTINUE INTO EARLY NEXT WEEK... MOIST AIR FROM THE GULF OF CALIFORNIA AND NORTHWEST MEXICO WILL OVERSPREAD SOUTHEAST CALIFORNIA AND SOUTHERN ARIZONA TONIGHT INTO SUNDAY. MAXIMUM HEAT INDICES IN THE GREATER PHOENIX AREA SUNDAY WILL APPROACH 105 TO 109 DEGREES...WITH SOME LOCATIONS IN THE YUMA...BLYTHE AND IMPERIAL AREAS LIKELY TO EXCEED 110 DEGREES. ON MONDAY...MOISTURE VALUES WILL LOWER SLIGHTLY BUT HIGH TEMPERATURES WILL CLIMB A FEW DEGREES. THE AIR WILL STILL FEEL MUGGY AND UNCOMFORTABLE AND SIMILAR HEAT INDICES ARE EXPECTED ACROSS THE LOWER DESERTS. ON TUESDAY...HIGH PRESSURE ALOFT IS FORECAST TO BECOME EVEN STRONGER AND MOISTURE VALUES ARE SLATED TO DECREASE FURTHER. THE RESULT WILL BE HIGH TEMPERATURES AND MAXIMUM HEAT INDICES THAT MAY EXCEED EXCESSIVE HEAT WARNING THRESHOLDS. MANY LOCATIONS ACROSS THE LOWER DESERTS OF SOUTHERN ARIZONA AND SOUTHEAST CALIFORNIA WILL REACH OR EXCEED 110 DEGREES TUESDAY...AND MAXIMUM HEAT INDICES MAY REACH 110 OVER SOUTH CENTRAL ARIZONA...AND MAY REACH TO 115 IN THE YUMA...BLYTHE AND IMPERIAL AREAS. AS SUCH...AN EXCESSIVE HEAT WATCH MAY NEED TO BE ISSUED FOR TUESDAY. IF YOU PLAN ON BEING OUTSIDE FOR AN EXTENDED PERIOD OF TIME SUNDAY INTO EARLY NEXT WEEK...REMEMBER TO STAY HYDRATED AND DRINK PLENTY OF FLUIDS. THE UNUSUALLY MUGGY CONDITIONS WILL STRESS THE BODY TO DANGEROUS LEVELS IF THE PROPER PRECAUTIONS ARE NOT TAKEN. STAY UP-TO-DATE ON THE LATEST FORECASTS BY LISTENING TO WEATHER RADIO ON THE PUBLIC SERVICE BAND. MORE DETAILED INFORMATION IS AVAILABLE FROM THE NATIONAL WEATHER SERVICE IN PHOENIX ON THE INTERNET AT WEATHER.GOV/PHOENIX BRECKENRIDGE
SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE PHOENIX AZ 733 PM MST SAT AUG 21 2010 AZZ024-028-220315- NORTHWEST AND NORTH CENTRAL PINAL COUNTY-SOUTHERN GILA/TONTO NF FOOTHILLS- 733 PM MST SAT AUG 21 2010 ...STRONG THUNDERSTORMS AFFECTING CENTRAL GILA COUNTY...EAST CENTRAL MARICOPA COUNTY...EXTREME NORTH CENTRAL PINAL COUNTY... AT 729 PM MST...NATIONAL WEATHER SERVICE METEOROLOGISTS DETECTED AN AREA OF STRONG THUNDERSTORMS BETWEEN THE COMMUNITIES OF ROOSEVELT AND TORTILLA FLAT ALONG STATE ROUTE 88...MOVING WEST AT 15 MPH. THE PRIMARY THREATS WILL BE CLOUD TO GROUND LIGHTNING STRIKES AND GUSTY WINDS OF 40 TO 45 MPH. SOME UNSECURED OBJECTS COULD BE BLOWN AROUND. HIGH PROFILE VEHICLES MAY BE DIFFICULT TO CONTROL. BLOWING DUST MAY TEMPORARILY REDUCE VISIBILITY. SEEK SHELTER INDOORS UNTIL THE STORM PASSES. WANEK
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE PHOENIX AZ
828 PM MST SAT AUG 21 2010
AZZ028-220415-
PINAL AZ-
828 PM MST SAT AUG 21 2010
THE NATIONAL WEATHER SERVICE IN PHOENIX HAS ISSUED A
SIGNIFICANT WEATHER ADVISORY FOR...
CENTRAL PINAL COUNTY IN SOUTH CENTRAL ARIZONA
UNTIL 915 PM MST
AT 815 PM MST...AN AREA OF THUNDERSTORMS WERE DEVELOPING AND MOVING
INTO PINAL COUNTY...ALONG A GUST FRONT...TOWARD CASA GRANDE...LA
PALMA...COOLIDGE...AND FLORENCE. BUILDING THUNDERSTORMS WILL SLOWLY
WORK THEIR WAY TOWARD SUN LAKES LATER IN THE EVENING.
THUNDERSTORMS HAVE THE POTENTIAL TO PRODUCE WIND GUSTS TO 45 MPH...
DENSE BLOWING DUST...HEAVY RAIN AT RAINFALL RATES OF 1 INCH PER
HOUR...AND FREQUENT LIGHTNING.
SOME UNSECURED OBJECTS COULD BE BLOWN AROUND. SEEK SHELTER INDOORS
UNTIL THE STORM PASSES.
LOCALLY DENSE BLOWING DUST IS POSSIBLE. IF YOU ENCOUNTER BLOWING DUST
WHILE DRIVING...PULL OVER AS FAR OFF THE ROADWAY AS POSSIBLE AND
PARK. TURN OFF YOUR HEADLIGHTS AND KEEP YOUR FOOT OFF THE BRAKE.
LAT...LON 3302 11181 3316 11156 3291 11140 3279 11155
3279 11157
TIME...MOT...LOC 0324Z 146DEG 10KT 3289 11152
HVThe national radar mosaic for the moment the first event began.
6 heavy rain, 1 dust storm. Local standard time, as filed.
Thunderstorms in the Florence area produced locally heavy rainfall, with rainfall rates in excess of 1.5 inches per hour. At 2115MST the Pinal County sheriff reported running washes with water water covering highway 79 near Florence. In addition, flooding was reported along the Hunt highway.
Spotter reported 0.76 inches of rain fell in 40 minutes.
Widespread blowing dust moved across the area on Saturday evening. The peak winds at the Magma weather station near Florence was 43 mph from the south.
Spotter reported heavy rain fall of 0.58 inches fell in 15 minutes.
Spotter reported heavy rain of 0.97 inches fell in 30 minutes.
Spotters in Mesa and other East Valley locations reported torrential downpours and small hail. One spotter indicated 0.50 inches of rain in 30 minutes.
Spotter reported heavy rain of 0.25 inches and gusty winds estimated to 40 mph.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Arizona in 2010Every state in 2010This day in weather historyWarnings in Arizona, August 2010
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: 252507, 250945, 252340, 250946, 250947, 250949, 250950.