The upper pattern was defined by a strong ridge of high pressure over the middle of the country, and a trough off the coast of the Pacific Northwest. An overnight MCS moved from southeast to northwest from Sonora, Mexico into southern Arizona.
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 TWC wrote it up.
The upper pattern was defined by a strong ridge of high pressure over the middle of the country, and a trough off the coast of the Pacific Northwest. An overnight MCS moved from southeast to northwest from Sonora, Mexico into southern Arizona. The leading edge of the complex caused wind damage in Nogales.
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 Tucson, AZ wrote its last area forecast discussion before the first event at Sep 2, 5:15 AM MST, 5 minutes earlier.
AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE TUCSON AZ 515 AM MST MON SEP 2 2013 .SYNOPSIS...SUFFICIENT MOISTURE WILL KEEP ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS OVER SOUTHEAST ARIZONA THIS WEEK. AFTERNOON HIGH TEMPERATURES WILL REMAIN SEVERAL DEGREES ABOVE NORMAL. && .UPDATE...OUTFLOW FROM SONORAN MCS MOVING NW KICKING OFF SCATTERED THUNDERSTORMS ACROSS SW COCHISE/ERN SANTA CRUZ COUNTIES. HAVE HAD A COUPLE RAINFALL REPORTS IN AND AROUND SIERRA VISTA BETWEEN 0.75"-1.25". WILL BE ISSUING SMALL STREAM ADVISORY FOR THESE AREAS SHORTLY. OUTFLOW WILL CONTINUE NW INTO ERN PIMA COUNTY THROUGH SUNRISE. UPDATE FORECAST TO UP POPS IN ABOVE MENTIONED AREAS THIS MORNING. && .DISCUSSION...SEVERAL FACTORS WILL BE INFLUENCING A COMPLEX FORECAST FOR TODAY. AS OF 245 AM...THE THUNDERSTORM COMPLEX SOUTH OF NOGALES WAS SLOWLY DECREASING WITH RADAR INDICATING THAT AN MCV WAS DEVELOPING FROM IT. THIS IDEA IS BEING HANDLED WELL BY THE LATEST RUNS OF THE HRRR. TO THE EAST ACROSS NE SONORA A LINE OF THUNDERSTORMS WAS PUSHING W-NW LIKELY BEING AIDED BY DISTURBANCE ALOFT THAT WAS MOVING ACROSS NW CHIHUAHUA MEXICO. SOME OF THESE STORMS WILL IMPACT THE INTERNATIONAL BORDER AREAS FROM NOGALES TO DOUGLAS THIS MORNING. BEST AREAL COVERAGE OF STORMS THIS AFTERNOON WILL FROM TUCSON WEST WHERE THE ABOVE MENTIONED MCV WILL MOVE INTO. WITH PW VALUES UP AROUND 1.5" WEST OF TUCSON...LOCALLY HEAVY RAIN WILL OCCUR. EAST OF TUCSON PW VALUES WILL BE AROUND 1" THUS EXPECT ONLY ISOLATED ACTIVITY THIS AFTERNOON. ISOLATED TO SCATTERED STORMS TONIGHT WILL BEST CHANCES FROM TUCSON WEST. TUESDAY CONTINUES TO LOOK LIKE THE MOST ACTIVE DAY OF THE WEEK WITH HIGHER TERRAIN STORMS MOVING INTO THE LOWER DESERTS DUE TO 15-20 MPH MID LEVEL STEERING FLOW. AGAIN HIGHEST PW VALUES WILL BE WEST OF TUCSON. WEDNESDAY...ISOLATED TO SCATTERED STORMS WITH BEST CHANCES OF STORMS BEING SOUTH AND WEST OF TUCSON. LOW GRADE MONSOON FORECAST THURSDAY INTO THE UPCOMING WEEKEND. ABOVE NORMAL HIGHS WILL CONTINUE THRU MUCH OF THE WEEK. && .AVIATION...SCTD -SHRA/TS SE OF KTUS THRU 02/17Z. TSRA/SHRA WILL INCR IN AREAL COVG MNLY FM KTUS S AND W AFT 02/18Z. THE STRONGER TSRA WILL PRODUCE MVFR CIGS/VSBYS AND BRIEF WIND GUSTS TO AROUND 45 KTS. SURFACE WIND WILL GENERALLY BE LESS THAN 10 KTS THRU MONDAY EVENING OR 03/03Z. AVIATION DISCUSSION NOT UPDATED FOR TAF AMENDMENTS. && .FIRE WEATHER...ISOLATED TO SCATTERED MAINLY AFTERNOON AND EVENING THUNDERSTORMS THIS WEEK. STRONG...GUSTY AND ERRATIC WINDS WILL OCCUR WITH THE STRONGER THUNDERSTORMS. OTHERWISE...SURFACE WIND DIURNALLY DRIVEN AND GENERALLY LESS THAN 12 MPH. && .TWC WATCHES/WARNINGS/ADVISORIES...NONE. && VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON
The Tucson radar (KEMX), 68 km away, was scanning. The volume nearest the first event began at 12:18 UTC.
1 thunderstorm wind. Local standard time, as filed.
Thunderstorm winds blew off a portion of a roof in Nogales.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Arizona in 2013Every state in 2013This day in weather historyWarnings in Arizona, September 2013
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: 477945.