Deeper moisture returned to far southern Arizona although southerly flow remained weak. Slow moving thunderstorms produced areas of heavy rain and flash flooding in Cochise County where one fatality occurred when flood waters swept away one motorist.
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.
Deeper moisture returned to far southern Arizona although southerly flow remained weak. Slow moving thunderstorms produced areas of heavy rain and flash flooding in Cochise County where one fatality occurred when flood waters swept away one motorist.
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 19, 9:50 AM MST, 3 hours 10 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TUCSON AZ 950 AM MST SAT SEP 19 2015 .SYNOPSIS...INCREASING MOISTURE EARLY IN THE UPCOMING WEEK WILL LEAD TO A GOOD CHANCE OF SHOWERS AND THUNDERSTORMS ESPECIALLY MONDAY INTO TUESDAY. HEAVY RAINFALL MAY RESULT FROM THESE SHOWERS AND THUNDERSTORMS...ESPECIALLY ACROSS WESTERN PORTIONS OF THE STATE. DRY CONDITIONS WILL THEN RETURN TO THE AREA DURING THE LATTER PART OF THE NEW WEEK. EXPECT BELOW NORMAL DAYTIME TEMPERATURES MONDAY AND TUESDAY FOLLOWED BY A WARMING TREND LATE NEXT WEEK. && .DISCUSSION...THE UPPER WEATHER PATTERN THIS MORNING WAS DEFINED BY A RIDGE OF HIGH PRESSURE ACROSS NORTHEAST MEXICO/TEXAS...AN UPPER LOW POSITIONED OFF THE SOUTHERN CALIFORNIA COAST NEAR 30N/125W AND A CLUSTER OF STORMS AROUND A LOW PRESSURE AREA SSW OF THE TIP OF THE BAJA. CLOSER TO SOUTHEAST ARIZONA...A WEAK DISTURBANCE IS MOVING NORTH THROUGH EASTERN SONORA MEXICO IN A WEAK DIFFLUENT AREA BETWEEN THE LARGER SCALE RIDGE AND UPPER LOW. THE 19/12Z KTWC UPPER SOUNDING INDICATED AN ELEVATED LAYER OF MOISTURE WITH A FAIRLY DRY LOW- LEVEL/SFC-800MB/. THIS MOISTURE LAYER WAS EVIDENT THIS MORNING WITH WIDESPREAD ALTOCUMULUS CASTELANUS PRESENT ACROSS THE SOUTHEAST HALF OF THE FORECAST AREA. SCATTERED LIGHT TO MODERATE SHOWERS WITH ISOLATED THUNDERSTORMS IN SOUTHWEST NM THIS MORNING WILL CONTINUE TO SPREAD WEST TODAY AS THE COMBINATION OF THE LIFT ASSOCIATED WITH THE WEAK DISTURBANCE MOVING THRU SONORA MEXICO MAKES IT WAY INTO THE FAR SE CORNER OF ARIZONA AND THE DIFFLUENT FIELD ALOFT EXPANDS INTO SOUTHEAST ARIZONA...MAINLY SOUTH AND EAST OF TUCSON. ALTHOUGH THESE STORMS ARE NOT EXPECTED TO PRODUCE SIGNIFICANT HEAVY RAINFALL...LOOK FOR EVAPORATIVE COOLING EFFECT TO ACCELERATE DOWNDRAFTS WITH THESE STORMS...RESULTING IN STRONGER THAN EXPECTED OUTFLOWS FROM THESE STORMS. THE PREVIOUS SHIFT INCLUDED MENTION OF BLOWING DUST IN THE FORECAST...AND I AM INCLINED TO LEAVE IT IN GIVEN THIS SCENARIO. CURRENT FORECAST LOOKS ON TRACK SO NO UPDATES THIS MORNING. OTHERWISE...AN ACTIVE PATTERN IS IN STORE FOR SOUTHEAST ARIZONA INTO THE MIDDLE OF NEXT WEEK. THE NATIONAL HURRICANE CENTER THIS MORNING IS STILL CLASSIFYING THE CLUSTER OF STORMS SSW OF THE TIP OF THE BAJA AS A DISTURBANCE WITH A 50 PCT CHANCE OF CYCLONE FORMATION IN THE NEXT 48 HOURS AS IT MOVES NNW AT 10 MPH. IT IS THIS FEATURE THAT WILL BE A SIGNIFICANT PLAYER IN OUR FORECAST. ALTHOUGH THIS SYSTEM WILL WEAKEN OVER THE COLDER WATERS AND STRIPPED BY THE UPPER LOW...IT WILL IMPORT SIGNIFICANT MOISTURE NE INTO ARIZONA... ESPECIALLY THE WESTERN PORTIONS OF THE STATE. QUICK INSPECTION OF THE 12Z MODELS INDICATES THAT THE GFS IS MORE BULLISH THAN THE NAM AND 00Z ECMWF WITH THE REMNANT FEATURE MOVING INTO SW ARIZONA. BECAUSE OF THIS...THE GFS HAS A BULLSEYE OF HEAVY RAINFALL ACROSS SOUTHWEST ARIZONA DURING THE DAY MONDAY. THE NAM IS A BIT SLOWER...WITH MONDAY NIGHT BEING PRIME TIME FOR THE HEAVY RAIN EVENT. SOUTHEAST ARIZONA WILL ALSO GET IN ON SOME OF THE RAINFALL...BUT IT MAY BE MORE ON TUESDAY AS THE TRAILING UPPER LOW MOVES ACROSS THE AREA THROUGH THE MOIST ENVIRONMENT IN PLACE. && .PREV DISCUSSION...THE BROAD SCALE PATTERN EARLY THIS MORNING IS CHARACTERIZED BY AN AREA OF HIGH PRESSURE OVER THE SRN CONUS PLAINS...AND A WEAK UPPER LOW WEST OF NRN BAJA CALIFORNIA CENTERED VICINITY 29N/125W. THERE IS ALSO A DISTURBANCE PRODUCING AN AREA OF SHOWERS/TSTMS ABOUT 400 MILES SOUTHWEST OF THE SOUTHERN TIP OF THE BAJA CALIFORNIA PENINSULA. 19/00Z GFS/ECMWF/CMC AND RESPECTIVE ENSEMBLES WERE IN BETTER AGREEMENT VERSUS 24 HOURS AGO...AND THUS FORECAST CONFIDENCE HAS INCREASED REGARDING PRECIP POTENTIAL FOR SOUTHEAST ARIZONA. A SLIGHT CHANCE OF SHOWERS/TSTMS EXISTS THIS MORNING...THEN ISOLATED TO SCATTERED SHOWERS/TSTMS WILL OCCUR MAINLY FROM THE TUCSON METRO AREA EAST AND SOUTH THIS AFTERNOON AND EVENING. GIVEN THE DRY NEAR- SURFACE ENVIRONMENT...THE MAIN IMPACT ASSOCIATED WITH THE STRONGER THUNDERSTORMS WILL BE THE POTENTIAL FOR STRONG GUSTY WINDS. FOR THIS FORECAST PACKAGE...HAVE MAINTAINED PATCHY BLOWING DUST LATE THIS AFTERNOON/EARLY EVENING GENERALLY WEST-TO-NORTHWEST OF TUCSON. A SLIGHT CHANCE OF SHOWERS/TSTMS CONTINUES LATE TONIGHT ESPECIALLY EAST AND SOUTH OF TUCSON. MOISTURE IS EXPECTED TO INCREASE ACROSS THE AREA SUN AS THE UPPER LOW REMAINS QUASI-STATIONARY WNW OF THE BAJA CALIFORNIA SPUR. MEANWHILE...THE AFOREMENTIONED DISTURBANCE WELL SOUTHWEST OF THE SRN TIP OF BAJA CALIFORNIA EARLY THIS MORNING IS PROGGED TO MOVE NWD AND BE CENTERED OVER CENTRAL BAJA CALIFORNIA SUN EVENING. THE 19/00Z NAM/GFS/ECMWF ACTUALLY SUGGEST THAT THE COVERAGE OF SHOWERS/TSTMS SUN MAY BE FAIRLY LIMITED...WITH THE BEST PRECIP CHANCES TO OCCUR WEST-TO-SOUTH OF TUCSON. FOR THIS FORECAST ISSUANCE...HAVE MAINTAINED A CHANCE OF SHOWERS/TSTMS ACROSS MUCH OF THE AREA SUN AFTERNOON/EVENING. A SLIGHT CHANCE OF SHOWERS/TSTMS CONTINUES LATE SUN NIGHT. MON-TUE... THE DISTURBANCE THAT IS PROGGED TO BE OVER CENTRAL BAJA CALIFORNIA SUN EVENING IS SUBSEQUENTLY PROGGED TO ADVANCE NWD INTO SRN ARIZONA MON AS THE WEAK UPPER LOW REMAINS QUASI-STATIONARY NEAR 28N/124W. THE DISTURBANCE SHOULD BE NORTH OF THE AREA BY MON NIGHT...BUT AMPLE MOISTURE WILL REMAIN ACROSS SE ARIZONA MON NIGHT-TUE AHEAD OF THE FILLING UPPER LOW NEAR THE SRN CALIFORNIA/NRN BAJA CALIFORNIA COASTS. HAVE NOTED THAT THE ECMWF WAS THE FURTHEST WEST OF THE DETERMINISTIC SOLUTIONS WITH HIGHER QPF/S...AND FAVORED SOUTHWEST/SOUTH CENTRAL ARIZONA WITH THE HEAVIER RAINFALL AMOUNTS. MEANWHILE...THE GFS/NAM WERE SOMEWHAT FURTHER EAST WITH THE HIGHER QPF/S...AND GENERALLY FAVORED THE TOHONO O'ODHAM NATION...SE PINAL COUNTY AND ERN PIMA COUNTY INCLUDING TUCSON WITH THE HEAVIER RAINFALL AMOUNTS. BASED ON THESE 19/00Z NWP SOLUTIONS AND PER COORD WITH NEIGHBORING WFO/S...POPS WERE GENERALLY INCREASED ABOUT 5-20 PERCENT AREA-WIDE MON-TUE. HAVE TRIED TO EMPHASIZE THE BEST CHANCE OF RAINFALL TO OCCUR MAINLY FROM TUCSON WWD INTO THE WESTERN DESERTS MON-TUE. ALTHOUGH THE PROSPECT FOR AT LEAST LOCALLY HEAVY RAINFALL EXISTS AND APPEARS INCREASINGLY LIKELY...STILL TOO EARLY FOR THE ISSUANCE OF A FLOOD WATCH OR A FLASH FLOOD WATCH. A CHANCE OF SHOWERS AND A SLIGHT CHANCE OF TSTMS CONTINUES TUE NIGHT. WED... INCREASINGLY WLY FLOW ALOFT WILL SHUNT DEEPER MOISTURE EWD INTO THE SRN ROCKIES. HOWEVER...MOISTURE SHOULD REMAIN SUFFICIENT TO JUSTIFY A CHANCE OF SHOWERS/TSTMS ACROSS THE HIGHER TERRAIN EAST OF TUCSON... AND A SLIGHT CHANCE OF SHOWERS/TSTMS FURTHER WWD INTO WRN PIMA COUNTY. THUR-FRI... PERHAPS A FEW SHOWERS/TSTMS MAY YET OCCUR THUR MAINLY NEAR THE NEW MEXICO BORDER. OTHERWISE...DRY CONDITIONS WILL PREVAIL DURING THE LATTER PART OF THE UPCOMING WEEK. HIGH TEMPS TODAY WILL BE QUITE SIMILAR TO TEMPS ACHIEVED FRI...THEN A COOLING TREND WILL OCCUR SUN-TUE. HIGH TEMPS MON-TUE ARE FORECAST TO AVERAGE ABOUT 4-7 DEGS F BELOW NORMAL. A WARMING TREND IS ON TAP WED-FRI...WITH HIGH TEMPS PERHAPS A FEW DEGS ABOVE NORMAL BY FRI. && .AVIATION...VALID THRU 20/18Z. EXPECT ISOLATED TO SCATTERED -TSRA/-SHRA MAINLY FROM KTUS VICINITY EAST AND SOUTH TO THE NEW MEXICO/INTERNATIONAL BORDERS INTO SUNDAY MORNING. THE BULK OF THESE SHOWERS AND THUNDERSTORMS ARE FORECAST TO PREVAIL THIS AFTERNOON AND EVENING. MVFR CONDITIONS AND WIND GUSTS OF 35-45 KTS WILL OCCUR WITH THE STRONGER THUNDERSTORMS. OTHERWISE... CLOUD DECKS WILL GENERALLY BE ABOVE 10K FT AGL AND SURFACE WIND WILL MAINLY BE LESS THAN 10 KTS THROUGH THE PERIOD. AVIATION DISCUSSION NOT UPDATED FOR TAF AMENDMENTS. && .FIRE WEATHER...RAIN CHANCES WILL INCREASE INTO EARLY NEXT WEEK WITH WIDESPREAD SHOWERS AND EMBEDDED THUNDERSTORMS LIKELY BY MONDAY AND CONTINUING INTO TUESDAY. A DRYING TREND WILL THEN BEGIN WEDNESDAY FOLLOWED BY DRY CONDITIONS RETURNING DURING THE LATTER PART OF THE UPCOMING WEEK. OUTSIDE OF THUNDERSTORM OUTFLOWS...GENERALLY LIGHT TERRAIN DRIVEN WINDS WILL PREVAIL DURING THE NEXT SEVERAL DAYS. && .TWC WATCHES/WARNINGS/ADVISORIES...NONE. && VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON
The Tucson radar (KEMX), 58 km away, was scanning. The volume nearest the first event began at 20:01 UTC.
1 flash flood. Local standard time, as filed.
A woman in her vehicle was swept into flash flood waters when attempting to cross a wash on High Knoll Rd east of Sierra Vista. Rescuers found the car had been swept downstream, but were unable to locate the driver.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Arizona in 2015Every state in 2015This day in weather historyWarnings in Arizona, September 2015
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: 602346.