High pressure was located near the western Texas panhandle with weak easterly steering flow and a lifted index of -6 on the morning KTWC upper air sounding. A few thunderstorms moving west off the White Mountains encountered some weak low-level vorticity which developed a brief landspout tornado in Graham County.
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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 TWC wrote it up.
High pressure was located near the western Texas panhandle with weak easterly steering flow and a lifted index of -6 on the morning KTWC upper air sounding. A few thunderstorms moving west off the White Mountains encountered some weak low-level vorticity which developed a brief landspout tornado in Graham County.
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 Jul 31, 2:25 PM MST, 2 hours 5 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TUCSON AZ 225 PM MST FRI JUL 31 2015 .SYNOPSIS...A MORE ACTIVE THUNDERSTORM DAY ACROSS SOUTHEAST ARIZONA TODAY. ALTHOUGH SOME DRIER AIR WILL MOVE ACROSS THE AREA THIS WEEKEND INTO NEXT WEEK...THERE WILL BE ENOUGH MOISTURE AROUND FOR A CHANCE OF SHOWERS AND THUNDERSTORMS...MAINLY ALONG THE INTERNATIONAL BORDER AS WELL AS THE MOUNTAIN TOPS. && .DISCUSSION...WATER VAPOR IMAGERY AND 31/12Z UPPER-AIR PLOTS SHOW THE CENTER OF HIGH PRESSURE IN THE GENERAL VICINITY OF THE TEXAS PANHANDLE...WITH A PACIFIC LOW PRESSURE SYSTEM WELL OFF THE SOUTHERN CALIFORNIA AND NORTHERN BAJA COASTS. WHAT A DIFFERENCE 12 HOURS CAN MAKE. YESTERDAYS 31/00Z KTWC SOUNDING REVEALED A PW OF 1.10 INCHES AND THE 31/12Z KTWC SOUNDING CAME IN WITH A PW OF 1.68 INCHES. THIS MORNINGS SOUNDING PARAMETERS SHOWED A MU CAPE OF AROUND 2200 J/KG AND A LIFTED INDEX OF MINUS 6. THE MOST RECENT RADAR MOSAIC SHOWS SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS CONTINUING TO PROGRESS WESTWARD WEST OF AJO AND ORGAN PIPE. ELSEWHERE ACROSS SOUTHEAST ARIZONA...ISOLATED TO SCATTERED THUNDERSTORMS HAVE BEEN DEVELOPING DURING THE PAST HOUR OR TWO... WITH CELLS EXTENDING FROM EAST OF ELOY TO PICTURE ROCKS AND TOWARD ARIVACA. WEAK SHOWERS HAVE ALSO DEVELOPED OVER PARTS OF THE TUCSON METRO AS WELL. ADDITIONAL CELLS ARE OCCURRING OVER THE HIGHER TERRAIN OF GRAHAM...GREENLEE AND SANTA CRUZ COUNTIES...WITH ACTIVITY MOVING WEST OR WEST NORTHWEST AT 5 TO 10 MPH. U OF A 12Z WRF/NAM & GFS...AS WELL AS HRRR ALL SUGGEST THAT STORMS WILL CONTINUE TO BLOSSOM OVER CENTRAL AND WESTERN PORTIONS OF THE FORECAST AREA THIS AFTERNOON AND PUSH TO THE WEST OR WEST NORTHWEST EARLY THIS EVENING. ACTIVITY NOT AS WIDESPREAD BETWEEN TUCSON AND THE NEW MEXICO BORDER...WITH THE EXCEPTION OF THE MOUNTAIN TOPS. KEPT A MENTION OF BLOWING DUST OVER PARTS OF PIMA AND PINAL COUNTIES LATE THIS AFTERNOON AND EARLY THIS EVENING AS STORMS EXPECTED TO FIRE OFF AND MOVE IN THAT GENERAL DIRECTION. THIS ALSO MESHES WELL WITH THE FORECAST FROM THE PHOENIX OFFICE. MODELS INDICATE THAT A WEAK DISTURBANCE COMING UP FROM THE SOUTH WILL MOVE ACROSS SOUTH CENTRAL ARIZONA THIS EVENING AND THEN OVER SOUTHWEST ARIZONA EARLY SATURDAY AND WESTERN ARIZONA MIDDAY SATURDAY. AS THIS OCCURS...THIS SYSTEM WILL HELP TO ENHANCE ACTIVITY THIS AFTERNOON AND EVENING...BUT BY SATURDAY WE SHOULD SEE LESS THUNDERSTORM ACTIVITY AS THIS SYSTEM WILL BE OVER SRN NEVADA LATE IN THE AFTERNOON AND MOISTURE IS EXPECTED TO DECREASE A BIT LATE IN THE AFTERNOON OR INTO THE EVENING. BY SUNDAY AND CONTINUING THROUGH AROUND WEDNESDAY THE HIGH IS EXPECTED TO RECONSOLIDATE IN A WEST TO EAST ORIENTATION ACROSS NORTHERN MEXICO AND THEN MOVE NORTH OVER THE DESERT SOUTHWEST BY TUESDAY. AS A RESULT...DRIER SOUTHWEST TO WEST FLOW WILL REDUCE RAIN CHANCES A BIT AND KEEP THE BEST THREAT FOR SHOWERS AND THUNDERSTORMS...MAINLY BETWEEN NOGALES AND DOUGLAS AS WELL AS THE WHITE MOUNTAINS. THIS WILL ALSO RESULT IN WARMER DAYTIME TEMPS MONDAY THROUGH WEDNESDAY. FOR LATE WEEK THE HIGH WILL SHIFT TOWARD THE EAST AND RESULT IN A RETURN FLOW FROM THE SOUTH TO SOUTHEAST AND PULL IN MORE MOISTURE AND INCREASING THUNDERSTORM CHANCES...BUT STILL JUST ISOLATED TO SCATTERED IN NATURE. FOR TUCSON...HIGHS WILL BE NEAR NORMAL SATURDAY...THEN 4 TO 7 DEGS ABOVE NORMAL EACH DAY THROUGH FRIDAY. HOWEVER...THE WARMEST DAY WILL LIKELY OCCUR TUESDAY. LOWS WILL RANGE FROM 2 TO 4 DEGS ABOVE NORMAL EACH MORNING. HOWEVER...THE COOLEST MORNINGS WILL LIKELY OCCUR MONDAY AND TUESDAY. && .AVIATION...VALID THRU 02/00Z. SCT TO BKN CLOUDS 7-10K FT AGL WITH SCT-NMRS SHRA/TSRA GENERALLY BEFORE 01/04Z...AND MAINLY WEST OF A LINE FROM KOLS TO KSAD AND IN THE WHITE MOUNTAINS. BRIEF MVFR CONDITIONS WITH ERRATIC WIND GUSTS TO 45 KTS POSSIBLE IN AND AROUND THE STRONGER TSRA. AREAS OF BLDU PSBL W AND NW OF KTUS AFT 31/22Z. OUTSIDE OF STORM INFLUENCES SFC WINDS WILL GENERALLY BE LESS THAN 12 KTS WITH A FEW HIGHER GUSTS IN THE AFTERNOON/EARLY EVENING HOURS. SHRA/TSRA WILL OCCUR AGAIN SATURDAY AFTERNOON...ALTHOUGH WITH LESS COVERAGE THAN TODAY. AVIATION DISCUSSION NOT UPDATED FOR TAF AMENDMENTS. && .FIRE WEATHER...SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS TODAY WITH STRONG OUTFLOW WINDS LIKELY...ESPECIALLY FROM TUCSON WEST. SATURDAY WILL SEE SLIGHTLY LESS CONVECTION. INCREASING SW WINDS ALOFT ON SUNDAY WILL BRING DRIER AIR INTO THE REGION FOR ISOLATED TO SCATTERED THUNDERSTORM COVERAGE TO BEGIN NEXT WEEK...WITH A FOCUS MAINLY SOUTH AND EAST OF TUCSON. OUTSIDE OF THUNDERSTORM WIND GUSTS...20-FT WINDS WILL GENERALLY BE TERRAIN DRIVEN AND LESS THAN 15 MPH. HOWEVER SOME AFTERNOON AND EARLY EVENING BREEZINESS IS LIKELY DUE TO DAYTIME HEATING...ESPECIALLY THROUGH THE GILA VALLEY NEAR SAFFORD. && .TWC WATCHES/WARNINGS/ADVISORIES...NONE. && PUBLIC...MOLLERE AVIATION/FIRE WEATHER...FRENCH VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON
SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE TUCSON AZ 1158 AM MST FRI JUL 31 2015 AZZ501-502-311930- WESTERN PIMA COUNTY INCLUDING AJO/ORGAN PIPE CACTUS NATIONAL MONUMENT AZ-TOHONO O'ODHAM NATION INCLUDING SELLS AZ- 1158 AM MST FRI JUL 31 2015 ...SIGNIFICANT WEATHER ADVISORY FOR NORTHWESTERN PIMA COUNTY UNTIL 1230 PM MST... AT 1156 AM MST...NATIONAL WEATHER SERVICE METEOROLOGISTS WERE TRACKING A LINE OF STRONG THUNDERSTORMS EXTENDING FROM 6 MILES NORTH OF WHY TO 7 MILES EAST OF ORGAN PIPE NATIONAL MONUMENT...AND MOVING NORTHWEST AT 15 MPH. HALF INCH HAIL...TORRENTIAL RAIN AND WINDS IN EXCESS OF 40 MPH WILL BE POSSIBLE WITH THESE STORMS. LOCATIONS IMPACTED INCLUDE... ORGAN PIPE NATIONAL MONUMENT...AJO...WHY...GUNSIGHT AND KUAKATCH. LAT...LON 3250 11292 3195 11292 3191 11262 3240 11264 TIME...MOT...LOC 1856Z 122DEG 11KT 3236 11271 3194 11268 FRENCH
SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE TUCSON AZ 401 PM MST FRI JUL 31 2015 AZZ504>506-312345- SOUTH CENTRAL PINAL COUNTY INCLUDING ELOY/PICACHO PEAK STATE PARK AZ- TUCSON METRO AREA INCLUDING TUCSON/GREEN VALLEY/MARANA/VAIL AZ- SOUTHEAST PINAL COUNTY INCLUDING KEARNY/MAMMOTH/ORACLE AZ- 401 PM MST FRI JUL 31 2015 ...SIGNIFICANT WEATHER ADVISORY FOR SOUTH CENTRAL PINAL AND NORTHERN PIMA COUNTIES UNTIL 445 PM MST... AT 358 PM MST...DOPPLER RADAR WAS TRACKING A STRONG THUNDERSTORM CENTERED NORTH OF DOVE MOUNTAIN...MOVING WEST AT 15 MPH. VERY HEAVY RAINFALL...STRONG WINDS...AND AREAS OF LOCALIZED BLOWING DUST WILL BE POSSIBLE WITH THIS STORM. REDUCED VISIBILITIES DUE TO BLOWING DUST AND WINDS IN EXCESS OF 40 MPH WILL BE POSSIBLE WITH THIS STORM. NOT TO MENTION...HEAVY DOWNPOURS WITH MINOR STREET OR ROAD FLOODING. LOCATIONS IMPACTED INCLUDE...NORTHWEST PORTIONS OF ORO VALLEY... NORTHERN MARANA...TORTOLITA...RED ROCK...AND DOVE MOUNTAIN. PRECAUTIONARY/PREPAREDNESS ACTIONS... TORRENTIAL RAINFALL IS ALSO OCCURRING WITH THIS STORM...AND MAY LEAD TO FLASH FLOODING. DO NOT DRIVE YOUR VEHICLE THROUGH FLOODED ROADWAYS. && LAT...LON 3261 11089 3238 11101 3251 11138 3280 11115 TIME...MOT...LOC 2258Z 108DEG 21KT 3256 11107
The Tucson radar (KEMX), 138 km away, was scanning. The volume nearest the first event began at 23:29 UTC.
1 tornado. Local standard time, as filed.
A dust devil was stretched into a small landspout tornado by a passing thunderstorm near Safford. No damage was reported.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Arizona in 2015Every state in 2015This day in weather historyThe tornado archive for Arizona, 2015Warnings in Arizona, July 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: 593852.