A moist air mass combined with surface heating to induce thunderstorms on this day. Some of the thunderstorms contained strong winds and large hail.
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 MFR wrote it up.
A moist air mass combined with surface heating to induce thunderstorms on this day. Some of the thunderstorms contained strong winds and large hail.
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 Medford, OR wrote its last area forecast discussion before the first event at Apr 23, 1:30 PM PST, 1 hour 42 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MEDFORD OR 230 PM PDT MON APR 23 2012 .SHORT TERM...CONVECTION IS WELL UNDERWAY THIS AFTERNOON AS HEATING CONTINUES TO DESTABILIZE THE ATMOSPHERE AND AN UPPER SHORT WAVE APPROACHES. THUNDERSTORMS HAVE ERUPTED IN THE SIERRA WHICH ARE NOW MOVING INTO MODOC COUNTY. ADDITIONAL TOWERS HAVE FORMED OVER THE MOUNTAINS FURTHER WEST BUT ARE STILL WORKING AGAINST A BIT OF A CAP. THIS CAP WILL ERODE OVER THE NEXT COUPLE OF HOURS ALLOWING CONVECTION TO INCREASE IN COVERAGE. STORMS SHOULD BE MOST PROMINENT OVER THE MOUNTAINS AND EAST OF AN AXIS OF MIXED LAYER CAPE OF AROUND 1000 J/KG WHICH LIES FROM WESTERN SISKIYOU COUNTY THROUGH JACKSON AND INTO EASTERN DOUGLAS COUNTY. GIVEN STRONG INSTABILITY, INCREASING MOISTURE AND MODERATE SHEAR, ANY OF THE STORMS WILL BE CAPABLE OF SMALL HAIL AND GUSTY WINDS. HOWEVER, SOME STORMS COULD BE SEVERE WITH LARGE HAIL AND DAMAGING WINDS, BUT THAT WILL BE THE EXCEPTION. CONVECTION WILL RAPIDLY DIE OFF THIS EVENING AS THINGS STABILIZE AND THE SHORT WAVE MOVES NORTH. COULD STILL SEE A FEW SHOWERS OVERNIGHT, BUT POPS ARE MUCH LOWER. MODELS STILL SHOW A GOOD PUSH OF STRATUS INTO THE UMPQUA (IT NEVER REALLY LEAVES AT MOST OF THE COAST) AND THAT WILL COOL THINGS DOWN FOR TOMORROW. STRATUS MAY SPILL OVER THE UMPQUA DIVIDE INTO THE REST OF THE WEST SIDE AS WELL. THIS WILL LEAD TO A COOL DOWN FOR THE REST OF THE WEST SIDE, BUT NOT AS DRAMATIC. WE WILL HAVE ENOUGH INSTABILITY AROUND TOMORROW FOR FEW MORE SHOWERS AND STORMS, MAINLY OVER THE MOUNTAINS, BUT COVERAGE SHOULD NOT BE MUCH. A COLD FRONT WILL APPROACH THE COAST ON WEDNESDAY AND WILL MAKE FOR A WET DAY ON THE WEST SIDE. THIS COMES IN TWO BATCHES, THE FIRST BEING PRE-FRONTAL SHOWERS (OF WHICH THE MODELS SHOW A CONSIDERABLE AMOUNT) AND THEN FRONTAL BAND RAIN IN THE LATE AFTERNOON AND THROUGH THE NIGHT. TEMPERATURES WILL NECESSARILY COOLER ON WEDNESDAY. LOOKS LIKE A WET NIGHT FOR MOST OF THE FORECAST AREA WEDNESDAY NIGHT AS THE FRONT MOVES THROUGH. POST FRONTAL SHOWERS WILL KEEP THURSDAY COOL AND WET. -WRIGHT .LONG TERM...FRIDAY THROUGH MONDAY...THE MEAN UPPER LEVEL TROUGH WILL SLOWLY EXIT OUR AREA DURING THE DAY ON FRIDAY. THIS WILL ALLOW THE PACIFIC RIDGE TO START TO NOSE BACK NORTHWARD ON SATURDAY. MOST OF THE AREA WILL REMAIN CAUGHT BETWEEN THE TWO FEATURES AND UNDER PREDOMINANTLY NORTHWEST FLOW. THIS WILL KEEP OUR TEMPERATURES JUST SLIGHTLY BELOW NORMAL. SHOWERS WILL SLOWLY TAPER OFF ON FRIDAY AND WILL BE CONFINED PRIMARILY TO THE NW SLOPES OF THE WEST SIDE AREAS ON SATURDAY. THE GFS WANTS TO PAINT A BIT MORE RAINFALL THAN THE 12Z/EC ON SATURDAY. AT THIS TIME, WITH THE RIDGE BUILDING OFFSHORE, HAVE LEANED TOWARDS THE DRIER EC SOLUTION. ON SUNDAY THE PACIFIC RIDGE BUILDS IN EARNEST AND DRIFTS JUST ENOUGH EASTWARD TO EXERT A STRONGER WARMING AND DRYING TREND THROUGH OUR AREA. WE HAVE BUMPED AFTERNOON HIGHS UP A COUPLE OF DEGREES FRIDAY THROUGH SUNDAY. TEMPERATURES SHOULD BE NEAR NORMALS ON SATURDAY BEFORE GETTING BACK TO ABOUT 5 DEGREES ABOVE NORMAL ON SUNDAY. NO MAJOR CHANGES IN THE FORECAST TO START NEXT WEEK. THE RIDGE REMAINS IN PLACE AND WEAK IMPULSES CONTINUE TO RIDE OVER ITS PERIPHERY FROM THE NW. THE EXACT STRENGTH AND TIMING OF THESE IMPULSES COULD TRIGGER ISOLATED SHOWERS AND THUNDERSTORMS ...ESPECIALLY FOR NW FACING SLOPES. && .AVIATION...ONSHORE FLOW WILL KEEP IFR CIGS AT THE COAST THIS AFTERNOON THROUGH TONIGHT. CIGS COULD WORSEN TO LIFR AFTER SUNSET. VIS WILL REMAIN IN THE MVFR RANGE THIS AFTERNOON THROUGH EARLY EVENING BUT THAT COULD COME DOWN TO IFR LATE TONIGHT. FURTHER INLAND THE AIR MASS IS UNSTABLE AND CUMULONIMBUS CLOUDS HAVE ALREADY DEVELOPED THIS AFTERNOON. THIS WILL LEAD TO GUSTY AND ERRATIC WINDS NEAR THE STORMS. CIGS MAY ALSO LOWER TO MVFR NEAR THE STORMS. THIS EVENING A COLD FRONT IS EXPECTED TO MOVE INLAND AND EXPECT WIND SHIFT TOWARD THIS EVENING. THE WINDSHIFT WILL ALSO BRING ONSHORE FLOW INTO THE UMPQUA BASIN...LEADING TO MVFR CIGS AT KRBG. TOWARD TUESDAY MORNING ONSHORE FLOW COULD SPILL OVER THE UMPQUA DIVIDE WITH LCL MVFR CIGS DOWN INTO JOSEPHINE AND JACKSON COUNTIES. IT DOES NOT APPEAR THAT LOW CLOUDS WILL CROSS THE SISKIYOUS INTO NORTHERN CALIFORNIA. && .MFR WATCHES/WARNINGS/ADVISORIES... OR...NONE. CA...NONE. PZ...NONE.
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE MEDFORD OR 408 AM PDT MON APR 23 2012 CAZ080>085-ORZ023>031-240800- WESTERN SISKIYOU COUNTY-CENTRAL SISKIYOU COUNTY- SOUTH CENTRAL SISKIYOU COUNTY- NORTH CENTRAL AND SOUTHEAST SISKIYOU COUNTY- NORTHEAST SISKIYOU AND NORTHWEST MODOC COUNTIES-MODOC COUNTY- CENTRAL DOUGLAS COUNTY-EASTERN CURRY COUNTY AND JOSEPHINE COUNTY- EASTERN DOUGLAS COUNTY FOOTHILLS-JACKSON COUNTY- SOUTH CENTRAL OREGON CASCADES- SISKIYOU MOUNTAINS AND SOUTHERN OREGON CASCADES-KLAMATH BASIN- NORTHERN AND EASTERN KLAMATH COUNTY AND WESTERN LAKE COUNTY- CENTRAL AND EASTERN LAKE COUNTY- 408 AM PDT MON APR 23 2012 THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF NORTHERN CALIFORNIA...SOUTH CENTRAL OREGON AND SOUTHWEST OREGON. .DAY ONE...TODAY AND TONIGHT THUNDERSTORMS WILL DEVELOP THIS AFTERNOON AND EVENING ACROSS PORTIONS OF THE AREA. THE MAIN THREAT FROM THE STORMS WILL BE CLOUD TO GROUND LIGHTNING AND HEAVY RAINFALL. BUT THERE IS ALSO THE POTENTIAL FOR SOME OF THE STRONGEST STORMS TO PRODUCE GUSTY OUTFLOW WINDS AND HAIL. THUNDERSTORMS WILL DIMINISH TO SHOWERS LATER TONIGHT AS THE ATMOSPHERE STABILIZES. .DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME. .SPOTTER INFORMATION STATEMENT... SPOTTER REPORTS OF LIGHTNING...STRONG WIND GUSTS AND HAIL ARE ENCOURAGED THIS AFTERNOON AND EVENING. SPILDE
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE MEDFORD OR
314 PM PDT MON APR 23 2012
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0312 PM HAIL 3 SSW APPLEGATE 42.22N 123.19W
04/23/2012 E0.25 INCH JACKSON OR TRAINED SPOTTER
ESTIMATED TO BE PEA SIZED OR SLIGHTLY LARGER. STORM
PRODUCED AROUND 0.10 INCH OF RAIN.
&&
WOODHEADThe Medford radar (KMAX), 130 km away, was scanning. The volume nearest the first event began at 23:13 UTC.
2 thunderstorm wind, 1 hail. Local standard time, as filed.
NWS Doppler radar picked up a 3-body scatter spike and a mesocyclone in this thunderstorm at 23/1538 PST. The spike was behind a 65-70 dbz core in a severe thunderstorm. No reports were received, so it is assumed that severe hail fell from this storm.
The ASOS at Sexton Summit recorded a wind gust to 67 mph as this thunderstorm moved by. The gust was recorded on the 23/1547 PST observation.
A member of the public said that an oak tree was blown down by strong thunderstorm winds onto a car at 1630 PST. This occurred near Milo Oregon.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Oregon in 2012Every state in 2012This day in weather historyWarnings in Oregon, April 2012
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: 369237, 369238, 369242.