Clear skies and long nights allowed freezing temperature to develop in some parts of south central Oregon.
Every event with a place to put it; 2 filed by county or forecast zone are drawn at its center, in a lighter ring. 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.
Clear skies and long nights allowed freezing temperature to develop in some parts of south central Oregon.
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 Aug 24, 12:00 AM PST, 2 hours earlier.
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MEDFORD OR
100 AM PDT FRI AUG 24 2012
.DISCUSSION...24/00Z NAM/GFS IN.
MOSTLY CLEAR SKIES PREVAIL THIS MORNING OVER THE MEDFORD CWA WITH
DRY OFFSHORE LOW LEVEL FLOW IN PLACE.
WEAK TROUGHING ALOFT WILL GIVE WAY TO WEAK RIDGING FRIDAY. IT
WILL REMAIN MOSTLY CLEAR WITH NEAR SEASONABLE TEMPERATURES...ALTHOUGH
IT WILL BE COLD THIS MORNING EAST OF THE CASCADES WITH SOME AREAS
OF FROST AND FREEZING TEMPERATURES. THE LOW LEVEL OFFSHORE FLOW
WILL WEAKEN TODAY...AND THERE WILL BE SOME ONSHORE WINDS NEAR THE
COAST THIS AFTERNOON AND EVENING.
THE RIDGE WILL MOVE ON TO THE EAST FRIDAY NIGHT...THEN A STRONG
UPPER LEVEL LOW WILL DROP SOUTH FROM THE GULF OF ALASKA. FLOW
ALOFT OVER THE PACIFIC NORTHWEST WILL BECOME SOUTHWESTERLY LATE
FRIDAY NIGHT THEN GRADUALLY STRENGTHEN THROUGH SUNDAY.
EXPECT DRY WEATHER TO CONTINUE WITH INLAND TEMPERATURES WARMING
TO ABOVE NORMAL VALUES SATURDAY...WHICH WILL BE THE HOTTEST DAY
FROM NOW THROUGH NEXT FRIDAY. MARINE STRATUS WILL RETURN TO THE
COAST AT SOME POINT THIS WEEKEND AND TEMPERATURES THERE WILL BE
NEAR NORMAL SATURDAY.
THE MODELS ARE IN VERY GOOD AGREEMENT ON THE STRENGTH AND POSITION
OF THE LOW THROUGH SATURDAY NIGHT...THEN THEY START TO DIVERGE ON
POSITION. THE EC FORECAST IS THE MOST PROGRESSIVE AND THE
CONSENSUS FROM THE MEDIUM-RANGE FOLKS IS THAT IT IS TOO PROGRESSIVE.
THE NAM/GFS REMAIN IN AGREEMENT THROUGH THE END OF THE NAM
FORECAST. SUNDAY WILL BE A COOLER DAY INLAND WITH STRONGER
ONSHORE FLOW AND A MARINE PUSH OVER AT LEAST PART OF...IF NOT ALL
OF THE WEST SIDE. THE UPPER LOW MAY BE CLOSE ENOUGH BY THAT TIME
TO PUSH A WEAK FRONT ONSHORE WITH SOME SHOWERS ALONG THE COAST
NORTH OF CAPE BLANCO. THE FRONT WILL STALL THERE...SO THE SHOWERS
MAY BE AROUND THROUGH MONDAY.
EXTENDED DISCUSSION FROM THE THURSDAY AFTERNOON AFD...SUNDAY
THROUGH TUESDAY THERE REMAINS SOME UNCERTAINTIES IN THE FORECAST.
AN UPPER LEVEL TROUGH NOW CROSSING THE ALEUTIAN ISLANDS AND MOVING
INTO THE GULF OF ALASKA WILL MOVE SOUTHEASTWARD TO NEAR THE
PACIFIC NORTHWEST COAST. IT WILL THEN PUSH ONSHORE, BUT HOW STRONG
IT WILL BE, HOW FAR SOUTH IT WILL BE, AND HOW FAST IT WILL MOVE IN
ARE UNCERTAIN. HAVE STUCK WITH A FORECAST MODEL BLEND PREFERRED BY
THE HYDROMETEOROLOGICAL PREDICTION CENTER, WHICH IS TO BLEND
AVAILABLE MODELS WITH THE IDEA THAT THE ECMWF IS LIKELY TOO FAST
AND TOO STRONG, AND THAT THE GFS IS TOO SLOW. THIS HAS RESULTED IN
THE IDEA THAT THE MARINE LAYER WILL IMPINGE ON THE COAST ON
SUNDAY, AND THEN THE UPPER TROUGH MAY THEN PUSH SOME CHANCES FOR
SHOWERS ONTO THE COAST, COASTAL MOUNTAINS, AND POSSIBLY THE UMPQUA
BASIN LATER SUNDAY THROUGH TUESDAY. KEPT PRECIP CHANCES MOSTLY IN
THE SLIGHT CHANCE RANGE AND IN CLIMATOLOGICALLY FAVORED AREAS DUE
TO IT STILL BEING AUGUST. EXPECT WE WILL HAVE MORE CONFIDENCE IN
THE FORECAST FOR THIS PERIOD IN THE NEXT 24 HOURS.
TROUGHING THEN LOOKS TO LINGER INTO LATE NEXT WEEK. THEREAFTER,
RIPPLES IN THE JET STREAM ASSOCIATED WITH THE REMNANTS OF TYPHOON
BOLAVEN IN THE WESTERN PACIFIC MAY LEAD TO INCREASED RIDGING IN
THE AREA. HOWEVER, CONFIDENCE IN THIS IS LOW AT THIS TIME. BTL
&&
.AVIATION...VFR CONDITIONS ARE AT THE COAST THIS EVENING AND WITH
OFFSHORE FLOW DEVELOPING AND A THERMAL TROUGH BUILDING NORTH
SHOULD KEEP THE MARINE STRATUS FROM DEVELOPING. CURRENT GUIDANCE
SUGGEST CLEAR SKIES CONTINUE THROUGH FRIDAY MORNING. THE MODEL
SOUNDING ALSO SUPPORTS THE IDEA OF NO MARINE STRATUS. HOWEVER
THERE IS A CHANCE FOR TEMPORARY STRATUS TO DEVELOP AT KOTH BETWEEN
13-15Z. FOR NOW WE'LL KEEP THE TAF VFR...BUT LATER SHIFTS MAY HAVE
TO RE EVALUATE. ELSEWHERE VFR CONDITIONS CONTINUE.
&&
.MFR WATCHES/WARNINGS/ADVISORIES...
OR...FROST ADVISORY FROM 2 AM TO 8 AM PDT FRIDAY FOR ORZ029>031.
FREEZE WARNING FROM 2 AM TO 8 AM PDT FRIDAY FOR ORZ029>031.
CA...NONE.
PZ...SMALL CRAFT ADVISORY FOR WINDS UNTIL 5 AM PDT SATURDAY FOR
PZZ350-356-370.
SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 5 AM PDT SATURDAY
FOR PZZ350-356-370.
GALE WARNING UNTIL 11 PM PDT FRIDAY FOR PZZ376.
HAZARDOUS SEAS WARNING UNTIL 2 AM PDT SATURDAY FOR PZZ376.
15/15/16The national radar mosaic for the moment the first event began.
2 frost/freeze. Local standard time, as filed.
The only reported low temperature in the zone was 26 degrees in Chemult.
Reported low temperatures in the zone ranged from 30 to 42 degrees.
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, August 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: 400992, 400993.