Clearing skies and a cold air mass allowed temperatures to drop below freezing at a number of locations in southwest Oregon on this morning.
Every event with a place to put it; 3 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.
Clearing skies and a cold air mass allowed temperatures to drop below freezing at a number of locations in southwest Oregon on this morning.
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 Mar 29, 7:08 PM PST, 4 hours 52 minutes earlier.
Area Forecast Discussion
National Weather Service Medford OR
808 PM PDT Mon Mar 29 2021
.DISCUSSION...30/00Z NAM in.
Mostly clear skies prevail across the Medford CWA this evening,
except for dissipating stratocumulus over Coos and Douglas
counties, as well as the coastal waters. A long wave ridge remains
offshore, and dry northwest flow aloft is in place over the
Pacific Northwest.
The near term weather will be, aside from the cold morning
temperatures, pretty non-eventful. Clear skies and a cold, dry
air mass will allow temperatures to drop quite low tonight into
Tuesday morning, with frost and freeze conditions expected all
the way to the coast. It is very early in the growing season, but
coastal agriculture, as well as the early blooms of local inland
fruit orchards, could be at risk from the cold temperatures
expected tonight into tomorrow morning.
A warming trend will commence Tuesday as the offshore upper ridge
edges toward the west coast. Wednesday highs will approach 80
degrees over the warmest west side valleys Wednesday. If this
occurs in Medford, it would be the first day when the temperature
reached that value since October 20th, 2020. Meanwhile, a Chetco
Effect will keep temperatures along the south coast near Brookings
much higher than normal Tuesday into Wednesday.
The ridge will move onshore Wednesday, and flow aloft will become
southwesterly. This will open up the storm door, but weak short
waves embedded in the flow will not be strong enough to bring any
precipitation that will reach the surface in such a warm and dry
air mass. Cloud cover will increase, however, and Thursday will
be cooler than Wednesday over the west side.
Long term discussion from the Monday afternoon AFD...Fri 02 Apr
through Mon 05 Apr 2021. The extended forecast begins with the
upper ridge that brings unseasonably warm high temperatures. This
pattern finally shifts Friday night when the ridge shifts east and
an upper trough brings the first weak front into the region
Saturday morning. Models then begin to diverge greatly, with
spaghetti plots looking like, well spaghetti. With this in mind
from Saturday onward have kept a chance of precipitation through
to the end of the extended forecast. -Sven
&&
.AVIATION...For the 30/00Z TAF Cycle...Winds will diminish at
all terminals this evening and VFR conditions will prevail through
the TAF period. -Petrucelli
&&
.MARINE...Updated 800 PM PDT Monday 29 Mar 2021....Gusty north
winds are expected through Tuesday night with winds strongest south
of Cape Blanco. Seas today through early Tuesday will be a mix of
wind seas and northwest swell at 11 seconds, with short period wind
seas dominant in the areas of gale. Winds and seas will lower
briefly tonight into Tuesday morning.
Then Tuesday afternoon and evening, north winds will peak with gales
expected to extend from near Port Orford south beyond 4 nm from
shore. Seas will be dominated by short period wind seas across the
waters from Cape Blanco Tuesday afternoon and evening with a mix of
short period wind seas and northwest swell north of Cape Blanco.
There is moderate confidence that very steep seas will affect the
waters from Charleston south to Cape Blanco beyond 2 nm from shore
and high confidence that very steep seas will affect the waters from
Cape blanco south beyond 2 nm from shore.
Winds and seas should begin to subside Wednesday as the thermal
trough pattern becomes disrupted and weakens. Light seas and light
southerly winds are expected to develop late Wednesday and Wednesday
night. Thursday and Friday expect relatively light northwest winds
and seas across the waters. -CC/Petrucelli
&&
.MFR WATCHES/WARNINGS/ADVISORIES...
OR...Frost Advisory from 3 AM to 9 AM PDT Tuesday for ORZ021-022.
Freeze Warning from 3 AM to 9 AM PDT Tuesday for ORZ021.
Freeze Warning from 1 AM to 9 AM PDT Tuesday for ORZ024-026.
CA...None.
Pacific Coastal Waters...Small Craft Advisory until 11 AM PDT
Wednesday for PZZ350-356-370.
Gale Warning until 11 PM PDT Tuesday for PZZ356-376.
Hazardous Seas Warning from 2 PM to 11 PM PDT Tuesday for
PZZ350-370.
Small Craft Advisory from 11 PM Tuesday to 11 AM PDT Wednesday
for PZZ376.
Hazardous Seas Warning from 11 PM Tuesday to 11 AM PDT Wednesday
for PZZ376.
15/15/10The national radar mosaic for the moment the first event began.
3 frost/freeze. Local standard time, as filed.
Reported low temperatures ranged from 26 to 37 degrees.
Reported low temperatures ranged from 20 to 31 degrees.
Reported low temperatures ranged from 30 to 33 degrees.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Oregon in 2021Every state in 2021This day in weather historyWarnings in Oregon, March 2021
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: 940972, 940973, 940970.