High pressure and a dry air mass supported very hot temperatures over inland areas during this interval. Minimum temperatures were quite warm as well.
Every event with a place to put it; 4 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.
High pressure and a dry air mass supported very hot temperatures over inland areas during this interval. Minimum temperatures were quite warm as well. The heat was occasionally tempered by high clouds streaming over the area.
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 14, 8:24 AM PST, 1 hour 36 minutes earlier.
Area Forecast Discussion
National Weather Service Medford OR
924 AM PDT Fri Aug 14 2020
.UPDATE...
A couple of updates have been made to the forecast for today.
These updates were to remove the mention of thunderstorms from
the forecast for this evening that were in over the Warner
Mountains and to adjust the smoke and related wording in and near
Siskiyou County into SW Oregon.
&&
.DISCUSSION...
Satellite imagery clearly indicates significant smoke in the
Klamath River Valley from the Orleans area north to Happy Camp to
about Seiad Valley. Given current and expected conditions we've
increased the smoke wording there, as air quality issues should
generally be expected there. Some of this smoke has and will
continue to filter into portions of SW Oregon, particularly in the
Siskiyou Mountains, though mixing this afternoon is likely to
keep concentrations from being significant in terms of air
quality.
Thunderstorms were removed from the forecast in the Warner
Mountains area as instability is insufficient for these to form
today.
Today we'll be focusing on the thunderstorm threat for this
weekend into Monday and associated fire weather and short term
product concerns. Data this morning continues to support isolated
coverage with a mix of cloud cover, instability, and significant
moisture moving northward this weekend, but does not support a
significant thunderstorm outbreak despite the expected extreme
heat and pre-existing dryness.
Numerical models indicate a stronger shortwave could move through
Monday, but this is a new development and is not supported by
some guidance, so we'll be assessing that impulse further today.
~BTL
&&
.AVIATION...For the 14/12Z TAFs... Clear skies are expected to
continue for most areas through the TAF period. The one exception is
smoke from the Red Salmon Fire, which will reduce visibilities in
Siskiyou County in the vicinity of it and mainly west-north of it.
Breezy to gusty north winds are expected at the coast and into the
Umpqua Valley, including at KRBG this afternoon. -CC
&&
.MARINE...Updated 900 AM PDT Friday, 14 August 2020...A thermal
trough along the coast is bringing gusty north winds and elevated
seas to the waters today. Steep seas will be present across most
the waters with very steep seas across portions of the waters from
Gold Beach southward beyond 10 nm from shore. Winds and seas will
gradually subside Friday night into Saturday. A wind reversal to
southerlies is expected late Saturday into Sunday which is likely
to result in fog, low clouds, and a possibility of drizzle. Light
northerly winds are expected to return Monday. Light winds and
seas are expected to continue through Tuesday. Gusty north winds
and steep seas may redevelop late Tuesday into Wednesday,
especially for areas south of Cape Blanco. -CC
&&
.FIRE WEATHER...Updated 400 AM PDT Friday 14 August
2020...Temperatures will warm and the air mass will continue drying
out today. Although humidity values will be lower than yesterday,
the winds should be a little lighter. The exception to this will be
for the Umpqua Vally and the Coast range in Coos County where gusty
north winds and low humidity will occur this afternoon. It will be
very hot inland this weekend with high temperatures near record
values. This will mean that fuels will become significantly drier
than normal during the typically- driest time of the year. This will
work to create near-critical conditions across many parts of the
area through at least Sunday.
So any lightning that's expected over the weekend is especially
concerning. Deep southerly flow, initially associated with the
remnants of Tropical Cyclone Elida, will reach the area tonight.
Isolated thunderstorms could develop on Saturday afternoon over the
area, and how far north and west these storms reach is still a
question. Right now we think there's a good chance for isolated
storms from Agness eastward and from the Umpqua Divide and Chemult
Southward on Saturday. Sunday, however, looks to be the more
problematic day for isolated thunderstorms where a slight chance
exists across the entirety of the area except for the western half
of the Umpqua Valley and the Coast and Coast Range. Will need to
keep an eye on the forecast as things will undoubtedly change.
-Schaaf
&&
.PREV DISCUSSION... /Issued 645 AM PDT Fri Aug 14 2020/
DISCUSSION...There are several things to note with this new
forecast package. The first is the excessive heat southern Oregon
and northern California will be seeing west of the Cascades as
well as some hot conditions for areas east of the Cascades. The
excessive heat warnings and heat advisories will begin today at
11 AM and will continue through Sunday, with Saturday being the
warmest day of the the forecast--and for many areas of the year so
far. There is a possibility that additional heat products may be
needed for Monday and Tuesday, but will allow the current suite to
begin running their course before adding days. Overall, we will
expect temperatures in the 90s for most places in southern Oregon
and northern California and low 100s for west side valleys south
of the Umpqua Divide. The exception to this will be for the coast
and terrain features above 6000 feet. Still, these temperatures
are still pretty warm for these areas. Saturday, expect
temperatures to range between 5 and 10 degrees warmer, including
at the coast and higher terrain-- bringing temperatures to
105-110 degrees in some parts of the Rogue and Illinois Valleys.
Sunday will still be hot, but a few degrees cooler than Saturday.
Please make sure you are doing what you can to prevent heat
exhaustion and heat stroke, and check in on your neighbors and
anyone else who may not have air conditioning. Overnight low
temperatures will be warm enough that there will not be
significant relief from the heat during the day, thus the
reasoning for the heat products. Please see the NPWMFR for more
details.
The second aspect of the short term forecast to worry about will
be chances for Thunderstorm this weekend. Moisture from the
remnants of Hurricane Elida will move into our area from south to
north beginning as early as Friday. Do not expect any thunderstorm
chances for today as the first day is not likely to produce enough
moisture into the area along with other factors. Saturday, on the
other hand, will have had the moisture moving in long enough as
well as being highly unstable thanks to the hot temperatures that
thunderstorms will be possible. Have started looking at convection
allowing models (which are generally available only in the very
short-term) as well as other more traditional parameters. Have
added thunderstorms to fill in holes in the Rogue Valley and
portions of the East Side from Chemult south to Klamath Falls
while keeping the previous thunderstorm chances in tact. The
biggest change to the forecast is for Sunday as additional
moisture from the southwestern US monsoon also moves into our
area. Have added thunderstorms for most places except for portions
of the Umpqua Valley and the Coast. My general thought is that
Sunday will be the more problematic day for thunderstorms. There
are a couple of limiting factors which may hinder thunderstorm
development--namely a cirrus shield early in the day on Saturday
which could provide a sort of capping effect. Still, don't see
capping to be a huge deterrent for thunderstorm initiation when
we get to temperatures in the 100s. For those of you who will
understandably try to beat the heat by recreating in the mountains
and lakes and rivers, make sure that you have a plan if a
thunderstorm develops. Remember, the safest place in a
thunderstorm is in a building that completely encloses like a
house. A car with a metal frame/roof would also work--just don't
touch anything metal within the vehicle. When thunder roars, go
indoors.
One of the other things to note with the complexity of this
forecast is that if thunderstorms do indeed form, these storm
clouds will work to "shade" some of these areas, preventing the
temperatures from realizing their peaks. This situation will
continue to evolve, so please stay tuned to the forecast.
Thunderstorm chances will largely end on Monday, and after
Tuesday, temperatures will be much closer to normal with winds
from the west helping to push the Marine layer in a little bit
farther than the immediate coast. This will provide some relief in
our otherwise high-impact forecast. -Schaaf
&&
.MFR WATCHES/WARNINGS/ADVISORIES...
OR...Heat Advisory from 8 AM Saturday to 11 PM PDT Sunday for
ORZ027>029.
Excessive Heat Warning until 11 PM PDT Sunday for ORZ024-026.
Heat Advisory until 11 PM PDT Saturday for ORZ021-022.
Excessive Heat Warning from 8 AM Saturday to 11 PM PDT Sunday
for ORZ023-025.
CA...Heat Advisory from 8 AM Saturday to 11 PM PDT Sunday for
CAZ082>084.
Excessive Heat Warning until 11 PM PDT Sunday for CAZ080-081.
Pacific Coastal Waters...Small Craft Advisory until 5 PM PDT Saturday for
PZZ350-356-370-376.
Hazardous Seas Warning until 5 AM PDT Saturday for PZZ376.
BTL/MAS/BMSThe national radar mosaic for the moment the first event began.
4 excessive heat. Local standard time, as filed.
High temperatures in this zone ranged from 89 to 110 degrees. Low temperatures in this zone ranged from 46 to 66 degrees.
High temperatures in this zone ranged from 85 to 100 degrees. Low temperatures in this zone ranged from 46 to 60 degrees.
High temperatures in this zone ranged from 86 to 111 degrees. Low temperatures in this zone ranged from 48 to 72 degrees.
High temperatures in this zone ranged from 88 to 108 degrees. Low temperatures in this zone ranged from 45 to 69 degrees.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Oregon in 2020Every state in 2020This day in weather historyWarnings in Oregon, August 2020
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: 903948, 903949, 903954, 903955.