Red Flag Warning 14, NWS Medford, OR

781 
WWUS86 KMFR 190306
RFWMFR

URGENT - FIRE WEATHER MESSAGE
National Weather Service Medford OR
806 PM PDT Tue Aug 18 2020

...Strong, gusty winds with low relative humidity expected on 
Wednesday for Fire Weather Zones 624 and 285...

ORZ625-190415-
/O.CAN.KMFR.FW.W.0013.000000T0000Z-200819T0600Z/
South Central Oregon Desert including the BLM Land in Eastern Lake
and Western Harney Counties-
806 PM PDT Tue Aug 18 2020

...RED FLAG WARNING IS CANCELLED FOR ABUNDANT LIGHTNING ON DRY
FUELS FOR FIRE WEATHER ZONE 625...

The National Weather Service in Medford has cancelled the Red Flag
Warning.

Although an isolated storm may still be possible over the next
couple of hours, we are not expecting scattered storms or abundant
lightning.

$$

CAZ285-ORZ624-191515-
/O.CON.KMFR.FW.W.0014.200819T2100Z-200820T0300Z/
Modoc County Except for the Surprise Valley-
Klamath Basin and the Fremont-Winema National Forest-
806 PM PDT Tue Aug 18 2020

...RED FLAG WARNING REMAINS IN EFFECT FROM 2 PM TO 8 PM PDT
WEDNESDAY FOR STRONG GUSTY WINDS AND LOW RH FOR FIRE WEATHER ZONES
285 AND 624...

* Impacts:  Strong, gusty wind with low relative humidity and high
  fire danger will likely contribute to a significant spread of new
  and existing fires.

* Affected area: 
 In South Central OR Fire Zone....eastern and southeastern part of
 624.
 In Northern CA Fire Zone... most of fire zone 285. 

* Wind: Southwest 10 to 20 mph with gusts up to 35 mph.

* Relative Humidity: 10 to 15 percent.

* View the hazard area in detail at:
https://www.wrh.noaa.gov/mfr/HAZARD

$$


Visit us at www.weather.gov/Medford

957 
WWUS86 KMFR 191232
RFWMFR

URGENT - FIRE WEATHER MESSAGE
National Weather Service Medford OR
532 AM PDT Wed Aug 19 2020

...Strong, gusty winds with low relative humidity expected on
Wednesday for Fire Weather Zones 624 and 285...

CAZ285-ORZ624-200045-
/O.CON.KMFR.FW.W.0014.200819T2100Z-200820T0300Z/
Modoc County Except for the Surprise Valley-
Klamath Basin and the Fremont-Winema National Forest-
532 AM PDT Wed Aug 19 2020

...RED FLAG WARNING REMAINS IN EFFECT FROM 2 PM THIS AFTERNOON TO
8 PM PDT THIS EVENING FOR STRONG GUSTY WINDS AND LOW RH FOR FIRE
WEATHER ZONES 285 AND 624...

* Impacts:  Strong, gusty wind with low relative humidity and high
fire danger will likely contribute to a significant spread of new
and existing fires.

* Affected area: 
 In Northern CA.... Areas east of Tionesta in fire weather 
	zone 285.
 In South Central OR....Southeastern section of fire weather 
   	zone 624.

* Wind: Southwest 10 to 20 mph with gusts up to 30 mph.

* Relative Humidity: 10 to 15 percent.

* View the hazard area in detail at:
https://www.wrh.noaa.gov/mfr/HAZARD

$$

Visit us at www.weather.gov/Medford

994 
WWUS86 KMFR 192057
RFWMFR

URGENT - FIRE WEATHER MESSAGE
National Weather Service Medford OR
157 PM PDT Wed Aug 19 2020

...Strong, gusty winds with low relative humidity expected on
Wednesday for Fire Weather Zones 624 and 285...

CAZ285-ORZ624-200300-
/O.CON.KMFR.FW.W.0014.200819T2100Z-200820T0300Z/
Modoc County Except for the Surprise Valley-
Klamath Basin and the Fremont-Winema National Forest-
157 PM PDT Wed Aug 19 2020

...RED FLAG WARNING REMAINS IN EFFECT UNTIL 8 PM PDT THIS EVENING
FOR STRONG GUSTY WINDS AND LOW RH FOR FIRE WEATHER ZONES 285 AND
624...

* Impacts:  Strong, gusty wind with low relative humidity and high
fire danger will likely contribute to a significant spread of new
and existing fires.

* Affected area: 
 In Northern CA Fire Zone....Fire weather zone 285 mainly east of
 Tionesta. 
 In South Central OR Fire Zone....Mainly east of Sprague 
 River.

* Wind: Southwest 10 to 20 mph with gusts up to 30 mph.

* Relative Humidity: 10 to 15 percent.

* View the hazard area in detail at:
https://www.wrh.noaa.gov/mfr/HAZARD

$$


Visit us at www.weather.gov/Medford

147 
WWUS86 KMFR 200304
RFWMFR

URGENT - FIRE WEATHER MESSAGE
National Weather Service Medford OR
804 PM PDT Wed Aug 19 2020

CAZ285-ORZ624-200415-
/O.EXP.KMFR.FW.W.0014.000000T0000Z-200820T0300Z/
Modoc County Except for the Surprise Valley-
Klamath Basin and the Fremont-Winema National Forest-
804 PM PDT Wed Aug 19 2020

...RED FLAG WARNING HAS EXPIRED FOR STRONG GUSTY WINDS AND LOW RH
FOR FIRE WEATHER ZONES 285 AND 624...

Winds have decreased and humidities have increased beyond critical
levels, and the Red Flag Warning has been allowed to expire.

$$


Visit us at www.weather.gov/Medford

Area Forecast Discussion
National Weather Service Medford OR
1036 AM PDT Tue Aug 18 2020

.UPDATE...Updated Aviation Section.

&&

.AVIATION...For the 18/18Z TAFs...Along the coast and over the
coastal waters...Marine stratus remains from Brookings south, as
well as in the Coquille Valley. Stratus in the Coquille will burn
off by noon.

Inland...VFR conditions will prevail across most of the area through
today, though there will high based clouds around. One exception
will be in portions of western Siskiyou County where reduced
visibilities are expected due to smoke from the Red Salmon Fire.
Another round of isolated thunderstorms are expected this
afternoon along and east of the Cascades. Strong, gusty, erratic
winds are expected with these thunderstorms. -Miles/Sven

&&

.PREV DISCUSSION... /Issued 915 AM PDT Tue Aug 18 2020/

DISCUSSION...As of 9:15 am Tuesday...Four corners high remains
firmly in place with mid and high level clouds streaming northeast
across northern CA and southern OR. Another hot day in store for
the area...with temperatures generally between 7 and 10 degrees
above normal for the middle of August.

Short term models continue to indicate convective initiation later
this afternoon/early evening across Modoc and Lake counties as
well as possibly northern Klamath county. Less thunderstorm
coverage is expected today compared to the past few days.

Otherwise...forecast looks right on track. Please see below for
additional information.

-Riley

MARINE...Updated 900 AM PDT Tuesday 18 August 2020...Relatively
light winds and low seas will persist through much of the week.
There will be periods of poor visibility in low clouds and fog.
A weak front will move onshore Friday, then a thermal trough will
develop near the coast. This will bring increasing north winds to
the area Saturday, and seas may become steep south of Cape Blanco.

PREV DISCUSSION... /Issued 357 AM PDT Tue Aug 18 2020/

DISCUSSION...

Thunderstorms remain the topic of discussion for today and even
for this morning as two to three small cells moved through Mt
Shasta City around 2 am this morning. There appears to still be
plenty of moisture lingering around the region with dewpoints in
Medford sitting at 57. Water vapor on satellite is also plentiful
with precipitable water (PWAT) around 1.0 to 1.2 inches. Given the
moisture, strong surface heating and upper level energy moving
through, we'll keep isolated thunderstorms in the forecast for the
Cascades and areas east of the Cascades this afternoon. Most of
the high resolution guidance isn't too excited about storms
across northern California. However, thunderstorm probabilities
are around 20 to 30 percent around Modoc and eastern Siskiyou
County, so the mention of isolated thunderstorms seem reasonable
there.

The other topic worth mentioning is the potential for some
stronger storms around Lake County. Given the high PWAT, we would
expect a little more potential instability for storms to work
with. 0-6 km winds are around 35 to 40 knots out of the south west
this evening, so storms should be able to sustain and become
organize with more potential instability. If more instability does
develop today, a 5% chance for severe storms seem reasonable
around Lake County, so that will be something to watch on RADAR
later this evening.

Onshore flow continues into Wednesday with the marine layer and
relatively cooler and drier air pushing into areas west of the
Cascades. One could argue the cooler air starts pushing in today,
Tuesday. However, it is more noticeable looking at 700 mb
temperatures on Wednesday. This will lead to some breezy winds
east of the Cascades. Given all the lightning occuring east of the
Cascades, these winds will create some fire weather issues.

The ridge of high pressure that has been impacting the west coast
the last few days will begin to retreat to the east as a deep low
lingers over the Gulf of Alaska. We'll see westerly winds continue
to bring the relatively cooler air into the region. Highs will
trend lower and reach the lower 90's Thursday and Friday in the
southern valleys west of the Cascades. The coast should see highs
in the mid 70's.

Thursday, a shortwave will impact the north western portion of
Oregon and bring a cold front through the central Oregon
coastline. Some of the models are predicting some rain for the
coast and we're forecasting a 20% chance for rain around the Coos
Bay and Florence region. Precipitation probabilities decrease
sharply inland and this is usually the case with these summer
systems.

Eventually, high pressure will begin to slowly build to the
northwest through the weekend into next week. Temperatures will
trend warmer as a result. We were interested in the potential of
hitting 100 degrees in Medford again next week. Ensemble data
suggests we'll miss that target, yet upper 90's seems highly
probable.

-Smith

&&

.MFR WATCHES/WARNINGS/ADVISORIES...
OR...Red Flag Warning until 11 PM PDT this evening for ORZ625.
     Fire Weather Watch from Wednesday afternoon through Wednesday
     evening for ORZ624.

CA...Fire Weather Watch from Wednesday afternoon through Wednesday
     evening for CAZ285.

Pacific Coastal Waters...None.