Alert archive / Oregon / Red Flag Warnings in 2019

Red Flag Warning 9, NWS Medford, OR

September 4, 2019Modoc County, Siskiyou County, California; 9 counties in Oregon

NWS Medford, OR issued this red flag warning at Sep 4, 2019, 3:24 AM PDT for Modoc County, Siskiyou County, California; 9 counties in Oregon. It took effect at Sep 4, 2019, 11:07 PM PDT. It was in force for 24 hr. 4 reports came from inside the area while it was in force.

The area

The counties it named, with what was reported inside it.

The facts

Issued
Sep 4, 2019, 3:24 AM PDT (10:24 UTC)
In effect from
Sep 4, 2019, 11:07 PM PDT
Expired
Sep 5, 2019, 11:00 PM PDT
In force
24 hr
Issued by
NWS Medford, OR

Counties Modoc County, CA, Siskiyou County, CA, Coos County, OR, Curry County, OR, Douglas County, OR, Harney County, OR, Jackson County, OR, Josephine County, OR, Klamath County, OR, Lake County, OR, Lane County, OR

The radar

The Medford radar (KMAX), 76 km from the middle of the area, began a volume at 10:28 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

What was reported inside it

TimeReportWhereRemark
Sep 5, 3:20 PM PDTHAIL 11 N Prospect, ORREPORTED AT PROSPECT, OR AT ODOT STATION. TREES DOWN AS WELL. ESTIMATED 320PM.
Sep 5, 3:45 PM PDTTSTM WND GST 55Riley, ORSUSTAINED 29 GUST 55 MPH.
Sep 5, 4:00 PM PDTHAIL 0.75Westfir, OR
Sep 5, 7:46 PM PDTHEAVY RAIN 0.261 Nnw Fort Bidwell, CAMESONET STATION DW0735 FORT BIDWELL.

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The nearest sounding before it

Medford/Jackson, OR (KMFR), launched 00:00Z, 10.4 hours before the alert went out and 55 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.

Skew-T log-pSkew-T log-p diagram, Medford/Jackson, OR at 00:00Z on 2019-09-04Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Medford/Jackson, OR at 00:00Z on 2019-09-04The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 22 square meters per square second.19395878Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.
Mixed-layer CAPE
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
2510 m above ground
0-6 km bulk shear
24 kt
0-1 km storm-relative helicity
22 m²/s²
0-3 km storm-relative helicity
125 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

368 
WWUS86 KMFR 041024
RFWMFR

URGENT - FIRE WEATHER MESSAGE
National Weather Service Medford OR
324 AM PDT Wed Sep 4 2019

.isolated thunderstorms are expected during Wednesday night with 
little to no rainfall. Thunderstorms are then expected to become 
more frequent and increase in coverage during Thursday with
the peak of thunderstorms late Thursday morning into Thursday 
evening. There is also a better chance for wetting rain Thursday, 
but lightning can occur outside of the rain core of 
thunderstorms, so the risk of new fire starts is still high.

CAZ280-281-041130-
/O.CAN.KMFR.FW.A.0006.190905T1200Z-190906T0600Z/
Western Klamath National Forest-
Central Siskiyou County Including Shasta Valley-
324 AM PDT Wed Sep 4 2019

...FIRE WEATHER WATCH IS CANCELLED FOR ABUNDANT LIGHTNING ON DRY
FUELS FOR FIRE WEATHER ZONES 280 AND 281...

The National Weather Service in Medford has cancelled the Fire
Weather Watch.

We are no longer expecting scattered thunderstorms in this region.
We're still expecting some isolated thunderstorms Wednesday night.

$$

CAZ285-ORZ624-625-042230-
/O.UPG.KMFR.FW.A.0006.190905T1200Z-190906T0600Z/
/O.NEW.KMFR.FW.W.0009.190905T1200Z-190906T0600Z/
Modoc County Except for the Surprise Valley-
Klamath Basin and the Fremont-Winema National Forest-
South Central Oregon Desert including the BLM Land in Eastern Lake
and Western Harney Counties-
324 AM PDT Wed Sep 4 2019

...RED FLAG WARNING IN EFFECT FROM 5 AM TO 11 PM PDT THURSDAY FOR
ABUNDANT LIGHTNING ON DRY FUELS FOR FIRE WEATHER ZONES 285...
624 AND 625...

The National Weather Service in Medford has issued a Red Flag
Warning...which is in effect from 5 AM to 11 PM PDT Thursday. The
Fire Weather Watch has been upgraded.

* Impacts: Abundant lightning on dry fuels may produce numerous 
  new starts that pose a threat to life and property, and may 
  overwhelm initial attack capabilities. Gusty winds near 
  thunderstorms could contribute to fire spread. Despite rainfall, 
  initial attack resources could be overwhelmed and holdover fires 
  are possible.

* Affected area: 
 In Fire Zone 285....The entire zone except for the
  southwest portion. 
 In South Central OR Fire Zones... 624 and 625 .

* Thunderstorms: will be isolated Wednesday night, but increase 
  in coverage Thursday evening.
	

Precautionary/preparedness actions...

&&

$$

ORZ616-617-620>623-042230-
/O.CON.KMFR.FW.A.0006.190905T1200Z-190906T0600Z/
Umpqua Basin-Umpqua National Forest-
Western Rogue Basin including the Illinois Valley-
Siskiyou Mountains-Eastern Rogue Valley-Southern Oregon Cascades-
324 AM PDT Wed Sep 4 2019

...FIRE WEATHER WATCH REMAINS IN EFFECT FROM LATE TONIGHT THROUGH
THURSDAY EVENING FOR ABUNDANT LIGHTNING ON DRY FUELS FOR FIRE
WEATHER ZONES 616...617...620...621...622 AND 623...

* Impacts: Abundant lightning on dry fuels may produce numerous 
  new starts that pose a threat to life and property, and may 
  overwhelm initial attack capabilities. Gusty winds near 
  thunderstorms could contribute to fire spread. Despite rainfall, 
  initial attack resources could be overwhelmed and holdover fires 
  are possible.

* Affected area: 
  In Fire Zone 616....Areas east of Roseburg.
  In Fire Zone 620....Areas east of Galice and Selma.
  Fire Zones...617...621...622...623.

* Thunderstorms: will be isolated Wednesday night close to the Oregon
  and California border.  Storms may become scattered Thursday evening
  over the areas listed above.  

$$


Visit us at www.weather.gov/Medford
6 follow-up statements
908 
WWUS86 KMFR 042130
RFWMFR

URGENT - FIRE WEATHER MESSAGE
National Weather Service Medford OR
230 PM PDT Wed Sep 4 2019

.Isolated thunderstorms will develop tonight with little to no 
rainfall. Thunderstorms will increase in coverage Thursday, 
peaking late Thursday morning into Thursday evening. The
thunderstorms Thursday will mostly be wet, but lightning can 
occur outside of the rain core, so the risk of new fire starts
will remain high.

ORZ616-042230-
/O.CAN.KMFR.FW.A.0006.190905T1200Z-190906T0600Z/
Umpqua Basin-
230 PM PDT Wed Sep 4 2019

...FIRE WEATHER WATCH IS CANCELLED FOR ABUNDANT LIGHTNING ON DRY
   FUELS FOR FIRE WEATHER ZONES 616...617...620...621...622 AND 
   623...

The National Weather Service in Medford has cancelled the Fire
Weather Watch.

Only isolated thunderstorm activity is forecast for this zone. 
However, scattered thunderstorms are forecast to the east of 
this area. 

$$

ORZ617-620>623-051400-
/O.UPG.KMFR.FW.A.0006.190905T1200Z-190906T0600Z/
/O.EXA.KMFR.FW.W.0009.190905T1200Z-190906T0600Z/
Umpqua National Forest-
Western Rogue Basin including the Illinois Valley-
Siskiyou Mountains-Eastern Rogue Valley-Southern Oregon Cascades-
230 PM PDT Wed Sep 4 2019

...RED FLAG WARNING IN EFFECT FROM 5 AM TO 11 PM PDT THURSDAY FOR
   ABUNDANT LIGHTNING ON DRY FUELS FOR FIRE WEATHER ZONES 617...
   620...621...622 AND 623...

The National Weather Service in Medford has issued a Red Flag
Warning...which is in effect from 5 AM to 11 PM PDT Thursday. The
Fire Weather Watch is no longer in effect.

* Impacts: Lightning and high fire danger will likely result in new
  fire starts. Gusty thunderstorm winds could contribute to fire 
  spread. Despite rainfall, initial attack resources could be 
  overwhelmed and holdover fires are possible.

* Affected area: In Southwest OR...Fire Weather Zones 617...620...
  621...622 and 623.

* Thunderstorms: Isolated activity tonight will become scattered 
  Thursday, then diminish Thursday might. Winds may be gusty and 
  erratic near thunderstorms. 

Precautionary/preparedness actions...

Abundant lightning on existing very dry fuels could cause numerous
new fire ignitions. Gusty and erratic outflow winds could also
create extreme fire growth potential.

&&

$$

CAZ280-281-284-051400-
/O.EXA.KMFR.FW.W.0009.190905T1200Z-190906T0600Z/
Western Klamath National Forest-
Central Siskiyou County Including Shasta Valley-
Siskiyou County from the Cascade Mountains East and South to Mt
Shasta-
230 PM PDT Wed Sep 4 2019

...RED FLAG WARNING IN EFFECT FROM 5 AM TO 11 PM PDT THURSDAY FOR
   ABUNDANT LIGHTNING ON DRY FUELS FOR FIRE WEATHER ZONES 280...
   281 AND 284...

The National Weather Service in Medford has issued a Red Flag
Warning...which is in effect from 5 AM to 11 PM PDT Thursday.

* Impacts: Lightning and high fire danger will likely result in new
  fire starts. Gusty thunderstorm winds could contribute to fire 
  spread. Despite rainfall, initial attack resources could be 
  overwhelmed and holdover fires are possible.

* Affected area: In Northern CA...Fire Weather Zones 280...281 and
  284.

* Thunderstorms: Isolated activity tonight will become scattered 
  Thursday, then diminish Thursday might. Winds may be gusty and 
  erratic near thunderstorms. 

Precautionary/preparedness actions...

Abundant lightning on existing very dry fuels could cause numerous
new fire ignitions. Gusty and erratic outflow winds could also 
create extreme fire growth potential.

$$

CAZ285-ORZ624-625-051400-
/O.CON.KMFR.FW.W.0009.190905T1200Z-190906T0600Z/
Modoc County Except for the Surprise Valley-
Klamath Basin and the Fremont-Winema National Forest-
South Central Oregon Desert including the BLM Land in Eastern Lake
and Western Harney Counties-
230 PM PDT Wed Sep 4 2019

...RED FLAG WARNING REMAINS IN EFFECT FROM 5 AM TO 11 PM PDT
   THURSDAY FOR ABUNDANT LIGHTNING ON DRY FUELS FOR FIRE WEATHER
   ZONES 285...624 AND 625...

* Impacts: Lightning and high fire danger will likely result in new
  fire starts. Gusty thunderstorm winds could contribute to fire 
  spread. Despite rainfall, initial attack resources could be 
  overwhelmed and holdover fires are possible.

* Affected area: In Northern CA Fire Zone....285. In South Central 
  OR Fire Zones...624...625.

* Thunderstorms: Isolated activity tonight will become scattered 
  Thursday, then diminish Thursday might. Winds may be gusty and 
  erratic near thunderstorms. 

Precautionary/preparedness actions...

Abundant lightning on existing very dry fuels could cause numerous
new fire ignitions. Gusty and erratic outflow winds could also 
create extreme fire growth potential.

$$

Visit us at www.weather.gov/Medford
041 
WWUS86 KMFR 050607
RFWMFR

URGENT - FIRE WEATHER MESSAGE
National Weather Service Medford OR
1107 PM PDT Wed Sep 4 2019

.Isolated thunderstorms will develop tonight with little to no
rainfall. Thunderstorms will increase in coverage Thursday,
peaking late Thursday morning into Thursday evening. Thunderstorms
Thursday will mostly be wet, but lightning can occur outside of 
the rain core, so the risk of new fire starts will remain high.

CAZ280-281-052130-
/O.EXT.KMFR.FW.W.0009.190905T0607Z-190906T0600Z/
Western Klamath National Forest-
Central Siskiyou County Including Shasta Valley-
1107 PM PDT Wed Sep 4 2019

...RED FLAG WARNING NOW IN EFFECT UNTIL 11 PM PDT THURSDAY FOR   
ABUNDANT LIGHTNING ON DRY FUELS FOR FIRE WEATHER ZONES 280 AND
281...

* Impacts:  Lightning and high fire danger will likely result in
new fire starts. Gusty thunderstorm winds could contribute to fire
spread. Despite rainfall, initial attack resources could be
overwhelmed and holdover fires are possible.

* Affected area: 
  In Northern CA...Fire Weather Zones 280 and 281.

* Thunderstorms: Isolated activity tonight will feature little to
  no rain tonight and will become scattered Thursday, then diminish
  Thursday night. Winds will be gusty and erratic near 
  thunderstorms.

$$

CAZ284-285-ORZ617-620>625-052130-
/O.CON.KMFR.FW.W.0009.190905T1200Z-190906T0600Z/
Siskiyou County from the Cascade Mountains East and South to Mt
Shasta-Modoc County Except for the Surprise Valley-
Umpqua National Forest-
Western Rogue Basin including the Illinois Valley-
Siskiyou Mountains-Eastern Rogue Valley-Southern Oregon Cascades-
Klamath Basin and the Fremont-Winema National Forest-
South Central Oregon Desert including the BLM Land in Eastern Lake
and Western Harney Counties-
1107 PM PDT Wed Sep 4 2019

...RED FLAG WARNING REMAINS IN EFFECT FROM 5 AM TO 11 PM PDT
THURSDAY FOR ABUNDANT LIGHTNING ON DRY FUELS FOR FIRE WEATHER   
ZONES 284...285...624...625...617...620...621...622...623...

* Impacts:  Lightning and high fire danger will likely result in
new fire starts. Gusty thunderstorm winds could contribute to fire
spread. Despite rainfall, initial attack resources could be
overwhelmed and holdover fires are possible.

* Affected area: 
 In Northern CA Fire Zones...284...285. 
 In South Central OR Fire Zones...624...625.
 In Southwest OR Fire Zones...617...Eastern 620...621...622...623.

* Thunderstorms: Isolated activity tonight will become scattered
  Thursday, then diminish Thursday night. Some storms could become
  severe. Winds will be gusty and erratic near thunderstorms.

$$


Visit us at www.weather.gov/Medford
728 
WWUS86 KMFR 051141
RFWMFR

URGENT - FIRE WEATHER MESSAGE
National Weather Service Medford OR
441 AM PDT Thu Sep 5 2019

.Thunderstorms will continue this morning and increase in coverage
this afternoon and evening. Thunderstorms will mostly be wet this
afternoon, but lightning can occur outside of the rain core, so 
the risk of new fire starts will remain high.

CAZ284-285-ORZ617-620>625-052345-
/O.CON.KMFR.FW.W.0009.190905T1200Z-190906T0600Z/
Siskiyou County from the Cascade Mountains East and South to Mt
Shasta-Modoc County Except for the Surprise Valley-
Umpqua National Forest-
Western Rogue Basin including the Illinois Valley-
Siskiyou Mountains-Eastern Rogue Valley-Southern Oregon Cascades-
Klamath Basin and the Fremont-Winema National Forest-
South Central Oregon Desert including the BLM Land in Eastern Lake
and Western Harney Counties-
441 AM PDT Thu Sep 5 2019

...RED FLAG WARNING REMAINS IN EFFECT UNTIL 11 PM PDT THIS EVENING
FOR ABUNDANT LIGHTNING ON DRY FUELS FOR FIRE WEATHER ZONES 284...
285...617...620...621...622...623...624 AND 625...

* Impacts:  Lightning and high fire danger will likely result in
new fire starts. Gusty thunderstorm winds could contribute to fire
spread. Despite rainfall, initial attack resources could be
overwhelmed and holdover fires are possible.

* Affected area: 
  In Northern CA Fire Zones...284...285. 
  In South Central OR Fire Zones...624...625.
  In Southwest OR Fire Zones...617...621...622...623. 
  In Fire Weather Zone 620... The eastern section east of Grants Pass.

* Thunderstorms: Isolated thunderstorms will continue this morning
  and increase in coverage this afternoon and evening. Winds will 
  be gusty and erratic near thunderstorms.

$$

CAZ280-281-052345-
/O.CON.KMFR.FW.W.0009.000000T0000Z-190906T0600Z/
Western Klamath National Forest-
Central Siskiyou County Including Shasta Valley-
441 AM PDT Thu Sep 5 2019

...RED FLAG WARNING REMAINS IN EFFECT UNTIL 11 PM PDT THIS EVENING
FOR ABUNDANT LIGHTNING ON DRY FUELS FOR FIRE WEATHER ZONES 280 AND
281...

* Impacts:  Lightning and high fire danger will likely result in
new fire starts. Gusty thunderstorm winds could contribute to fire
spread. Despite rainfall, initial attack resources could be
overwhelmed and holdover fires are possible.

* Affected area: 
  In Northern CA Fire Zones...280...281. 

* Thunderstorms: Scattered thunderstorms will continue this morning
  before becoming more isolated after sunrise. Storms should 
  remain isolated into the afternoon and evening hours.

$$

Visit us at www.weather.gov/Medford
919 
WWUS86 KMFR 051434
RFWMFR

URGENT - FIRE WEATHER MESSAGE
National Weather Service Medford OR
734 AM PDT Thu Sep 5 2019

.Thunderstorms will continue this morning and increase in coverage
this afternoon and evening. Thunderstorms will mostly be wet this
afternoon, but lightning can occur outside of the rain core, so
the risk of new fire starts will remain high. Strong, gusty winds
are possible near thunderstorms. 

ORZ616-060245-
/O.EXA.KMFR.FW.W.0009.000000T0000Z-190906T0600Z/
Umpqua Basin-
734 AM PDT Thu Sep 5 2019

...RED FLAG WARNING IN EFFECT UNTIL 11 PM PDT THIS EVENING FOR
ABUNDANT LIGHTNING ON DRY FUELS FOR FIRE WEATHER ZONE 616...

The National Weather Service in Medford has issued a Red Flag
Warning...which is in effect until 11 PM PDT this evening.

* Impacts:  Lightning and high fire danger will likely result in
new fire starts. Gusty thunderstorm winds could contribute to fire
spread. Despite rainfall, initial attack resources could be
overwhelmed and holdover fires are possible.

* Affected area: 
  In...Fire Weather Zone 616...southern and eastern Douglas County
  from Tri-City south and east of I-5 for areas north of Tri-City.

* Thunderstorms: Isolated thunderstorms will develop this morning
and increase in coverage this afternoon and evening. Winds will be
gusty and erratic near thunderstorms.

Precautionary/preparedness actions...

Abundant lightning on existing dry fuels could cause numerous
new fire ignitions. Gusty and erratic outflow winds could also
create extreme fire growth potential.


&&

$$

CAZ280-281-284-285-ORZ617-620>625-060245-
/O.CON.KMFR.FW.W.0009.000000T0000Z-190906T0600Z/
Western Klamath National Forest-
Central Siskiyou County Including Shasta Valley-
Siskiyou County from the Cascade Mountains East and South to Mt
Shasta-Modoc County Except for the Surprise Valley-
Umpqua National Forest-
Western Rogue Basin including the Illinois Valley-
Siskiyou Mountains-Eastern Rogue Valley-Southern Oregon Cascades-
Klamath Basin and the Fremont-Winema National Forest-
South Central Oregon Desert including the BLM Land in Eastern Lake
and Western Harney Counties-
734 AM PDT Thu Sep 5 2019

...RED FLAG WARNING REMAINS IN EFFECT UNTIL 11 PM PDT THIS EVENING
FOR ABUNDANT LIGHTNING ON DRY FUELS FOR FIRE WEATHER ZONES 284...
285...617...620...621...622...623...624 AND 625...

* Impacts:  Lightning and high fire danger will likely result in
new fire starts. Gusty thunderstorm winds could contribute to fire
spread. Despite rainfall, initial attack resources could be
overwhelmed and holdover fires are possible.

* Affected area: 
  In Northern CA Fire Zones...280...281...284...285. 
  In South Central OR Fire Zones...624...625. 
  In Southwest OR Fire Zones...617...621...622...623.
  In Fire Weather Zone 620... The eastern section east of highway 199
  and from Grants Pass east.

* Thunderstorms: Isolated thunderstorms will continue this morning
and increase in coverage this afternoon and evening. Winds will be
gusty and erratic near thunderstorms.

Precautionary/preparedness actions...

Abundant lightning on existing dry fuels could cause numerous
new fire ignitions. Gusty and erratic outflow winds could also
create extreme fire growth potential.

$$


Visit us at www.weather.gov/Medford
776 
WWUS86 KMFR 052058
RFWMFR

URGENT - FIRE WEATHER MESSAGE
National Weather Service Medford OR
158 PM PDT Thu Sep 5 2019

.Thunderstorms will increase in coverage this afternoon and evening. 
Thunderstorms will mostly be wet this afternoon, but lightning can 
occur outside of the rain core, so the risk of new fire starts will 
remain high. Strong, gusty winds are possible near thunderstorms.

CAZ280-281-284-285-ORZ616-617-620>625-060600-
/O.CON.KMFR.FW.W.0009.000000T0000Z-190906T0600Z/
Western Klamath National Forest-
Central Siskiyou County Including Shasta Valley-
Siskiyou County from the Cascade Mountains East and South to Mt
Shasta-Modoc County Except for the Surprise Valley-Umpqua Basin-
Umpqua National Forest-
Western Rogue Basin including the Illinois Valley-
Siskiyou Mountains-Eastern Rogue Valley-Southern Oregon Cascades-
Klamath Basin and the Fremont-Winema National Forest-
South Central Oregon Desert including the BLM Land in Eastern Lake
and Western Harney Counties-
158 PM PDT Thu Sep 5 2019

...RED FLAG WARNING REMAINS IN EFFECT UNTIL 11 PM PDT THIS EVENING
FOR ABUNDANT LIGHTNING ON DRY FUELS FOR FIRE WEATHER ZONES 280...
281...284...285...616...617...620...621...622...623...624 AND
625...

* Impacts:  Lightning and high fire danger will likely result in
new fire starts. Gusty thunderstorm winds could contribute to fire
spread. Despite rainfall, initial attack resources could be
overwhelmed and holdover fires are possible.

* Affected area: 
  In Northern CA Fire Zones...280...281...284...285.
  In South Central OR Fire Zones...624...625.
  In Southwest OR Fire Zones...617...621...622...623.
  In Southwest OR Fire Weather Zone 616...southern and eastern Douglas 
    County from Tri-City south and east of I-5 for areas north of Tri-City.
  In Southwest OR Fire Weather Zone 620... The eastern section, east of  
    highway 199 and from Grants Pass north and east.

* Thunderstorms: Isolated thunderstorms will continue this morning
and increase in coverage this afternoon and evening. Winds will be
gusty and erratic near thunderstorms.

Precautionary/preparedness actions...

Abundant lightning on existing dry fuels could cause numerous
new fire ignitions. Gusty and erratic outflow winds could also
create extreme fire growth potential.

$$


Visit us at www.weather.gov/Medford
130 
WWUS86 KMFR 060549
RFWMFR

URGENT - FIRE WEATHER MESSAGE
National Weather Service Medford OR
1049 PM PDT Thu Sep 5 2019

CAZ280-281-284-285-ORZ616-617-620>625-060700-
/O.EXP.KMFR.FW.W.0009.000000T0000Z-190906T0600Z/
Western Klamath National Forest-
Central Siskiyou County Including Shasta Valley-
Siskiyou County from the Cascade Mountains East and South to Mt
Shasta-Modoc County Except for the Surprise Valley-Umpqua Basin-
Umpqua National Forest-
Western Rogue Basin including the Illinois Valley-
Siskiyou Mountains-Eastern Rogue Valley-Southern Oregon Cascades-
Klamath Basin and the Fremont-Winema National Forest-
South Central Oregon Desert including the BLM Land in Eastern Lake
and Western Harney Counties-
1049 PM PDT Thu Sep 5 2019

...RED FLAG WARNING WILL EXPIRE AT 11 PM PDT THIS EVENING FOR
ABUNDANT LIGHTNING ON DRY FUELS FOR FIRE WEATHER ZONES 280...281...
284...285...616...617...620...621...622...623...624 AND 625...

A few additional lightning strikes are possible overnight but
abundant lightning is no longer expected.

$$


Visit us at www.weather.gov/Medford

What forecasters said that day

The local office's own words before this red flag warning went out, 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 this red flag warning went out at Sep 3, 8:32 PM PDT, 6 hours 52 minutes earlier.

Area forecast discussion, Sep 3, 8:32 PM PDT, 6 hours 52 minutes before
Area Forecast Discussion
National Weather Service Medford OR
832 PM PDT Tue Sep 3 2019

.DISCUSSION...Seasonably dry and warm conditions continued today, and
about 3 to 5 degrees of warming is expected tomorrow compared to
this afternoon. An upper ridge will build ahead of an approaching
upper low from the southwest, bringing Wednesday afternoon
temperatures to about 10 degrees above normal for this time of
year. Deep flow will turn southerly Wednesday, and midlevel
moisture will increase in the late afternoon. There's a slight
chance of thunderstorms in the late afternoon with the arrival of
this moisture. A better chance of storms exists Wednesday night
into Thursday as the brunt of energy with the upper low arrives
and acts in concert with increasing instability. Based on the
latest high resolution model data, we've expanded the area of
thunderstorm chances Wednesday evening to include most of Western
Siskiyou County. A Fire Weather Watch for Thursday has been issued
to account for this thunderstorm threat. Additionally, taking a
look at latest 0-6km bulk shear forecast values for Thursday
suggests the chance for strong to severe storms, pending enough
instability, so we'll be evaluating that further in upcoming
shifts. Please see the forecast discussion below for more details.

&&

.AVIATION...For the 04/00Z TAFs...MVFR/IFR stratus is expected to
develop over the coastal waters and in the Coquille Valley
(including North Bend) after 05Z late this evening, then locally in
the Umpqua Valley (including the vicinity of Roseburg) after 10Z.
These low clouds will dissipate during the morning with VFR expected
through Wednesday evening. Elsewhere, conditions will remain VFR
through Wednesday evening. But, cumulus buildups are likely over the
higher terrain from late afternoon into Wednesday evening with a
slight chance of thunderstorms over the Cascades and across eastern
Siskiyou County into Modoc County. -DW

&&

.MARINE...Updated 800 PM PDT Tuesday September 3 2019...An
inland thermal trough is beginning to deepen. North winds will
increase into Wednesday evening, with conditions hazardous to small
craft from late tonight through Wednesday night. Winds and seas ease
Thursday then remain low through the weekend as weak low pressure
moves through the waters then pushes inland. Models show west-
northwest swell modestly increasing early next week as the next
offshore low moves toward Washington. -DW

&&

.FIRE WEATHER...Updated 230 PM PDT Tuesday 3 September 2019...The
main concern ahead will be Thursday into Thursday evening with the
potential for abundant lightning with dry fuels. The details on this
will follow below.

Thursday will be the most active day of the forecast period in terms
of thunderstorm coverage, frequency of lighting and storm intensity.
The upper low that will be responsible for this is centered near 35N
and 133 W. The satellite image clearly shows some convective clouds
around the upper low with several lightning strikes over the waters.

There's good agreement the upper low will move northeastward over
the next 24 hours off the coast of northeast California. This is
will be working it's way north towards out area in the next 18-24
hours. The general consensus show an unstable air mass feeding in
from the south as early as Wednesday night. This could bring at
least a slight chance for thunderstorms Wednesday night. The better
instability arrives after sunset and overnight, but with the lack of
surface support there will be more showers and less lightning, and
this is the reason we did not have the start time for the fire
weather watch for Wednesday night. The steering winds are also
expected to be from the south to southeast, so there is a chance for
storms to develop and move west of the Cascades, including portions
of Josephine, Jackson and possibly southern Douglas County.

Plenty of dynamics will be ahead of the upper low during the day
Thursday and the models suggest the upper low/trough could become
negatively tilted Thursday afternoon during the time of max heating.
This pattern is one that is typically favorable for thunderstorms.
Thunderstorms are expected to become more frequent and increase in
coverage Thursday morning, peaking out late Thursday morning into
Thursday evening. Upper level winds will also be stronger Thursday,
so it's not out of the question a few storms could be strong
Thursday afternoon and early Thursday evening. Keep in mind that
gusty and erratic winds are possible near the core of thunderstorms.
The models are still in good agreement for Thursday, with all
showing widespread instability extending from Northern California
into Oregon, from the I-5 corridor across the east side. Given the
above scenario and increasing confidence Thursday will be an active
day we decided to issue a Fire Weather Watch. Please see RFWMFR for
more details.

The focus for thunderstorms are expected to shift north and east as
the upper trough swings through the area Thursday night. After
Thursday, no concern are expected with dry weather returning Friday
with shortwave ridging building into the area.

Cooler weather is on tap for the weekend as an upper trough
approaches from the west to northwest Saturday afternoon with the
trough moving overhead Saturday night. The weak or flat ridging
follows Sunday. There is a chance for showers Saturday afternoon
into Sunday, but the pattern is not one that is favorable for
thunderstorms, so the forecast is for isolated to scattered showers.
-Petrucelli

&&

.PREV DISCUSSION... /Issued 246 PM PDT Tue Sep 3 2019/

DISCUSSION...2:30 PM Satellite shows some higher cirrostratus
clouds across the Umpqua Divide extending southwestward through
Brookings and offshore. There is some additional coastal
altocumulus that is dissipating in Coos County. This afternoon and
evening will continue to be mainly benign.

Tomorrow will begin a pattern shift to more active weather. A low
pressure system is moving northeastward toward the Oregon and
California border. This low will be offshore tomorrow, that we
are not really expecting much in the way of showers or
Thunderstorms, but as the low approaches, showers and thunderstorm
chances will begin Wednesday night into Thursday.

Thursday will be our active day for thunderstorms as the low
pressure system and trough becomes negatively tilted. This will
create some isolated storms east of the Coastal Range and more
scattered storms along and east of the Cascades. A few showers
will also be possible along the coast and in the Coquille Valley,
and these are the only places we're not expecting thunderstorms.

Bulk shear is going to be high enough that the storms will not be
stuck to the terrain, but it generally won't be high enough to
predicate an organized severe weather event. That's not to say
that an isolated storm couldn't become strong and produce gusty
winds or small hail. Additionally, precipitable water amounts are
significantly high across southern Oregon and northern California,
so the primary storm mode will be wet (with the potential for more
elevated storms with light rain to start the event on Wednesday
night.)

The thunderstorms may continue late into Thursday evening before
lifting northeast toward Central Oregon Thursday night into
Friday. Conditions return to relatively dry and normal
temperatures through Saturday before the next trough approaches
the same area on Sunday. This trough will likely be as strong as
the last one, and also negatively tilted. Have decided to not add
thunderstorms chances for now, but will need to continue
monitoring the forecast to see if that changes in the coming
shifts.

As far as temperatures are concerned, expect temperatures to be
above normal tomorrow, then drop close to normal with this trough,
then continue to drop to slightly below normal for the weekend
with the second trough. -Schaaf

&&

.MFR WATCHES/WARNINGS/ADVISORIES...
OR...Fire Weather Watch from late Wednesday night through Thursday
     evening for ORZ616-617-620>625.
     Beach Hazards Statement through Wednesday morning for
     ORZ021-022.

CA...Fire Weather Watch from late Wednesday night through Thursday
     evening for CAZ280-281-285.

Pacific Coastal Waters...Small Craft Advisory from 2 AM Wednesday to 5 AM PDT Thursday
     for PZZ350-356-370-376.

The office that day

Everything else NWS Medford, OR issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Sep 4, 1:03 PM PDTHazardous Seas WarningMFR13 hr

Nearby

Red Flag Warnings in Oregon, 2019Red Flag Warnings in California, 2019Every red flag warning in 2019

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.