Red Flag Warning 5, NWS Denver/Boulder, CO

150 
WWUS85 KBOU 250825
RFWBOU

URGENT - FIRE WEATHER MESSAGE
National Weather Service Denver/Boulder CO
225 AM MDT Sun Aug 25 2019

COZ211-213>215-238-242-251800-
/O.CON.KBOU.FW.W.0005.190825T1700Z-190826T0200Z/
Jackson County Below 9000 Feet-
Grand and Summit Counties Below 9000 Feet-
Central and Southeast Park County-
Larimer and Boulder Counties Between 6000 and 9000 Feet-
Larimer County Below 6000 Feet/Northwest Weld County-
Northeast Weld County-
225 AM MDT Sun Aug 25 2019

...RED FLAG WARNING REMAINS IN EFFECT FROM 11 AM THIS MORNING TO
8 PM MDT THIS EVENING FOR WIND AND LOW RELATIVE HUMIDITY FOR
NORTH PARK, MIDDLE PARK, SOUTH PARK, THE FRONT RANGE FOOTHILLS 
AND THE CHEYENNE RIDGE...

* Affected Area...Fire Weather Zones 211...213...214...215... 
  238 and 242.

* Winds...West 15 to 25 mph with gusts up to 40 mph.

* Timing...Late Sunday morning through early Sunday evening.

* Relative Humidity...As low as 14 percent.

* Impacts...Fires will start easily and spread rapidly.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Red Flag Warning means that critical fire weather conditions
are either occurring now....or will shortly. A combination of
strong winds...low relative humidity...and warm temperatures can
contribute to extreme fire behavior.

&&

$$

Gimmestad

450 
WWUS85 KBOU 251647
RFWBOU

URGENT - FIRE WEATHER MESSAGE
National Weather Service Denver/Boulder CO
1047 AM MDT Sun Aug 25 2019

COZ211-213>215-238-242-260100-
/O.CON.KBOU.FW.W.0005.190825T1700Z-190826T0200Z/
Jackson County Below 9000 Feet-
Grand and Summit Counties Below 9000 Feet-
Central and Southeast Park County-
Larimer and Boulder Counties Between 6000 and 9000 Feet-
Larimer County Below 6000 Feet/Northwest Weld County-
Northeast Weld County-
1047 AM MDT Sun Aug 25 2019

...RED FLAG WARNING REMAINS IN EFFECT UNTIL 8 PM MDT THIS EVENING
FOR WIND AND LOW RELATIVE HUMIDITY FOR NORTH PARK, MIDDLE PARK,
SOUTH PARK, THE FRONT RANGE FOOTHILLS AND THE CHEYENNE RIDGE...

* Affected Area...Fire Weather Zones 211...213...214...215... 
  238 and 242.

* Winds...West 15 to 25 mph with gusts up to 40 mph.

* Timing...Late Sunday morning through early Sunday evening.

* Relative Humidity...As low as 13 percent.

* Impacts...Fires will start easily and spread rapidly.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Red Flag Warning means that critical fire weather conditions
are either occurring now....or will shortly. A combination of
strong winds...low relative humidity...and warm temperatures can
contribute to extreme fire behavior.

&&

$$

231 
WWUS85 KBOU 260205
RFWBOU

URGENT - FIRE WEATHER MESSAGE
National Weather Service Denver/Boulder CO
805 PM MDT Sun Aug 25 2019

COZ211-213>215-238-242-260315-
/O.EXP.KBOU.FW.W.0005.000000T0000Z-190826T0200Z/
Jackson County Below 9000 Feet-
Grand and Summit Counties Below 9000 Feet-
Central and Southeast Park County-
Larimer and Boulder Counties Between 6000 and 9000 Feet-
Larimer County Below 6000 Feet/Northwest Weld County-
Northeast Weld County-
805 PM MDT Sun Aug 25 2019

...RED FLAG WARNING HAS EXPIRED FOR WIND AND LOW RELATIVE
HUMIDITY FOR THE HIGH MOUNTAIN PARKS...NORTHERN FRONT RANGE
FOOTHILLS AND NORTHERN WELD COUNTY...

Temperatures have cooled this evening, allowing relative humidity
levels to rise. Winds have also decreased and the threat of
dangerous fire behavior has ended. Cooler temperatures and lighter
winds are expected Monday which will help keep fire danger levels
below very high or extreme categories.

$$

Area Forecast Discussion
National Weather Service Denver/Boulder CO
913 AM MDT Sat Aug 24 2019

.UPDATE...
Issued at 902 AM MDT Sat Aug 24 2019

Water vapor imagery showing upper trof center across east central
Wyoming and tail end of trof extending into northeast Colorado and
supported by 60kt jet streak. QG fields still showing weak to
moderate ascent over the far northeast Corner this morning.
Result of this feature has been showers that have developed and
has expanded in the past hour. Given still a moist, southeast low
level flow, expect a few thunderstorms as well this morning. Have
already adjusted forecast to add some showers this morning over
the northeast corner but will need to expand this area a bit more
west into Washington and Logan county as well.

Further west, a drier airmass will continue to filter in from the
west and northwest as a moderate northwest flow aloft develops.
Already seeing some gusty winds in the mountains with Berthoud
Pass gusty winds to 50 mph. No thunderstorms expected anywhere
today except the far northeast corner of Colorado.

&&

.SHORT TERM...(Today and tonight)
Issued at 406 AM MDT Sat Aug 24 2019

There are still a few tiny showers over the plains, a little
surprise apparently reflecting a little pocket of weaker capping
behind last night's shortwave trough. These should dissipate
quickly as the expected warming aloft and drying moves in from the
west. There are a few patches of stratus over the plains but so
far higher than the last couple of mornings. This should increase
through sunrise, especially over the eastern part of the plains
and it should be slower to dissipate in that area as well. This
will keep temperatures cooler through the day, which should also
keep convection from forming on the west edge of the moisture.
There will likely be some late afternoon storms further east where
the moisture is richer, but this will likely be along or east of
the state line.

Further west, it should be too dry for much more than cumulus
clouds this afternoon, and if the warming aloft comes fast enough
that may even be difficult. There will be some wind mixing down
this afternoon, mainly over the mountains, which will cause fire
weather concerns. East of the mountains the low level flow will be
dominated by the shedding of a Denver cyclone vortex that should
develop in the next few hours and move east, leaving north winds
into Denver. This could transition to a better mixed northwest
flow near the end of the day, but even then it would likely be
northwest near Wyoming and curl around into Denver from the north
or northeast. Forecast temperatures for today remain a bit above
guidance and still look good given the amount of sun and drying we
expect today. It will be a mild night in most areas with enough
wind to keep some mixing, though calm spots could drop more under
clear skies.

.LONG TERM...(Sunday through Friday)
Issued at 406 AM MDT Sat Aug 24 2019

High to extreme fire danger expected on Sunday, reference the
fire weather discussion below. For Sunday and Sunday night, a
strong northwesterly flow will be over the region with the passage
of a 110 kt upper level jet max moving across Wyoming. Forecast
models keep northern Colorado on the warm and subsident part of
the right exit region of the jet. 250 mb winds over northern CO in
the 60-70kt range for Sunday. In addition, high temperatures will
be just shy of record highs. The record high in Denver for the
25th is 99 set in 2011. A lee trough over eastern CO should help
to enhance the downslope warming over the foothills with min rh
below 15 percent. Expect very gusty winds in the Front Range
mountains and foothills, anywhere from 35 to 55 mph. There will be
a slow recovery Sunday evening with gusty winds persisting
especially along the Front Range ahead of an approaching cool
front. This feature should push into the region from the
north/northeast after 06z Sunday night. Monday through Tuesday,
temperatures across the urban corridor and northeast plains will
drop back into the low to mid 80s. The flow aloft will continue
to be northwesterly across the forecast area with a secondary cool
front pushing through the northeast plains around 12z Tuesday.
The fire danger will not be as extreme but will remain elevated in
the mountains west of the Continental Divide where these fronts
will have no significant impact. From the Front Range Foothills
eastward however, the models show at least enough moisture over
the plains for a slight chance of showers/thunderstorms Tuesday
into Wednesday. Temperatures are expected to start climbing back
up on Wednesday, with a few solutions forecasting highs back around
90. Consensus however keeps the highs just shy of that. Thursday
through Saturday, the upper ridge is forecast to be over the
Desert Southwest with a zonal flow aloft over Colorado. The models
indicate another front bringing cooler temperatures and better
moisture into the northeast plains from the Great Plains. It may
be overdone but overall there should be a better chance of
thunderstorms each day, mainly from the Front Range Foothills
eastward with a drier zonal flow over the mountains.

&&

.AVIATION...(For the 18Z TAFS through 18Z Sunday afternoon)
Issued at 902 AM MDT Sat Aug 24 2019

VFR with drier airmass today and no thunderstorms expected.
Surface winds shifting northwest this morning before shifting
east and southeast later this afternoon and evening. Speeds
generally 15kt or less through the period.

&&

.FIRE WEATHER...
Issued at 406 AM MDT Sat Aug 24 2019

Warmer and drier air will move in today along with a little
stronger winds aloft. This will create conditions near Red Flag
criteria over the northern Colorado mountains and near the
foothills north of Denver this afternoon. Both the weather and
fuel conditions look marginal in most areas, so no warning will be
issued for today, but heightened caution is still advised.

Critical fire weather conditions are forecast for Sunday
afternoon. The combination of hot temperatures, low relative
humidities and gusty northwest winds will likely impact favored
elevated locations. The wind will be strongest in the mountains
north of I-70 and along the Wyoming border.  The main areas set
for high to extreme fire conditions will be the Medicine Bow and
Front Range mountain ranges below 10 thousand feet, the high
mountain valleys as well as areas in and near the northern Front
Range foothills and Cheyenne Ridge. Some question as to whether
zone 242 in northeast Weld County should be included in the
watch. Observed rainfall in the last 7 days is in the 2-4 inch
range. Will leave the watch as is for now and let the day shift
have the final call on that zone.

&&

.BOU WATCHES/WARNINGS/ADVISORIES...
Fire Weather Watch from Sunday morning through Sunday evening
for COZ211-213>215-238-242.

&&

UPDATE...Entrekin
SHORT TERM...Gimmestad
LONG TERM...Cooper
AVIATION...Entrekin
FIRE WEATHER...Gimmestad/Cooper

Hazardous Weather Outlook
National Weather Service Denver/Boulder CO
930 AM MDT Sat Aug 24 2019

COZ030>051-251530-
Jackson County Below 9000 Feet-
West Jackson and West Grand Counties Above 9000 Feet-
Grand and Summit Counties Below 9000 Feet-
South and East Jackson/Larimer/North and Northeast Grand/
Northwest Boulder Counties Above 9000 Feet-
South and Southeast Grand/West Central and Southwest Boulder/
Gilpin/Clear Creek/Summit/North and West Park Counties Above
9000 Feet-Larimer and Boulder Counties Between 6000 and 9000 Feet-
Jefferson and West Douglas Counties Above 6000 Feet/Gilpin/Clear
Creek/Northeast Park Counties Below 9000 Feet-
Central and Southeast Park County-
Larimer County Below 6000 Feet/Northwest Weld County-
Boulder And Jefferson Counties Below 6000 Feet/West Broomfield
County-
North Douglas County Below 6000 Feet/Denver/West Adams and
Arapahoe Counties/East Broomfield County-
Elbert/Central and East Douglas Counties Above 6000 Feet-
Northeast Weld County-Central and South Weld County-Morgan County-
Central and East Adams and Arapahoe Counties-
North and Northeast Elbert County Below 6000 Feet/North Lincoln
County-
Southeast Elbert County Below 6000 Feet/South Lincoln County-
Logan County-Washington County-Sedgwick County-Phillips County-
930 AM MDT Sat Aug 24 2019

...High to Extreme Fire Danger this Weekend...

This hazardous weather outlook is for northeast and north central
Colorado.

.DAY ONE...Today and Tonight

Areas in and near the mountains will be warmer and drier today.
Wind gusts of 20 to 30 mph will be common this afternoon in the
mountains, causing elevated fire danger. Over the high mountain
passes, gusts up to 50 mph can be expected.

Scattered showers and a few thunderstorms will continue over the
far northeast plains of Colorado through this afternoon, mainly
east a line from Akron to Sterling. Brief rain and gusty winds
will accompany the showers.

.DAYS TWO THROUGH SEVEN...Sunday through Friday

Hot, windy and dry conditions on Sunday will produce high to
extreme fire danger. Conditions will be most extreme in the Front
Range mountains below 10 thousand feet, high mountain valleys, in
and near the northern foothills and Cheyenne Ridge. A Fire
Weather Watch is in effect for most of these areas on Sunday
afternoon.

Temperatures will be closer to normal through most of next week as
a series of cool fronts move into the northeast plains. There
will be a slight chance of thunderstorms by the mid-week, with a
better chance of thunderstorms by the end of the week.

.SPOTTER INFORMATION STATEMENT...

Spotter activation will not be needed today or tonight.