High Wind Warning 1, NWS Denver/Boulder, CO

978 
WWUS75 KBOU 192155
NPWBOU

URGENT - WEATHER MESSAGE
National Weather Service Denver CO
255 PM MST Sun Feb 19 2023

COZ033>036-201300-
/O.CON.KBOU.HW.W.0001.230219T2200Z-230221T1900Z/
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-
Including the cities of Bailey, East Slopes Mosquito Range,
Winter Park, Rabbit Ears Range, Indian Peaks, Central City,
Willow Creek Pass, Williams Fork Mountains, Evergreen, Cameron
Pass, Rocky Mountain National Park, Berthoud Pass, East Slopes
Southern Gore Range, Idaho Springs, Estes Park, Kenosha
Mountains, Westcreek, Glendevey, Mount Evans, Eisenhower Tunnel,
Laramie and Medicine Bow Mountains, Breckenridge, Red Feather
Lakes, Georgetown, and Nederland
255 PM MST Sun Feb 19 2023

...HIGH WIND WARNING REMAINS IN EFFECT UNTIL NOON MST TUESDAY...

* WHAT...West winds 40 to 50 mph with gusts up to 85 mph expected.

* WHERE...Rocky Mountain National Park and the Medicine Bow Range, 
  The Mountains of Summit County, the Mosquito Range, and the Indian 
  Peaks, The Northern Front Range Foothills, and The Southern Front 
  Range Foothills.

* WHEN...From 3 PM this afternoon to Noon MST Tuesday. There may be 
  multiple periods of strongest winds during this prolonged wind 
  event. One is forecast for this evening through the overnight 
  tonight, and another is possible Monday night into Tuesday morning.

* IMPACTS...Damaging winds may blow down trees and power lines. 
  Isolated power outages are expected. Travel will be difficult, 
  especially for high profile vehicles.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Watch for falling debris and tree limbs. Use caution if you must 
drive.

&&

$$

For more information from the National Weather Service, visit 
https://weather.gov/bou

EJD

335 
WWUS75 KBOU 200927
NPWBOU

URGENT - WEATHER MESSAGE
National Weather Service Denver CO
227 AM MST Mon Feb 20 2023

COZ033>036-201800-
/O.CON.KBOU.HW.W.0001.000000T0000Z-230221T1900Z/
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-
Including the cities of Cameron Pass, Winter Park, Rabbit Ears
Range, Mount Evans, Williams Fork Mountains, Idaho Springs, Estes
Park, East Slopes Southern Gore Range, Indian Peaks, Kenosha
Mountains, Glendevey, Bailey, Rocky Mountain National Park,
Berthoud Pass, Nederland, Eisenhower Tunnel, Evergreen,
Breckenridge, Laramie and Medicine Bow Mountains, East Slopes
Mosquito Range, Georgetown, Central City, Willow Creek Pass, Red
Feather Lakes, and Westcreek
227 AM MST Mon Feb 20 2023

...HIGH WIND WARNING REMAINS IN EFFECT UNTIL NOON MST TUESDAY...

* WHAT...West winds 35 to 45 mph with gusts up to 75 mph ongoing.

* WHERE...Rocky Mountain National Park and the Medicine Bow Range, 
  The Mountains of Summit County, the Mosquito Range, and the Indian 
  Peaks, The Northern Front Range Foothills, and The Southern Front 
  Range Foothills.

* WHEN...While there may be a few lulls in the wind, peak wind gusts 
  are expected to reach 75 mph or more in wind prone areas. The 
  strongest winds are expected to occur this morning, with perhaps a 
  bigger lull in the winds late this afternoon and evening, followed 
  by another blast of high winds late tonight and Tuesday morning.

* IMPACTS...Damaging winds may blow down trees and power lines. 
  Isolated power outages are expected. Travel will be difficult, 
  especially for high profile vehicles.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Watch for falling debris and tree limbs. Use caution if you must 
drive.

&&

$$

For more information from the National Weather Service, visit 
https://weather.gov/bou

Barjenbruch

510 
WWUS75 KBOU 201635
NPWBOU

URGENT - WEATHER MESSAGE
National Weather Service Denver CO
935 AM MST Mon Feb 20 2023

COZ033>036-210045-
/O.CON.KBOU.HW.W.0001.000000T0000Z-230221T1900Z/
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-
Including the cities of East Slopes Mosquito Range, Laramie and
Medicine Bow Mountains, Nederland, East Slopes Southern Gore
Range, Glendevey, Bailey, Cameron Pass, Rabbit Ears Range,
Westcreek, Eisenhower Tunnel, Indian Peaks, Estes Park,
Georgetown, Berthoud Pass, Rocky Mountain National Park, Mount
Evans, Winter Park, Idaho Springs, Breckenridge, Kenosha
Mountains, Evergreen, Red Feather Lakes, Williams Fork Mountains,
Central City, and Willow Creek Pass
935 AM MST Mon Feb 20 2023

...HIGH WIND WARNING REMAINS IN EFFECT UNTIL NOON MST TUESDAY...

* WHAT...West winds 30 to 50 mph with gusts up to 85 mph expected.

* WHERE...Rocky Mountain National Park and the Medicine Bow Range, 
  The Mountains of Summit County, the Mosquito Range, and the Indian 
  Peaks, The Northern Front Range Foothills, and The Southern Front 
  Range Foothills.

* WHEN...Winds are expected to peak this morning, with some decrease 
  later today, then increase again Tuesday morning.

* IMPACTS...Gusty winds will blow around unsecured objects and a few 
  power outages may result. Damage to trees and buildings is 
  possible.

* ADDITIONAL DETAILS...Morning wind reports include 88 mph in the 
  Sunshine area west of Boulder and 72 mph at Rocky Flats.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Winds this strong can make driving difficult, especially for high 
profile vehicles. Use extra caution. Wind prone areas will be 
highway 93 between Golden and Boulder, highway 36 between 
Broomfield, Boulder, and Lyons, the Peak-to-Peak highway from Black 
Hawk to Estes Park. Drivers of high profile vehicles should consider 
avoiding these areas this morning.

&&

$$

For more information from the National Weather Service, visit 
https://weather.gov/bou

Gimmestad

322 
WWUS75 KBOU 202207
NPWBOU

URGENT - WEATHER MESSAGE
National Weather Service Denver CO
307 PM MST Mon Feb 20 2023

COZ033>036-211200-
/O.CON.KBOU.HW.W.0001.000000T0000Z-230221T1900Z/
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-
Including the cities of East Slopes Mosquito Range, Laramie and
Medicine Bow Mountains, Nederland, East Slopes Southern Gore
Range, Glendevey, Bailey, Cameron Pass, Rabbit Ears Range,
Westcreek, Eisenhower Tunnel, Indian Peaks, Estes Park,
Georgetown, Berthoud Pass, Rocky Mountain National Park, Mount
Evans, Winter Park, Idaho Springs, Breckenridge, Kenosha
Mountains, Evergreen, Red Feather Lakes, Williams Fork Mountains,
Central City, and Willow Creek Pass
307 PM MST Mon Feb 20 2023

...HIGH WIND WARNING REMAINS IN EFFECT UNTIL NOON MST TUESDAY...

* WHAT...West winds 30 to 45 mph with gusts up to 80 mph.

* WHERE...Rocky Mountain National Park and the Medicine Bow Range, 
  The Mountains of Summit County, the Mosquito Range, and the Indian 
  Peaks, The Northern Front Range Foothills, and The Southern Front 
  Range Foothills.

* WHEN...It will remain windy through Tuesday morning with 40 to 60 
  mph gusts common. The greatest threat of damaging winds up to 80 
  mph is late tonight and early Tuesday morning.

* IMPACTS...Gusty winds will blow around unsecured objects and a few 
  power outages may result.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Winds this strong can make driving difficult, especially for high 
profile vehicles. Use extra caution.

&&

$$

For more information from the National Weather Service, visit 
https://weather.gov/bou

Gimmestad

040 
WWUS75 KBOU 211107
NPWBOU

URGENT - WEATHER MESSAGE
National Weather Service Denver CO
407 AM MST Tue Feb 21 2023

COZ033>036-211900-
/O.CON.KBOU.HW.W.0001.000000T0000Z-230221T1900Z/
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-
Including the cities of Westcreek, Willow Creek Pass, Rabbit Ears
Range, Winter Park, Rocky Mountain National Park, Estes Park,
East Slopes Mosquito Range, Central City, Georgetown, Bailey,
Berthoud Pass, Cameron Pass, Williams Fork Mountains, Eisenhower
Tunnel, Breckenridge, Mount Evans, Indian Peaks, Red Feather
Lakes, Nederland, Evergreen, Laramie and Medicine Bow Mountains,
Glendevey, East Slopes Southern Gore Range, Kenosha Mountains,
and Idaho Springs
407 AM MST Tue Feb 21 2023

...HIGH WIND WARNING REMAINS IN EFFECT UNTIL NOON MST TODAY...

* WHAT...West winds 40 to 50 mph with gusts up to 75 mph ongoing.

* WHERE...Rocky Mountain National Park and the Medicine Bow Range, 
  The Mountains of Summit County, the Mosquito Range, and the Indian 
  Peaks, The Northern Front Range Foothills, and The Southern Front 
  Range Foothills.

* WHEN...Until Noon MST today.

* IMPACTS...Gusty winds will blow around unsecured objects and a few 
  power outages may result.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Winds this strong can make driving difficult, especially for high 
profile vehicles. Use extra caution.

&&

$$

For more information from the National Weather Service, visit 
https://weather.gov/bou

AD

771 
WWUS75 KBOU 211854
NPWBOU

URGENT - WEATHER MESSAGE
National Weather Service Denver CO
1154 AM MST Tue Feb 21 2023

COZ033>036-212000-
/O.EXP.KBOU.HW.W.0001.000000T0000Z-230221T1900Z/
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-
Including the cities of Willow Creek Pass, Winter Park,
Evergreen, Kenosha Mountains, Westcreek, Rabbit Ears Range,
Berthoud Pass, Red Feather Lakes, Estes Park, Central City, East
Slopes Southern Gore Range, Indian Peaks, Rocky Mountain National
Park, Williams Fork Mountains, Breckenridge, Laramie and Medicine
Bow Mountains, Mount Evans, East Slopes Mosquito Range, Cameron
Pass, Nederland, Bailey, Idaho Springs, Eisenhower Tunnel,
Glendevey, and Georgetown
1154 AM MST Tue Feb 21 2023

...HIGH WIND WARNING WILL EXPIRE AT NOON MST TODAY...

The threat of high winds has ended. Winds will gradually decrease 
this afternoon, with gusts of 50 to 75 mph above timberline in the 
Front Range and 30 to 50 mph over the east slopes.

$$

For more information from the National Weather Service, visit 
https://weather.gov/bou

Gimmestad

Area Forecast Discussion
National Weather Service Denver/Boulder CO
1048 PM MST Sat Feb 18 2023

.UPDATE...
Issued at 859 PM MST Sat Feb 18 2023

Other than breezy conditions in the high country and adjacent
plains, weather has been quiet this evening. Satellite imagery
shows scattered clouds across the plains. Not a whole lot of
moisture over the region which is to be expected as the upper
trough hasn't begun to influence the area just yet. After
midnight, moisture increases in the high country and with some
weak ascent, will initiate snow up there. Made some minor
adjustments to the PoPs such as increasing chances in the
Park range/Rabbit Ears Pass area since they will be more favored
in this incoming round of snow. Accumulations from the previous
forecast still look reasonable with Park Range and Rabbit Ears
Pass on the higher end at 4-9" with localized higher amounts. 2-6"
for the I-70 mountain corridor and US40. With breezy conditions
expected tomorrow, blowing snow will be one of the main concerns
to travel tomorrow. This may result in hazardous travel, including
the anticipated weekend ski traffic, so please travel carefully
and be prepared.

&&

.SHORT TERM...(This evening through Sunday)
Issued at 325 PM MST Sat Feb 18 2023

Latest satellite pictures are showing the mountains to be pretty
sunny right now. There are still cloudy skies over the plains and
some of the foothills at this time. Winds over the plains and
foothills are variable and pretty light. West-northwesterly winds
prevail in the high country.

Models show weak upper troughing in fairly strong westerly flow
aloft to push into the CWA later tonight and Sunday.  The QG Omega
fields have only weak upward vertical velocity for the forecast
area. Models keep lee troughing over the plains tonight and
Sunday. The low level pressure gradient is fairly strong. The
cross sections do show a bit of a mountains wave set-up
overnight. It shows a better one developing by late day Sunday.
Will make sure the grids have ample wind speeds. No highlights for
winds tonight or Sunday.

Looking at moisture, the current upper level cloudiness is expected
to push off to the east this evening.  The cross sections show lower
and mid level moisture push into the mountains around 12Z Sunday
morning. The moisture is short lived and sticks around into early
afternoon before decreasing significantly by 00Z late Sunday
afternoon. Will adjust the sky cover and pops accordingly. Will
go with "likely" pops in all the mountains on Sunday, less in the
high valleys. No pops for the plains. Will leave the Snow
Advisory going in Zone 31 with marginal snowfall totals expected
on Sunday.

For temperatures, Sunday's highs are 1-3 C cooler than today's
readings.

.LONG TERM...(Sunday night through Saturday)
Issued at 325 PM MST Sat Feb 18 2023

Warm advection and subsidence aloft combined with the strong mid
level northwesterly flow will create favorable conditions for an
amplified mountain wave Sunday night into Monday. There's little
shear and a nice inversion to trap the wave, and the flow in the
600-500 mb layer is around 50 knots. This looks like a chinook-
type event with the wave likely to stay focused on the foothills,
but there's nothing to stop it from surfacing and at its peak it
could be a situation with the strongest winds at the bottom near
the base of the foothills. We're lacking cold advection or much
low level gradient for a widespread downward forcing of the
momentum, but the wave itself should be pretty good. The main
threat of strong amplification looks to be Sunday night, with the
inversion fading by Monday afternoon. There may be another window
of high wind threat on Tuesday ahead of the next trough. We'll
maintain the current watch and will need to give some
consideration to marginal high winds in wave prone areas east of
the foothills like Boulder and Broomfield.

We'll still be fighting the snowpack and resulting shallow stable
layer over the plains where temperatures will remain cooler with
lighter winds. However, the westerlies above it will be making
progress on the depth and intensity of the inversion. Temperatures
Monday and Tuesday will likely be near 60 along the foothills with
the snow disappearing fast, with 40s over the areas with the more
persistent snow cover.

With the mid to late week long wave trough over the west, there
continues to be a gradual trend toward more cold air and deeper
troughing on the back side of the long wave trough over the
southwest. There's still a substantial cold front Tuesday night
that gets overrun by moist air and a strong lead shortwave that
has slowed a bit more and may bring the strongest lift late
Wednesday. Differences remain about how strong the cold push is.
The consensus is still for plains highs in the 20s or 30s
Wednesday and Friday and teens or 20s Thursday, with the warmer
models mostly about 10 degrees warmer. There are still a few that
have a much weaker push of cold air, but less of that in the
ensemble each day. The increased focus on the west side of the
long wave trough means more ridging over our area Thursday and
Friday, which is really pronounced in the 12z model suite. There's
a battle between this ridging aloft and the surface pressure
falls to the south that tries to pull in another surge of cold air
Friday. But the ridging trend would mean a better chance of a warm
up Saturday and maybe into Sunday depending on the eventual fate
of the next shortwave/low in the base of the larger trough.

The NBM remains like a pretty reasonable forecast with all this
and we've stayed pretty close to it. The result is mainly light
snow starting Tuesday night in the mountains and probably
Wednesday morning on the plains, ending for the most part by
Thursday morning. Thursday would be the coldest day. We're showing
below zero lows Thursday morning but that might be counting on
clearing and if that comes more slowly the cold could be
mitigated.

&&

.AVIATION...(For the 06Z TAFS through 06Z Sunday night)
Issued at 1048 PM MST Sat Feb 18 2023

Main challenge will be the wind forecasts through the entire
period. There is a bit of mountain wave activity noted this
evening with some potential for variable winds through about 09Z,
before winds finally settle down to typical south/southwest winds
overnight. On Sunday, we still see stronger west/northwest winds
developing but unsure of the start time since slight variations in
temperature/pressure fields will have impacts. Most mesoscale
models start the stronger and gusty winds closer to 15Z, before
boundary layer warming begins. That seems early given the lack of
mixing, so we think closer to 17Z may end up reality but still a
fair amount of uncertainty give or take an hour or two. With the
strength of the flow, we've trended the gusts upward from the
previous forecast and could see crosswind limitations exceeded at
times for north/south runway operations at KDEN 17Z Sun - 00Z Mon
with occasional gusts up to 35 knots possible at KDEN and KAPA.

KBJC will likely see west winds a couple hours earlier, and they
will be stronger there with gusts around 40 knots. Can't even rule
out stronger gusts to 50 knots after 03Z Mon due to stronger
mountain wave development, or even light/variable winds if
mountain wave holds in the foothills. Odds favor the latter at
this point.

&&

.BOU WATCHES/WARNINGS/ADVISORIES...
Winter Weather Advisory from 2 AM to 5 PM MST Sunday for COZ031.

High Wind Watch from Sunday afternoon through Monday evening for
COZ033>036.

&&

UPDATE...Mensch
SHORT TERM...RJK
LONG TERM....Gimmestad
AVIATION...Barjenbruch

Hazardous Weather Outlook
National Weather Service Denver/Boulder CO
1107 AM MST Sat Feb 18 2023

COZ030>051-191815-
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-
1107 AM MST Sat Feb 18 2023

...SNOW AND BLOWING SNOW FOR THE NORTHERN MOUNTAINS LATE TONIGHT
AND SUNDAY...
...HIGH WIND WATCH FOR THE FRONT RANGE MOUNTAINS AND FOOTHILLS
SUNDAY EVENING THROUGH MONDAY EVENING...

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

.DAY ONE...Today and Tonight

Snow and areas of blowing snow will move into the northern
mountains late tonight, with hazardous winter travel conditions
developing by Sunday morning. Gusty westerly winds up to 60 mph
can be expected in wind prone areas of the mountains and
foothills by later tonight.

.DAYS TWO THROUGH SEVEN...Sunday through Friday

Snow and blowing snow will continue over the mountains Sunday. The
heaviest accumulation will be north of Berthoud Pass where totals
of 4-8 inches are expected. Snow will be lighter further south.

Strong westerly winds will blow over the higher elevations and
east slopes through Monday. Gusts of 40 to 60 mph will be common
in those areas, and may occasionally spill onto the plains just
east of the mountains. Damaging wind gusts up to 80 mph are
possible in the foothills with the greatest threat Sunday night.

Another weather system will bring much colder temperatures for
Wednesday through Friday. Snow is likely in the mountains, and
light snow is likely at lower elevations mainly Wednesday and
Wednesday night.

.SPOTTER INFORMATION STATEMENT...

Spotter activation will not be needed today or tonight.

RJK/Gimmestad