High Wind Warning 5, NWS Denver/Boulder, CO

022 
WWUS75 KBOU 090402
NPWBOU

URGENT - WEATHER MESSAGE
National Weather Service Denver/Boulder CO
902 PM MST Fri Mar 8 2019

...VERY WINDY IN THE FOOTHILLS LATE TONIGHT INTO SATURDAY
MORNING...

.Strong west winds will increase after midnight in the high
country and foothills east of the Continental Divide. The normal
wind prone areas will likely see the highest gusts, Berthoud
Pass, along the Peak to Peak Highway, and along Coal Creek
Canyon. Some stronger gusts may reach down into the nearby plains
affecting areas west of I-25, including but not limited to
Highway 93 between Golden and Boulder, and up along the Cheyenne
Ridge.

COZ035-036-091300-
/O.CON.KBOU.HW.W.0005.190309T0700Z-190309T1900Z/
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 Estes Park, Glendevey, Nederland, 
Red Feather Lakes, Bailey, Central City, Evergreen, Georgetown, 
Idaho Springs, and Westcreek
902 PM MST Fri Mar 8 2019

...HIGH WIND WARNING REMAINS IN EFFECT FROM MIDNIGHT TONIGHT TO
NOON MST SATURDAY...

* WINDS...West 35 to 45 mph with gusts up to 75 mph.

* TIMING...Strong west winds will increase after midnight and 
  continue through Saturday morning, decreasing after noon.

* IMPACTS...The strong winds will create blowing snow, reducing 
  visibility to make driving hazardous in areas. Gusty winds 
  will blow around unsecured objects. Tree limbs could be blown 
  down and a few power outages may result. Travel will be 
  difficult for high profile vehicles.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A High Wind Warning means a hazardous high wind event is expected
or occurring. Strong winds may lead to property damage. Hazardous
driving conditions due to powerful cross winds will pose a
serious risk for drivers, especially for light weight and high
profile vehicles. Loose outdoor items should be brought inside or
secured properly.

&&

$$

673 
WWUS75 KBOU 091239
NPWBOU

URGENT - WEATHER MESSAGE
National Weather Service Denver/Boulder CO
539 AM MST Sat Mar 9 2019

...VERY WINDY IN THE FOOTHILLS THIS MORNING...

.Strong west winds have begun this morning in the high country 
and foothills east of the Continental Divide. The normal wind 
prone areas will likely see the highest gusts, Berthoud Pass, 
along the Peak to Peak Highway, and along Coal Creek Canyon. Some 
stronger gusts may reach down into the nearby plains affecting 
areas west of I-25, including but not limited to Highway 93 
between Golden and Boulder, and up along the Cheyenne Ridge. At
early morning wind speeds over 50 mph have been reported.

COZ035-036-091900-
/O.CON.KBOU.HW.W.0005.000000T0000Z-190309T1900Z/
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 Estes Park, Glendevey, Nederland, 
Red Feather Lakes, Bailey, Central City, Evergreen, Georgetown, 
Idaho Springs, and Westcreek
539 AM MST Sat Mar 9 2019

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

* WINDS...West 25 to 35 mph with gusts up to 55 mph.

* TIMING...Strong west winds will continue through this morning, 
  decreasing after noon.

* IMPACTS...Gusty winds will blow around unsecured objects. Tree 
  limbs could be blown down and a few power outages may result. 
  Travel will be difficult for high profile vehicles.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A High Wind Warning means a hazardous high wind event is expected
or occurring. Strong winds may lead to property damage. Hazardous
driving conditions due to powerful cross winds will pose a
serious risk for drivers, especially for light weight and high
profile vehicles. Loose outdoor items should be brought inside or
secured properly.

&&

$$

338 
WWUS75 KBOU 091610
NPWBOU

URGENT - WEATHER MESSAGE
National Weather Service Denver/Boulder CO
910 AM MST Sat Mar 9 2019


COZ035-036-091715-
/O.CAN.KBOU.HW.W.0005.000000T0000Z-190309T1900Z/
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 Estes Park, Glendevey, Nederland, 
Red Feather Lakes, Bailey, Central City, Evergreen, Georgetown, 
Idaho Springs, and Westcreek
910 AM MST Sat Mar 9 2019

...HIGH WIND WARNING IS CANCELLED...

The National Weather Service in Denver has cancelled the High
Wind Warning.

Although it will remain windy this morning, the winds are no
longer expected to reach high wind criteria. Therefore the High 
Wind Warning had been cancelled. The wind is expected to 
gradually decrease through the day.

$$

Area Forecast Discussion
National Weather Service Denver/Boulder CO
224 PM MST Fri Mar 8 2019

.SHORT TERM...(This evening through Saturday)
Issued at 224 PM MST Fri Mar 8 2019

Very active weather pattern over the next 12 hours. Water vapor
satellite imagery showing a short wave trough spinning over Utah.
This trough will track east across Colorado tonight. Lift ahead of
this trough will continue to produce widespread snow across the
mountains of Colorado. In addition to this, the airmass is
unstable with surface based CAPE off the RAP up to 400 J/kg.
Because of the lift and instability, showers and a few
thunderstorms will likely produce areas of heavy snowfall.
Snowfall rates will top 2 inches an hour for a short time under to
strongest convection. Mountain roads will become snowpacked and
slippery by sunset. Convection then rolls off the foothills after
00Z. The airmass should be warm enough for mainly rain. However,
under the stronger convection, snow and ice pellets will be
possible. If this occurs, expect accumulation to be less than an
inch. Over the far northeast corner of Colorado, ahead of the
convection, drizzle will be possible. Temperatures should be warm
enough that it would not be freezing drizzle.

Strongest mountain stable layer occurs 12Z to 18Z Saturday. This
combined with subsidence behind the exiting system and strong flow
aloft will result in very windy conditions for the higher
mountains and Front Range Foothills. Will upgrade the High Wind
Watch to a Warning. Will need a decent mountain wave to form to
help accelerate winds down the foothills. Models show a mountain
wave forming late tonight and Saturday morning. Will it be enough
to help winds reach 75mph? Tough call, so confidence on Warning is
on the low side. Windy conditions will prevail across northeast
Colorado as well Saturday. Right now, appears gust to 50 mph will
be possible, so no High Wind Warning at this time.

There will be enough moisture embedded in the strong flow aloft
to produce orographic snow showers over the mountains late tonight
and Saturday. Additional snowfall will be light for the mountains
Saturday. Most locations will see little if any snowfall,
orographic favored areas may see up to 2 inches of snow.

.LONG TERM...(Saturday night through Friday)
Issued at 224 PM MST Fri Mar 8 2019

For Saturday night, the winds will be diminishing across the far
northeast plains as the storm system rapidly shifts into the
upper Midwest. There will areas of continued light snow in the
mountains, but amounts will be minimal.

For Sunday and Sunday night, a more tranquil day across Colorado
as high pressure ridge builds into the state. The flow aloft will
be shifting back more southwest in response to the next Pacific
system which will be digging down into Baja by early next week.
There will still be some snow showers in the mountains, but
moisture trajectories look to keep most of the showers over
northwest Colorado, including portions of Jackson county and
lesser snow chances further south along the I70 corridor. The
plains will be dry and mild on Sunday but should see an influx of
low level moisture Sunday night into Monday morning. A developing
Denver cyclone may also result in low clouds and fog moving into
the Denver area as well. Deeper subtropical moisture riding along
a jet streak will also be advecting into the region during the
day on Monday in advance of the strong upper low over Baja. Expect
scattered showers to develop across the plains, especially
southern sections over the Palmer Divide and Lincoln county.

The main question through the middle of next week is the track
of the Baja low as it moves northeast through Wednesday.  There
is a bit better continuity in model track again today with the low
moving into southeast Colorado late Tuesday and early Wednesday
before moving it into eastern Nebraska by late Wednesday. The
European/Canadian solutions show this the most, while the GFS
track is still a bit further east and south. With this overall
track, there is a threat of heavy snow somewhere over eastern
Colorado early next week especially if European/Canadian verifies.

For Thursday and Friday, there will still be a fair amount of
troughiness over the region for a continued chance of snow
showers over the mountains. The plains will generally be dry for
later in the week.

&&

.AVIATION...(For the 18Z TAFS through 18Z Saturday afternoon)
Issued at 224 PM MST Fri Mar 8 2019

A circulation just east of KDEN is producing north winds at KDEN
and KBJC. Winds may shift to the southwest around 22Z if the
circulation lifts north. Some models show this winds shift, some
don't. It will be close and wouldn't be surprised if the boundary
stall over KDEN airport grounds. Focus then shifts to showers and
perhaps a couple thunderstorms moving off the foothills this
evening. Best chance for convection will be 01Z to 05Z. Expect
precipitation to be mainly rain, though under the heavier activity
would expect ice pellets and/or snow. If any accumulations were
to occur they will be light. On Saturday, partly cloudy to mostly
sunny skies will prevail Saturday. Gusty northwest winds to 30
knots will be possible after 15Z.

&&

.BOU WATCHES/WARNINGS/ADVISORIES...
High Wind Warning from midnight MST tonight through Saturday
morning for COZ035-036.

Winter Storm Warning until 6 AM MST Saturday for COZ031-033-034.

&&

SHORT TERM...Meier
LONG TERM...Entrekin
AVIATION...Meier

Hazardous Weather Outlook
National Weather Service Denver/Boulder CO
1000 AM MST Fri Mar 8 2019

COZ030>051-091700-
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-
1000 AM MST Fri Mar 8 2019

...WINTER STORM WARNING FOR HEAVY SNOW FOR THE NORTHERN AND
CENTRAL COLORADO MOUNTAINS THIS AFTERNOON AND TONIGHT...
...HIGH WIND WATCH FRONT RANGE FOOTHILLS LATE TONIGHT AND SATURDAY
MORNING...

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

.DAY ONE...Today and Tonight

An active weather patter remains in place over Colorado which will
bring more snow to the mountains this afternoon and tonight.
Additional snow amounts of 6 to 12 inches are possible, heaviest
amounts are expected over Rabbit Ears Pass and in Summit County. A
few embedded thunderstorms will also be possible, leading to
locally higher snow accumulations.

Plains locations will see scattered rain and snow showers. A few
thunderstorms will also be possible late this afternoon and
evening as the weather disturbance moves out of the mountains and
across northeast Colorado. Gusty west winds are expected in the
mountains and Front Range Foothills later tonight as a strong
upper level jet makes its way over the state. Winter Storm
Warnings for the mountains and a High Wind Watch for the Front
Range Foothills are in effect for this afternoon and tonight to
highlight the dangerous nature of this weather pattern.

.DAYS TWO THROUGH SEVEN...Saturday through Thursday

It will be very windy on Saturday over the higher terrain and
across the plains. Potential gusts up to 80 mph will be possible
in the foothills with up to 50 mph across the plains. Areas of
light snow will continue in the mountains.

Another weather system may affect the area Monday night through
Wednesday bringing another round of precipitation to the region.

.SPOTTER INFORMATION STATEMENT...

Snowfall reports from spotters will be appreciated.