Alert archive / Arizona / Winter Storm Watches in 2021

Winter Storm Watch 2, NWS Flagstaff, AZ

December 29, 20215 counties in Arizona

NWS Flagstaff, AZ issued this winter storm watch at Dec 29, 2021, 1:54 PM MST for 5 counties in Arizona. It took effect at Dec 30, 2021, 5:00 PM MST. It was in force for .

The area

The counties it named.

The facts

Issued
Dec 29, 2021, 1:54 PM MST (20:54 UTC)
In effect from
Dec 30, 2021, 5:00 PM MST
Expired
Dec 30, 2021, 2:12 PM MST
In force
Issued by
NWS Flagstaff, AZ

Counties Apache County, AZ, Coconino County, AZ, Gila County, AZ, Navajo County, AZ, Yavapai County, AZ

The radar

The Flagstaff radar (KFSX), 52 km from the middle of the area, began a volume at 20:54 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.

The nearest sounding before it

Flgstf/Belemont, AZ (KFGZ), launched 12:00Z, 8.9 hours before the alert went out and 78 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, Flgstf/Belemont, AZ at 12:00Z on 2021-12-29Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 4 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Flgstf/Belemont, AZ at 12:00Z on 2021-12-29The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 170 square meters per square second.1939587897Sfc1 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
4 J/kg
Mixed-layer CIN
0 J/kg
Mixed-layer LCL
538 m above ground
0-6 km bulk shear
52 kt
0-1 km storm-relative helicity
170 m²/s²
0-3 km storm-relative helicity
311 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

674 
WWUS45 KFGZ 292054
WSWFGZ

URGENT - WINTER WEATHER MESSAGE
National Weather Service Flagstaff AZ
154 PM MST Wed Dec 29 2021

AZZ004-006>008-015-016-018-300500-
/O.NEW.KFGZ.WS.A.0002.211231T0000Z-220101T1200Z/
Kaibab Plateau-Grand Canyon Country-Coconino Plateau-
Yavapai County Mountains-Western Mogollon Rim-
Eastern Mogollon Rim-Northern Gila County-
Including the cities of Jacob Lake, Grand Canyon Village, 
Flagstaff, and Happy Jack
154 PM MST Wed Dec 29 2021

...WINTER STORM WATCH IN EFFECT FROM THURSDAY AFTERNOON THROUGH
LATE FRIDAY NIGHT ABOVE 6000 FEET...

* WHAT...Snow expected above 6000 feet. Total snow accumulations
  of 4 to 12 inches possible, with locally higher amounts over the
  highest mountain peaks.

* WHERE...Areas above 6000 feet near Doney Park, Flagstaff, 
  Forest Lakes, Grand Canyon, Heber-Overgaard, Jacob Lake, North 
  Rim, Pine-Strawberry, Prescott, Valle and Williams.

* WHEN...From Thursday afternoon through late Friday night.

* IMPACTS...Slippery and snow covered roads could led to very
  difficult travel on New Years Eve. Hazardous conditions could 
  impact the morning or evening commute. 

  Snow forecast from 5 PM Thursday to 5 AM Saturday:

     Doney Park  2 to 4  inches       Flagstaff  5 to 9  inches
   Forest Lakes 10 to 16 inches    Grand Canyon  4 to 8  inches
Heber-Overgaard  3 to 5  inches      Jacob Lake  6 to 10 inches
      North Rim  7 to 11 inches Pine-Strawberry  2 to 4  inches
       Prescott  0 to 1  inches           Valle  1 to 3  inches
       Williams  4 to 8  inches.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Monitor the latest forecasts for updates on this situation. 

&&

$$

AZZ014-017-300500-
/O.NEW.KFGZ.WS.A.0002.211231T0600Z-220101T1800Z/
Little Colorado River Valley in Apache County-White Mountains-
Including the cities of Springerville, Show Low, and Greer
154 PM MST Wed Dec 29 2021

...WINTER STORM WATCH IN EFFECT FROM THURSDAY EVENING THROUGH
SATURDAY MORNING ABOVE 6000 FEET...

* WHAT...Snow expected above 6000 feet. Total snow accumulations 
  of 8 to 16 inches possible, with higher amounts over mountain 
  peaks. Winds could gust as high as 40 mph.

* WHERE...Areas above 6000 feet near Alpine, Eagar-
  Springerville, Pinetop-Lakeside and Show Low.

* WHEN...From Thursday evening through Saturday morning.

* IMPACTS...Slippery and snow covered roads could led to very
  difficult travel on New Years Eve. Patchy blowing snow could
  significantly reduce visibility. The hazardous conditions could
  impact the morning or evening commute.

  Snow forecast from 11 PM Thursday to 11 AM Saturday:

         Alpine  7 to 11 inches Eagar-Sprgrvlle  2 to 4  inches
 Pinetop-Lkside  8 to 12 inches        Show Low  4 to 8  inches
.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Monitor the latest forecasts for updates on this situation. 

&&

$$

AZZ011-039-040-300500-
/O.NEW.KFGZ.WS.A.0002.211231T1200Z-220101T1800Z/
Chuska Mountains and Defiance Plateau-Black Mesa Area-
Northeast Plateaus and Mesas South of Hwy 264-
Including the cities of Window Rock and Ganado
154 PM MST Wed Dec 29 2021

...WINTER STORM WATCH IN EFFECT FROM LATE THURSDAY NIGHT THROUGH
SATURDAY MORNING ABOVE 6000 FEET...

* WHAT...Snow expected above 6000 feet. Total snow accumulations 
  of 3 to 8 inches possible.

* WHERE...Areas above 6000 feet near Buffalo Pass, Dilkon, 
  Ganado, Shonto and Window Rock.

* WHEN...From late Thursday night through Saturday morning.

* IMPACTS...Slippery and snow covered roads could led to very
  difficult travel on New Years Eve. The hazardous conditions 
  could impact the morning or evening commute.

  Snow forecast from 5 AM Friday to 11 AM Saturday:

   Buffalo Pass  7 to 11 inches          Dilkon  2 to 4  inches
         Ganado  4 to 6  inches          Shonto  2 to 4  inches
    Window Rock  4 to 6  inches.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Monitor the latest forecasts for updates on this situation. 

&&

$$

For more information from the National Weather Service visit:
http://weather.gov/flagstaff

For a more detailed table of forecast snow amounts for counties,
reservations and roads go to:
http://weather.gov/flagstaff/SnowTables
3 follow-up statements
669 
WWUS45 KFGZ 292132
WSWFGZ

URGENT - WINTER WEATHER MESSAGE
National Weather Service Flagstaff AZ
232 PM MST Wed Dec 29 2021

AZZ004-006>008-015-016-018-301400-
/O.CON.KFGZ.WS.A.0002.211231T0000Z-220101T1200Z/
Kaibab Plateau-Grand Canyon Country-Coconino Plateau-
Yavapai County Mountains-Western Mogollon Rim-
Eastern Mogollon Rim-Northern Gila County-
Including the cities of Jacob Lake, Grand Canyon Village, 
Flagstaff, and Happy Jack
232 PM MST Wed Dec 29 2021

...WINTER STORM WATCH REMAINS IN EFFECT FROM THURSDAY AFTERNOON
THROUGH LATE FRIDAY NIGHT ABOVE 6000 FEET...

* WHAT...Snow expected above 6000 feet. Total snow accumulations 
  of 4 to 12 inches possible, with locally higher amounts over 
  the highest mountain peaks.

* WHERE...Areas above 6000 feet near Doney Park, Flagstaff, 
  Forest Lakes, Grand Canyon, Heber-Overgaard, Jacob Lake, North 
  Rim, Pine-Strawberry, Prescott, Valle and Williams.

* WHEN...From Thursday afternoon through late Friday night.

* IMPACTS...Slippery and snow covered roads could led to very 
  difficult travel on New Years Eve. Hazardous conditions could 
  impact the morning or evening commute.

  Snow forecast from 5 PM Thursday to 5 AM Saturday:

     Doney Park  2 to 4  inches       Flagstaff  5 to 9  inches
   Forest Lakes 10 to 16 inches    Grand Canyon  4 to 8  inches
Heber-Overgaard  3 to 5  inches      Jacob Lake  6 to 10 inches
      North Rim  7 to 11 inches Pine-Strawberry  2 to 4  inches
       Prescott  0 to 1  inches           Valle  1 to 3  inches
       Williams  4 to 8  inches.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Monitor the latest forecasts for updates on this situation. 

&&

$$

AZZ014-017-301400-
/O.CON.KFGZ.WS.A.0002.211231T0600Z-220101T1800Z/
Little Colorado River Valley in Apache County-White Mountains-
Including the cities of Springerville, Show Low, and Greer
232 PM MST Wed Dec 29 2021

...WINTER STORM WATCH REMAINS IN EFFECT FROM THURSDAY EVENING
THROUGH SATURDAY MORNING ABOVE 6000 FEET...

* WHAT...Snow expected above 6000 feet. Total snow accumulations 
  of 8 to 16 inches possible, with higher amounts over mountain 
  peaks. Winds could gust as high as 40 mph.

* WHERE...Areas above 6000 feet near Alpine, Eagar-
  Springerville, Pinetop-Lakeside and Show Low.

* WHEN...From Thursday evening through Saturday morning.

* IMPACTS...Slippery and snow covered roads could led to very 
  difficult travel on New Years Eve. Patchy blowing snow could 
  significantly reduce visibility. The hazardous conditions 
  could impact the morning or evening commute.

  Snow forecast from 11 PM Thursday to 11 AM Saturday:

         Alpine  7 to 11 inches Eagar-Sprgrvlle  2 to 4  inches
 Pinetop-Lkside  8 to 12 inches        Show Low  4 to 8  inches
.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Monitor the latest forecasts for updates on this situation. 

&&

$$

AZZ011-039-040-301400-
/O.CON.KFGZ.WS.A.0002.211231T1200Z-220101T1800Z/
Chuska Mountains and Defiance Plateau-Black Mesa Area-
Northeast Plateaus and Mesas South of Hwy 264-
Including the cities of Window Rock and Ganado
232 PM MST Wed Dec 29 2021

...WINTER STORM WATCH REMAINS IN EFFECT FROM LATE THURSDAY NIGHT
THROUGH SATURDAY MORNING ABOVE 6000 FEET...

* WHAT...Snow expected above 6000 feet. Total snow accumulations 
  of 3 to 8 inches possible.

* WHERE...Areas above 6000 feet near Buffalo Pass, Dilkon, 
  Ganado, Shonto and Window Rock.

* WHEN...From late Thursday night through Saturday morning.

* IMPACTS...Slippery and snow covered roads could led to very 
  difficult travel on New Years Eve. The hazardous conditions 
  could impact the morning or evening commute.

  Snow forecast from 5 AM Friday to 11 AM Saturday:

   Buffalo Pass  7 to 11 inches          Dilkon  2 to 4  inches
         Ganado  4 to 6  inches          Shonto  2 to 4  inches
    Window Rock  4 to 6  inches.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Monitor the latest forecasts for updates on this situation. 

&&

$$

For more information from the National Weather Service visit:
http://weather.gov/flagstaff

For a more detailed table of forecast snow amounts for counties,
reservations and roads go to:
http://weather.gov/flagstaff/SnowTables
608 
WWUS45 KFGZ 301019
WSWFGZ

URGENT - WINTER WEATHER MESSAGE
National Weather Service Flagstaff AZ
319 AM MST Thu Dec 30 2021

AZZ004-006>008-015-310000-
/O.UPG.KFGZ.WS.A.0002.211231T0000Z-220101T1200Z/
/O.NEW.KFGZ.WW.Y.0015.211231T0000Z-220101T1200Z/
Kaibab Plateau-Grand Canyon Country-Coconino Plateau-
Yavapai County Mountains-Western Mogollon Rim-
Including the cities of Jacob Lake, Grand Canyon Village, 
and Flagstaff
319 AM MST Thu Dec 30 2021

...WINTER WEATHER ADVISORY IN EFFECT FROM 5 PM THIS AFTERNOON TO
5 AM MST SATURDAY ABOVE 6000 FEET...

* WHAT...Snow expected above 6000 feet. Total snow accumulations
  of 2 to 8 inches, with locally higher amounts over mountain
  peaks and the Kaibab Plateau above 8000 feet. The most hazardous
  travel conditions are likely Friday afternoon and evening. 
  Winds gusting as high as 30 mph.

* WHERE...Areas above 6000 feet near Doney Park, Flagstaff, 
  Grand Canyon, Jacob Lake, North Rim, Prescott, Valle and 
  Williams.

* WHEN...From 5 PM this afternoon to 5 AM MST Saturday.

* IMPACTS...Travel could be very difficult. The hazardous
  conditions could impact the morning or evening commute and any
  New Year's Eve travel plans.

  Snow forecast from 5 PM Today to 5 AM Saturday:

     Doney Park  1 to 3  inches       Flagstaff  4 to 8  inches
   Grand Canyon  3 to 5  inches      Jacob Lake  4 to 8  inches
      North Rim  6 to 10 inches        Prescott  0 to 1  inches
          Valle  1 to 3  inches        Williams  4 to 6  inches
.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Slow down and use caution while traveling. 

The latest road conditions for the state you are calling from can
be obtained by calling 5 1 1.

&&

$$

AZZ039-040-310000-
/O.UPG.KFGZ.WS.A.0002.211231T1200Z-220101T1800Z/
/O.NEW.KFGZ.WW.Y.0015.211231T1200Z-220101T1800Z/
Black Mesa Area-Northeast Plateaus and Mesas South of Hwy 264-
319 AM MST Thu Dec 30 2021

...WINTER WEATHER ADVISORY IN EFFECT FROM 5 AM FRIDAY TO 11 AM
MST SATURDAY ABOVE 6000 FEET...

* WHAT...Snow expected above 6000 feet. Total snow accumulations
  of 1 to 4 inches. Winds gusting as high as 30 mph.

* WHERE...Areas above 6000 feet near Dilkon and Shonto.

* WHEN...From 5 AM Friday to 11 AM MST Saturday.

* IMPACTS...Plan on slippery road conditions. The hazardous
  conditions could impact the morning or evening commute, and any
  New Year's Eve travel plans.

  Snow forecast from 5 AM Friday to 11 AM Saturday:

         Dilkon  1 to 2  inches          Shonto  1 to 3  inches
.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Slow down and use caution while traveling. 

The latest road conditions for the state you are calling from can
be obtained by calling 5 1 1.

&&

$$

AZZ014-016>018-310000-
/O.EXT.KFGZ.WS.A.0002.211231T1200Z-220101T1800Z/
Little Colorado River Valley in Apache County-
Eastern Mogollon Rim-White Mountains-Northern Gila County-
Including the cities of Springerville, Happy Jack, Show Low, 
and Greer
319 AM MST Thu Dec 30 2021

...WINTER STORM WATCH NOW IN EFFECT FROM LATE TONIGHT THROUGH
SATURDAY MORNING ABOVE 6000 FEET...

* WHAT...Heavy snow possible above 6000 feet. Total snow
  accumulations of 3 to 11 inches possible, with 12 to 20 inches
  above 8000 feet. For locations between 6000 and 7000 feet
  including Show Low, Springerville, and Pinetop-Lakeside, snow
  accumulation will be minimal until after 5 PM Friday as colder 
  air arrives. Winds could gust as high as 35 mph.

* WHERE...Areas above 6000 feet near Alpine, Eagar-
  Springerville, Forest Lakes, Heber-Overgaard, Pine-Strawberry, 
  Pinetop-Lakeside and Show Low.

* WHEN...From late tonight through Saturday morning.

* IMPACTS...Travel could be very difficult to impossible. Patchy
  blowing snow could significantly reduce visibility. The
  hazardous conditions could impact the morning or evening
  commute, and any New Year's Eve travel plans.

  Snow forecast from 5 AM Friday to 11 AM Saturday:

         Alpine  6 to 10 inches Eagar-Sprgrvlle  2 to 4  inches
   Forest Lakes  7 to 11 inches Heber-Overgaard  2 to 4  inches
Pine-Strawberry  1 to 3  inches  Pinetop-Lkside  6 to 10 inches
       Show Low  3 to 5  inches.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Monitor the latest forecasts for updates on this situation. 

&&

$$

AZZ011-310000-
/O.CON.KFGZ.WS.A.0002.211231T1200Z-220101T1800Z/
Chuska Mountains and Defiance Plateau-
Including the cities of Window Rock and Ganado
319 AM MST Thu Dec 30 2021

...WINTER STORM WATCH REMAINS IN EFFECT FROM LATE TONIGHT THROUGH
SATURDAY MORNING ABOVE 6000 FEET...

* WHAT...Heavy snow possible above 6000 feet. Total snow
  accumulations of 3 to 7 inches possible, with up to a foot above
  8000 feet. Winds could gust as high as 35 mph.

* WHERE...Areas above 6000 feet near Buffalo Pass, Ganado and 
  Window Rock.

* WHEN...From late tonight through Saturday morning.

* IMPACTS...Plan on slippery road conditions. The hazardous 
  conditions could impact the morning or evening commute.

  Snow forecast from 5 AM Friday to 11 AM Saturday:

   Buffalo Pass  4 to 8  inches          Ganado  2 to 4  inches
    Window Rock  2 to 4  inches.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Monitor the latest forecasts for updates on this situation. 

&&

$$

For more information from the National Weather Service visit:
http://weather.gov/flagstaff

For a more detailed table of forecast snow amounts for counties,
reservations and roads go to:
http://weather.gov/flagstaff/SnowTables
322 
WWUS45 KFGZ 302112
WSWFGZ

URGENT - WINTER WEATHER MESSAGE
National Weather Service Flagstaff AZ
212 PM MST Thu Dec 30 2021

AZZ018-302215-
/O.CAN.KFGZ.WS.A.0002.211231T1200Z-220101T1800Z/
Northern Gila County-
212 PM MST Thu Dec 30 2021

...WINTER STORM WATCH IS CANCELLED...

Widespread heavy snowfall is no longer expected, with only 1 to 2
inches expected for elevations above 5000 feet Friday afternoon 
into Saturday morning. Use caution if traveling Friday night 
though as any untreated surfaces may become slick.

$$

AZZ017-310515-
/O.UPG.KFGZ.WS.A.0002.211231T1200Z-220101T1800Z/
/O.NEW.KFGZ.WS.W.0005.211231T1200Z-220101T1800Z/
White Mountains-
Including the city of Greer
212 PM MST Thu Dec 30 2021

...WINTER STORM WARNING IN EFFECT FROM 5 AM FRIDAY TO 11 AM MST
SATURDAY ABOVE 6500 FEET...

* WHAT...Heavy snow expected above 6500 feet and patchy blowing
  snow. Snow showers develop Friday morning and continue into
  Saturday morning, with the heaviest precipitation falling Friday
  evening into early Saturday. Total snow accumulations of 5 to 
  10 inches are expected, with higher amounts of 8 to 16 inches 
  possible above 8000 feet. Winds gusting as high as 45 mph 
  leading to areas of patchy blowing snow.

* WHERE...Areas above 6500 feet near Alpine, Pinetop-Lakeside 
  and Show Low.

* WHEN...From 5 AM Friday to 11 AM MST Saturday.

* IMPACTS...Travel could be very difficult to impossible. Patchy
  blowing snow could significantly reduce visibility. The
  hazardous conditions could impact the morning and evening
  commute, as well as any New Year's Eve travel.

  Snow forecast from 5 AM Friday to 11 AM Saturday:

         Alpine  8 to 12 inches  Pinetop-Lkside  6 to 10 inches
       Show Low  4 to 6  inches.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If you must travel, keep an extra flashlight, food, and water in
your vehicle in case of an emergency. 

The latest road conditions for the state you are calling from can
be obtained by calling 5 1 1.

&&

$$

AZZ011-310515-
/O.UPG.KFGZ.WS.A.0002.211231T1200Z-220101T1800Z/
/O.EXA.KFGZ.WW.Y.0015.211231T1200Z-220101T1800Z/
Chuska Mountains and Defiance Plateau-
Including the cities of Window Rock and Ganado
212 PM MST Thu Dec 30 2021

...WINTER WEATHER ADVISORY IN EFFECT FROM 5 AM FRIDAY TO 11 AM
MST SATURDAY ABOVE 6000 FEET...

* WHAT...Snow expected above 6000 feet. Snow showers develop  
  Friday morning and continue into Saturday morning, with the 
  heaviest precipitation falling Friday evening into early 
  Saturday. Total snow accumulations of 4 to 6 inches. Winds 
  gusting as high as 35 mph.

* WHERE...Areas above 6000 feet near Buffalo Pass, Ganado and 
  Window Rock.

* WHEN...From 5 AM Friday to 11 AM MST Saturday.

* IMPACTS...Plan on slippery road conditions. The hazardous
  conditions could impact the morning and evening commute, as 
  well as any New Year's Eve travel.

  Snow forecast from 5 AM Friday to 11 AM Saturday:

   Buffalo Pass  4 to 8  inches          Ganado  3 to 5  inches
    Window Rock  3 to 5  inches.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Slow down and use caution while traveling. 

The latest road conditions for the state you are calling from can
be obtained by calling 5 1 1.

&&

$$

AZZ014-016-310515-
/O.UPG.KFGZ.WS.A.0002.211231T1200Z-220101T1800Z/
/O.EXA.KFGZ.WW.Y.0015.211231T1200Z-220101T1800Z/
Little Colorado River Valley in Apache County-
Eastern Mogollon Rim-
Including the cities of Springerville and Happy Jack
212 PM MST Thu Dec 30 2021

...WINTER WEATHER ADVISORY IN EFFECT FROM 5 AM FRIDAY TO 11 AM
MST SATURDAY ABOVE 6500 FEET...

* WHAT...Snow expected above 6500 feet. Snow showers develop
  Friday morning and continue into Saturday morning, with the
  heaviest precipitation falling Friday evening into early
  Saturday. Total snow accumulations of 4 to 8 inches, with 
  higher amounts of 8 to 12 inches possible above 7000 feet. Winds
  gusting as high as 35 mph.

* WHERE...Areas above 6500 feet near Eagar-Springerville, Forest 
  Lakes and Heber-Overgaard.

* WHEN...From 5 AM Friday to 11 AM MST Saturday.

* IMPACTS...Travel could be very difficult. The hazardous
  conditions could impact the morning and evening commute, as 
  well as any New Year's Eve travel.

  Snow forecast from 5 AM Friday to 11 AM Saturday:

Eagar-Sprgrvlle  3 to 5  inches    Forest Lakes  9 to 15 inches
Heber-Overgaard  3 to 5  inches.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Slow down and use caution while traveling. 

The latest road conditions for the state you are calling from can
be obtained by calling 5 1 1.

&&

$$

AZZ004-006>008-015-310515-
/O.EXT.KFGZ.WW.Y.0015.211231T0600Z-220101T1200Z/
Kaibab Plateau-Grand Canyon Country-Coconino Plateau-
Yavapai County Mountains-Western Mogollon Rim-
Including the cities of Jacob Lake, Grand Canyon Village, 
and Flagstaff
212 PM MST Thu Dec 30 2021

...WINTER WEATHER ADVISORY NOW IN EFFECT FROM 11 PM THIS EVENING
TO 5 AM MST SATURDAY ABOVE 6000 FEET...

* WHAT...Snow expected above 6000 feet. Snow showers develop after
  midnight tonight and continue into Saturday morning, with the
  heaviest precipitation falling Friday evening into early
  Saturday. Total snow accumulations of 2 to 4 inches, with 4 to 
  8 inches possible above 7000 feet. Winds gusting as high as 35 
  mph.

* WHERE...Areas above 6000 feet near Flagstaff, Doney Park, Grand
  Canyon, Jacob Lake, North Rim, Valle and Williams.

* WHEN...From 11 PM this evening to 5 AM MST Saturday.

* IMPACTS...Travel could be very difficult. The hazardous
  conditions could impact the morning and evening commute, as 
  well as any New Year's Eve travel.

  Snow forecast from 11 PM Today to 5 AM Saturday:

     Doney Park  2 to 4  inches      Flagstaff  3 to 5  inches
   Grand Canyon  1 to 3  inches     Jacob Lake  4 to 6  inches
      North Rim  4 to 6  inches       Prescott  0 to 1  inches
          Valle  1 to 3  inches       Williams  3 to 5  inches.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Slow down and use caution while traveling. 

The latest road conditions for the state you are calling from can
be obtained by calling 5 1 1.

&&

$$

AZZ039-040-310515-
/O.CON.KFGZ.WW.Y.0015.211231T1200Z-220101T1800Z/
Black Mesa Area-Northeast Plateaus and Mesas South of Hwy 264-
212 PM MST Thu Dec 30 2021

...WINTER WEATHER ADVISORY REMAINS IN EFFECT FROM 5 AM FRIDAY TO
11 AM MST SATURDAY ABOVE 6000 FEET...

* WHAT...Snow expected above 6000 feet. Snow showers develop
  Friday morning and continue into Saturday morning, with the
  heaviest precipitation falling Friday evening into early
  Saturday. Total snow accumulations of 2 to 4 inches. Winds 
  gusting as high as 35 mph.

* WHERE...Areas above 6000 feet near Dilkon and Shonto.

* WHEN...From 5 AM Friday to 11 AM MST Saturday.

* IMPACTS...Plan on slippery road conditions. The hazardous 
  conditions could impact the morning and evening commute, as 
  well as any New Year's Eve travel.

  Snow forecast from 5 AM Friday to 11 AM Saturday:

         Dilkon  1 to 3  inches         Shonto  1 to 3  inches.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Slow down and use caution while traveling. 

The latest road conditions for the state you are calling from can
be obtained by calling 5 1 1.

&&

$$

For more information from the National Weather Service visit:
http://weather.gov/flagstaff

For a more detailed table of forecast snow amounts for counties,
reservations and roads go to:
http://weather.gov/flagstaff/SnowTables

What forecasters said that day

The local office's own words before this winter storm watch went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Flagstaff, AZ wrote its last area forecast discussion before this winter storm watch went out at Dec 29, 9:08 AM MST, 4 hours 46 minutes earlier.

Area forecast discussion, Dec 29, 9:08 AM MST, 4 hours 46 minutes before
Area Forecast Discussion
National Weather Service Flagstaff AZ
908 AM MST Wed Dec 29 2021

.SYNOPSIS...For today, the forecast calls for very light snow,
along with freezing drizzle or fog along south facing slopes of
the Mogollon Rim and the mountains of Yavapai County. Drier
conditions and less clouds are expected north of the Rim. Similar
conditions are forecast for Thursday. However, another Winter
Storm is poised to impact the region from late Thursday into early
Saturday morning, with the possibility of heavy snow above 6000
feet elevation.

&&

.DISCUSSION...Current satellite and radar imagery indicates that
the shortwave trough that brought moderate to heavy snowfall to
northern Arizona overnight has moved eastward into New Mexico.
Although, light, upslope snow showers are continuing along
portions of the Mogollon Rim this morning. Expect challenging
driving conditions above around 4000 feet due to a combination of
falling snow and icy roadways.

As the day progresses, shallow low-level moisture will likely cause
periods of light snow grains, along with freezing drizzle and/or
fog along south facing slopes of the Mogollon Rim and the
mountains of Yavapai County. Drier conditions and less clouds are
expected north of the Rim as much of the low-level moisture will
be scoured out before it downslope into the Little Colorado River
Valley. Otherwise, expect well below normal daytime temperatures,
with highs in the 30s and 40s across much of Arizona's High
Country.

In terms of forecast updates, only some minor updates to the
chances for precipitation this morning were made to account for
current radar trends.

&&

.PREV DISCUSSION /347 AM MST/...The potent shortwave trough that
brought a period of moderate to heavy snow above 5000 feet from
Tuesday evening through early this morning is moving east of the
region as of 3 AM. Some showers linger, mainly over the upslope
region of the Mogollon Rim from Flagstaff southeast into the White
Mountains. These showers should also start to diminish after 5 AM
and the remaining Winter Weather Advisories will end at that time.
Later this afternoon through most of Thursday we will see a return
of shallow moisture profiles with saturation only up to about 10K
ft msl where temperatures will be -10C to -12C. Breezy upslope
winds will keep higher terrain areas cloudy through this period,
with some light snow showers or even freezing fog or mist at
times. Additional snow accumulations are expected to remain light
above 5500 feet, on the order of an inch or two. Conditions remain
favorable for rime icing on some of the mountain peaks which has
already impacted some communication equipment including some of
our own on Mt Elden.

By Thursday evening, things get more interesting and somewhat
complicated. An upper low diving off the coast of southern
California will act to bring deeper moisture northward into our
region as a cold trough approaches from the north. While models
are still not in great agreement on the details of how well these
two features phase together, there is a high likelihood of
additional moderate to heavy precipitation from Thursday evening
through early Saturday morning. Snow levels will be fairly high to
start due to the southerly tap, around 6000 feet or even a bit
higher through Friday afternoon before crashing to below 4000 feet
as the precipitation is ending from NW to SE Friday night into
Saturday morning. Preliminary snowfall projections above 6000 feet
elevation for this last system are in the 5-10 inch range, with
generally up to an inch down to 5000 feet just as the storm is
ending. Keep this in mind for your New Year's Eve plans as there
is likely to be some tricky travel around the high country. The
air mass behind the final wave is very cold, and high temperatures
for the first day of 2022 will be 15-20 degrees below normal,
remaining in the 20s above 6000 feet. Lows by Sunday morning will
likely be some of the coldest of the season so far, with
widespread single digits to below zero along and north of the
Mogollon Rim.

Sunday through Tuesday - fair weather with gradually warmer
daytime temperatures is likely. Overnight lows will remain cold.

&&

.AVIATION...For the 18Z package...Expect improving conditions across
the region today as snow tapers from west to east. Lcl LIFR/IFR
conditions will continue near the higher terrain, leading to
MVFR/VFR CIGS/VIS into early afternoon. This afternoon and tonight,
expect terrain-based BKN to OVC skies and mainly VFR conditions with
periods of MVFR CIGS/VIS and mountain obscuration due to lingering
-SHSN over higher terrain. Southwest winds remain breezy during this
 time sustained 10-20 kts with gusts to 25-30 kts. Aviation
 discussion not updated for TAF amendments.

&&

.FIRE WEATHER...Precipitation will become showery and decrease in
coverage today through Thursday afternoon. Another storm system will
bring more rain, snow, and breezy winds beginning late Thursday.

Friday through Sunday...Rain and snow will continue Friday through
early Saturday morning, with precipitation ending from west to east
by Saturday afternoon as much drier air moves in. Very cold
temperatures are expected Sunday morning, with clear skies and
slightly warmer temperatures Sunday afternoon.

&&

.FGZ WATCHES/WARNINGS/ADVISORIES...NONE.

&&

PUBLIC...RR/JJ
AVIATION...RR
FIRE WEATHER...JJ

For Northern Arizona weather information visit
weather.gov/flagstaff

In the hours before

Local storm report, Dec 29, 11:52 AM MST, 2 hours 2 minutes before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
1152 AM MST WED DEC 29 2021

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

1100 AM     SNOW             SHUMWAY                 34.40N 110.07W
12/29/2021  M1.8 INCH        NAVAJO             AZ   PUBLIC

&&

BAK
Local storm report, Dec 29, 12:05 PM MST, 1 hour 49 minutes before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
1205 PM MST WED DEC 29 2021

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

1204 PM     SNOW             BURNSIDE (5 NW GANADO)  35.75N 109.63W
12/29/2021  E1.8 INCH        APACHE             AZ   PUBLIC

&&

BAK
Local storm report, Dec 29, 12:08 PM MST, 1 hour 46 minutes before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
1208 PM MST WED DEC 29 2021

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0700 AM     SNOW             4 WNW PRESCOTT AIRPORT  34.66N 112.50W
12/29/2021  M1.3 INCH        YAVAPAI            AZ   COCORAHS

            COCORAHS STATION AZ-YV-184 PRESCOTT 8.9 NNW.

&&

BAK
Local storm report, Dec 29, 12:40 PM MST, 1 hour 14 minutes before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
1240 PM MST WED DEC 29 2021

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

1239 PM     SNOW             1 E FOREST LAKES        34.34N 110.79W
12/29/2021  M8.0 INCH        COCONINO           AZ   TRAINED SPOTTER

            STORM TOTAL SINCE LATE TUESDAY.

&&

BAK
Local storm report, Dec 29, 12:57 PM MST, 57 minutes before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
1257 PM MST WED DEC 29 2021

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

1100 AM     SNOW             FLAGSTAFF AIRPORT       35.14N 111.67W
12/29/2021  M10.1 INCH       COCONINO           AZ   PUBLIC

            MEASURED STORM TOTAL SNOWFALL.

&&

BAK
Local storm report, Dec 29, 1:03 PM MST, 51 minutes before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE FLAGSTAFF AZ
103 PM MST WED DEC 29 2021

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

1100 AM     SNOW             FLAGSTAFF AIRPORT       35.14N 111.67W
12/29/2021  M10.1 INCH       COCONINO           AZ   OFFICIAL NWS OBS

            CORRECTS REPORT SOURCE (OFFICIAL). MEASURED
            STORM TOTAL SNOWFALL.

&&

BAK

Nearby

Winter Storm Watches in Arizona, 2021Every winter storm watch in 2021

Sources

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