Alert archive / Arizona / Winter Storm Watches in 2021

Winter Storm Watch 2, NWS Tucson, AZ

December 29, 20216 counties in Arizona

NWS Tucson, AZ issued this winter storm watch at Dec 29, 2021, 2:27 PM MST for 6 counties in Arizona. It took effect at Dec 30, 2021, 11:00 PM MST. It was in force for .

The area

The counties it named.

The facts

Issued
Dec 29, 2021, 2:27 PM MST (21:27 UTC)
In effect from
Dec 30, 2021, 11:00 PM MST
Expired
Dec 30, 2021, 2:25 PM MST
In force
Issued by
NWS Tucson, AZ

Counties Cochise County, AZ, Graham County, AZ, Greenlee County, AZ, Pima County, AZ, Pinal County, AZ, Santa Cruz County, AZ

The radar

The Tucson radar (KEMX), 61 km from the middle of the area, began a volume at 21:29 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

Tuscon, AZ (KTUS), launched 12:00Z, 9.5 hours before the alert went out and 49 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, Tuscon, AZ at 12:00Z on 2021-12-29Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 29 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Tuscon, AZ at 12:00Z on 2021-12-29The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 271 square meters per square second.1939587897117Sfc1 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
29 J/kg
Mixed-layer CIN
-6 J/kg
Mixed-layer LCL
705 m above ground
0-6 km bulk shear
80 kt
0-1 km storm-relative helicity
271 m²/s²
0-3 km storm-relative helicity
278 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

286 
WWUS45 KTWC 292127
WSWTWC

URGENT - WINTER WEATHER MESSAGE
National Weather Service Tucson AZ
227 PM MST Wed Dec 29 2021

AZZ511>514-301200-
/O.NEW.KTWC.WS.A.0002.211231T0000Z-220101T1800Z/
Galiuro and Pinaleno Mountains-Chiricahua Mountains-
Dragoon and Mule and Huachuca and Santa Rita Mountains-
Catalina and Rincon Mountains-
Including the cities of Mount Graham, Chiricahua NM, Bisbee, 
Canelo Hills, Mount Lemmon, and Summerhaven
227 PM MST Wed Dec 29 2021

...WINTER STORM WATCH IN EFFECT ABOVE 7000 FT FROM LATE THURSDAY 
AFTERNOON THROUGH SATURDAY MORNING...

* WHAT...Heavy wet snow possible. Total snow accumulations of 12
  to 24 inches are possible above 7000 ft. Winds could gust as 
  high as 40 mph Friday and Friday night. 

* WHERE...Galiuro and Pinaleno Mountains, Chiricahua Mountains, 
  Huachuca and Santa Rita Mountains and Catalina and Rincon 
  Mountains above 7000 ft. 

* WHEN...From Late Thursday afternoon through Saturday morning.

* IMPACTS...Plan on slippery road conditions and significantly
  reduced visibility in any blowing snow. Bursts of heavy snow may
  make travel very difficult at best. 

* ADDITIONAL DETAILS...At this time the focus of the heaviest
  precipitation should be late Thursday night into Friday evening. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Winter Storm Watch means there is potential for significant
snow accumulations that may seriously impact travel. Gusty winds
and blowing snow is also possible. Those planning travel into the
watch area should prepare for difficult winter driving
conditions. 

&&

$$

AZZ510-301200-
/O.NEW.KTWC.WS.A.0002.211231T0600Z-220101T1800Z/
White Mountains of Graham and Greenlee Counties-
Including the city of Hannagan Meadow
227 PM MST Wed Dec 29 2021

...WINTER STORM WATCH IN EFFECT ABOVE 7000 FT FROM LATE THURSDAY 
EVENING THROUGH SATURDAY MORNING...

* WHAT...Heavy wet snow possible. Total snow accumulations of 12
  to 24 inches are possible above 7000 ft. Winds could gust as 
  high as 40 mph Friday and Friday night. 

* WHERE...White Mountains of Graham and Greenlee Counties.

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

* IMPACTS...Plan on slippery road conditions and significantly
  reduced visibility in any blowing snow. Bursts of heavy snow may
  make travel very difficult at best. 

* ADDITIONAL DETAILS...At this time the focus of the heaviest
  precipitation should be late Thursday night into Friday evening. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Winter Storm Watch means there is potential for significant
snow accumulations that may seriously impact travel. Gusty winds
and blowing snow is also possible. Those planning travel into the
watch area should prepare for difficult winter driving
conditions. 

&&

$$
Cerniglia
Visit us on Facebook...Twitter...YouTube...and at weather.gov/Tucson
2 follow-up statements
406 
WWUS45 KTWC 300919
WSWTWC

URGENT - WINTER WEATHER MESSAGE
National Weather Service Tucson AZ
219 AM MST Thu Dec 30 2021

AZZ511>514-302300-
/O.EXT.KTWC.WS.A.0002.211231T0600Z-220101T1800Z/
Galiuro and Pinaleno Mountains-Chiricahua Mountains-
Dragoon and Mule and Huachuca and Santa Rita Mountains-
Catalina and Rincon Mountains-
Including the cities of Mount Graham, Chiricahua NM, Bisbee, 
Canelo Hills, Mount Lemmon, and Summerhaven
219 AM MST Thu Dec 30 2021

...WINTER STORM WATCH NOW IN EFFECT FROM LATER TONIGHT THROUGH 
SATURDAY MORNING...

* WHAT...Heavy wet snow possible. Total snow accumulations of 12 
  to 24 inches are possible above 7000 ft. Winds could gust as 
  high as 40 mph Friday and Friday night.

* WHERE...Galiuro and Pinaleno Mountains, Chiricahua Mountains, 
  Huachuca and Santa Rita Mountains and Catalina and Rincon 
  Mountains above 7000 ft.

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

* IMPACTS...Plan on slippery road conditions and significantly 
  reduced visibility in any blowing snow. Bursts of heavy snow 
  may make travel very difficult at best.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Winter Storm Watch means there is potential for significant
snow accumulations that may seriously impact travel. Gusty winds
and blowing snow is also possible. Those planning travel into the
watch area should prepare for difficult winter driving
conditions. 

&&

$$

AZZ510-302300-
/O.EXT.KTWC.WS.A.0002.211231T1200Z-220101T1800Z/
White Mountains of Graham and Greenlee Counties-
Including the city of Hannagan Meadow
219 AM MST Thu Dec 30 2021

...WINTER STORM WATCH NOW IN EFFECT FROM FRIDAY MORNING THROUGH 
SATURDAY MORNING...

* WHAT...Heavy wet snow possible. Total snow accumulations of 12 
  to 24 inches are possible above 7000 ft. Winds could gust as 
  high as 40 mph Friday and Friday night.

* WHERE...White Mountains of Graham and Greenlee Counties.

* WHEN...From early Friday morning through Saturday morning.

* IMPACTS...Plan on slippery road conditions and significantly 
  reduced visibility in any blowing snow. Bursts of heavy snow 
  may make travel very difficult at best.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Winter Storm Watch means there is potential for significant
snow accumulations that may seriously impact travel. Gusty winds
and blowing snow is also possible. Those planning travel into the
watch area should prepare for difficult winter driving
conditions. 

&&

$$

Meyer

Visit us on Facebook...Twitter...YouTube...and at weather.gov/Tucson
599 
WWUS45 KTWC 302125
WSWTWC

URGENT - WINTER WEATHER MESSAGE
National Weather Service Tucson AZ
225 PM MST Thu Dec 30 2021


AZZ511-311200-
/O.UPG.KTWC.WS.A.0002.211231T0600Z-220101T1800Z/
/O.NEW.KTWC.WS.W.0002.211231T1200Z-220101T1800Z/
Galiuro and Pinaleno Mountains-
Including the city of Mount Graham
225 PM MST Thu Dec 30 2021

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

* WHAT...Heavy snow expected. Total snow accumulations of 12 to 24
  inches above 8000 feet and 6 to 18 inches between 6500 feet and
  8000 feet. Winds gusting as high as 45 mph.

* WHERE...Pinaleno Mountains.

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

* IMPACTS...Travel could be very difficult to impossible. The 
  hazardous conditions could impact the morning or evening 
  commute. Gusty winds could bring down tree branches.


PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Winter Storm Warning means heavy snow accumulations are
expected. Gusty winds and blowing snow are also possible. This
will make travel very difficult or impossible...especially in the
mountains. 

Stay tuned to NOAA Weather Radio...commercial television or radio
stations...or your cable television service provider for updates
on this Winter Storm. 

&&

$$

AZZ510-311200-
/O.UPG.KTWC.WS.A.0002.211231T1200Z-220101T1800Z/
/O.NEW.KTWC.WS.W.0002.211231T1200Z-220101T1800Z/
White Mountains of Graham and Greenlee Counties-
Including the city of Hannagan Meadow
225 PM MST Thu Dec 30 2021

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

* WHAT...Heavy snow expected. Total snow accumulations 12 to 24
  inches above 8000 feet and 6 to 18 inches between 6500 feet and
  8000 feet. Winds gusting as high as 45 mph.

* WHERE...White Mountains of Graham and Greenlee Counties.

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

* IMPACTS...Travel could be very difficult to impossible. The 
  hazardous conditions could impact the morning or evening 
  commute.


PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Winter Storm Warning means heavy snow accumulations are
expected. Gusty winds and blowing snow are also possible. This
will make travel very difficult or impossible...especially in the
mountains. 

Stay tuned to NOAA Weather Radio...commercial television or radio
stations...or your cable television service provider for updates
on this Winter Storm. 

&&

$$

AZZ514-311200-
/O.UPG.KTWC.WS.A.0002.211231T0600Z-220101T1800Z/
/O.NEW.KTWC.WS.W.0002.211231T1800Z-220101T1800Z/
Catalina and Rincon Mountains-
Including the cities of Mount Lemmon and Summerhaven
225 PM MST Thu Dec 30 2021

...WINTER STORM WARNING IN EFFECT ABOVE 7000 FEET FROM 11 AM 
FRIDAY TO 11 AM MST SATURDAY...

* WHAT...Heavy snow expected. Total snow accumulations 12 to 24
  inches above 8000 feet and 6 to 18 inches between 6500 feet and
  8000 feet. Winds gusting as high as 45 mph.

* WHERE...Catalina and Rincon Mountains.

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

* IMPACTS...Travel could be very difficult to impossible. The 
  hazardous conditions could impact the morning or evening 
  commute. Gusty winds could bring down tree branches.


PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Winter Storm Warning means heavy snow accumulations are
expected. Gusty winds and blowing snow are also possible. This
will make travel very difficult or impossible...especially in the
mountains. 

Stay tuned to NOAA Weather Radio...commercial television or radio
stations...or your cable television service provider for updates
on this Winter Storm. 

&&

$$

AZZ512-513-311200-
/O.UPG.KTWC.WS.A.0002.211231T0600Z-220101T1800Z/
/O.NEW.KTWC.WW.Y.0006.211231T1800Z-220101T1800Z/
Chiricahua Mountains-
Dragoon and Mule and Huachuca and Santa Rita Mountains-
Including the cities of Chiricahua NM and Canelo Hills
225 PM MST Thu Dec 30 2021

...WINTER WEATHER ADVISORY IN EFFECT ABOVE 7000 FEET FROM 11 AM 
FRIDAY TO 11 AM MST SATURDAY...

* WHAT...Heavy snow expected. Total snow accumulations 6 to 12
  inches above 7000 feet, locally higher on the mountain peaks. 
  Winds gusting as high as 45 mph.

* WHERE...Chiricahua Mountains and Huachuca and Santa Rita 
  Mountains.

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

* IMPACTS...Plan on slippery road conditions. The hazardous 
  conditions could impact the morning or evening commute. Gusty 
  winds could bring down tree branches.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Slow down and use caution while traveling. 

Stay tuned to NOAA Weather Radio...commercial television or radio
stations...or your cable television service provider for updates
on this Winter Storm. 

&&

$$

Visit us on Facebook...Twitter...YouTube...and at weather.gov/Tucson

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.