Alert archive / Arizona / Special Weather Statements in 2021

Special Weather Statement, NWS Tucson, AZ

January 25, 2021Pima County, Pinal County, Arizona

NWS Tucson, AZ issued this special weather statement at Jan 25, 2021, 2:30 PM MST for Pima County, Pinal County, Arizona. It was in force for 45 min. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued: Jan 25, 2021, 2:30 PM MST (21:30 UTC)
Expired: Jan 25, 2021, 3:15 PM MST
In force: 45 min
Issued by: NWS Tucson, AZ

Counties Pima County, AZ, Pinal County, AZ

The radar

The Phoenix radar (KIWA), 89 km from the middle of the area, began a volume at 21:31 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 114 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 996 m above ground
0-6 km bulk shear: 55 kt
0-1 km storm-relative helicity: 83 m²/s²
0-3 km storm-relative helicity: 191 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

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What forecasters said that day

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

NWS Tucson, AZ wrote its last area forecast discussion before this special weather statement went out at Jan 25, 3:05 AM MST, 11 hours 25 minutes earlier.

Area forecast discussion, Jan 25, 3:05 AM MST, 11 hours 25 minutes before

Area Forecast Discussion
National Weather Service Tucson AZ
305 AM MST Mon Jan 25 2021

.SYNOPSIS...The next winter storm will pass through the state this
afternoon into Tuesday bringing another round of rain and snow
showers. A few thunderstorms with small hail will also be possible
this afternoon and evening. The storm will usher in a much colder
airmass and strong winds, with snow levels likely reaching the
desert floors including the Tucson area tonight into Tuesday.
Significant snow accumulations can be expected for elevations
generally above 4,000 feet. Improving weather conditions will follow
by Wednesday afternoon after a chilly and frosty morning. Generally
dry and cool conditions will continue on Thursday before yet another
storm system enters the region late Friday into Saturday.

&&

.DISCUSSION...After a brief break in the weather last night and
early this morning, the next winter storm will pass through the area
this afternoon into Tuesday. No notable changes to the previous
forecast as the timing and precipitation amounts still appeared to
be on track for this afternoon into Tuesday. Strong and gusty winds
along with a much colder airmass will accompany this storm. Snow
levels will lower significantly tonight and early Tuesday as low as
2,500 to 3,000 feet. Winter Weather Advisories remain in effect this
afternoon into Tuesday for lower elevations with a Winter Storm
Warning for the mountains. The windy conditions will result in near
blizzard like conditions at times, especially in the mountains. The
storm system will exit Arizona by Tuesday evening with precipitation
ending and skies clearing from west to east. The clearing skies will
result in a hard freeze and frost Wednesday morning in the valleys.
Models were showing a break in the weather Wednesday and Thursday
before yet another storm system enters the region late in the week.

&&

.AVIATION...Valid through 26/12Z.
BKN-OVC cloud decks at 3k-6k ft AGL thru 25/20Z, then BKN-OVC cloud
decks lowering to 1k-4k ft AGL thru the remainder of the forecast
period. Isolated -SHRA thru 25/18Z, then increasing precipitation
chances, with widespread valley SHRA/mountain SHSN by 25/22Z. There
will also be a slight chance of -TSRA from 25/21Z thru the remainder
of the forecast cycle. Mountain obscurations and widespread MVFR
conditions (and local IFR conditions) aft 25/21Z. SFC wind SLY/SWLY
at 5-12 kts thru 25/16Z, then increasing SFC wind, with SFC wind at
most locations of 17-22 kts and gusts to around 30 kts aft 25/18Z
thru the end of the forecast period. Stronger gusts near any -TSRA.
In the vicinity of KALK, expect SWLY SFC wind to increase to 20-28
kts and gusts to 35-40 kts between 25/22Z and 26/12Z. Aviation
discussion not updated for TAF amendments.

&&

.FIRE WEATHER...A strong storm system will move across the region
through Tuesday, resulting in valley rain and mountain snow, along
with colder temperatures. Snow levels may fall as low as 3,000 to
4,000 feet today and down to 2,500 feet late tonight and Tuesday.
Strong and gusty winds are expected this afternoon and tonight, with
gusts to between 30-40 mph. Dry conditions are then expected
Wednesday through Thursday night. Another storm system will then
move across the area Friday into Saturday, resulting in another
chance of precipitation.

&&

.CLIMATE...
January Snowfall Records for Reference (Low Elevation Sites).

Location...........1-Day..............................Monthly......
Tucson.............4.3".....Jan. 16,.1987.............4.7".....1987
Oracle.............15.0"....Jan. 29,.1979.............17.0"....1979
Nogales............5.5".....Jan. 6,..1997.............5.5".....1997
Benson.............2.0".....Jan. 22,.2007.............2.0".....2007
Tombstone..........12.0"....Jan. 16,.1916.............14.0"....1916
Sierra Vista.......4.0".....Jan. 7,..1997.............4.1".....1997
Willcox............6.0".....Jan. 22,.1938.............9.0".....1916
Bisbee.............11.5"....Jan. 18,.1988.............15.5"....1998
Douglas............4.0".....Jan. 12,.1951.............7.0".....1949
Safford............3.0".....Jan. 14,.1997.............5.0".....1997

&&

.TWC WATCHES/WARNINGS/ADVISORIES...
  Winter Storm Warning from 1 PM today to 5 PM MST Tuesday for
  AZZ503-507-508-510>514.

  Winter Weather Advisory from 1 PM today to 5 PM MST Tuesday for
  AZZ503-506>510-512-514-515.

  Winter Weather Advisory from 8 PM today to 5 PM MST Tuesday for
  AZZ504.

&&

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In the hours before

Special weather statement, Jan 25, 1:47 PM MST, 43 minutes before

Special Weather Statement
National Weather Service Tucson AZ
147 PM MST Mon Jan 25 2021

AZZ502-504-252130-
Tohono O'odham Nation including Sells-Tucson Metro Area including
Tucson/Green Valley/Marana/Vail-
147 PM MST Mon Jan 25 2021

...SIGNIFICANT WEATHER ADVISORY FOR NORTH CENTRAL PIMA AND
SOUTHWESTERN PINAL COUNTIES UNTIL 230 PM MST...

At 146 PM MST, Doppler radar was tracking a strong thunderstorm 13
miles north of Pisinemo, or 30 miles northwest of Sells, moving
northeast at 35 mph.

Hail up to half an inch and wind gusts up to 50 mph will be possible
with this storm.

Locations impacted include...
Santa Rosa, Covered Wells, Anegam, San Simon, North Komelik, Kohatk,
Palo Verde Stand, Ventana, Ak Chin, Vaya Chin, Mountain Village, San
Luis, Santa Rosa School and San Simon West.

LAT...LON 3232 11251 3251 11235 3251 11221 3267 11220
      3268 11220 3268 11216 3272 11215 3272 11211
      3233 11167 3202 11229
TIME...MOT...LOC 2046Z 236DEG 32KT 3222 11226

RH

Special weather statement, Jan 25, 2:30 PM MST, 0 minutes before

Special Weather Statement
National Weather Service Tucson AZ
230 PM MST Mon Jan 25 2021

AZZ501-502-504-505-252215-
Western Pima County Including Ajo/Organ Pipe Cactus National
Monument-Tohono O'odham Nation including Sells-Tucson Metro Area
including Tucson/Green Valley/Marana/Vail-South Central Pinal County
including Eloy/Picacho Peak State Park-
230 PM MST Mon Jan 25 2021

...SIGNIFICANT WEATHER ADVISORY FOR CENTRAL PIMA AND SOUTHWESTERN
PINAL COUNTIES UNTIL 315 PM MST...

At 228 PM MST, Doppler radar was tracking strong thunderstorms along
a line extending across central Pima County up through western
Pinal County. Movement was east at 35 mph.

Hail up to half an inch will be possible and wind gusts up to 50 mph.

Locations impacted include...
Sells, Eloy, Santa Rosa, Picacho, Topawa, Pisinemo, Chui-Chu, San
Isidro, Picacho Peak State Park, Cactus Forest, Ali Chukson, Covered
Wells, Anegam, Ali Chugk, Gu Oidak, Vamori, Cockleburr, San Simon,
North Komelik and Kohatk.

LAT...LON 3184 11268 3251 11230 3251 11221 3268 11220
      3268 11216 3272 11215 3272 11205 3277 11205
      3277 11188 3279 11187 3279 11178 3273 11174
      3273 11167 3307 11120 3159 11187
TIME...MOT...LOC 2128Z 262DEG 33KT 3302 11175 3162 11253

RH

The office that day

Everything else NWS Tucson, AZ issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Jan 24, 5:05 PM MST	Special Weather Statement	TWC	Pinal	40 min
Jan 25, 1:47 PM MST	Special Weather Statement	TWC	Pima	43 min
Jan 25, 2:44 PM MST	Severe Thunderstorm Warning	TWC	Pima	46 min
Jan 25, 3:20 PM MST	Special Weather Statement	TWC	Pima	40 min
Jan 25, 3:24 PM MST	Severe Thunderstorm Warning	TWC	Pima	36 min

Nearby

Special Weather Statements in Arizona, 2021 Every special weather statement 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.