Alert archive / Arizona / Mesoscale Discussions in 2021

Mesoscale Discussion 31

January 25, 2021Pima County, Pinal County, Arizona

The Storm Prediction Center issued this mesoscale discussion at Jan 25, 2021, 1:48 PM MST for Pima County, Pinal County, Arizona. It was in force for 117 min.

The area

The outline as issued.

The facts

Issued
Jan 25, 2021, 1:48 PM MST (20:48 UTC)
Expired
Jan 25, 2021, 3:45 PM MST
In force
117 min
Issued by
the Storm Prediction Center
Concerning
Severe potential...watch unlikely
Chance of a watch
5%

Counties Pima County, AZ, Pinal County, AZ

The radar

The Phoenix radar (KIWA), 68 km from the middle of the area, began a volume at 20:48 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, 8.8 hours before the alert went out and 98 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 2021-01-25Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Tuscon, AZ at 12:00Z on 2021-01-25The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 83 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
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.

850 
ACUS11 KWNS 252048
SWOMCD
SPC MCD 252048 
AZZ000-252245-

Mesoscale Discussion 0031
NWS Storm Prediction Center Norman OK
0248 PM CST Mon Jan 25 2021

Areas affected...South-Central AZ

Concerning...Severe potential...Watch unlikely 

Valid 252048Z - 252245Z

Probability of Watch Issuance...5 percent

SUMMARY...A few stronger gusts may occur across south-central AZ as
a shallow convective line moves through the region.

DISCUSSION...Strong forcing for ascent attendant to an intense
shortwave trough approaching the region from southern CA has lead to
the development of a line of relatively deeper convection from
north-central Maricopa County southward into western Pima County.
This line is expected to continue eastward into a area with slightly
warmer temperatures (i.e. low to mid 50s) and steep low-level lapse
rates. These thermodynamic conditions combined with the deeper
convection could result in enhanced downward momentum transfer of
the stronger mid-level flow, resulting in a few stronger gusts at
the surface.

..Mosier.. 01/25/2021

...Please see www.spc.noaa.gov for graphic product...

ATTN...WFO...TWC...PSR...

LAT...LON   32521235 33711221 33691153 33201103 32581093 32341100
            31601180 31981257 32521235

Nearby

Mesoscale Discussions in Arizona, 2021Every mesoscale discussion 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.