Alert archive / Pennsylvania / Snow Squall Warnings in 2021

Snow Squall Warning 1, NWS State College, PA

January 22, 2021Potter County, Pennsylvania

NWS State College, PA issued this snow squall warning at Jan 22, 2021, 11:42 AM EST for Potter County, Pennsylvania. It was in force for 48 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 22, 2021, 11:42 AM EST (16:42 UTC)
Expired
Jan 22, 2021, 12:30 PM EST
In force
48 min
Issued by
NWS State College, PA
Area
Storm-based polygon

County Potter County, PA

The radar

The State College radar (KCCX), 96 km from the middle of the area, began a volume at 16:43 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

Buffalo Intl Airport, NY (KBUF), launched 12:00Z, 4.7 hours before the alert went out and 143 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, Buffalo Intl Airport, NY at 12:00Z on 2021-01-22Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 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, Buffalo Intl Airport, NY at 12:00Z on 2021-01-22The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 76 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
919 m above ground
0-6 km bulk shear
55 kt
0-1 km storm-relative helicity
76 m²/s²
0-3 km storm-relative helicity
83 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

342 
WWUS51 KCTP 221644
SQWCTP

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Snow Squall Warning
National Weather Service State College PA
1142 AM EST Fri Jan 22 2021

PAC105-221730-
/O.NEW.KCTP.SQ.W.0001.210122T1642Z-210122T1730Z/
Potter PA-
1142 AM EST Fri Jan 22 2021

The National Weather Service in State College PA has issued a

* Snow Squall Warning for...
  Central Potter County in north central Pennsylvania...

* Until 1230 PM EST.

* At 1142 AM EST, a dangerous snow squall was located over
  Coudersport, moving east at 25 mph.

  HAZARD...Extremely poor visibility in snow and blowing snow. Wind 
           gusts up to 30 mph.

  SOURCE...Radar indicated.

  IMPACT...Expect hazardous road conditions.

The snow squall will move along parallel to Route 6 from Coudersport 
to Denton Hill State Park. Near whiteout conditions and rapidly 
deteriorating road conditions will occur as it crosses the region. 
Consider delaying travel until the squall passes.

Locations impacted include...
Coudersport, Roulette, Galeton, Denton Hill State Park, Lyman Run
State Park, Sweden Valley and Ski Denton Ski Area.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Reduce your speed and turn on headlights! During snow squalls, the
visibility may suddenly drop to near zero in whiteout conditions.

&&

LAT...LON 4182 7761 4167 7760 4173 7806 4177 7821
      4182 7821 4188 7809
TIME...MOT...LOC 1642Z 284DEG 21KT 4180 7801 

$$

DeVoir

The office that day

Everything else NWS State College, PA issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jan 22, 9:51 AM ESTSpecial Weather StatementCTPElk, McKean54 min
Jan 22, 11:54 AM ESTSpecial Weather StatementCTPCameron66 min
Jan 22, 12:46 PM ESTSnow Squall WarningCTPLycoming, Potter, Tioga44 min
Jan 22, 1:43 PM ESTSnow Squall WarningCTPColumbia, Lycoming, Sullivan, Tioga77 min
Jan 22, 1:48 PM ESTSpecial Weather StatementCTPClinton57 min
Jan 22, 4:00 PM ESTSpecial Weather StatementCTPSullivan30 min

Nearby

Snow Squall Warnings in Pennsylvania, 2021Every snow squall warning 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.