Alert archive / Pennsylvania / Freeze Warnings in 2020

Freeze Warning 9, NWS State College, PA

September 18, 2020Elk County, McKean County, Potter County, Pennsylvania

NWS State College, PA issued this freeze warning at Sep 18, 2020, 1:03 PM EDT for Elk County, McKean County, Potter County, Pennsylvania. It took effect at Sep 19, 2020, 1:00 AM EDT. It was in force for 7 hr. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued
Sep 18, 2020, 1:03 PM EDT (17:03 UTC)
In effect from
Sep 19, 2020, 1:00 AM EDT
Expired
Sep 19, 2020, 8:00 AM EDT
In force
7 hr
Issued by
NWS State College, PA

Counties Elk County, PA, McKean County, PA, Potter County, PA

The radar

The State College radar (KCCX), 87 km from the middle of the area, began a volume at 17:02 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

Pittsburgh, PA (KPIT), launched 12:00Z, 5.1 hours before the alert went out and 201 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, Pittsburgh, PA at 12:00Z on 2020-09-18Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1 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, Pittsburgh, PA at 12:00Z on 2020-09-18The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -32 square meters per square second.19395878Sfc1 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
1 J/kg
Mixed-layer CIN
-40 J/kg
Mixed-layer LCL
625 m above ground
0-6 km bulk shear
42 kt
0-1 km storm-relative helicity
-32 m²/s²
0-3 km storm-relative helicity
97 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The office that day

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

IssuedProductOfficeCountiesLasted
Sep 18, 3:31 AM EDTFrost AdvisoryCTPCameron, Clearfield, Sullivan, Tioga, Warren28 hr
Sep 18, 3:31 AM EDTFreeze WatchCTPElk, McKean, Potter10 hr

Nearby

Freeze Warnings in Pennsylvania, 2020Every freeze warning in 2020

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.