Alert archive / Pennsylvania / Frost Advisories in 2021

Frost Advisory 3, NWS State College, PA

May 12, 202115 counties in Pennsylvania

NWS State College, PA issued this frost advisory at May 12, 2021, 3:58 AM EDT for 15 counties in Pennsylvania. It took effect at May 13, 2021, 2:00 AM EDT. It was in force for 6 hr.

The area

The counties it named.

The facts

Issued
May 12, 2021, 3:58 AM EDT (07:58 UTC)
In effect from
May 13, 2021, 2:00 AM EDT
Expired
May 13, 2021, 8:00 AM EDT
In force
6 hr
Issued by
NWS State College, PA

Counties Bedford County, PA, Blair County, PA, Cambria County, PA, Cameron County, PA, Centre County, PA, Clearfield County, PA, Clinton County, PA, Elk County, PA, Lycoming County, PA, McKean County, PA, Potter County, PA, Somerset County, PA, Sullivan County, PA, Tioga County, PA, Warren County, PA

The radar

The State College radar (KCCX), 25 km from the middle of the area, began a volume at 08:01 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 00:00Z, 8.0 hours before the alert went out and 184 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 00:00Z on 2021-05-12Temperature 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°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Pittsburgh, PA at 00:00Z on 2021-05-12The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 1 square meters per square second.1939587897117136156175Sfc1 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
1828 m above ground
0-6 km bulk shear
93 kt
0-1 km storm-relative helicity
1 m²/s²
0-3 km storm-relative helicity
103 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

440 
WWUS71 KCTP 120758
NPWCTP

URGENT - WEATHER MESSAGE
National Weather Service State College PA
358 AM EDT Wed May 12 2021

PAZ004>006-010>012-017-018-024-033-037-041-042-130330-
/O.NEW.KCTP.FR.Y.0003.210513T0600Z-210513T1200Z/
Warren-McKean-Potter-Elk-Cameron-Northern Clinton-Clearfield-
Northern Centre-Cambria-Somerset-Tioga-Northern Lycoming-Sullivan-
Including the cities of Warren, Bradford, Coudersport, St. Marys,
Ridgway, Emporium, Renovo, DuBois, Clearfield, Philipsburg, 
Johnstown, Somerset, Mansfield, Wellsboro, Trout Run, and Laporte
358 AM EDT Wed May 12 2021

...FROST ADVISORY IN EFFECT FROM 2 AM TO 8 AM EDT THURSDAY...

* WHAT...Temperatures as low as 33 will result in frost 
  formation.

* WHERE...The Northern and Western Mountains of Pennsylvania.

* WHEN...From 2 AM to 8 AM EDT Thursday.

* IMPACTS...Frost could kill sensitive outdoor vegetation if 
  left uncovered.

* ADDITIONAL DETAILS...The frost will occur mainly in valley
  locations. Unprotected early season plantings may freeze,
  especially in some of the high mountains valleys, where the
  temperatures could dip to 31 or 32 degrees for a few hours just 
  before sunrise Thursday.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Take steps now to protect tender plants and vegetation from the
cold. Potted plants should be brought inside.

The latest forecast information can be found on the
NWS State College Facebook page and Twitter @NWSStateCollege,
or on the web at weather.gov/ctp.

&&

$$

For more information from the National Weather Service visit
http://weather.gov/ctp
2 follow-up statements
705 
WWUS71 KCTP 121756
NPWCTP

URGENT - WEATHER MESSAGE
National Weather Service State College PA
156 PM EDT Wed May 12 2021

PAZ019-025-034-045-130600-
/O.EXA.KCTP.FR.Y.0003.210513T0600Z-210513T1200Z/
Southern Centre-Blair-Bedford-Southern Clinton-
Including the cities of State College, Altoona, Bedford, 
and Lock Haven
156 PM EDT Wed May 12 2021

...FROST ADVISORY IN EFFECT FROM 2 AM TO 8 AM EDT THURSDAY...

* WHAT...Temperatures as low as 35 will allow frost formation.

* WHERE...Southern Centre, Blair, Bedford and Southern Clinton 
  Counties.

* WHEN...From 2 AM to 8 AM EDT Thursday.

* IMPACTS...Frost could kill sensitive outdoor vegetation if 
  left uncovered.

* ADDITIONAL DETAILS...The frost will occur mainly in valley
  locations. Unprotected early season plantings may freeze,
  especially in some of the high mountain valleys, where the
  temperatures could dip near freezing for an hour or two just
  before sunrise Thursday. Frost can occur when air temperatures
  taken a few feet off the ground are still above freezing. The 
  air right at ground level can be a few degrees colder.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Take steps now to protect tender plants and vegetation from the
cold. Potted plants should be brought inside.

The latest forecast information can be found on the
NWS State College Facebook page and Twitter @NWSStateCollege,
or on the web at weather.gov/ctp.

&&

$$

PAZ004>006-010>012-017-018-024-033-037-041-042-130600-
/O.CON.KCTP.FR.Y.0003.210513T0600Z-210513T1200Z/
Warren-McKean-Potter-Elk-Cameron-Northern Clinton-Clearfield-
Northern Centre-Cambria-Somerset-Tioga-Northern Lycoming-Sullivan-
Including the cities of Warren, Bradford, Coudersport, St. Marys,
Ridgway, Emporium, Renovo, DuBois, Clearfield, Philipsburg, 
Johnstown, Somerset, Mansfield, Wellsboro, Trout Run, and Laporte
156 PM EDT Wed May 12 2021

...FROST ADVISORY REMAINS IN EFFECT FROM 2 AM TO 8 AM EDT
THURSDAY...

* WHAT...Temperatures as low as 33 will result in frost 
  formation.

* WHERE...The Northern and Western Mountains of Pennsylvania.

* WHEN...From 2 AM to 8 AM EDT Thursday.

* IMPACTS...Frost could kill sensitive outdoor vegetation if 
  left uncovered.

* ADDITIONAL DETAILS...The frost will occur mainly in valley
  locations. Unprotected early season plantings may freeze,
  especially in some of the high mountain valleys, where the
  temperatures could dip to 31 or 32 degrees for a few hours just
  before sunrise Thursday. Frost can occur when air temperatures
  taken a few feet off the ground are still above freezing. The 
  air right at ground level can be a few degrees colder.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Take steps now to protect tender plants and vegetation from the
cold. Potted plants should be brought inside.

The latest forecast information can be found on the NWS State
College Facebook page and Twitter @NWSStateCollege, or on the web
at weather.gov/ctp.

&&

$$

For more information from the National Weather Service visit
http://weather.gov/ctp
872 
WWUS71 KCTP 130329
NPWCTP

URGENT - WEATHER MESSAGE
National Weather Service State College PA
1129 PM EDT Wed May 12 2021

PAZ004>006-010>012-017>019-024-025-033-034-037-041-042-045-131200-
/O.CON.KCTP.FR.Y.0003.210513T0600Z-210513T1200Z/
Warren-McKean-Potter-Elk-Cameron-Northern Clinton-Clearfield-
Northern Centre-Southern Centre-Cambria-Blair-Somerset-Bedford-
Tioga-Northern Lycoming-Sullivan-Southern Clinton-
Including the cities of Warren, Bradford, Coudersport, St. Marys,
Ridgway, Emporium, Renovo, DuBois, Clearfield, Philipsburg, 
State College, Johnstown, Altoona, Somerset, Bedford, Mansfield, 
Wellsboro, Trout Run, Laporte, and Lock Haven
1129 PM EDT Wed May 12 2021

...FROST ADVISORY REMAINS IN EFFECT UNTIL 8 AM EDT THURSDAY...

* WHAT...Air temperatures as low as 34 will result in frost 
  formation.

* WHERE...Portions of central Pennsylvania.

* WHEN...Until 8 AM EDT Thursday.

* IMPACTS...Near ground freezing temperatures could kill 
  sensitive outdoor vegetation if left uncovered.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Take steps now to protect tender plants and vegetation from the
cold. Potted plants should be brought inside.

The latest forecast information can be found on the
NWS State College Facebook page and Twitter @NWSStateCollege,
or on the web at weather.gov/ctp.

&&

$$

For more information from the National Weather Service visit
http://weather.gov/ctp

DeVoir

Nearby

Frost Advisories in Pennsylvania, 2021Every frost advisory 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.