Alert archive / Oregon / Frost Advisories in 2021

Frost Advisory 2, NWS Medford, OR

March 11, 2021Coos County, Curry County, Douglas County, Oregon

NWS Medford, OR issued this frost advisory at Mar 11, 2021, 4:48 AM PST for Coos County, Curry County, Douglas County, Oregon. It took effect at Mar 12, 2021, 1:00 AM PST. It was in force for 7 hr.

The area

The counties it named.

The facts

Issued
Mar 11, 2021, 4:48 AM PST (12:48 UTC)
In effect from
Mar 12, 2021, 1:00 AM PST
Expired
Mar 12, 2021, 8:00 AM PST
In force
7 hr
Issued by
NWS Medford, OR

Counties Coos County, OR, Curry County, OR, Douglas County, OR

The radar

The Medford radar (KMAX), 135 km from the middle of the area, began a volume at 12:47 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

Medford/Jackson, OR (KMFR), launched 12:00Z, 0.8 hours before the alert went out and 108 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, Medford/Jackson, OR at 12:00Z on 2021-03-11Temperature 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, Medford/Jackson, OR at 12:00Z on 2021-03-11The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -23 square meters per square second.193958Sfc1 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
689 m above ground
0-6 km bulk shear
6 kt
0-1 km storm-relative helicity
-23 m²/s²
0-3 km storm-relative helicity
14 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

737 
WWUS76 KMFR 111248
NPWMFR

URGENT - WEATHER MESSAGE
National Weather Service Medford OR
448 AM PST Thu Mar 11 2021

ORZ021-022-112300-
/O.NEW.KMFR.FR.Y.0002.210312T0900Z-210312T1600Z/
South Central Oregon Coast-Curry County Coast-
Including the cities of Coos Bay, North Bend, Reedsport, Bandon, 
Port Orford, and Coquille
448 AM PST Thu Mar 11 2021

...FROST ADVISORY IN EFFECT FROM 1 AM TO 8 AM PST FRIDAY...

* WHAT...Temperatures as low as 33 will result in frost formation.
  Coldest spots may briefly touch freezing early Friday morning.

* WHERE...South Central Oregon Coast and Curry County Coast
  including Reedsport, North Bend, Bandon, Port Orford, Myrtle
  Point, and Coquille.

* WHEN...From 1 AM to 8 AM PST Friday.

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

* View the hazard area in detail at 
  https://www.wrh.noaa.gov/mfr/HAZARD

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Take steps now to protect tender plants from the cold.

&&

$$

Visit us at https://www.weather.gov/Medford
2 follow-up statements
009 
WWUS76 KMFR 112200
NPWMFR

URGENT - WEATHER MESSAGE
National Weather Service Medford OR
200 PM PST Thu Mar 11 2021

ORZ021-022-121600-
/O.CON.KMFR.FR.Y.0002.210312T0900Z-210312T1600Z/
South Central Oregon Coast-Curry County Coast-
Including the cities of Coos Bay, North Bend, Reedsport, Bandon, 
Port Orford, and Coquille
200 PM PST Thu Mar 11 2021

...FROST ADVISORY REMAINS IN EFFECT FROM 1 AM TO 8 AM PST
   FRIDAY...

* WHAT...Temperatures as low as 33 will result in frost 
  formation. Coldest spots may briefly touch freezing early 
  Friday morning.

* WHERE...South Central Oregon Coast and Curry County Coast
  including Reedsport, North Bend, Bandon, and Port Orford.

* WHEN...From 1 AM to 8 AM PST Friday.

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

* View the hazard area in detail at 
  https://www.wrh.noaa.gov/mfr/HAZARD

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Take steps now to protect tender plants from the cold.

&&

$$

Visit us at https://www.weather.gov/Medford
364 
WWUS76 KMFR 121323
NPWMFR

URGENT - WEATHER MESSAGE
National Weather Service Medford OR
523 AM PST Fri Mar 12 2021

ORZ021-121600-
/O.NEW.KMFR.FG.Y.0008.210312T1323Z-210312T1600Z/
/O.CON.KMFR.FR.Y.0002.000000T0000Z-210312T1600Z/
South Central Oregon Coast-
Including the cities of Coos Bay, North Bend, Reedsport, Bandon, 
Port Orford, and Coquille
523 AM PST Fri Mar 12 2021

...DENSE FOG ADVISORY IN EFFECT UNTIL 8 AM PST THIS MORNING...
...FROST ADVISORY REMAINS IN EFFECT UNTIL 8 AM PST THIS MORNING...

* WHAT...For the Frost Advisory, temperatures in the mid 30s, and
  locally in the lower 30s, will result in frost formation. For 
  the Dense Fog Advisory, visibility of one quarter a mile or less
  in dense fog.

* WHERE...For the Frost Advisory, portions of the Coos, Douglas
  and Curry County coast including Reedsport, Charleston, Bandon,
  Langlois, Sixes, Port Orford and areas just inland of Gold Beach
  and Brookings. For the Dense Fog Advisory, the Coos coast near
  North Bend and Coos Bay and areas in and near the Coquille
  Valley including Coquille, Myrtle Point, and Powers.
 
* WHEN...Until 8 AM PST this morning.

* IMPACTS...Frost could kill sensitive outdoor vegetation if left
  uncovered. Hazardous driving conditions due to low visibility.

* View the hazard area in detail at 
  https://www.wrh.noaa.gov/mfr/HAZARD

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Take steps now to protect tender plants from the cold.

If driving, slow down, use your headlights, and leave plenty of
distance ahead of you.

&&

$$

ORZ022-121600-
/O.CON.KMFR.FR.Y.0002.000000T0000Z-210312T1600Z/
Curry County Coast-
523 AM PST Fri Mar 12 2021

...FROST ADVISORY REMAINS IN EFFECT UNTIL 8 AM PST THIS MORNING...

* WHAT...Temperatures as low as 33 will result in frost 
  formation. Coldest spots may briefly touch freezing early 
  Friday morning.

* WHERE...South Central Oregon Coast and Curry County Coast 
  including Reedsport, North Bend, Bandon, and Port Orford.

* WHEN...From 1 AM to 8 AM PST Friday.

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

* View the hazard area in detail at 
  https://www.wrh.noaa.gov/mfr/HAZARD

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Take steps now to protect tender plants from the cold.

&&

$$

Visit us at https://www.weather.gov/Medford

Nearby

Frost Advisories in Oregon, 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.