Alert archive / Oregon / Freeze Warnings in 2021

Freeze Warning 4, NWS Medford, OR

April 5, 2021Curry County, Jackson County, Josephine County, Oregon

NWS Medford, OR issued this freeze warning at Apr 5, 2021, 9:00 PM PDT for Curry County, Jackson County, Josephine County, Oregon. It took effect at Apr 6, 2021, 3:00 AM PDT. It was in force for 6 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
Apr 5, 2021, 9:00 PM PDT (04:00 UTC)
In effect from
Apr 6, 2021, 3:00 AM PDT
Expired
Apr 6, 2021, 9:00 AM PDT
In force
6 hr
Issued by
NWS Medford, OR

Counties Curry County, OR, Jackson County, OR, Josephine County, OR

The radar

The Medford radar (KMAX), 75 km from the middle of the area, began a volume at 04:01 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

Medford/Jackson, OR (KMFR), launched 00:00Z, 4.0 hours before the alert went out and 58 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 00:00Z on 2021-04-06Temperature 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 00:00Z on 2021-04-06The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 2 square meters per square second.1939Sfc1 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
2733 m above ground
0-6 km bulk shear
28 kt
0-1 km storm-relative helicity
2 m²/s²
0-3 km storm-relative helicity
-54 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

109 
WWUS76 KMFR 060400
NPWMFR

URGENT - WEATHER MESSAGE
National Weather Service Medford OR
900 PM PDT Mon Apr 5 2021

ORZ024-026-061600-
/O.NEW.KMFR.FZ.W.0004.210406T1000Z-210406T1600Z/
Eastern Curry County and Josephine County-Jackson County-
Including the city of Cave Junction
900 PM PDT Mon Apr 5 2021

...FREEZE WARNING IN EFFECT FROM 3 AM TO 9 AM PDT TUESDAY...

* WHAT...Sub-freezing temperatures as low as 28 expected.

* WHERE...The Illinois Valley, the Applegate Valley, and rural
  portions of the Rogue Valley. Additionally, the communities of
  Rogue River, Gold Hill, and Shady Cove are included.

* WHEN...From 3 AM to 9 AM PDT Tuesday.

* IMPACTS...Freeze conditions will kill crops, other sensitive 
  vegetation and possibly damage unprotected outdoor plumbing.

* ADDITIONAL DETAILS...The inversion will be relatively strong
  tonight, so wind machines may be effective in mixing warmer air
  aloft to the surface.

* View the hazard area in detail at 
  https://www.wrh.noaa.gov/map/?wfo=mfr

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Take steps now to protect tender plants from the cold. To prevent
freezing and possible bursting of outdoor water pipes they should
be wrapped, drained, or allowed to drip slowly. Those that have
in-ground sprinkler systems should drain them and cover above-
ground pipes to protect them from freezing.

&&

$$

Visit us at https://www.weather.gov/Medford
1 follow-up statement
862 
WWUS76 KMFR 061607
NPWMFR

URGENT - WEATHER MESSAGE
National Weather Service Medford OR
907 AM PDT Tue Apr 6 2021

ORZ024-026-061715-
/O.EXP.KMFR.FZ.W.0004.000000T0000Z-210406T1600Z/
Eastern Curry County and Josephine County-Jackson County-
Including the city of Cave Junction
907 AM PDT Tue Apr 6 2021

...FREEZE WARNING HAS EXPIRED...

The freeze warning has expired. Morning lows in the valleys of
Josephine and Jackson counties ranged from the mid 20s to lower
30s.

$$

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

The office that day

Everything else NWS Medford, OR issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Apr 6, 2:23 PM PDTFreeze WarningMFRCurry, Jackson, Josephine19 hr

Nearby

Freeze Warnings in Oregon, 2021Every freeze 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.