Alert archive / Oregon / Frost Advisories in 2020

Frost Advisory 11, NWS Medford, OR

April 1, 2020Coos County, Curry County, Douglas County, Oregon

NWS Medford, OR issued this frost advisory at Apr 1, 2020, 4:31 AM PDT for Coos County, Curry County, Douglas County, Oregon. It took effect at Apr 1, 2020, 10:00 PM PDT. It was in force for 11 hr.

The area

The counties it named.

The facts

Issued
Apr 1, 2020, 4:31 AM PDT (11:31 UTC)
In effect from
Apr 1, 2020, 10:00 PM PDT
Expired
Apr 2, 2020, 9:00 AM PDT
In force
11 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 11:32 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, 11.5 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 00:00Z on 2020-04-01Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 3 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, Medford/Jackson, OR at 00:00Z on 2020-04-01The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 66 square meters per square second.1939587897Sfc1 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
3 J/kg
Mixed-layer CIN
-63 J/kg
Mixed-layer LCL
1099 m above ground
0-6 km bulk shear
74 kt
0-1 km storm-relative helicity
66 m²/s²
0-3 km storm-relative helicity
176 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The office that day

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

IssuedProductOfficeCountiesLasted
Apr 1, 2:22 AM PDTSmall Craft AdvisoryMFR21 hr
Apr 1, 4:31 AM PDTFreeze WatchMFRCoos, Douglas, Jackson10 hr
Apr 1, 2:37 PM PDTFreeze WatchMFRCoos, Curry, Douglas, Jackson, Josephine22 hr
Apr 1, 2:37 PM PDTFreeze WarningMFRCoos, Curry, Douglas, Jackson, Josephine18 hr

Nearby

Frost Advisories in Oregon, 2020Every frost advisory 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.