Alert archive / Oregon / Frost Advisories in 2009

Frost Advisory 21, NWS Medford, OR

April 4, 20095 counties in Oregon

NWS Medford, OR issued this frost advisory at Apr 4, 2009, 2:52 PM PDT for 5 counties in Oregon. It took effect at Apr 5, 2009, 2:00 AM PDT. It was in force for 6 hr.

The area

The counties it named.

The facts

Issued
Apr 4, 2009, 2:52 PM PDT (21:52 UTC)
In effect from
Apr 5, 2009, 2:00 AM PDT
Expired
Apr 5, 2009, 8:29 AM PDT
In force
6 hr
Issued by
NWS Medford, OR

Counties Coos County, OR, Curry County, OR, Douglas County, OR, Jackson County, OR, Josephine County, OR

The radar

The Medford radar (KMAX), 101 km from the middle of the area, began a volume at 21:52 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, 9.9 hours before the alert went out and 75 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 2009-04-04Temperature 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 2009-04-04The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -98 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
738 m above ground
0-6 km bulk shear
34 kt
0-1 km storm-relative helicity
-98 m²/s²
0-3 km storm-relative helicity
15 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

000 
WWUS76 KMFR 042152
NPWMFR

URGENT - WEATHER MESSAGE
NATIONAL WEATHER SERVICE MEDFORD OR
252 PM PDT SAT APR 4 2009

...FROST EXPECTED TONIGHT...

.CLEAR SKIES AND A DRYING ATMOSPHERE WILL CREATE AREAS OF FROST BY
EARLY SUNDAY MORNING.

ORZ023>026-051600-
/O.NEW.KMFR.FR.Y.0021.090405T0900Z-090405T1600Z/
CENTRAL DOUGLAS COUNTY-EASTERN CURRY COUNTY AND JOSEPHINE COUNTY-
EASTERN DOUGLAS COUNTY FOOTHILLS-JACKSON COUNTY-
INCLUDING THE CITIES OF...ROSEBURG...SUTHERLIN...GREEN...
STEAMBOAT...TOKETEE FALLS...MEDFORD...ASHLAND
252 PM PDT SAT APR 4 2009

...FROST ADVISORY IN EFFECT FROM 2 AM TO 9 AM PDT SUNDAY...

THE NATIONAL WEATHER SERVICE IN MEDFORD HAS ISSUED A FROST
ADVISORY...WHICH IS IN EFFECT FROM 2 AM TO 9 AM PDT SUNDAY. 

LOW TEMPERATURES WILL GENERALLY FALL INTO THE LOW TO MID 30S
TONIGHT OVER INTERIOR VALLEYS IN SOUTHWEST OREGON. LOCALLY...
TEMPERATURES COULD BRIEFLY DIP BELOW FREEZING. HOWEVER...SUB
FREEZING TEMPERATURES SHOULD OCCUR FOR PERIODS NO LONGER THAN 2
HOURS.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A FROST ADVISORY MEANS THAT FROST IS POSSIBLE. SENSITIVE OUTDOOR
PLANTS MAY BE KILLED IF LEFT UNCOVERED.

&&

$$
MWJ
1 follow-up statement
000 
WWUS76 KMFR 051529
NPWMFR

URGENT - WEATHER MESSAGE
NATIONAL WEATHER SERVICE MEDFORD OR
829 AM PDT SUN APR 5 2009

...FROST THREAT HAS ENDED...

ORZ023>026-051630-
/O.CAN.KMFR.FR.Y.0021.000000T0000Z-090405T1600Z/
CENTRAL DOUGLAS COUNTY-EASTERN CURRY COUNTY AND JOSEPHINE COUNTY-
EASTERN DOUGLAS COUNTY FOOTHILLS-JACKSON COUNTY-
INCLUDING THE CITIES OF...ROSEBURG...SUTHERLIN...GREEN...
STEAMBOAT...TOKETEE FALLS...MEDFORD...ASHLAND
829 AM PDT SUN APR 5 2009

...FROST ADVISORY IS CANCELLED...

THE NATIONAL WEATHER SERVICE IN MEDFORD HAS CANCELLED THE FROST
ADVISORY. 

THE FROST THREAT HAS ENDED SINCE TEMPERATURES ARE GENERALLY ABOVE 36
DEGREES AS OF 830 AM.

$$
MWJ

The office that day

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

IssuedProductOfficeCountiesLasted
Apr 3, 11:26 PM PDTSmall Craft Advisory for Hazardous SeasMFR12 hr

Nearby

Frost Advisories in Oregon, 2009Every frost advisory in 2009

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.