Alert archive / Oregon / Frost Advisories in 2007

Frost Advisory 5, NWS Medford, OR

April 17, 20075 counties in Oregon

NWS Medford, OR issued this frost advisory at Apr 17, 2007, 2:33 PM PDT for 5 counties in Oregon. It took effect at Apr 18, 2007, 2:00 AM PDT. It was in force for 6 hr.

The area

The counties it named.

The facts

Issued: Apr 17, 2007, 2:33 PM PDT (21:33 UTC)
In effect from: Apr 18, 2007, 2:00 AM PDT
Expired: Apr 18, 2007, 8:00 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 21:32 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 12:00Z, 9.6 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 956 m above ground
0-6 km bulk shear: 70 kt
0-1 km storm-relative helicity: 2 m²/s²
0-3 km storm-relative helicity: 104 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

What forecasters said that day

The local office's own words before this frost advisory went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Medford, OR wrote its last area forecast discussion before this frost advisory went out at Apr 17, 2:25 PM PDT, 8 minutes earlier.

Area forecast discussion, Apr 17, 2:25 PM PDT, 8 minutes before

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In the hours before

Local storm report, Apr 17, 2:22 PM PDT, 11 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE MEDFORD OR
222 PM PDT TUE APR 17 2007

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0220 PM     LIGHTNING        30 SW ASHLAND           41.88N 123.11W
04/17/2007                   SISKIYOU           CA   PUBLIC

            SKI PATROL AT MT ASHLAND REPORTED HEARING THUNDER DURING
            A SNOW SHOWER. CLOUD TO GROUND LIGHTNING WAS OBSERVED
            THROUGH NLDN DATA.

&&

SMITH

Nearby

Frost Advisories in Oregon, 2007 Every frost advisory in 2007

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.