Alert archive / Nebraska / Frost Advisories in 2017

Frost Advisory 1, NWS Omaha, NE

April 26, 201730 counties in Nebraska; 8 counties in Iowa

NWS Omaha, NE issued this frost advisory at Apr 26, 2017, 3:54 AM CDT for 30 counties in Nebraska; 8 counties in Iowa. It took effect at Apr 27, 2017, 12:00 AM CDT. It was in force for 9 hr.

The area

The counties it named.

The facts

Issued: Apr 26, 2017, 3:54 AM CDT (08:54 UTC)
In effect from: Apr 27, 2017, 12:00 AM CDT
Expired: Apr 27, 2017, 9:00 AM CDT
In force: 9 hr
Issued by: NWS Omaha, NE

All 38 counties

Fremont County, IA, Harrison County, IA, Mills County, IA, Monona County, IA, Montgomery County, IA, Page County, IA, Pottawattamie County, IA, Shelby County, IA, Antelope County, NE, Boone County, NE, Burt County, NE, Butler County, NE, Cass County, NE, Cedar County, NE, Colfax County, NE, Cuming County, NE, Dodge County, NE, Douglas County, NE, Gage County, NE, Jefferson County, NE, Johnson County, NE, Knox County, NE, Lancaster County, NE, Madison County, NE, Nemaha County, NE, Otoe County, NE, Pawnee County, NE, Pierce County, NE, Platte County, NE, Richardson County, NE, Saline County, NE, Sarpy County, NE, Saunders County, NE, Seward County, NE, Stanton County, NE, Thurston County, NE, Washington County, NE, Wayne County, NE

The radar

The Omaha radar (KOAX), 16 km from the middle of the area, began a volume at 08:52 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

Topeka, KS (KFOE), launched 00:00Z, 8.9 hours before the alert went out and 269 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: 12 J/kg
Mixed-layer CIN: -55 J/kg
Mixed-layer LCL: 1167 m above ground
0-6 km bulk shear: 59 kt
0-1 km storm-relative helicity: 108 m²/s²
0-3 km storm-relative helicity: 223 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 Omaha, NE wrote its last area forecast discussion before this frost advisory went out at Apr 25, 11:47 PM CDT, 4 hours 7 minutes earlier.

Area forecast discussion, Apr 25, 11:47 PM CDT, 4 hours 7 minutes before

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Hazardous weather outlook, Apr 25, 4:19 PM CDT, 11 hours 35 minutes before

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The office that day

Everything else NWS Omaha, NE issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Apr 26, 8:33 AM CDT	Freeze Warning	OAX	Antelope, Boone, Burt, Butler, Cedar, Colfax and 8 more	24 hr

Nearby

Frost Advisories in Nebraska, 2017 Frost Advisories in Iowa, 2017 Every frost advisory in 2017

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.