Alert archive / Nebraska / Freeze Watches in 2021

Freeze Watch 1, NWS Omaha, NE

April 19, 202115 counties in Nebraska; 5 counties in Iowa

NWS Omaha, NE issued this freeze watch at Apr 19, 2021, 3:55 AM CDT for 15 counties in Nebraska; 5 counties in Iowa. It took effect at Apr 20, 2021, 10:00 PM CDT. It was in force for .

The area

The counties it named.

The facts

Issued
Apr 19, 2021, 3:55 AM CDT (08:55 UTC)
In effect from
Apr 20, 2021, 10:00 PM CDT
Expired
Apr 19, 2021, 2:29 PM CDT
In force
Issued by
NWS Omaha, NE

Counties Fremont County, IA, Mills County, IA, Montgomery County, IA, Page County, IA, Pottawattamie County, IA, Butler County, NE, Cass County, NE, Douglas County, NE, Gage County, NE, Jefferson County, NE, Johnson County, NE, Lancaster County, NE, Nemaha County, NE, Otoe County, NE, Pawnee County, NE, Richardson County, NE, Saline County, NE, Sarpy County, NE, Saunders County, NE, Seward County, NE

The radar

The Omaha radar (KOAX), 65 km from the middle of the area, began a volume at 08:56 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

Omaha, NE (KOAX), launched 00:00Z, 8.9 hours before the alert went out and 65 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, Omaha, NE at 00:00Z on 2021-04-19Temperature 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°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Omaha, NE at 00:00Z on 2021-04-19The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 42 square meters per square second.193958Sfc1 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
2635 m above ground
0-6 km bulk shear
40 kt
0-1 km storm-relative helicity
42 m²/s²
0-3 km storm-relative helicity
177 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The office that day

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

IssuedProductOfficeCountiesLasted
Apr 19, 3:54 AM CDTWinter Weather AdvisoryOAXGage, Jefferson, Johnson, Nemaha, Pawnee, Richardson29 hr
Apr 19, 2:29 PM CDTFreeze WarningOAXButler, Cass, Douglas, Gage, Jefferson, Johnson and 9 more19 hr
Apr 19, 2:29 PM CDTFreeze WarningOAXButler, Cass, Douglas, Gage, Jefferson, Johnson and 9 more43 hr

Nearby

Freeze Watches in Nebraska, 2021Freeze Watches in Iowa, 2021Every freeze watch 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.