Alert archive / Alabama / Frost Advisories in 2020

Frost Advisory 2, NWS Huntsville, AL

April 14, 202011 counties in Alabama

NWS Huntsville, AL issued this frost advisory at Apr 14, 2020, 2:13 AM CDT for 11 counties in Alabama. It took effect at Apr 15, 2020, 1:00 AM CDT. It was in force for 7 hr.

The area

The counties it named.

The facts

Issued: Apr 14, 2020, 2:13 AM CDT (07:13 UTC)
In effect from: Apr 15, 2020, 1:00 AM CDT
Expired: Apr 15, 2020, 8:00 AM CDT
In force: 7 hr
Issued by: NWS Huntsville, AL

Counties Colbert County, AL, Cullman County, AL, DeKalb County, AL, Franklin County, AL, Jackson County, AL, Lauderdale County, AL, Lawrence County, AL, Limestone County, AL, Madison County, AL, Marshall County, AL, Morgan County, AL

The radar

The Northeast Alabama radar (KHTX), 85 km from the middle of the area, began a volume at 07:17 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

Birmingham, AL (KBMX), launched 00:00Z, 7.2 hours before the alert went out and 156 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: 860 m above ground
0-6 km bulk shear: 64 kt
0-1 km storm-relative helicity: 95 m²/s²
0-3 km storm-relative helicity: 165 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 Huntsville, AL wrote its last area forecast discussion before this frost advisory went out at Apr 13, 6:51 PM CDT, 7 hours 22 minutes earlier.

Area forecast discussion, Apr 13, 6:51 PM CDT, 7 hours 22 minutes before

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Hazardous weather outlook, Apr 13, 5:02 PM CDT, 9 hours 11 minutes before

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The office that day

Everything else NWS Huntsville, AL issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Apr 14, 5:07 AM CDT	Areal Flood Warning	HUN	Cullman	5 hr
Apr 14, 2:13 AM CDT	Freeze Watch	HUN	Franklin, Lincoln, Moore	12 hr
Apr 14, 2:27 PM CDT	Freeze Warning	HUN	Franklin, Lincoln, Moore	18 hr

Nearby

Frost Advisories in Alabama, 2020 Every 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.