Alert archive / Kansas / Dense Fog Advisories in 2021

Dense Fog Advisory 4, NWS Topeka, KS

February 19, 2021Marshall County, Republic County, Washington County, Kansas

NWS Topeka, KS issued this dense fog advisory at Feb 19, 2021, 10:03 PM CST for Marshall County, Republic County, Washington County, Kansas. It took effect at Feb 20, 2021, 4:00 AM CST. It was in force for 6 hr.

The area

The counties it named.

The facts

Issued
Feb 19, 2021, 10:03 PM CST (04:03 UTC)
In effect from
Feb 20, 2021, 4:00 AM CST
Expired
Feb 20, 2021, 10:00 AM CST
In force
6 hr
Issued by
NWS Topeka, KS

Counties Marshall County, KS, Republic County, KS, Washington County, KS

The radar

The Topeka radar (KTWX), 115 km from the middle of the area, began a volume at 04:09 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, 4.1 hours before the alert went out and 180 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 2021-02-20Temperature 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 2021-02-20The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 118 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
1319 m above ground
0-6 km bulk shear
55 kt
0-1 km storm-relative helicity
118 m²/s²
0-3 km storm-relative helicity
249 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The office that day

Everything else NWS Topeka, KS issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Feb 20, 3:11 PM CSTWinter Weather AdvisoryTOPBrown, Clay, Cloud, Dickinson, Geary, Jackson and 12 more20 hr

Nearby

Dense Fog Advisories in Kansas, 2021Every dense fog advisory 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.