Alert archive / Alabama / Dense Fog Advisories in 2021

Dense Fog Advisory 21, NWS Birmingham, AL

December 6, 20216 counties in Alabama

NWS Birmingham, AL issued this dense fog advisory at Dec 6, 2021, 5:22 AM CST for 6 counties in Alabama. It was in force for 4 hr.

The area

The counties it named.

The facts

Issued
Dec 6, 2021, 5:22 AM CST (11:22 UTC)
Expired
Dec 6, 2021, 9:00 AM CST
In force
4 hr
Issued by
NWS Birmingham, AL

Counties Barbour County, AL, Bullock County, AL, Lee County, AL, Macon County, AL, Pike County, AL, Russell County, AL

The radar

The Maxwell AFB radar (KMXX), 46 km from the middle of the area, began a volume at 11:25 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, 11.4 hours before the alert went out and 161 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, Birmingham, AL at 00:00Z on 2021-12-06Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 94 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Birmingham, AL at 00:00Z on 2021-12-06The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 80 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
94 J/kg
Mixed-layer CIN
-9 J/kg
Mixed-layer LCL
1096 m above ground
0-6 km bulk shear
34 kt
0-1 km storm-relative helicity
80 m²/s²
0-3 km storm-relative helicity
180 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.2

Open this sounding in Storm Lab

The text

As transmitted.

615 
WWUS74 KBMX 061122
NPWBMX

URGENT - WEATHER MESSAGE
National Weather Service Birmingham AL
522 AM CST Mon Dec 6 2021

ALZ045>050-061500-
/O.NEW.KBMX.FG.Y.0021.211206T1122Z-211206T1500Z/
Macon-Bullock-Lee-Russell-Pike-Barbour-
Including the cities of Tuskegee, Union Springs, Auburn, Opelika,
Phenix City, Troy, and Eufaula
522 AM CST Mon Dec 6 2021

...DENSE FOG ADVISORY IN EFFECT UNTIL 9 AM CST THIS MORNING...

* WHAT...Visibility one quarter mile or less in dense fog.

* WHERE...Macon, Bullock, Lee, Russell, Pike and Barbour 
  Counties.

* WHEN...Until 9 AM CST this morning.

* IMPACTS...Hazardous driving conditions due to low visibility.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If driving, slow down, use your headlights, and leave plenty of
distance ahead of you.

&&

$$

08

The office that day

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

IssuedProductOfficeCountiesLasted
Dec 6, 7:55 AM CSTSpecial Weather StatementBMXFayette, Lamar, Pickens50 min
Dec 6, 8:36 AM CSTSevere Thunderstorm WarningBMXFayette, Lamar, Pickens, Tuscaloosa54 min
Dec 6, 9:09 AM CSTSevere Thunderstorm WarningBMXWalker21 min
Dec 6, 9:17 AM CSTSpecial Weather StatementBMXJefferson43 min
Dec 6, 9:33 AM CSTSpecial Weather StatementBMXBibb, Shelby42 min
Dec 6, 9:51 AM CSTSpecial Weather StatementBMXMarshall24 min
Dec 6, 10:02 AM CSTSpecial Weather StatementBMXSt. Clair43 min
Dec 6, 10:15 AM CSTSpecial Weather StatementBMXChilton, Shelby, Talladega45 min
Dec 6, 10:42 AM CSTSevere Thunderstorm WarningBMXClay, Coosa, Talladega39 min
Dec 6, 10:51 AM CSTSpecial Weather StatementBMXGreene, Hale, Sumter39 min
Dec 6, 10:53 AM CSTSpecial Weather StatementBMXCoosa, Elmore, Tallapoosa52 min
Dec 6, 11:24 AM CSTSpecial Weather StatementBMXChambers, Randolph66 min
Dec 6, 11:36 AM CSTSpecial Weather StatementBMXElmore24 min
Dec 6, 11:37 AM CSTSpecial Weather StatementBMXHale, Perry38 min
Dec 6, 12:03 PM CSTSpecial Weather StatementBMXLee57 min

Nearby

Dense Fog Advisories in Alabama, 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.