Alert archive / Alabama / Red Flag Warnings in 2012

Red Flag Warning 4, NWS Huntsville, AL

February 11, 201211 counties in Alabama

NWS Huntsville, AL issued this red flag warning at Feb 11, 2012, 2:43 PM CST for 11 counties in Alabama. It took effect at Feb 12, 2012, 11:00 AM CST. It was in force for 4 hr. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued
Feb 11, 2012, 2:43 PM CST (20:43 UTC)
In effect from
Feb 12, 2012, 11:00 AM CST
Expired
Feb 12, 2012, 2:35 PM CST
In force
4 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 20:47 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 12:00Z, 8.7 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-pSkew-T log-p diagram, Birmingham, AL at 12:00Z on 2012-02-11Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1 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 12:00Z on 2012-02-11The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -89 square meters per square second.1939587897117Sfc1 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
1 J/kg
Mixed-layer CIN
-13 J/kg
Mixed-layer LCL
621 m above ground
0-6 km bulk shear
64 kt
0-1 km storm-relative helicity
-89 m²/s²
0-3 km storm-relative helicity
-48 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

052 
WWUS84 KHUN 112043
RFWHUN

URGENT - FIRE WEATHER MESSAGE
NATIONAL WEATHER SERVICE HUNTSVILLE AL
243 PM CST SAT FEB 11 2012

ALZ001>010-016-130000-
/O.UPG.KHUN.FW.A.0003.120212T1800Z-120213T0000Z/
/O.NEW.KHUN.FW.W.0004.120212T1700Z-120213T0000Z/
LAUDERDALE-COLBERT-FRANKLIN AL-LAWRENCE-LIMESTONE-MADISON-MORGAN-
MARSHALL-JACKSON-DEKALB-CULLMAN-
243 PM CST SAT FEB 11 2012

...RED FLAG WARNING IN EFFECT FROM 11 AM TO 6 PM CST SUNDAY FOR 
ALL FIRE WEATHER ZONES IN NORTHERN ALABAMA FOR 4 OR MORE 
CONSECUTIVE HOURS OF RELATIVE HUMIDITY AT OR BELOW 25 PERCENT...

THE NATIONAL WEATHER SERVICE IN HUNTSVILLE HAS ISSUED A RED FLAG 
WARNING...WHICH IS IN EFFECT FROM 11 AM TO 6 PM CST SUNDAY. THIS 
WARNING REPLACES THE FIRE WEATHER WATCH THAT WAS PREVIOUSLY IN 
EFFECT.

* AFFECTED AREAS: LAUDERDALE...COLBERT...FRANKLIN AL...LAWRENCE... 
  LIMESTONE...MADISON...MORGAN...MARSHALL...JACKSON...DEKALB... 
  AND CULLMAN COUNTIES.

* TIMING: SUNDAY AFTERNOON.

* RELATIVE HUMIDITY: VALUES WILL FALL INTO THE 20-25 PERCENT RANGE 
  FOR AROUND FIVE HOURS ON SUNDAY AFTERNOON.

* IMPACTS: A DRY ARCTIC AIR MASS WILL PERSIST ACROSS NORTHERN ALABAMA 
  ON SUNDAY...RESULTING IN CRITICAL FIRE WEATHER CONDITIONS.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A RED FLAG WARNING MEANS THAT CRITICAL FIRE WEATHER CONDITIONS 
ARE EITHER OCCURRING NOW...OR WILL SHORTLY. LOW RELATIVE HUMIDITY 
OVER A PROLONGED PERIOD WILL INCREASE FIRE GROWTH POTENTIAL.

&&

$$

70/DD
2 follow-up statements
461 
WWUS84 KHUN 121155
RFWHUN

URGENT - FIRE WEATHER MESSAGE
NATIONAL WEATHER SERVICE HUNTSVILLE AL
555 AM CST SUN FEB 12 2012

ALZ001>010-016-130000-
/O.CON.KHUN.FW.W.0004.120212T1700Z-120213T0000Z/
LAUDERDALE-COLBERT-FRANKLIN AL-LAWRENCE-LIMESTONE-MADISON-MORGAN-
MARSHALL-JACKSON-DEKALB-CULLMAN-
555 AM CST SUN FEB 12 2012

...RED FLAG WARNING REMAINS IN EFFECT FROM 11 AM THIS MORNING TO
6 PM CST THIS EVENING FOR LOW HUMIDITY FOR ALL OF NORTHERN ALABAMA...

* AFFECTED AREAS: LAUDERDALE...COLBERT...FRANKLIN AL...
  LAWRENCE...LIMESTONE...MADISON...MORGAN...MARSHALL...
  JACKSON...DEKALB... AND CULLMAN COUNTIES. 

* TIMING: MAINLY THIS AFTERNOON.

* RELATIVE HUMIDITY: VALUES WILL FALL WELL BELOW 25 PERCENT FOR AT
  LEAST FOUR HOURS OR MORE LATER TODAY.

* IMPACTS: A DRY ARCTIC AIR MASS WILL PERSIST ACROSS NORTHERN ALABAMA
  TODAY...RESULTING IN CRITICAL FIRE WEATHER CONDITIONS. LOW RELATIVE
  HUMIDITY VALUES ARE AGAIN POSSIBLE ON MONDAY BEFORE GULF MOISTURE
  INCREASES ACROSS THE REGION MONDAY NIGHT AND TUESDAY.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A RED FLAG WARNING MEANS THAT CRITICAL FIRE WEATHER CONDITIONS
ARE EITHER OCCURRING NOW...OR WILL SHORTLY. LOW RELATIVE HUMIDITY
OVER A PROLONGED PERIOD WILL INCREASE FIRE GROWTH POTENTIAL.

&&

$$
977 
WWUS84 KHUN 122035
RFWHUN

URGENT - FIRE WEATHER MESSAGE
NATIONAL WEATHER SERVICE HUNTSVILLE AL
235 PM CST SUN FEB 12 2012

...RED FLAG WARNING IS CANCELLED FOR ALL COUNTIES IN NORTHERN 
ALABAMA...

ALZ001>010-016-122145-
/O.CAN.KHUN.FW.W.0004.000000T0000Z-120213T0000Z/
LAUDERDALE-COLBERT-FRANKLIN AL-LAWRENCE-LIMESTONE-MADISON-MORGAN-
MARSHALL-JACKSON-DEKALB-CULLMAN-
235 PM CST SUN FEB 12 2012

...RED FLAG WARNING IS CANCELLED FOR ALL COUNTIES IN NORTHERN 
ALABAMA...

THE NATIONAL WEATHER SERVICE IN HUNTSVILLE HAS CANCELLED THE RED FLAG
WARNING THAT WAS PREVIOUSLY IN EFFECT FOR ALL COUNTIES ACROSS
NORTHERN ALABAMA. AFTERNOON TEMPERATURES HAVE STRUGGLED TO WARM INTO
THE MID 30S...LIMITING MINIMUM RELATIVE HUMIDITY VALUES TO THE 25-30
PERCENT RANGE IN ONLY A FEW LOCATIONS. RELATIVE HUMIDITY VALUES WILL
SLOWLY INCREASE THROUGH LATE THIS AFTERNOON AS TEMPERATURES BEGIN TO
FALL ONCE AGAIN.

$$

70/DD

The office that day

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

IssuedProductOfficeCountiesLasted
Feb 11, 9:56 AM CSTWind AdvisoryHUNColbert, Cullman, DeKalb, Franklin, Jackson, Lauderdale and 5 more8 hr

Nearby

Red Flag Warnings in Alabama, 2012Every red flag warning in 2012

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.