Alert archive / Alabama / Red Flag Warnings in 2012

Red Flag Warning 9, NWS Huntsville, AL

April 9, 20124 counties in Alabama

NWS Huntsville, AL issued this red flag warning at Apr 9, 2012, 4:02 AM CDT for 4 counties in Alabama. It took effect at Apr 9, 2012, 1:00 PM CDT. It was in force for 6 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
Apr 9, 2012, 4:02 AM CDT (09:02 UTC)
In effect from
Apr 9, 2012, 1:00 PM CDT
Expired
Apr 9, 2012, 7:00 PM CDT
In force
6 hr
Issued by
NWS Huntsville, AL

Counties DeKalb County, AL, Jackson County, AL, Madison County, AL, Marshall County, AL

The radar

The Northeast Alabama radar (KHTX), 38 km from the middle of the area, began a volume at 09:00 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, 9.0 hours before the alert went out and 167 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 2012-04-09Temperature 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°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Birmingham, AL at 00:00Z on 2012-04-09The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 17 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
2175 m above ground
0-6 km bulk shear
38 kt
0-1 km storm-relative helicity
17 m²/s²
0-3 km storm-relative helicity
-29 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.

989 
WWUS84 KHUN 090902
RFWHUN

URGENT - FIRE WEATHER MESSAGE
NATIONAL WEATHER SERVICE HUNTSVILLE AL
402 AM CDT MON APR 9 2012

ALZ006-008>010-100000-
/O.NEW.KHUN.FW.W.0009.120409T1800Z-120410T0000Z/
MADISON-MARSHALL-JACKSON-DEKALB-
402 AM CDT MON APR 9 2012

...RED FLAG WARNING IN EFFECT FROM 1 PM THIS AFTERNOON TO 7 PM
CDT THIS EVENING FOR LOW HUMIDITY ACROSS NORTHEAST ALABAMA...

THE NATIONAL WEATHER SERVICE IN HUNTSVILLE HAS ISSUED A RED FLAG
WARNING...WHICH IS IN EFFECT FROM 1 PM THIS AFTERNOON TO 7 PM CDT
THIS EVENING. 

* AFFECTED AREA: MADISON...MARSHALL...JACKSON...AND DEKALB 
  COUNTIES. 

* TIMING: FROM 1 PM THIS AFTERNOON TO 7 PM CDT THIS EVENING. 

* RELATIVE HUMIDITY: VALUES ARE EXPECTED TO DROP TO BETWEEN 20 TO 25
  PERCENT.

* IMPACTS: THE DRY AIRMASS IN PLACE ACROSS THE REGION WILL RESULT 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.

&&

$$
2 follow-up statements
935 
WWUS84 KHUN 091809 AAA
RFWHUN

URGENT - FIRE WEATHER MESSAGE...UPDATED
NATIONAL WEATHER SERVICE HUNTSVILLE AL
109 PM CDT MON APR 9 2012

ALZ006-008>010-100000-
/O.CON.KHUN.FW.W.0009.000000T0000Z-120410T0000Z/
MADISON-MARSHALL-JACKSON-DEKALB-
109 PM CDT MON APR 9 2012

...RED FLAG WARNING REMAINS IN EFFECT UNTIL 7 PM CDT THIS EVENING
FOR LOW HUMIDITY ACROSS NORTHEAST ALABAMA...

* AFFECTED AREA: MADISON...MARSHALL...JACKSON...AND DEKALB 
  COUNTIES. 

* TIMING: FROM 1 PM THIS AFTERNOON TO 7 PM CDT THIS EVENING.

* RELATIVE HUMIDITY: VALUES ARE EXPECTED TO DROP TO BETWEEN 20 
  TO 25 PERCENT. 

* IMPACTS: THE DRY AIRMASS IN PLACE ACROSS THE REGION WILL 
  RESULT 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.

&&

$$

TT
195 
WWUS84 KHUN 100001
RFWHUN

URGENT - FIRE WEATHER MESSAGE
NATIONAL WEATHER SERVICE HUNTSVILLE AL
701 PM CDT MON APR 9 2012

...RED FLAG WARNING WILL EXPIRE AT 7 PM CDT THIS EVENING FOR
NORTHEAST ALABAMA...

ALZ006-008>010-100115-
/O.EXP.KHUN.FW.W.0009.000000T0000Z-120410T0000Z/
MADISON-MARSHALL-JACKSON-DEKALB-
701 PM CDT MON APR 9 2012

...RED FLAG WARNING WILL EXPIRE AT 7 PM CDT THIS EVENING FOR
NORTHEAST ALABAMA...

ALTHOUGH SOME PORTIONS OF JACKSON AND DEKALB COUNTIES MAY STILL
EXPERIENCE SUBCRITICAL RELATIVE HUMIDITY VALUES BETWEEN 7 AND 730
PM CDT...LOCAL SURFACE OBSERVATIONS INDICATE THAT RELATIVE HUMIDITY
VALUES ARE RISING OUT OF THE 20 TO 25 PERCENT RANGE ACROSS
NORTHEASTERN ALABAMA. THIS TREND IS EXPECTED TO CONTINUE INTO THE
EVENING AS AIR TEMPERATURES COOL...AND THE RED FLAG WARNING WILL BE
ALLOWED TO EXPIRE ON SCHEDULE AT 7 PM CDT.

$$

70/DD

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.