Alert archive / Alabama / Severe Thunderstorm Warnings in 2013

Severe Thunderstorm Warning 120, NWS Birmingham, AL

July 23, 2013Macon County, Alabama

NWS Birmingham, AL issued this severe thunderstorm warning at Jul 23, 2013, 4:33 PM CDT for Macon County, Alabama. It was in force for 42 min. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued: Jul 23, 2013, 4:33 PM CDT (21:33 UTC)
Expired: Jul 23, 2013, 5:15 PM CDT
In force: 42 min
Issued by: NWS Birmingham, AL
Area: Storm-based polygon

County Macon County, AL

The radar

The Maxwell AFB radar (KMXX), 19 km from the middle of the area, began a volume at 21:35 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 watch it was issued in

The SPC watch in force over the same counties when this warning went out.

Issued	Product	Office	Lasted
Jul 23, 1:15 PM CDT	Severe Thunderstorm Watch	SPC	7 hr

The nearest sounding before it

Birmingham, AL (KBMX), launched 12:00Z, 9.6 hours before the alert went out and 135 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: 1182 J/kg
Mixed-layer CIN: -28 J/kg
Mixed-layer LCL: 535 m above ground
0-6 km bulk shear: 25 kt
0-1 km storm-relative helicity: 103 m²/s²
0-3 km storm-relative helicity: 42 m²/s²
Significant tornado parameter: 0.3
Supercell composite: 2.8

Open this sounding in Storm Lab

What forecasters said that day

The local office's own words before this severe thunderstorm warning went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Birmingham, AL wrote its last area forecast discussion before this severe thunderstorm warning went out at Jul 23, 3:02 PM CDT, 1 hour 31 minutes earlier.

Area forecast discussion, Jul 23, 3:02 PM CDT, 1 hour 31 minutes before

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BIRMINGHAM AL
302 PM CDT TUE JUL 23 2013

.DISCUSSION...

A MCS PRODUCING SPORADIC WIND DAMAGE AND SOME FLOODING IS ONGOING
ACROSS CENTRAL ALABAMA THIS AFTERNOON. EXPECT THE MCS AND
ASSOCIATED SEVERE THREAT TO EXIT OUR AREA EARLY THIS EVENING AS
IT MOVES OFF TO THE SOUTHEAST. THIS SHOULD END OUR RAIN CHANCES
FOR THE REST OF TODAY AND PROBABLY OVERNIGHT SINCE MANY AREAS WILL
HAVE BEEN WORKED OVER TWICE TODAY BY CONVECTION.

UNFORTUNATELY ONE MORE SHORTWAVE TROUGH IN THE OVERALL NORTHWEST
FLOW ALOFT IS FORECAST TO MOVE OVER THE GULF COAST STATES TOMORROW
AFTERNOON. MAINTAINED THE LIKELY POPS WEDNESDAY AFTERNOON FOR ALL
OF OUR CWA. THE MIDNIGHT CREW WILL HAVE TO EVALUATE ANY
SEVERE/FLOODING POTENTIAL FOR TOMORROW.

THE REMAINDER OF THE FORECAST PACKAGE WAS LEFT ESSENTIALLY
UNCHANGED. BOTH THE GFS AND ECMWF ADVERTISE AN ANOMALOUS UPPER
TROUGH MOVING OVER THE SOUTHEAST AT SOME POINT THIS WEEKEND...
WITH THE 12Z ECMWF BEING FAR STRONGER IN ITS DEPICTION OF THE
UPPER TROUGH. WITH THE DISCREPANCIES IN THE MODELS CONTINUING...
KEPT POPS AS THEY ARE FOR THE WEEKEND.

77/GLEASON

&&

.AVIATION...
18Z TAF DISCUSSION.

YET ANOTHER LINE OF THUNDERSTORMS WILL IMPACT MUCH OF CENTRAL
ALABAMA THIS AFTERNOON AS A TROPICAL AIRMASS REMAINS IN PLACE OVER
THE AREA. AS OF 18Z... THIS LINE STRETCHES FROM NEAR GWO TO GTR TO
JFX... MOVING SOUTH/SOUTHEAST. TRIED MY BEST TO TIME OUT TSRA FOR
BHM... EET... AND TCL. WILL PROBABLY HAVE TO DO A FEW AMENDMENTS
THROUGH THE AFTERNOON AS STORMS WILL LIKELY IMPACT ALL TAF SITES
AT SOME POINT BEFORE SUNSET.

LIKE YESTERDAY... SHOWERS AND THUNDERSTORMS SHOULD DIMINISH IN
COVERAGE AND INTENSITY THIS EVENING AND OVERNIGHT. WITH ALL THE
RECENT RAINFALL... EXPECTING SOME PATCHY FOG OVERNIGHT FOR MOST
SITES IF CLOUDS CAN CLEAR OUT.

77/GLEASON

&&

.PRELIMINARY POINT TEMPS/POPS...
GADSDEN     70  87  69  87  65 /  40  60  20  10  10
ANNISTON    71  86  68  87  66 /  40  60  20  10  10
BIRMINGHAM  72  88  69  88  68 /  40  60  20  10  10
TUSCALOOSA  72  89  71  91  67 /  40  60  20  10  10
CALERA      71  87  70  88  68 /  40  60  20  10  10
AUBURN      69  87  70  89  68 /  40  60  20  20  10
MONTGOMERY  72  89  72  90  70 /  40  60  20  20  10
TROY        71  88  71  92  69 /  50  60  30  20  10

&&

.BMX WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

Hazardous weather outlook, Jul 23, 4:15 PM CDT, 18 minutes before

HAZARDOUS WEATHER OUTLOOK...UPDATED
NATIONAL WEATHER SERVICE BIRMINGHAM AL
415 PM CDT TUE JUL 23 2013

ALZ011>015-017>050-242115-
MARION-LAMAR-FAYETTE-WINSTON-WALKER-BLOUNT-ETOWAH-CALHOUN-CHEROKEE-
CLEBURNE-PICKENS-TUSCALOOSA-JEFFERSON-SHELBY-ST. CLAIR-TALLADEGA-
CLAY-RANDOLPH-SUMTER-GREENE-HALE-PERRY-BIBB-CHILTON-COOSA-TALLAPOOSA-
CHAMBERS-MARENGO-DALLAS-AUTAUGA-LOWNDES-ELMORE-MONTGOMERY-MACON-
BULLOCK-LEE-RUSSELL-PIKE-BARBOUR-
415 PM CDT TUE JUL 23 2013

THIS HAZARDOUS WEATHER OUTLOOK IS FOR THE COUNTIES SERVED BY THE
NATIONAL WEATHER SERVICE OFFICE IN BIRMINGHAM.

.DAY ONE...THIS AFTERNOON AND TONIGHT.

THUNDERSTORMS WILL CONTINUE TO SLIDE SOUTH AND EAST THROUGH
SOUTHEASTERN SECTIONS OF CENTRAL ALABAMA THROUGH THE EVENING.
SOME AREAS MAY EXPERIENCE HEAVY RAINFALL LEADING TO LOCALIZED
FLASH FLOODING. ADDITIONALLY... SOME OF THE THUNDERSTORMS WILL BE
CAPABLE OF PRODUCING WIND GUSTS UP TO 60 MPH. THE ACTIVITY SHOULD
LOSE SOME INTENSITY BY 10 PM.

.DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY.

NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

.SPOTTER INFORMATION STATEMENT...

ACTIVATION OF STORM SPOTTERS AND EMERGENCY MANAGEMENT MAY BE NEEDED
THROUGH THIS EVENING DUE TO SEVERE WEATHER.

In the hours before

Local storm report, Jul 23, 4:02 PM CDT, 31 minutes before

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Local storm report, Jul 23, 4:04 PM CDT, 29 minutes before

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Local storm report, Jul 23, 4:07 PM CDT, 26 minutes before

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Local storm report, Jul 23, 4:08 PM CDT, 25 minutes before

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Local storm report, Jul 23, 4:11 PM CDT, 22 minutes before

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Local storm report, Jul 23, 4:30 PM CDT, 3 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE BIRMINGHAM AL
430 PM CDT TUE JUL 23 2013

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0420 PM     HEAVY RAIN       4 WNW TRUSSVILLE        33.65N 86.66W
07/23/2013  U0.00 INCH       JEFFERSON          AL   PUBLIC

            PONDING ON SWEENY HOLLOW ROAD IN CHALKVILLE.

&&

AA

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 23, 4:44 AM CDT	Special Weather Statement	BMX	Fayette, Lamar, Marion	46 min
Jul 23, 5:14 AM CDT	Special Weather Statement	BMX	Walker, Winston	61 min
Jul 23, 5:28 AM CDT	Special Weather Statement	BMX	Fayette	47 min
Jul 23, 6:16 AM CDT	Special Weather Statement	BMX	Jefferson	44 min
Jul 23, 10:53 AM CDT	Areal Flood Advisory	BMX	Etowah	112 min
Jul 23, 10:56 AM CDT	Special Weather Statement	BMX	Marion	64 min
Jul 23, 11:12 AM CDT	Severe Thunderstorm Warning	BMX	Lamar, Marion	48 min
Jul 23, 11:26 AM CDT	Special Weather Statement	BMX	Fayette	49 min
Jul 23, 11:41 AM CDT	Flash Flood Warning	BMX	Fayette, Lamar, Marion, Winston	3 hr
Jul 23, 12:07 PM CDT	Special Weather Statement	BMX	Fayette, Lamar, Walker, Winston	53 min
Jul 23, 12:16 PM CDT	Severe Thunderstorm Warning	BMX	Fayette	44 min
Jul 23, 12:33 PM CDT	Special Weather Statement	BMX	Pickens, Tuscaloosa	57 min
Jul 23, 12:44 PM CDT	Severe Thunderstorm Warning	BMX	Tuscaloosa, Walker	61 min
Jul 23, 1:11 PM CDT	Special Weather Statement	BMX	Jefferson	64 min
Jul 23, 1:29 PM CDT	Areal Flood Advisory	BMX	Blount, Jefferson, Pickens, St. Clair, Tuscaloosa, Walker	3 hr
Jul 23, 1:34 PM CDT	Special Weather Statement	BMX	Greene, Hale, Sumter	56 min
Jul 23, 1:58 PM CDT	Areal Flood Advisory	BMX	Bibb, Greene, Hale, Jefferson, St. Clair, Shelby and 3 more	2 hr
Jul 23, 2:00 PM CDT	Severe Thunderstorm Warning	BMX	Greene, Hale, Marengo, Perry, Sumter	60 min
Jul 23, 2:09 PM CDT	Special Weather Statement	BMX	Bibb, Chilton, Coosa, Shelby, Talladega	66 min
Jul 23, 2:25 PM CDT	Areal Flood Advisory	BMX	Bibb, Chilton, Clay, Coosa, Hale, Marengo and 3 more	2 hr
Jul 23, 2:30 PM CDT	Flash Flood Warning	BMX	Blount, Jefferson, St. Clair	3 hr
Jul 23, 2:59 PM CDT	Areal Flood Advisory	BMX	Autauga, Chilton, Clay, Coosa, Dallas, Marengo and 2 more	2 hr
Jul 23, 3:01 PM CDT	Special Weather Statement	BMX	Autauga, Chambers, Clay, Dallas, Elmore, Lowndes and 2 more	59 min
Jul 23, 3:14 PM CDT	Flash Flood Warning	BMX	Montgomery	3 hr
Jul 23, 3:27 PM CDT	Areal Flood Advisory	BMX	Autauga, Clay, Coosa, Dallas, Elmore, Lowndes and 2 more	2 hr
Jul 23, 3:38 PM CDT	Severe Thunderstorm Warning	BMX	Elmore	52 min
Jul 23, 3:58 PM CDT	Special Weather Statement	BMX	Bullock, Chambers, Lee, Macon, Montgomery, Pike	62 min
Jul 23, 4:10 PM CDT	Areal Flood Advisory	BMX	Barbour, Bullock, Chambers, Lee, Macon, Montgomery and 3 more	2 hr
Jul 23, 4:56 PM CDT	Special Weather Statement	BMX	Barbour, Lee, Russell	64 min
Jul 23, 5:23 PM CDT	Severe Thunderstorm Warning	BMX	Russell	37 min

Nearby

Severe Thunderstorm Warnings in Alabama, 2013 Every severe thunderstorm warning in 2013

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.