Alert archive / Alabama / Heat Advisories in 2017

Heat Advisory 1, NWS Birmingham, AL

July 21, 201726 counties in Alabama

NWS Birmingham, AL issued this heat advisory at Jul 21, 2017, 11:45 AM CDT for 26 counties in Alabama. It was in force for 7 hr.

The area

The counties it named.

The facts

Issued
Jul 21, 2017, 11:45 AM CDT (16:45 UTC)
Expired
Jul 21, 2017, 7:00 PM CDT
In force
7 hr
Issued by
NWS Birmingham, AL
All 26 counties

Autauga County, AL, Barbour County, AL, Bibb County, AL, Bullock County, AL, Chilton County, AL, Dallas County, AL, Elmore County, AL, Fayette County, AL, Greene County, AL, Hale County, AL, Jefferson County, AL, Lamar County, AL, Lowndes County, AL, Macon County, AL, Marengo County, AL, Marion County, AL, Montgomery County, AL, Perry County, AL, Pickens County, AL, Pike County, AL, Russell County, AL, Shelby County, AL, Sumter County, AL, Tuscaloosa County, AL, Walker County, AL, Winston County, AL

The radar

The Birmingham radar (KBMX), 40 km from the middle of the area, began a volume at 16:46 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, 4.8 hours before the alert went out and 40 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 2017-07-21Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1369 joules per kilogram.LCLLFCEL10008507005003002001001 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, Birmingham, AL at 12:00Z on 2017-07-21The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 33 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
1369 J/kg
Mixed-layer CIN
-48 J/kg
Mixed-layer LCL
1108 m above ground
0-6 km bulk shear
18 kt
0-1 km storm-relative helicity
33 m²/s²
0-3 km storm-relative helicity
77 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

What forecasters said that day

The local office's own words before this heat advisory 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 heat advisory went out at Jul 21, 7:24 AM CDT, 4 hours 21 minutes earlier.

Area forecast discussion, Jul 21, 7:24 AM CDT, 4 hours 21 minutes before
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Hazardous weather outlook, Jul 21, 3:32 AM CDT, 8 hours 13 minutes before
Hazardous Weather Outlook
National Weather Service Birmingham AL
332 AM CDT Fri Jul 21 2017

ALZ011>015-017>050-221145-
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-
332 AM CDT Fri Jul 21 2017

This Hazardous Weather Outlook is for the counties served by the
National Weather Service office in Birmingham.

.DAY ONE...Outlook through Tonight.

High temperatures are forecast to be in the middle 90s this
afternoon. Heat indices could reach 105 or slightly higher across
isolated areas of western and southern Alabama during the
afternoon. Confidence remains low at this time.

.DAYS TWO THROUGH SEVEN...Saturday through Thursday.

No hazardous weather is expected at this time.

.SPOTTER INFORMATION STATEMENT...

Activation of storm spotters and emergency management is not
expected at this time.

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 21, 3:23 PM CDTSpecial Weather StatementBMXGreene, Hale37 min
Jul 21, 4:43 PM CDTSpecial Weather StatementBMXSumter32 min
Jul 21, 5:05 PM CDTSpecial Weather StatementBMXMacon25 min
Jul 21, 5:17 PM CDTSpecial Weather StatementBMXSumter28 min
Jul 21, 5:18 PM CDTSpecial Weather StatementBMXLowndes27 min
Jul 21, 5:41 PM CDTSevere Thunderstorm WarningBMXLowndes24 min
Jul 21, 5:48 PM CDTSpecial Weather StatementBMXMontgomery27 min
Jul 21, 6:07 PM CDTSpecial Weather StatementBMXLowndes38 min
Jul 21, 6:34 PM CDTSpecial Weather StatementBMXAutauga41 min
Jul 21, 6:44 PM CDTSpecial Weather StatementBMXMacon31 min

Nearby

Heat Advisories in Alabama, 2017Every heat advisory in 2017

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.