High pressure producing abundant sunshine combined with humid conditions (dewpoints in lower 70s) caused heat index values to climb to between 105 and 106 degrees in portions of northwest Alabama. HEMSI officials received the most heat-related calls up to this point in 2021 in Madison county.
Every event with a place to put it; 3 filed by county or forecast zone are drawn at its center, in a lighter ring. Tap one for its entry below.
Deaths and injuries are direct and indirect together, as the offices filed them. Damage is property and crops in the dollars of the year, not adjusted for inflation, and only where an office estimated it.
The episode as NWS HUN wrote it up.
High pressure producing abundant sunshine combined with humid conditions (dewpoints in lower 70s) caused heat index values to climb to between 105 and 106 degrees in portions of northwest Alabama. HEMSI officials received the most heat-related calls up to this point in 2021 in Madison county.
The local office's own words before the first event, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.
NWS Huntsville, AL wrote its last area forecast discussion before the first event at Jul 28, 8:45 AM CST, 1 hour 15 minutes earlier.
Area Forecast Discussion National Weather Service Huntsville AL 945 AM CDT Wed Jul 28 2021 .NEAR TERM...(Rest of Today) Issued at 945 AM CDT Wed Jul 28 2021 A hot and humid day is on tap for the Tennessee Valley as high pressure promotes mostly sunny and dry weather over the area. Given the lack of cloud cover, temperatures should be able to make it well into the mid 90s by this afternoon, with dewpoints remaining in the lower 70s. This will push heat index values just over Advisory criteria in many areas across northwest and north central Alabama this afternoon and for this reason, we have issued a Heat Advisory until 7 PM. In other locations across northeast Alabama and southern middle Tennessee temperature/heat indices will remain a little bit lower, but regardless it's going to feel hot outside today. For this reason, caution is urged no matter where you live. Take it easy and limit your time outdoors. .SHORT TERM...(Tonight through Friday night) Issued at 406 AM CDT Wed Jul 28 2021 Dry weather will continue into Friday evening, as upper ridging remains to our west. Somewhat drier air filtering in tonight should help minimize fog issues tonight across the area. Low temperatures otherwise should cool into the lower 70s with light winds. Thursday, slightly higher heights will move over the region, as the upper ridge, maintaining upper 590s decameter heights over the Central Plains brings even warmer conditions. High temperatures again will range in the mid 90s. This time, dewpoint values should remain in the mid 70s, boosting heat index values above 105 degrees for much of the forecast area. Heat Advisory conditions look likely on Thu for most of the greater Huntsville forecast area. Lows Thu night should remain a tad warmer, only cooling into the mid 70s. Friday looks to be even hotter with high temperatures in the mid/upper 90s. Dewpoints in the low/mid 70s will result in more of the area above 105 degrees, continuing a Heat Advisory conditions. A few pixels in the apparent temperatures rise to 110 degrees on Fri, that would warrant Excessive Heat Warnings if more of the area was to be impacted by such warmth. A continued dry trend in the mid troposphere should keep a damper on shower chances through Fri night. .LONG TERM...(Saturday through Tuesday) Issued at 406 AM CDT Wed Jul 28 2021 The overall pattern across much of the region becomes more unsettled heading into the weekend period. The latter half of the global model suites continue to suggest more of a NW flow regime setting up over much of the SE region starting Sat, as a weak frontal boundary moves into much of the area from the north. This will translate into a favorable pattern for MCS activity traversing NW to SE into the first half of the new week. In fact, latest model runs are still suggesting Sun as the more active day for any potential MCS, with enhanced deep layer shear hinting at the potential for some strong/marginally svr tstms capable of damaging wind gusts. Timing though is uncertain at this point, in addition to the number/strength of any possible MCS. The active wx continues into Mon before diminishing Tue, as the weak frontal boundary moves south of the area. Much of the unseasonably hot/humid wx conditions will linger into Sat, as afternoon highs climb into the lower/mid 90s and max heat indices trend near the 100-105F range. The increase in clouds/rain will then allow some cooler temps from Sun into Tue, with highs more in the mid/upper 80s for most spots. Overnight lows early Sun will start out in the lower 70s/near 70F, before trending more in the mid/upper 60s Mon/Tue mornings. && .AVIATION...(For the 12Z TAFS through 12Z Thursday morning) Issued at 639 AM CDT Wed Jul 28 2021 At daybreak, patchy fog was affecting parts of the Tennessee Valley, especially across NE AL and adjacent TN/GA. MVFR fog was also present at KMSL. The fog should dissipate over the next couple hours as resultant daytime heating and mixing dominates. VFR weather otherwise is forecast, as high pressure at the surface and aloft control the weather. Calm winds should become NE around 5kt in late morning and afternoon. Winds will become light/variable this evening under clear skies. && .HUN WATCHES/WARNINGS/ADVISORIES... AL...Heat Advisory until 7 PM CDT this evening for ALZ001>007-016. TN...NONE. && NEAR TERM...AMP.24 SHORT TERM...RSB LONG TERM...09 AVIATION...RSB For more information please visit our website at weather.gov/huntsville.
Hazardous Weather Outlook National Weather Service Huntsville AL 921 AM CDT Wed Jul 28 2021 ALZ001>010-016-TNZ076-096-097-290530- Lauderdale-Colbert-Franklin AL-Lawrence-Limestone-Madison-Morgan- Marshall-Jackson-DeKalb-Cullman-Moore-Lincoln-Franklin TN- 921 AM CDT Wed Jul 28 2021 This Hazardous Weather Outlook is for north Alabama and portions of southern middle Tennessee. .DAY ONE...This Afternoon and Tonight... Hot and humid conditions are forecast across the Tennessee Valley this afternoon. A Heat Advisory is in effect for northwest and north central Alabama until 7 PM this evening. Heat Index values should remain just below advisory criteria of 105 degrees across northeast Alabama and southern middle Tennessee. Regardless, caution is urged and residents of the Tennessee Valley are urged to drink plenty of water, stay in an air-conditioned room, stay out of the sun, and check up on relatives and neighbors. .DAYS TWO THROUGH SEVEN...Thursday through Tuesday... A short-lived heat wave is expected across the Tennessee Valley later this week, with dangerously high heat indices in the 105-110 degree range for much of northern Alabama and southern middle Tennessee, Thursday through Saturday. Isolated to scattered thunderstorm chances return on Saturday, as a cold front approaches the region from the north. The front will stall across the region early next week, resulting in several rounds of thunderstorms from Saturday through Monday. Conditions do appear favorable for strong to severe thunderstorms, especially on Sunday and Sunday night. .SPOTTER CALL TO ACTION STATEMENT... Activation of storm spotters and emergency management personnel is not anticipated at this time.
The national radar mosaic for the moment the first event began.
3 heat. Local standard time, as filed.
Afternoon temperatures in the lower 90s and humid conditions (dewpoints lower 70s) produced heat index values between 100 and 101 degrees. HEMSI officials were reported to have received the most heat related calls up to that day in 2021.
Early to mid-afternoon temperatures in the mid 90s and humid conditions produced dangerously hot conditions with heat index values reaching 105 to 106 degree range.
Early to mid-afternoon temperatures in the mid 90s and humid conditions produced dangerously hot conditions with heat index values reaching 105 to 106 degree range.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Alabama in 2021Every state in 2021This day in weather historyWarnings in Alabama, July 2021
NOAA National Centers for Environmental Information, Storm Events Database, compiled from the National Weather Service’s monthly Storm Data. Complete through 2026-06; NCEI adds each month about 75 days after it ends and revises past years a few times a year. Rebuilt 2026-09-24. Each event’s entry at NCEI: 976618, 976614, 976627.