Slow-moving thunderstorms repeatedly trained over the same locations in Decatur. Several reports all along 6th Avenue and other parts of downtown Decatur indicated about a foot or more of water inundating the road and intersections in a few locations.
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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.
Slow-moving thunderstorms repeatedly trained over the same locations in Decatur. Several reports all along 6th Avenue and other parts of downtown Decatur indicated about a foot or more of water inundating the road and intersections in a few locations.
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, 8:07 AM CST, 18 minutes earlier.
Area Forecast Discussion National Weather Service Huntsville AL 907 AM CDT Fri Jul 28 2017 .NEAR TERM...(Rest of Today) Issued at 845 AM CDT Fri Jul 28 2017 A mid-level wave embedded in NW flow aloft has enhanced low-lvl flow and convergence across southern middle TN this morning, resulting in a near persistent area of deep convection. Flood warnings have resulted to our north this morning and a Flash Flood Warning has just been issued for parts of our area, generally from near Courtland and Moulton, eastward and northeastward to include the Decatur- Huntsville-Athens metro area. Recent GOES-16 IR data shows persistent deep convection and cold cloud tops with the area of convection that is drifting southward. So, deep convection and very high rainfall rates (estimated to be around 3-4 in/hr) are occurring with the strongest activity in the very moist environment (PW values around 2.1-2.3 inches). This feature will likely continue to drift southward with enhanced convection developing in our area over the next few hours. Regional models indicate the mid-level wave moving off to the east and gradually lessening upr-lvl support by early afternoon. Nevertheless, added broad scale support from the impending low-lvl front will continue to generate boundary lyr convergence and support for convection into the afternoon. Area wide QPF was increased in the forecast and a few other adjustments were made to the forecast...mainly for clouds and POPs. .SHORT TERM...(Tonight) Issued at 335 AM CDT Fri Jul 28 2017 The front will pass across the area rapidly, with the initial wind shift occurring by 06Z and final wind shift by daybreak. Showers will linger through about midnight but should taper off rapidly afterwards as the deep moisture is quickly shunted to the south (in fact PWats will fall to around 1 inch by 12Z Saturday). The forecast will continue to show mid-range PoPs early this evening but taper off to 10% by daybreak tomorrow. The cooler and drier low-level air will be slower to arrive, so lows should only fall to the upper 60s/around 70. .LONG TERM...(Saturday through Thursday) Issued at 335 AM CDT Fri Jul 28 2017 The cold front will be well to the south of the forecast area by sunrise on Saturday, with high pressure building southward through the day. The northerly flow at the surface will filter in a much drier airmass, with dewpoints dropping into the lower 60s by the afternoon. This airmass will behind the front will also bring some cooler temperatures, with highs barely reaching into the mid 80s. Thus, a rather pleasant Saturday is in store for the TN Valley. Clear skies will prevail through the overnight hours, and as winds become calm, temperatures will plummet into the lower 60s, with a few spots even dropping into the upper 50s early Sunday morning. The dry conditions will prevail through much of the long term period, as high pressure dominates at the surface. Upper level ridging tries to build into the region on Sunday, however it will have a hard time overcoming the broad upper trough that will be in place over the eastern CONUS. This keeps the TN Valley within northwesterly flow through at least Wednesday. However, winds don't really shift back to the south until late Tuesday, and flow will be rather light, limiting the amount of moisture advection. By Wednesday, a shortwave will dig southward and amplify across the Ohio and Tennessee Valleys. Despite some potential forcing on Tuesday and Wednesday, the lack of moisture will limit any thunderstorms from developing. Thus, have kept a dry forecast in through Wednesday. A return of diurnally driven thunderstorms will begin on Thursday, as moisture continues to increase and finally reaches above climatological averages for the beginning of August. This may be aided by a weak frontal boundary that the ECMWF shows moving through the forecast area. However, not overly confident on the front making it through on day 7 and will only include isolated thunderstorms at this point. Temperatures through the first half of next week will remain slightly below normal, with highs in the lower to mid 80s Sunday through Tuesday. However a moderate trend, due to some return flow, will send temperatures towards more normal values by Wednesday and highs will warm to around 90 degrees on Wednesday and Thursday. && .AVIATION...(For the 12Z TAFS through 12Z Saturday morning) Issued at 649 AM CDT Fri Jul 28 2017 KHSV is likely to see poorer flight conditions early this morning as it will be closer to a persistent band of showers/storms. Initially this will be handled with MVFR showers and TEMPO group for heavier thunder, with improving conditions at 15z as the storms become more scattered. Confidence in improvement timing is low to medium. For KMSL, scattered thunderstorms will still affect the terminal at first, but it will not be quite as persistent or heavy, and conditions will improve with scattered thunderstorms by 14z. After 14-15z, lower clouds around 1000ft could develop, although confidence is not high enough to include beyond a scattered deck at either site. The frontal passage will occur 00-01z with a return to VFR at 08-09z. && .HUN WATCHES/WARNINGS/ADVISORIES... AL...Flash Flood Watch through this evening for ALZ001>010-016. TN...Flash Flood Watch through this evening for TNZ076-096-097. && NEAR TERM...KDW SHORT TERM...BCC LONG TERM...73 AVIATION...BCC For more information please visit our website at weather.gov/huntsville.
Hazardous Weather Outlook National Weather Service Huntsville AL 434 AM CDT Fri Jul 28 2017 ALZ001>010-016-TNZ076-096-097-290000- Lauderdale-Colbert-Franklin AL-Lawrence-Limestone-Madison-Morgan- Marshall-Jackson-De Kalb-Cullman-Moore-Lincoln-Franklin TN- 434 AM CDT Fri Jul 28 2017 This Hazardous Weather Outlook is for north Alabama and portions of southern middle Tennessee. .DAY ONE...Today and Tonight... Numerous to widespread showers and thunderstorms will be possible through the day, as a cold front approaches the area. An isolated strong storm is possible during the afternoon, with gusty winds up to 50 MPH and locally heavy rainfall possible. Thunderstorms will gradually end from northwest to southeast by midnight, as the cold front passes through the area. One to two inches of rainfall is forecast, though locally higher amounts are possible, leading to isolated instances of flash flooding. For more information, see the Flash Flood Watch in effect for later this morning through early evening. .DAYS TWO THROUGH SEVEN...Saturday through Thursday... Isolated afternoon thunderstorms will be possible on Thursday. .SPOTTER CALL TO ACTION STATEMENT... Activation of storm spotters and emergency management personnel is not anticipated at this time. However, timely reports of flash flooding or other weather impacts will be appreciated.
The Northeast Alabama radar (KHTX), 88 km away, was scanning. The volume nearest the first event began at 14:25 UTC.
6 flash flood. Local standard time, as filed.
At least 8 inches of water was reported over the road on 11th Street.
At least 8 inches of water reported over the road on 8th Street.
At least 6 inches of water reported over portions of Stratford Road SE. Portions of the road barricaded.
At least 6 inches of water over the roadway and portions of Dogwood Lane SE and Elliott Streets Barricaded.
More than 6 inches of water and barricaded roads reported on Church Street and 6th Avenue.
Up to a foot of water reported over portions of Knight Street.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Alabama in 2017Every state in 2017This day in weather historyWarnings in Alabama, July 2017
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: 714637, 714639, 714641, 714643, 714644, 714646.