Afternoon showers and thunderstorms developed within a tropical airmass. Some storms were slow moving and produced localized flash flooding.
Every event with a place to put it. 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 JAN wrote it up.
Afternoon showers and thunderstorms developed within a tropical airmass. Some storms were slow moving and produced localized flash flooding.
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 Jackson, MS wrote its last area forecast discussion before the first event at Aug 19, 2:08 PM CST, 22 minutes earlier.
Area Forecast Discussion National Weather Service Jackson MS 308 PM CDT Thu Aug 19 2021 .DISCUSSION... This afternoon through Friday: the ArkLaMiss region will continue to experience a hot and humid weather pattern as we finish up the work week. Weakly cyclonic flow is bringing broadscale ascent and this combined with very moist (precipitable water > 2.2 inches and H850 Td ~ 16 C) and unstable air helping to enhance the diurnally driven convective rainfall. This activity should continue to increase in coverage for the remainder of the afternoon, and a localized flash flood threat could materialize given the very moist air and high precipitation efficiency. The activity should diminish with sunset, but chances for showers and storms could linger through the overnight hours. As we go into Friday, more hot and humid weather can be expected, and the resulting instability may bring considerable afternoon convective rainfall coverage. /EC/ Tomorrow night through Thursday: The forecast period starts off tomorrow night with sub-tropical ridging building across the Lower Mississippi Valley while a closed low lingers over the Mid-Atlantic. This synoptic pattern will favor a brief period of northwest flow on the poleward side of the ridge Saturday and Sunday across the Golden Triangle and portions of eastern Mississippi. Several weak embedded perturbations will help foster multiple rounds of isolated to scattered showers and storms with the greatest rain chances on Saturday. The main focus, however, will be on dangerous heat as temperatures warm beneath the building ridge. Heat indices are forecast to climb into the 105-110 degree range across the Delta on Saturday with widespread low 100s likely elsewhere. An elevated threat area for heat has been added to the HWO/graphics and it's likely that a heat advisory will eventually be needed. Sub-tropical ridging will continue to strengthen over the ArkLaTex and into the Lower Mississippi Valley Sunday into early next week with heights rising across much of the area. High temperatures will soar into the mid to upper 90s, especially along and west of I-55. This heat combined with a very humid airmass will support oppressive heat indices of 106-112 degrees with the highest values across the ArkLaMiss Delta. An elevated threat area for dangerous heat has been added for the vast majority of the area for Sunday to Tuesday. Heat products will likely be needed and excessive heat warnings cannot be ruled out. Overnight low temperatures will continue to be mild in the low to mid 70s. Diurnally driven showers and thunderstorms will become suppressed further south as the ridge builds in and mainly confined to along and south of I-20. The greatest rain chances will be south of the Hwy 84 corridor as sea breeze convection penetrates inland into the Pine Belt. The good news is that the oppressive heat will be short lived with the upper ridge progged to retrograde into the Southern Plains by mid to late next week. While temperatures will still be in the low to mid 90s, heat indices are forecast to be in the 100-105 degree range. Isolated to scattered diurnally driven showers and thunderstorms will return to much of the area as well. /TW/ && .AVIATION... 18Z TAF discussion: Considerable SHRA/TSRA activity will potentially impact sites, at least briefly, this afternoon/early evening. We will likely see sub VFR ceilings and perhaps some fog develop early Friday morning. Mixing will likely be a slow process again Friday morning and so the stratus, where it develops, could be slow to lift with VFR conditions not returning until early Friday aftn. /EC/ && .PRELIMINARY POINT TEMPS/POPS... Jackson 74 90 74 94 / 62 48 8 23 Meridian 73 87 72 92 / 61 67 14 39 Vicksburg 76 93 75 95 / 54 32 3 12 Hattiesburg 75 92 74 94 / 54 44 6 28 Natchez 74 92 73 94 / 56 24 1 10 Greenville 74 92 75 94 / 58 45 7 16 Greenwood 73 89 74 93 / 57 62 13 27 && .JAN WATCHES/WARNINGS/ADVISORIES... MS...None. LA...None. AR...None. &&
Hazardous Weather Outlook National Weather Service Jackson MS 1230 PM CDT Thu Aug 19 2021 ARZ074-075-LAZ007>009-015-016-023>026-MSZ018-019-025>066-072>074- 201730- Ashley-Chicot-Morehouse-West Carroll-East Carroll-Richland- Madison LA-Franklin LA-Catahoula-Tensas-Concordia-Bolivar- Sunflower-Leflore-Grenada-Carroll-Montgomery-Webster-Clay-Lowndes- Choctaw-Oktibbeha-Washington-Humphreys-Holmes-Attala-Winston- Noxubee-Issaquena-Sharkey-Yazoo-Madison MS-Leake-Neshoba-Kemper- Warren-Hinds-Rankin-Scott-Newton-Lauderdale-Claiborne-Copiah- Simpson-Smith-Jasper-Clarke-Jefferson-Adams-Franklin MS-Lincoln- Lawrence-Jefferson Davis-Covington-Jones-Marion-Lamar-Forrest- 1230 PM CDT Thu Aug 19 2021 This hazardous weather outlook is for portions of southeast Arkansas, northeast Louisiana, central Mississippi, north central Mississippi, and south central Mississippi. .DAY ONE...Today and Tonight The probability for widespread hazardous weather is low. .DAYS TWO THROUGH SEVEN...Friday through Wednesday Hot and humid conditions are forecast to return to the area on Saturday. This will result in heat stress conditions, especially across the upper Delta where heat indices will range from 105 to 110 degrees. Heat exhaustion will be likely with prolonged outdoor activity. Drink plenty of fluids and take breaks. (https://www.weather.gov/images/jan/graphicast/1.png) Dangerous heat stress will continue through the weekend and into early next week. Heat indices of 105 to 110 degrees are expected across much of the area. Heat exhaustion will be likely with prolonged outdoor activity. Drink plenty of fluids and take breaks. (https://www.weather.gov/images/jan/graphicast/2.png) .SPOTTER CALL TO ACTION STATEMENT... The activation of storm spotters, HAM radio operators, and emergency management personnel in support of severe weather operations is not expected through next Wednesday. 1 && ...HAZARD LEGEND... No short term hazards expected. ...USEFUL WEATHER WEB PAGES (URLS)... NWS JAN Home page... https://www.weather.gov/jan Stay Aware, Stay Safe NWS JAN Briefing Page... https://www.weather.gov/jan/safe Latest Weather Briefing... https://www.weather.gov/jan/weather_briefing Tropical page... https://www.weather.gov/srh/tropical?office=jan National Hurricane Center Home Page... https://www.nhc.noaa.gov/ Find NWS JAN on Facebook... https://www.facebook.com/NWSJacksonMS Follow NWS JAN on Twitter... @NWSJacksonMS Follow NWS JAN on Youtube... https://www.youtube.com/user/NWSJacksonMiss
Special Weather Statement
National Weather Service Jackson MS
142 PM CDT Thu Aug 19 2021
MSZ038-191915-
Winston MS-
142 PM CDT Thu Aug 19 2021
...A strong thunderstorm will impact portions of northeastern Winston
County through 215 PM CDT...
At 142 PM CDT, Doppler radar was tracking a strong thunderstorm over
Louisville, moving east at 25 mph.
HAZARD...Winds in excess of 40 mph.
SOURCE...Radar indicated.
IMPACT...Gusty winds could knock down tree limbs and blow around
unsecured objects.
Locations impacted include...
Louisville, Betheden and Millcreek.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
If outdoors, consider seeking shelter inside a building.
&&
LAT...LON 3304 8911 3320 8913 3320 8911 3323 8911
3328 8881 3303 8882
TIME...MOT...LOC 1842Z 266DEG 21KT 3315 8904
MAX HAIL SIZE...0.00 IN
MAX WIND GUST...40 MPH
ECSpecial Weather Statement
National Weather Service Jackson MS
218 PM CDT Thu Aug 19 2021
MSZ031-039-191945-
Lowndes MS-Noxubee MS-
218 PM CDT Thu Aug 19 2021
...Strong thunderstorms will impact portions of northern Noxubee and
southwestern Lowndes Counties through 245 PM CDT...
At 217 PM CDT, Doppler radar was tracking an area of strong
thunderstorms near Mashulaville, or 19 miles east of Louisville,
moving east at 35 mph.
HAZARD...Winds in excess of 40 mph.
SOURCE...Radar indicated.
IMPACT...Gusty winds could knock down tree limbs and blow around
unsecured objects.
Locations impacted include...
Macon, Brooksville, Crawford, Prairie Point, Deerbrook and
Mashulaville.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
If outdoors, consider seeking shelter inside a building.
&&
LAT...LON 3309 8834 3308 8881 3327 8881 3329 8873
3329 8867 3330 8867 3336 8838
TIME...MOT...LOC 1917Z 261DEG 29KT 3319 8873
MAX HAIL SIZE...0.00 IN
MAX WIND GUST...40 MPH
NFThe Columbus AFB radar (KGWX), 48 km away, was scanning. The volume nearest the first event began at 20:29 UTC.
1 flash flood. Local standard time, as filed.
Flash flooding occurred on Beersheba Road, Widener Drive and New Hope Road.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Mississippi in 2021Every state in 2021This day in weather historyWarnings in Mississippi, August 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: 967887.