A warm and moist air mass, along with a series of disturbances across the region, allowed for the development of showers and thunderstorms. Some of these storms produced flash flooding and damaging winds.
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.
A warm and moist air mass, along with a series of disturbances across the region, allowed for the development of showers and thunderstorms. Some of these storms produced flash flooding and damaging winds.
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 17, 11:20 AM CST, 12 minutes earlier.
Area Forecast Discussion...UPDATED National Weather Service Jackson MS 1220 PM CDT Fri Aug 17 2018 .UPDATE... Updated for 18Z aviation discussion && .AVIATION... 18Z TAF discussion: An active convective period will be in store for most TAF sites through this evening. Abundant cloud cover this afternoon will lead to periods of MVFR ceilings, especially where storms occur as visibilities will be reduced and winds will be gusty. The convection will wind down somewhat by late evening, but possibilities will continue overnight and through the end of the period./26/ && .DISCUSSION... Latest CAM guidance showing convective area, over northwest AR at the moment, will drop into northwest portions of the forecast area during peak heating. Increased severe storms risk level to slight as near 40 knots of 0-3km bulk shear will be driving this convection southeast. This along with high microburst composite parameter should make for increased damaging wind potential over mostly northwest sections this afternoon into the evening. Lowered dewpoints somewhat this afternoon which should result in lower heat indices. The highest heat indices, around 105, will occur mainly west of the MS river, but thunderstorms developing during the afternoon will limit the duration of this heat./26/ Prior discussion below: Today and tonight: The southern fringe of a relatively strong upper level shortwave will be moving into the region today and this feature is already helping to generate numerous showers and thunderstorms just to our northwest early this morning. Latest radar imagery reveals outflow now progressing south toward the Arklamiss Delta and this boundary should help trigger scattered shower and thunderstorm activity this morning, at least along and north of the Highway 82 corridor. High resolution model guidance consensus is good that showers and thunderstorms will gradually build south and southwest during the midday through afternoon hours as outflow cascading south juxtaposes with increasing synoptic lift (from the mentioned incoming short wave) and moisture convergence and advection in the lower portion of the troposphere. Convection should be most numerous along and north of the I-20 corridor through early this evening and in these areas briefly training storms are possible. Considering the atmosphere fueling thunderstorms should have surface-based CAPE values of 2000+ j/kg and precipitable water values of 2+ inches, any training of storms could yield a quick deluge of a few inches of rainfall. The ground is not really saturated in too many locations, but lingering torrential downpours can still cause some flooding issues with these in situ conditions. For this reason we have introduced a LIMITED flood risk in the graphics and HWO. This flood risk (for mainly northern zones) will also continue tonight as model consensus suggests moisture convergence and advection into the backside of the upper trough over our region should spur some additional convection in the wake of the afternoon's activity. Instability should be tame enough late tonight to preclude organized severe weather concerns, which of course is good. Unfortunately, better instability today, with CAPE likely peaking from 3000 to 4000 j/kg in spots, should work in concert with modest wind shear in the low to mid levels to temporarily organize convective clusters (at least loosely). The main threat with any organized clusters will be damaging wind gusts and we agree with SPC that a MARGINAL risk of severe storms exists over central and northern zones. The main risk will be damaging wind gusts. Otherwise, high temperatures were boosted upward just a touch in many lcoations today given the prospect of some morning sun in central and southern zones. Still anticipating highs will remain less than 95 in nearly all areas, but humidity will be through the roof and thus yield pockets where heat index values could peak close to 105 degrees. The HWO and graphics has been updated to reflect this threat as well. Saturday through next week... The ArkLaMiss will experience a few active and wet mid August days this weekend and into early next week before a rare August cold front sweeps through the region by midweek next week. By Saturday morning, a stalled surface front that will stretch from New England down into the lower MS River Valley. This front will continue to serve as a focus for convective initiation for storms in our region through on Saturday and Sunday. The better coverage of storms will remain north of the I-20 corridor, closer to the boundary. Pwats will range from 2"-2.5" through the period providing the storms ample moisture to tap into. Storms during this period will be efficient rain producers and some training is possible. A limited flood threat was added to the HWO along and north of the I-20 corridor to account for the threat of flash flooding through the day on Saturday. Although the pattern will hold steady through the region on Sunday, there was not enough confidence in the flash flooding threat to extend the limited threat at this time. Although flash flooding will be the main threat through the weekend, there will be enough instability and shear around on Saturday and Sunday to support some severe storms with the primary threat of gusty winds. A deeper disturbance will begin to cross the Plains as we get into early next week, eventually crossing the MS River Valley and into the Great Lakes region. WPC has noted that surface low pressure records for the upper Ohio Valley region in August could be in jeopardy as the strong surface low associated with this disturbance pushes east dragging a strong cold front with it. A very moist airmass will still be in place over the ArkLaMiss as the front approaches the region from the west late Monday into Tuesday. Storms along and ahead of the front will also be efficient rain producers with flash flooding becoming a threat once again. A cooler, drier airmass will begin to filter into the region behind the front, resulting in a dry end to the week. && .PRELIMINARY POINT TEMPS/POPS... Jackson 91 71 88 73 / 41 78 72 52 Meridian 90 72 89 73 / 43 46 71 52 Vicksburg 95 73 90 74 / 35 72 72 52 Hattiesburg 90 72 91 73 / 41 17 70 28 Natchez 93 72 90 74 / 27 33 70 32 Greenville 91 72 88 73 / 81 43 74 64 Greenwood 88 72 87 73 / 81 55 74 65 && .JAN WATCHES/WARNINGS/ADVISORIES... MS...None. LA...None. AR...None. &&
Hazardous Weather Outlook...UPDATED National Weather Service Jackson MS 903 AM CDT Fri Aug 17 2018 ARZ074-075-LAZ007>009-MSZ040-181415- Ashley-Chicot-Morehouse-West Carroll-East Carroll-Issaquena- 903 AM CDT Fri Aug 17 2018 This hazardous weather outlook is for portions of southeast Arkansas, northeast Louisiana, and west central Mississippi. .DAY ONE...Today and Tonight SEVERE THUNDERSTORMS THREAT...Slight TIMING...Today through Tonight FLOODING THREAT...Limited TIMING...Today through Tonight EXCESSIVE HEAT THREAT...Limited TIMING...Today Severe thunderstorms are possible for locations mainly north of the Interstate Twenty corridor midday today through this evening. The main risk will be damaging wind gusts. (https://www.weather.gov/images/jan/graphicast/1.png) Flash flooding will be possible this afternoon through tonight, again mainly for locations along and north of the Interstate Twenty corridor. In these areas isolated locations could receive 2 to 3 inches of rainfall in a short amount of time, which could lead to flash flooding. (https://www.weather.gov/images/jan/graphicast/2.png) Very high humidity today will lead to peak heat indices ranging from 100 to 105 degrees in the late morning through early afternoon hours. Expect numerous afternoon thunderstorms to help alleviate the heat some late in the day. (https://www.weather.gov/images/jan/graphicast/3.png) .DAYS TWO THROUGH SEVEN...Saturday through Thursday Flash flooding will continue to be possible for locations along and north of Interstate 20 on Saturday. (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 may be needed for portions of the region today through tonight. LAZ016-MSZ018-019-025>029-032-034>037-041>044-047>050-181415- Madison LA-Bolivar-Sunflower-Leflore-Grenada-Carroll-Montgomery- Webster-Choctaw-Washington-Humphreys-Holmes-Attala-Sharkey-Yazoo- Madison MS-Leake-Warren-Hinds-Rankin-Scott- 903 AM CDT Fri Aug 17 2018 This hazardous weather outlook is for portions of northeast Louisiana, central Mississippi, north central Mississippi, northwest Mississippi, and west central Mississippi. .DAY ONE...Today and Tonight SEVERE THUNDERSTORMS THREAT...Slight TIMING...Today through Tonight FLOODING THREAT...Limited TIMING...Today through Tonight Severe thunderstorms are possible for locations mainly north of the Interstate Twenty corridor midday today through this evening. The main risk will be damaging wind gusts. (https://www.weather.gov/images/jan/graphicast/1.png) Flash flooding will be possible this afternoon through tonight, again mainly for locations along and north of the Interstate Twenty corridor. In these areas isolated locations could receive 2 to 3 inches of rainfall in a short amount of time, which could lead to flash flooding. (https://www.weather.gov/images/jan/graphicast/2.png) .DAYS TWO THROUGH SEVEN...Saturday through Thursday Flash flooding will continue to be possible for locations along and north of Interstate 20 on Saturday. (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 may be needed for portions of the region today through tonight. MSZ030-031-033-038-039-045-046-051-052-181415- Clay-Lowndes-Oktibbeha-Winston-Noxubee-Neshoba-Kemper-Newton- Lauderdale- 903 AM CDT Fri Aug 17 2018 This hazardous weather outlook is for portions of east central Mississippi, and northeast Mississippi. .DAY ONE...Today and Tonight SEVERE THUNDERSTORMS THREAT...Marginal TIMING...Today through Tonight FLOODING THREAT...Limited TIMING...Today through Tonight Isolated severe thunderstorms are possible for locations mainly north of the Interstate Twenty corridor midday today through this evening. The main risk will be damaging wind gusts. (https://www.weather.gov/images/jan/graphicast/1.png) Flash flooding will be possible this afternoon through tonight, again mainly for locations along and north of the Interstate Twenty corridor. In these areas isolated locations could receive 2 to 3 inches of rainfall in a short amount of time, which could lead to flash flooding. (https://www.weather.gov/images/jan/graphicast/2.png) .DAYS TWO THROUGH SEVEN...Saturday through Thursday Flash flooding will continue to be possible for locations along and north of Interstate 20 on Saturday. (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 may be needed for portions of the region today through tonight. LAZ015-181415- Richland- 903 AM CDT Fri Aug 17 2018 This hazardous weather outlook is for portions of northeast Louisiana. .DAY ONE...Today and Tonight SEVERE THUNDERSTORMS THREAT...Marginal TIMING...Today through Tonight FLOODING THREAT...Limited TIMING...Today through Tonight EXCESSIVE HEAT THREAT...Limited TIMING...Today Isolated severe thunderstorms are possible for locations mainly north of the Interstate Twenty corridor midday today through this evening. The main risk will be damaging wind gusts. (https://www.weather.gov/images/jan/graphicast/1.png) Flash flooding will be possible this afternoon through tonight, again mainly for locations along and north of the Interstate Twenty corridor. In these areas isolated locations could receive 2 to 3 inches of rainfall in a short amount of time, which could lead to flash flooding. (https://www.weather.gov/images/jan/graphicast/2.png) Very high humidity today will lead to peak heat indices ranging from 100 to 105 degrees in the late morning through early afternoon hours. Expect numerous afternoon thunderstorms to help alleviate the heat some late in the day. (https://www.weather.gov/images/jan/graphicast/3.png) .DAYS TWO THROUGH SEVEN...Saturday through Thursday Flash flooding will continue to be possible for locations along and north of Interstate 20 on Saturday. (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 may be needed for portions of the region today through tonight. LAZ023-181415- Franklin LA- 903 AM CDT Fri Aug 17 2018 This hazardous weather outlook is for portions of northeast Louisiana. .DAY ONE...Today and Tonight SEVERE THUNDERSTORMS THREAT...Marginal TIMING...Today through Tonight EXCESSIVE HEAT THREAT...Limited TIMING...Today Isolated severe thunderstorms are possible for locations mainly north of the Interstate Twenty corridor midday today through this evening. The main risk will be damaging wind gusts. (https://www.weather.gov/images/jan/graphicast/1.png) Very high humidity today will lead to peak heat indices ranging from 100 to 105 degrees in the late morning through early afternoon hours. Expect numerous afternoon thunderstorms to help alleviate the heat some late in the day. (https://www.weather.gov/images/jan/graphicast/3.png) .DAYS TWO THROUGH SEVEN...Saturday through Thursday The probability for widespread hazardous weather is low. .SPOTTER CALL TO ACTION STATEMENT... The activation of storm spotters, HAM radio operators, and emergency management personnel in support of severe weather operations may be needed for portions of the region today through tonight. LAZ025-MSZ053>059-181415- Tensas-Claiborne-Copiah-Simpson-Smith-Jasper-Clarke-Jefferson- 903 AM CDT Fri Aug 17 2018 This hazardous weather outlook is for portions of northeast Louisiana, central Mississippi, east central Mississippi, and southwest Mississippi. .DAY ONE...Today and Tonight SEVERE THUNDERSTORMS THREAT...Marginal TIMING...Today through Tonight Isolated severe thunderstorms are possible for locations mainly north of the Interstate Twenty corridor midday today through this evening. The main risk will be damaging wind gusts. (https://www.weather.gov/images/jan/graphicast/1.png) .DAYS TWO THROUGH SEVEN...Saturday through Thursday The probability for widespread hazardous weather is low. .SPOTTER CALL TO ACTION STATEMENT... The activation of storm spotters, HAM radio operators, and emergency management personnel in support of severe weather operations may be needed for portions of the region today through tonight. MSZ060>066-072>074-181415- Adams-Franklin MS-Lincoln-Lawrence-Jefferson Davis-Covington- Jones-Marion-Lamar-Forrest- 903 AM CDT Fri Aug 17 2018 This hazardous weather outlook is for portions of and south central Mississippi. .DAY ONE...Today and Tonight The probability for widespread hazardous weather is low. .DAYS TWO THROUGH SEVEN...Saturday through Thursday The probability for widespread hazardous weather is low. .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 Thursday. LAZ024-026-181415- Catahoula-Concordia- 903 AM CDT Fri Aug 17 2018 This hazardous weather outlook is for portions of northeast Louisiana. .DAY ONE...Today and Tonight EXCESSIVE HEAT THREAT...Limited TIMING...Today Very high humidity today will lead to peak heat indices ranging from 100 to 105 degrees in the late morning through early afternoon hours. Expect numerous afternoon thunderstorms to help alleviate the heat some late in the day. (https://www.weather.gov/images/jan/graphicast/3.png) .DAYS TWO THROUGH SEVEN...Saturday through Thursday The probability for widespread hazardous weather is low. .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 Thursday. 26 && ...HAZARD LEGEND... *SEVERE THUNDERSTORMS* High...Significant severe thunderstorms are expected. Moderate...Severe storms expected with significant severe weather possible. Enhanced...Severe storms expected. Slight...Severe storms possible. Marginal...Isolated severe storms possible. *FLOODING* Extreme...Confident in significant flooding. Significant...Significant flooding possible. Elevated...Confident in flooding. Limited...Flooding possible. *EXCESSIVE HEAT* Extreme...Maximum heat index greater than 110 degrees for 3 or more days in a row and/or air temperatures greater than 107 degrees. Significant...Maximum heat index greater than 110 degrees and/or air temperatures greater than 105 degrees. Elevated...Maximum heat index 105 to 110 degrees and/or air temperatures greater than 103 degrees. Limited...Maximum heat index near 105 degrees and/or air temperatures 100 to 103 degrees. ...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/jan/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 ...ADDITIONAL URLS FOR SEVERE WEATHER ISSUES... Storm Prediction Center (SPC)... https://www.spc.noaa.gov/ Meso Analysis... https://www.spc.noaa.gov/exper/mesoanalysis/ Day 1 through 3 Outlooks... https://www.spc.noaa.gov/products/outlook/ Storm Reports... https://www.spc.noaa.gov/climo/online/ ...ADDITIONAL URLS FOR FLOODING ISSUES... Current Watches and Warnings... https://www.weather.gov/jan/safe_HeavyRain Observed Precipitation Images... https://www.weather.gov/jan/precipmaps River Forecast Center... https://www.weather.gov/lmrfc/ Significant River Flood Outlook... https://www.wpc.ncep.noaa.gov/nationalfloodoutlook/index.html Day 1 through 3 Excessive Rainfall... https://www.wpc.ncep.noaa.gov/qpf/excess_rain.shtml Excessive Rainfall Discussion... https://www.wpc.ncep.noaa.gov/discussions/qpferd.html Day 1 through 7 QPF... https://www.wpc.ncep.noaa.gov/qpf/qpf2.shtml QPF Discussion... https://www.wpc.ncep.noaa.gov/discussions/qpfpfd.html
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE JACKSON MS
713 AM CDT FRI AUG 17 2018
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0400 PM TSTM WND DMG 3 ENE BRANDON 32.30N 89.95W
08/16/2018 RANKIN MS NWS EMPLOYEE
A FEW TREES DOWN ALONG STRATFORD DR.
&&
TWPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE JACKSON MS
844 AM CDT FRI AUG 17 2018
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0439 PM TSTM WND DMG 3 WSW LOUISVILLE 33.11N 89.10W
08/16/2018 WINSTON MS PUBLIC
MULTIPLE LARGE LIMBS AND A TREE DOWN ON THE
SOUTHWEST SIDE OF LOUISVILLE. REPORT
RECEIVED VIA SOCIAL MEDIA.
&&
TWPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE JACKSON MS
924 AM CDT FRI AUG 17 2018
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0609 PM TSTM WND DMG TAYLORSVILLE 31.83N 89.43W
08/16/2018 SMITH MS LAW ENFORCEMENT
TREE DOWN ACROSS HWY 37.
&&
TWPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE JACKSON MS
933 AM CDT FRI AUG 17 2018
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0618 PM TSTM WND DMG 6 ENE BASSFIELD 31.54N 89.66W
08/16/2018 JEFFERSON DAVIS MS LAW ENFORCEMENT
TREE DOWN ACROSS WILLIE FORTENBERRY RD.
&&
TWPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE JACKSON MS
945 AM CDT FRI AUG 17 2018
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0623 PM TSTM WND DMG 1 WNW BASSFIELD 31.50N 89.75W
08/16/2018 JEFFERSON DAVIS MS PUBLIC
A FEW TREES DOWN ON THE NORTHWEST SIDE OF
BASSFIELD.
&&
TWPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE JACKSON MS
949 AM CDT FRI AUG 17 2018
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0722 PM FLASH FLOOD 2 E BASSFIELD 31.50N 89.70W
08/16/2018 JEFFERSON DAVIS MS PUBLIC
WATER WAS COVERING A FEW ROADS JUST EAST OF
BASSFIELD. REPORT RELAYED VIA THE PUBLIC.
&&
TWThe Little Rock radar (KLZK), 164 km away, was scanning. The volume nearest the first event began at 17:29 UTC.
2 thunderstorm wind, 1 flash flood. Local standard time, as filed.
One tree was blown down on power lines.
A tree was blown down along Highway 35.
There was flooding on Mazzanti Road.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Arkansas in 2018Every state in 2018This day in weather historyWarnings in Arkansas, August 2018
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: 768426, 768427, 768463.