Large clusters of slow-moving thunderstorms occurred along a warm front that extended southeast from a low pressure center over central Missouri. Locally heavy rain caused flash flooding in Perry County.
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 PAH wrote it up.
Large clusters of slow-moving thunderstorms occurred along a warm front that extended southeast from a low pressure center over central Missouri. Locally heavy rain caused flash flooding in Perry 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 Paducah, KY wrote its last area forecast discussion before the first event at May 20, 5:46 AM CST, 1 hour 15 minutes earlier.
Area Forecast Discussion National Weather Service Paducah KY 646 AM CDT Sat May 20 2017 .UPDATE... Updated aviation section for 12z taf issuance && .SHORT TERM...(Today) Issued at 330 AM CDT Sat May 20 2017 Very complicated forecast today due to a wide range of short-term model guidance. A synoptic warm frontal boundary appears to extend from the kmdh area eastward across the kowb area as of 08z. Scattered convection has been occurring along the warm front, with more widespread convection across Missouri. The models are in general agreement that the Missouri convection will reach the Mississippi River by 12z. After 12z, there is a wide spread among the short-range guidance. Residual outflow boundaries could generate new convection during the day. The timing, duration, and intensity of storms is quite variable between the nam, hrrr, and ruc. There is even quite a difference in their wind fields and deep-layer shear. In general, the more favorable shear parameters will be closer to the upper trough along and west of the Mississippi Valley. However, the potentially better instability will be east of the Mississippi River. Hourly mesoscale analyses will need to be watched closely. Forecast highs will be lowered just a bit due to expected widespread clouds and areas of precip. .LONG TERM...(Tonight through Friday) Issued at 330 AM CDT Sat May 20 2017 Frontal system will be crossing the region tonight. Though POPs will be fairly high, it looks as though the chances of any severe storms will be dwindling. Some locations, esp over wrn KY and sw IN may see an addition 1/4 to 1/2 of rain ahead of the front. Drier air will slowly work its way in from the west during the day on Sunday. Will leave some small rain chcs during the morning, mainly in the Pennyrile region of west KY. Even those locations will be rainfree by the PM hours. We will have sfc high pressure in our vicinity on Monday but that system will shift east through the day. Another frontal boundary will be incoming from the west. Various models as well as the GFS ensembles seem to have a pretty decent handle on the timing, and this was the case yesterday as well. We should see dry weather through the evening hours on Monday, but after midnight Monday night and into Tuesday, precipitation chances increase. How quickly the front makes it through Tuesday into Tuesday evening is still a bit in question. However, there will be a break in the action after the frontal passage Tuesday evening or late Tuesday night. The upper level trough/low will move across the area on Wednesday. This will mean more clouds, more chances for showers and a downright cool day with highs only in the 60s. Models have their differences on how quickly this upper system departs on Wednesday night. May have to linger some POPs in that period...higher POPs east. We could have a chance to see lows in the upper 40s in some areas Wednesday night. We will see improving conditions on Thursday, as well as an increase in our temperatures and more sunshine as sfc high pressure builds back into the region. The upper flow transitions to a more flat/zonal flow by Friday with no large signals for any major chances for rain. && .AVIATION... Issued at 646 AM CDT Sat May 20 2017 A complex of thunderstorms moving east across the Mississippi River early this morning has lost some organization, but it contains locally torrential downpours and gusty winds to 40+ knots. This complex will likely keep its identity as it crosses western KY and southwest IN this morning. This afternoon and tonight, additional storms and their future timing and intensity are the main concern during this taf period. The tafs contain periods of vcts mainly in the late afternoon and evening. Winds will be mainly south today and this evening, shifting to west behind a cold front late tonight. Low clouds arriving behind the front should result in local mvfr cigs. && .PAH WATCHES/WARNINGS/ADVISORIES... IL...None. MO...None. IN...None. KY...None. && SHORT TERM...MY LONG TERM...GM/CW AVIATION...MY
Hazardous Weather Outlook National Weather Service Paducah KY 439 AM CDT Sat May 20 2017 ILZ075>078-080>094-INZ081-082-085>088-KYZ001>022-MOZ076-086-087- 100-107>112-114-210945- Jefferson-Wayne IL-Edwards-Wabash-Perry IL-Franklin-Hamilton- White-Jackson-Williamson-Saline-Gallatin-Union-Johnson-Pope- Hardin-Alexander-Pulaski-Massac-Gibson-Pike-Posey-Vanderburgh- Warrick-Spencer-Fulton-Hickman-Carlisle-Ballard-McCracken-Graves- Livingston-Marshall-Calloway-Crittenden-Lyon-Trigg-Caldwell- Union KY-Webster-Hopkins-Christian-Henderson-Daviess-McLean- Muhlenberg-Todd-Perry MO-Bollinger-Cape Girardeau-Wayne MO-Carter- Ripley-Butler-Stoddard-Scott-Mississippi-New Madrid- 439 AM CDT Sat May 20 2017 This Hazardous Weather Outlook is for portions of southern Illinois, southwest Indiana, western Kentucky, and southeast Missouri. .DAY ONE...Today and Tonight Numerous thunderstorms are expected today and early tonight, and isolated thunderstorms may reach severe levels. The primary hazards will be damaging winds and large hail. Locally heavy rain will accompany some storms, with the possibility of flooding in a few locations. .DAYS TWO THROUGH SEVEN...Sunday through Friday There is a small chance of thunderstorms Tuesday and Tuesday night. The primary concern with these storms is lightning. .SPOTTER INFORMATION STATEMENT... Spotter activation may be requested today and early tonight.
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE PADUCAH KY
201 AM CDT SAT MAY 20 2017
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0134 AM HAIL GRASSY 37.25N 90.14W
05/20/2017 E0.75 INCH BOLLINGER MO BROADCAST MEDIA
&&
MYSpecial Weather Statement
National Weather Service Paducah KY
620 AM CDT SAT MAY 20 2017
ILZ075-080-081-084-085-088-092-MOZ087-201200-
Perry IL-Alexander IL-Franklin IL-Jackson IL-Union IL-Williamson IL-
Jefferson IL-Cape Girardeau MO-
620 AM CDT SAT MAY 20 2017
...SIGNIFICANT WEATHER ADVISORY FOR EASTERN PERRY...UNION...
JEFFERSON...WESTERN WILLIAMSON...EASTERN JACKSON...NORTHWESTERN
ALEXANDER...FRANKLIN AND NORTHEASTERN CAPE GIRARDEAU COUNTIES UNTIL
700 AM CDT...
At 616 AM CDT, Doppler radar was tracking a strong band of
thunderstorms with very heavy rains moving east into the region.
Wind gusts up to 50 mph or so will be possible with this storm. Cape
Girardeau airport recently reported a wind gust of 53 MPH.
Locations impacted include...
Cape Girardeau, Carbondale, Marion, Mount Vernon, Herrin, West
Frankfort, Murphysboro, Benton, Du Quoin, Carterville, Anna, Johnston
City, Christopher, Jonesboro, Rend Lake Area, Sesser, Zeigler, De
Soto, Crainville and Cambria.
LAT...LON 3844 8911 3829 8871 3733 8919 3733 8925
3732 8921 3728 8922 3729 8961 3822 8921
3821 8915 3836 8915
TIME...MOT...LOC 1116Z 194DEG 53KT 3790 8917PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE PADUCAH KY
626 AM CDT SAT MAY 20 2017
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0558 AM TSTM WND GST SCOTT CITY 37.22N 89.53W
05/20/2017 M53.00 MPH SCOTT MO ASOS
CAPE GIRARDEAU ASOS MEASURED 53 MPH GUST
&&
MYThe Paducah radar (KPAH), 113 km away, was scanning. The volume nearest the first event began at 13:03 UTC.
1 flash flood. Local standard time, as filed.
Flash flooding of streets was reported in Du Quoin. A portion of U.S. Highway 51 was closed just south of the city hall.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Illinois in 2017Every state in 2017This day in weather historyWarnings in Illinois, May 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: 694237.