A longwave trough across the Northern Plains became cutoff from the westerlies and slowly shifted southward into the Mid Mississippi Valley during the afternoon and evening hours of May 23rd. A piece of energy rotated around the large cutoff low itself and moved into the Southern Plains and Lower Mississippi Valley.
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 SHV wrote it up.
A longwave trough across the Northern Plains became cutoff from the westerlies and slowly shifted southward into the Mid Mississippi Valley during the afternoon and evening hours of May 23rd. A piece of energy rotated around the large cutoff low itself and moved into the Southern Plains and Lower Mississippi Valley. Overcast skies during the morning hours gave way to some sun during the afternoon which allowed the atmosphere to destabilize along and ahead of a cold front. Scattered to numerous showers and thunderstorms developed in this airmass across the region with a few of these storms producing strong damaging wind gusts and small hail.
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 Shreveport, LA wrote its last area forecast discussion before the first event at May 23, 2:46 PM CST, 1 hour 59 minutes earlier.
Area Forecast Discussion National Weather Service Shreveport LA 346 PM CDT Tue May 23 2017 .UPDATE... Precipitation continued to develop along and behind the front, as it near deep east TX and northwest LA with a quick movement to the southeast. Increasing instability provided by an upper level jet streak coupled with plentiful low-upper level moisture, may result in some of the storm activity to become strong to severe particularly across deep east Texas. The main threats will be large hail and damaging winds. A Severe Watch is in effect until 11 pm CDT. && .PREV DISCUSSION... /issued 300 PM CDT Tue May 23 2017/ DISCUSSION... A broad UA low across the Northern Plains late this aftn, was progressing south-southeast thus resulting in the sharpening of southwest flow aloft across the Four-State Region. Embedded in this southwest flow aloft is a 90+ kt jet max at 250 mb rounding the base of this trough, and moving across the region which is allowing for increasing UL diffluence. Looking at the sfc, a cold front has impinged upon the FA and located along a kcdh, to a ktxk to a ktyr line, with a movement to the southeast. Increased UL support provided by the aforementioned jet streak, coupled with frontogenetical forcing by the cold front and a rather moist atmospheric profile /PWATS of 1.20-1.60 inches/ has resulted in isolated showers and thunderstorms, mainly along and behind the cold front. The stratus deck has eroded but BKN-OVC VFR CIGS remained, further validating the moist atmosphere. Nonetheless, there have been breaks in the cloud cover which have allowed temps to warm into the 70s. As a result, some daytime destabilization/steepened lapse rates has been realized which could aid in a few of the storms nearing strong levels and producing small hail. The precip is expected to not stick around for long, as model solutions displayed precip exiting from west to east by tonight, as the UL jet streak will be pushing east and hence UL support will be fleeting. Overnight, skies are expected to scatter out and perhaps become clear across most of the region, whilst relatively light west- northwest sfc winds ensue. If this does indeed come into fruition, this could set the stage for decent radiational cooling and promote overnight temps to drop into the upper 40s across portions of southeast OK, extreme northeast TX and southwest AR to lower to upper 50s elsewhere. Tomorrow, as the UA low commence to near the middle/lower Mississippi Valley, the ARKLATEX will be on the backside of the disturbance and mid-upper level atmospheric drying will occur. However, southwest AR and northeast LA will be the last areas for the drier air to take effect, so a few lingering showers nearing/brushing across the said areas can not be ruled out during the day tomorrow. Otherwise, slight pressure rises tomorrow aftn will result in a tightened pressure gradient, which will lead to northwest sfc winds approaching Lake Wind Advisory speeds. Due to this close call, will elect to hold off on a Lake Wind Advisory for this forecast package and let the midnight shift make the call /and see if models continue to show this trend/. Tomorrow night, wind speeds will become light and at times variable a few hours after sunset, whilst clearing skies take place. This will once again result in excellent radiational cooling /and perhaps some patchy fog/ leading to tomorrow night temps plummeting into the lower 40s across the north to lower 50s elsewhere /or some 10-15 degrees below norm/. We continue to undercut model guidance by a few degrees for tomorrow night because guidance tends to trend towards climo and in this case, it is not representative. On Thursday, srly sfc flow will return to the region and the quick passage of UA ridging on Friday will result in temps rebounding into the upper 80s to lower 90s by the end of the week into early weekend /some 5 or so degrees above normal/. Thereafter, long term solutions hint at an UA trough getting carved out across the Southern Rockies by late weekend, resulting in flow aloft veering from near zonal to the west-southwest across the Four- State Region. The best UL dynamics will remain north of the region closest to the center of the disturbance, but a sfc trough and the impingement of another cold front will cause the generation of showers and thunderstorms. Furthermore, the front is progged to become quasi-stationary across the southern zones which will maintain the unsettled wx into early next week. It is too early to say with certainty whether or not a severe weather threat will exist this weekend, but we will continue to monitor this plausibility. && .PRELIMINARY POINT TEMPS/POPS... SHV 54 73 52 85 / 60 10 0 0 MLU 56 73 50 83 / 70 10 10 0 DEQ 49 72 43 83 / 30 10 0 0 TXK 52 72 49 83 / 50 10 0 0 ELD 52 71 46 83 / 70 10 0 0 TYR 53 75 54 86 / 40 0 0 0 GGG 53 73 52 87 / 40 0 0 0 LFK 56 78 54 89 / 60 0 0 0 && .SHV WATCHES/WARNINGS/ADVISORIES... AR...None. LA...None. OK...None. TX...None. && 29
Hazardous Weather Outlook National Weather Service Shreveport LA 329 PM CDT Tue May 23 2017 TXZ124-136-149-165-242030- Wood-Smith-Cherokee-Angelina- 329 PM CDT Tue May 23 2017 This Hazardous Weather Outlook is for portions of east Texas and northeast Texas. .DAY ONE...This Afternoon and Tonight... Isolated to scattered showers and thunderstorms will continue to develop along and behind a cold front this afternoon, spreading east across deep east Texas through this evening. Some of the thunderstorms could become strong to severe with large hail and damaging wind gusts being the primary threats. There is a Severe Thunderstorm Watch is in effect until 11 pm CDT this evening. .DAYS TWO THROUGH SEVEN...Wednesday through Monday... After a cool start to the morning on Thursday, temperatures should rebound quickly by the afternoon and especially on Friday and through the upcoming weekend, as we return to above normal warmth. An upper level disturbance will approach our region during the late weekend, early upcoming work week time frame, bringing with it a chance of showers and thunderstorms along and ahead of an associated cold front. It is too early to determine if severe thunderstorms will accompany the activity Sunday into early next week but this possibility will continue to be monitored. .SPOTTER INFORMATION STATEMENT... Activation of emergency management personnel...amateur radio operators...and storm spotters may be needed late this afternoon this evening. ARZ050-051-059>061-070>073-LAZ001>006-010>014-017>022-OKZ077- TXZ096-097-108>112-125-126-137-138-150>153-166-167-242030- Sevier-Howard-Little River-Hempstead-Nevada-Miller-Lafayette- Columbia-Union-Caddo-Bossier-Webster-Claiborne-Lincoln-De Soto- Red River-Bienville-Jackson-Ouachita-Sabine-Natchitoches-Winn- Grant-Caldwell-La Salle-McCurtain-Bowie-Franklin-Titus-Camp- Morris-Cass-Upshur-Marion-Gregg-Harrison-Rusk-Panola-Nacogdoches- Shelby-San Augustine- 329 PM CDT Tue May 23 2017 This Hazardous Weather Outlook is for portions of south central Arkansas, southwest Arkansas, north central Louisiana, northwest Louisiana, southeast Oklahoma, east Texas and northeast Texas. .DAY ONE...This Afternoon and Tonight... Isolated to scattered showers will continue to increase late this afternoon as a cold front impinges on the region, initially across portions of east Texas, southeast Oklahoma and southwest Arkansas, to across northern and central Louisiana and northeast Arkansas this evening. This activity will be exiting the region tonight. Some of the storms could approach strong levels, with small hail being and brief wind gusts being the primary threats. .DAYS TWO THROUGH SEVEN...Wednesday through Monday... After a cool start to the morning on Thursday, temperatures should rebound quickly by the afternoon and especially on Friday and through the upcoming weekend, as we return to above normal warmth. An upper level disturbance will approach our region during the late weekend, early upcoming work week time frame, bringing with it a chance of showers and thunderstorms along and ahead of an associated cold front. It is too early to determine if severe thunderstorms will accompany the activity Sunday into early next week but this possibility will continue to be monitored. .SPOTTER INFORMATION STATEMENT... Activation of emergency management personnel...amateur radio operators...and storm spotters should not be needed through tonight.
Special Weather Statement
National Weather Service Shreveport LA
357 PM CDT TUE MAY 23 2017
ARZ059-060-070>072-LAZ001-TXZ097-109>112-125-126-138-232145-
Lafayette AR-Little River AR-Miller AR-Columbia AR-Hempstead AR-
Caddo LA-Harrison TX-Marion TX-Morris TX-Upshur TX-Cass TX-Camp TX-
Bowie TX-Titus TX-
357 PM CDT TUE MAY 23 2017
...SIGNIFICANT WEATHER ADVISORY FOR SOUTHWESTERN HEMPSTEAD...
LAFAYETTE...SOUTHEASTERN LITTLE RIVER...MILLER AND NORTHWESTERN
COLUMBIA COUNTIES...NORTHWESTERN CADDO PARISH...MARION...BOWIE...
NORTHEASTERN UPSHUR...SOUTHERN TITUS...CASS...NORTHWESTERN
HARRISON...MORRIS AND EASTERN CAMP COUNTIES UNTIL 445 PM CDT...
At 357 PM CDT, Doppler radar was tracking strong thunderstorms along
a line extending from near Hooks to Mount Pleasant. Movement was
southeast at 30 mph.
Half inch hail and winds in excess of 30 mph will be possible with
these storms.
Locations impacted include...
Texarkana, Mount Pleasant, Atlanta, Wake Village, Ashdown, New
Boston, Stamps, Lewisville, Nash, Hooks, Daingerfield, Jefferson,
Linden, Hughes Springs, Lone Star, Queen City, Naples, Ore City,
Redwater and Maud.
LAT...LON 3334 9479 3332 9475 3336 9475 3377 9404
3334 9332 3260 9451 3317 9508
TIME...MOT...LOC 2057Z 305DEG 25KT 3351 9432 3317 9495
FBSpecial Weather Statement
National Weather Service Shreveport LA
514 PM CDT TUE MAY 23 2017
ARZ070-LAZ001-002-TXZ112-126-232300-
Miller AR-Bossier LA-Caddo LA-Cass TX-Marion TX-
514 PM CDT TUE MAY 23 2017
...SIGNIFICANT WEATHER ADVISORY FOR SOUTHWESTERN MILLER COUNTY...
NORTHWESTERN CADDO AND NORTHWESTERN BOSSIER PARISHES...SOUTHEASTERN
CASS AND EASTERN MARION COUNTIES UNTIL 600 PM CDT...
At 514 PM CDT, Doppler radar was tracking a strong thunderstorm over
Kildare, or 13 miles south of Atlanta, moving southeast at 30 mph.
Half inch hail and winds in excess of 40 mph will be possible with
this storm.
Locations impacted include...
Vivian, Blanchard, Oil City, Mooringsport, Hosston, Rodessa, Belcher,
Ida, Gilliam, Bivins, Lodi, Smithland, McLeod, Kildare, Gray, Dixie,
Caddo Lake and Cavett.
LAT...LON 3309 9423 3301 9369 3258 9388 3268 9405
3269 9405 3271 9410 3272 9409 3274 9410
3274 9414 3286 9434
TIME...MOT...LOC 2214Z 296DEG 27KT 3293 9422
FBSpecial Weather Statement
National Weather Service Shreveport LA
535 PM CDT TUE MAY 23 2017
TXZ152-165-232315-
Angelina TX-Nacogdoches TX-
535 PM CDT TUE MAY 23 2017
...SIGNIFICANT WEATHER ADVISORY FOR SOUTHERN NACOGDOCHES AND
NORTHWESTERN ANGELINA COUNTIES UNTIL 615 PM CDT...
At 535 PM CDT, Doppler radar was tracking a strong thunderstorm near
Pollok, or 8 miles north of Lufkin, moving east at 30 mph.
Half inch hail and winds in excess of 30 mph will be possible with
this storm.
Locations impacted include...
Lufkin, Nacogdoches, Hudson, Melrose, Etoile, Woden, Chireno, Oak
Ridge, Redland, Clawson and Central.
A severe thunderstorm watch remains in effect until 1100 PM CDT for
eastern Texas.
LAT...LON 3136 9484 3154 9484 3162 9436 3161 9435
3161 9434 3159 9431 3127 9435
TIME...MOT...LOC 2235Z 271DEG 28KT 3145 9476
FBThe Shreveport radar (KSHV), 53 km away, was scanning. The volume nearest the first event began at 22:45 UTC.
3 thunderstorm wind, 1 hail. Local standard time, as filed.
A few trees were downed on Old Atlanta Road north of Vivian, Louisiana.
Nickel size hail fell at the Vivian Police Department.
Multiple trees were reported downed on Cass County Road and Stateline Road northwest of Vivian. Power lines were downed as well.
A tree was downed across East Linton Road that took out powerlines about 200 yards north of Pilkington Cemetary.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Louisiana in 2017Every state in 2017This day in weather historyWarnings in Louisiana, 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: 688420, 688421, 688422, 688423.