Alert archive / Arkansas / Tornado Watches in 2020

Tornado Watch 59

March 19, 20205 states

The Storm Prediction Center issued this tornado watch at Mar 19, 2020, 9:50 PM CDT for 5 states. It was in force for 6 hr.

The area

The outline as issued.

The facts

Issued
Mar 19, 2020, 9:50 PM CDT (02:50 UTC)
Expired
Mar 20, 2020, 4:00 AM CDT
In force
6 hr
Issued by
the Storm Prediction Center
Largest hail expected
1.5 in
Strongest gust expected
60 kt
All 84 counties

Clark County, AR, Clay County, AR, Cleburne County, AR, Craighead County, AR, Cross County, AR, Dallas County, AR, Faulkner County, AR, Garland County, AR, Grant County, AR, Greene County, AR, Hot Spring County, AR, Independence County, AR, Jackson County, AR, Jefferson County, AR, Lawrence County, AR, Lonoke County, AR, Mississippi County, AR, Perry County, AR, Pike County, AR, Poinsett County, AR, Prairie County, AR, Pulaski County, AR, Randolph County, AR, Saline County, AR, Sharp County, AR, White County, AR, Woodruff County, AR, Alexander County, IL, Franklin County, IL, Gallatin County, IL, Hamilton County, IL, Hardin County, IL, Johnson County, IL, Massac County, IL, Pope County, IL, Pulaski County, IL, Saline County, IL, Union County, IL, White County, IL, Williamson County, IL, Ballard County, KY, Caldwell County, KY, Calloway County, KY, Carlisle County, KY, Christian County, KY, Crittenden County, KY, Daviess County, KY, Fulton County, KY, Graves County, KY, Hancock County, KY, Henderson County, KY, Hickman County, KY, Hopkins County, KY, Livingston County, KY, Lyon County, KY, Marshall County, KY, McCracken County, KY, McLean County, KY, Muhlenberg County, KY, Ohio County, KY, Todd County, KY, Trigg County, KY, Union County, KY, Webster County, KY, Bollinger County, MO, Butler County, MO, Cape Girardeau County, MO, Carter County, MO, Dunklin County, MO, Mississippi County, MO, New Madrid County, MO, Pemiscot County, MO, Ripley County, MO, Scott County, MO, Stoddard County, MO, Wayne County, MO, Crockett County, TN, Dyer County, TN, Gibson County, TN, Henry County, TN, Lake County, TN, Lauderdale County, TN, Obion County, TN, Weakley County, TN

The radar

The Memphis radar (KNQA), 121 km from the middle of the area, began a volume at 02:51 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

What SPC expected

The probabilities SPC published with the watch, for the watch area over its life.

Two or more tornadoes
60%
One or more EF2 to EF5 tornadoes
30%
Ten or more severe wind reports
60%
One or more gusts of 65 knots or more
20%
Ten or more severe hail reports
50%
One or more hailstones of 2 inches or more
10%
Six or more combined severe hail and wind reports
90%

Warnings issued inside it

14 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.

IssuedProductOfficeCountiesLasted
Mar 19, 10:05 PM CDTFlash Flood WarningPAHBollinger, Carter, Wayne8 hr
Mar 19, 10:17 PM CDTSevere Thunderstorm WarningLZKClark, Hot Spring, Pike43 min
Mar 19, 10:26 PM CDTSevere Thunderstorm WarningLZKLawrence, Randolph, Sharp34 min
Mar 20, 12:08 AM CDTSevere Thunderstorm WarningPAHNew Madrid, Stoddard52 min
Mar 20, 12:16 AM CDTSevere Thunderstorm WarningMEGDunklin8 min
Mar 20, 12:38 AM CDTFlash Flood WarningPAHHamilton, White6 hr
Mar 20, 12:48 AM CDTSevere Thunderstorm WarningPAHAlexander27 min
Mar 20, 1:40 AM CDTTornado WarningPAHGraves, McCracken13 min
Mar 20, 2:00 AM CDTSevere Thunderstorm WarningMEGDyer, Gibson, Lake, Obion30 min
Mar 20, 2:30 AM CDTTornado WarningMEGCrockett, Dyer, Gibson30 min
Mar 20, 2:48 AM CDTSevere Thunderstorm WarningPAHHopkins, McLean, Webster27 min
Mar 20, 2:54 AM CDTTornado WarningPAHHopkins, McLean, Webster21 min
Mar 20, 3:07 AM CDTSevere Thunderstorm WarningPAHDaviess, McLean23 min
Mar 20, 3:56 AM CDTSevere Thunderstorm WarningPAHCalloway19 min

Discussions around it

SPC mesoscale discussions over the same counties from four hours before the watch to its end.

The nearest sounding before it

Little Rock, AR (KLZK), launched 00:00Z, 2.8 hours before the alert went out and 138 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.

Skew-T log-pSkew-T log-p diagram, Little Rock, AR at 00:00Z on 2020-03-20Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 251 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Little Rock, AR at 00:00Z on 2020-03-20The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 311 square meters per square second.1939587897Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.
Mixed-layer CAPE
251 J/kg
Mixed-layer CIN
-30 J/kg
Mixed-layer LCL
961 m above ground
0-6 km bulk shear
62 kt
0-1 km storm-relative helicity
311 m²/s²
0-3 km storm-relative helicity
338 m²/s²
Significant tornado parameter
0.4
Supercell composite
5.6

Open this sounding in Storm Lab

The text

As transmitted.

786 
WWUS20 KWNS 200247
SEL9  
SPC WW 200247
ARZ000-ILZ000-INZ000-KYZ000-MOZ000-TNZ000-200900-

URGENT - IMMEDIATE BROADCAST REQUESTED
Tornado Watch Number 59
NWS Storm Prediction Center Norman OK
950 PM CDT Thu Mar 19 2020

The NWS Storm Prediction Center has issued a

* Tornado Watch for portions of 
  Central and Northeast Arkansas
  Southern Illinois
  Southern Indiana
  Western Kentucky
  Southeast Missouri
  Northwest Tennessee

* Effective this Thursday night and Friday morning from 950 PM
  until 400 AM CDT.

* Primary threats include...
  A few tornadoes likely with a couple intense tornadoes possible
  Scattered damaging wind gusts to 70 mph likely
  Scattered large hail events to 1.5 inches in diameter possible

SUMMARY...A line of intense thunderstorms over central Arkansas will
track eastward across the watch area overnight.  Extremely strong
wind fields will promote a risk of tornadoes and locally damaging
wind gusts.

The tornado watch area is approximately along and 65 statute miles
east and west of a line from 35 miles south of Hot Springs AR to 35
miles west northwest of Owensboro KY. For a complete depiction of
the watch see the associated watch outline update (WOUS64 KWNS
WOU9).

PRECAUTIONARY/PREPAREDNESS ACTIONS...

REMEMBER...A Tornado Watch means conditions are favorable for
tornadoes and severe thunderstorms in and close to the watch
area. Persons in these areas should be on the lookout for
threatening weather conditions and listen for later statements
and possible warnings.

&&

OTHER WATCH INFORMATION...CONTINUE...WW 56...WW 57...WW 58...

AVIATION...Tornadoes and a few severe thunderstorms with hail
surface and aloft to 1.5 inches. Extreme turbulence and surface wind
gusts to 60 knots. A few cumulonimbi with maximum tops to 450. Mean
storm motion vector 24035.

...Hart

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Mar 19, 8:36 PM CDTMesoscale DiscussionSPCCleburne, Independence, Lawrence, Sharp, Stone, Van Buren114 min
Mar 20, 2:22 AM CDTMesoscale DiscussionSPCAllen, Anderson, Barren, Boone, Bracken, Breckinridge and 49 more83 min
Mar 19, 8:40 PM CDTMesoscale DiscussionSPCGentry, Harrison, Mercer, Nodaway, Putnam, Worth95 min

Nearby

Tornado Watches in Arkansas, 2020Tornado Watches in Kentucky, 2020Tornado Watches in Illinois, 2020Every tornado watch in 2020

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.