Alert archive / Kansas / Special Weather Statements in 2020

Special Weather Statement, NWS Kansas City, MO

July 20, 2020Clay County, Platte County, Missouri; Johnson County, Leavenworth County, Wyandotte County, Kansas

NWS Kansas City, MO issued this special weather statement at Jul 20, 2020, 7:56 AM CDT for Clay County, Platte County, Missouri; Johnson County, Leavenworth County, Wyandotte County, Kansas. It was in force for 49 min. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued: Jul 20, 2020, 7:56 AM CDT (12:56 UTC)
Expired: Jul 20, 2020, 8:45 AM CDT
In force: 49 min
Issued by: NWS Kansas City, MO

Counties Johnson County, KS, Leavenworth County, KS, Wyandotte County, KS, Clay County, MO, Platte County, MO

The radar

The Pleasant Hill radar (KEAX), 54 km from the middle of the area, began a volume at 13:00 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.

The nearest sounding before it

Topeka, KS (KTOP), launched 12:00Z, 0.9 hours before the alert went out and 72 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 658 J/kg
Mixed-layer CIN: -155 J/kg
Mixed-layer LCL: 1119 m above ground
0-6 km bulk shear: 24 kt
0-1 km storm-relative helicity: 226 m²/s²
0-3 km storm-relative helicity: 184 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

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What forecasters said that day

The local office's own words before this special weather statement went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Kansas City, MO wrote its last area forecast discussion before this special weather statement went out at Jul 20, 7:07 AM CDT, 49 minutes earlier.

Area forecast discussion, Jul 20, 7:07 AM CDT, 49 minutes before

AREA FORECAST DISCUSSION
National Weather Service Kansas City/Pleasant Hill MO
707 AM CDT Mon Jul 20 2020

.Discussion...
Issued at 430 AM CDT MON JUL 20 2020

Showers and Thunderstorms in eastern Nebraska will continue moving
towards northern half of Missouri today. Remnants of a weak
surface front along with a weak upper short wave will help to
anchor showers and storms through at least mid day today. Shear is
very weak but some isentropic lift on 310K surface and increasing
MUCAPE to around 2000 J/KG will provide increasing chances for
thunder this afternoon. The precipitable water remains close to 2
inches so expect chances for some localized flooding in areas
where slow moving cells develop and redevelop in the weak flow
aloft. Given the uncertainty at this point in coverage and amount
will not issue any headlines for widespread flooding at this time.

Models keep good chance of continued showers and thunderstorms
overnight tonight and through around noon on Tuesday as additional
shortwave trofs move across the region.

Upper flow remains rather weak and from the west northwest as we
head into the middle of the work week with plenty of moisture in
the boundary layer to provide chances of showers and thunderstorms
through the work week. The good news besides the needed rain
includes lower temperatures, although dewpoints remain in the low
to middle 70s so it will be very humid through the week so it will
feel like lower to middle 90s Wednesday and broaching upper 90s as
we head into the end of the week and weekend.

&&

.Aviation...(For the 12Z TAFS through 12Z Tuesday Morning)
Issued at 710 AM CDT MON JUL 20 2020

Showers and thunderstorms with cigs and vsby occasionally IFR over
the terminals mainly between 12Z and 15Z and again this afternoon
around 21Z. There is also a chance for another round of showers
and thunderstorms late in the period.

&&

.EAX WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
MO...NONE.
&&

Discussion...Adolphson
Aviation...Adolphson

Hazardous weather outlook, Jul 20, 4:47 AM CDT, 3 hours 9 minutes before

Hazardous Weather Outlook
National Weather Service Kansas City/Pleasant Hill MO
447 AM CDT Mon Jul 20 2020

KSZ025-057-060-102>105-MOZ001>008-011>017-020>025-028>033-037>040-
043>046-053-054-211000-
Atchison KS-Miami-Linn KS-Doniphan-Leavenworth-Wyandotte-Johnson KS-
Atchison MO-Nodaway-Worth-Gentry-Harrison-Mercer-Putnam-Schuyler-
Holt-Andrew-De Kalb-Daviess-Grundy-Sullivan-Adair-Buchanan-Clinton-
Caldwell-Livingston-Linn MO-Macon-Platte-Clay-Ray-Carroll-Chariton-
Randolph-Jackson-Lafayette-Saline-Howard-Cass-Johnson MO-Pettis-
Cooper-Bates-Henry-
447 AM CDT Mon Jul 20 2020

This hazardous weather outlook is for northwest...north central and
west central Missouri...as well as extreme eastern Kansas.

.DAY ONE...Today and Tonight

A few strong storms with wind gusts and hail will be possible this
morning and again later this afternoon into tonight.

 More detailed information can be accessed at...
 https://www.weather.gov/eax/hwo

.DAYS TWO THROUGH SEVEN...Tuesday through Sunday

Chances for thunderstorms will continue into Tuesday. Locally heavy
rainfall totals of 1-3" will be possible today into Tuesday.

 More detailed information can be accessed at...
 https://www.weather.gov/eax/hwo

In the hours before

Special weather statement, Jul 20, 7:56 AM CDT, 0 minutes before

Special Weather Statement
National Weather Service Kansas City/Pleasant Hill MO
756 AM CDT Mon Jul 20 2020

KSZ103>105-MOZ028-029-037-043-201345-
Johnson KS-Wyandotte KS-Leavenworth KS-Platte MO-Cass MO-Jackson MO-
Clay MO-
756 AM CDT Mon Jul 20 2020

...SIGNIFICANT WEATHER ADVISORY FOR WYANDOTTE...SOUTHEASTERN
LEAVENWORTH...JOHNSON...NORTHWESTERN CASS...CLAY...PLATTE AND WESTERN
JACKSON COUNTIES UNTIL 845 AM CDT...

At 756 AM CDT, Doppler radar was tracking strong thunderstorms along
a line extending from Camden Point to near Lansing to near Eudora.
Movement was southeast at 45 mph.

Winds in excess of 40 mph will be possible with these storms.

Locations impacted include...
Kansas City, Overland Park, Olathe, Independence, Lee's Summit,
Shawnee, Blue Springs, Lenexa, Leavenworth, Leawood, Raytown,
Liberty, Gladstone, Grandview, Belton, Prairie Village, Gardner,
Lansing, Merriam and Mission.

This includes the following highways...
 Interstate 70 in Missouri between mile markers 0 and 17.
 Interstate 70 in Kansas between mile markers 410 and 423.
 Interstate 35 in Missouri between mile markers 0 and 23.
 Interstate 35 in Kansas between mile markers 208 and 235.
 Interstate 29 between mile markers 0 and 27.
 Interstate 635 between mile markers 0 and 12.
 Interstate 470 between mile markers 0 and 7, and between mile
markers 14 and 16.
 Interstate 435 between mile markers 0 and 83.
 Kansas Turnpike between mile markers 206 and 226.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Torrential rainfall is also occurring with these storms, and may lead
to localized flooding. Do not drive your vehicle through flooded
roadways.

&&

LAT...LON 3950 9477 3926 9421 3921 9421 3921 9417
      3899 9436 3873 9461 3874 9485 3886 9505
      3899 9507 3898 9509 3896 9508 3898 9516
      3896 9517 3897 9519 3903 9519
TIME...MOT...LOC 1256Z 305DEG 37KT 3944 9473 3928 9488 3898 9516

Barham

The office that day

Everything else NWS Kansas City, MO issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Jul 20, 6:42 AM CDT	Flash Flood Warning	EAX	Buchanan	5 hr
Jul 20, 7:30 AM CDT	Flash Flood Warning	EAX	Clay, Clinton, Platte	5 hr
Jul 20, 8:41 AM CDT	Special Weather Statement	EAX	Cass, Clay, Jackson	49 min
Jul 20, 8:45 AM CDT	River Flood Warning	EAX	Clay, Ray	54 hr
Jul 20, 8:50 AM CDT	River Flood Warning	EAX	Ray	68 hr
Jul 20, 9:18 AM CDT	Areal Flood Advisory	EAX	Ray	3 hr
Jul 20, 12:52 PM CDT	Areal Flood Warning	EAX	Buchanan, Clay, Clinton, Platte, Ray	117 min
Jul 20, 2:42 PM CDT	Areal Flood Warning	EAX	Buchanan, Clay, Clinton, Platte, Ray	21 hr
Jul 19, 9:07 PM CDT	Areal Flood Advisory	EAX	Linn	3 hr

Nearby

Special Weather Statements in Kansas, 2020 Special Weather Statements in Missouri, 2020 Every special weather statement 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.