Alert archive / Kansas / Flash Flood Watches in 2021

Flash Flood Watch 1, NWS Topeka, KS

May 20, 202113 counties in Kansas

NWS Topeka, KS issued this flash flood watch at May 20, 2021, 2:48 PM CDT for 13 counties in Kansas. It was in force for 6 hr.

The area

The counties it named.

The facts

Issued
May 20, 2021, 2:48 PM CDT (19:48 UTC)
Expired
May 20, 2021, 8:42 PM CDT
In force
6 hr
Issued by
NWS Topeka, KS
Flood severity
None

Counties Anderson County, KS, Brown County, KS, Coffey County, KS, Douglas County, KS, Franklin County, KS, Jackson County, KS, Jefferson County, KS, Lyon County, KS, Nemaha County, KS, Osage County, KS, Pottawatomie County, KS, Shawnee County, KS, Wabaunsee County, KS

The radar

The Topeka radar (KTWX), 43 km from the middle of the area, began a volume at 19:50 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, 7.8 hours before the alert went out and 9 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, Topeka, KS at 12:00Z on 2021-05-20Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Topeka, KS at 12:00Z on 2021-05-20The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 76 square meters per square second.19395878Sfc1 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
584 m above ground
0-6 km bulk shear
50 kt
0-1 km storm-relative helicity
76 m²/s²
0-3 km storm-relative helicity
59 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

608 
WGUS63 KTOP 201948
FFATOP

URGENT - IMMEDIATE BROADCAST REQUESTED
Flood Watch
National Weather Service Topeka KS
248 PM CDT Thu May 20 2021

KSZ011-012-023-024-026-038>040-054>056-058-059-211200-
/O.NEW.KTOP.FF.A.0001.210520T1948Z-210521T1200Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Nemaha-Brown-Pottawatomie-Jackson-Jefferson-Wabaunsee-Shawnee-
Douglas-Lyon-Osage-Franklin-Coffey-Anderson-
Including the cities of Perry, Grantville, Overbrook, Maple Hill, 
Oskaloosa, Holton, Eskridge, Alta Vista, Burlington, Meriden, 
Wamego, Carbondale, Emporia, Osage City, Horton, St. Marys, 
Nortonville, Lawrence, Burlingame, Lyndon, Valley Falls, McFarland, 
McLouth, Alma, Lebo, Harveyville, Hiawatha, Topeka, Ottawa, Paxico, 
Seneca, Sabetha, and Garnett
248 PM CDT Thu May 20 2021

...FLASH FLOOD WATCH IN EFFECT THROUGH FRIDAY MORNING...

The National Weather Service in Topeka has issued a

* Flash Flood Watch for portions of east central Kansas and 
  northeast Kansas, including the following areas, in east central 
  Kansas, Anderson, Coffey, Douglas, Franklin, Lyon, Osage, Shawnee 
  and Wabaunsee. In northeast Kansas, Brown, Jackson, Jefferson, 
  Nemaha and Pottawatomie.

* Through Friday morning

* Additional rounds of heavy precipitation are expected this 
  afternoon into this evening with 1-2 inches of additional 
  rainfall. This could lead to flash flooding as well as additional 
  flooding of streams, creeks, and low lying areas.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Flash Flood Watch means that conditions may develop that lead to 
Flash Flooding. Flash Flooding is a very dangerous situation. You 
should monitor later forecasts and be prepared to take action should 
Flash Flood Warnings be issued.

Stay away or be swept away. River banks and culverts can become 
unstable and unsafe.

&&

$$

BD
1 follow-up statement
960 
WGUS63 KTOP 210142
FFATOP

Flood Watch
National Weather Service Topeka KS
842 PM CDT Thu May 20 2021

KSZ011-012-023-024-026-038>040-054>056-058-059-210245-
/O.CAN.KTOP.FF.A.0001.000000T0000Z-210521T1200Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Nemaha-Brown-Pottawatomie-Jackson-Jefferson-Wabaunsee-Shawnee-
Douglas-Lyon-Osage-Franklin-Coffey-Anderson-
Including the cities of Perry, Grantville, Overbrook, Maple Hill, 
Oskaloosa, Holton, Eskridge, Alta Vista, Burlington, Meriden, 
Wamego, Carbondale, Emporia, Osage City, Horton, St. Marys, 
Nortonville, Lawrence, Burlingame, Lyndon, Valley Falls, McFarland, 
McLouth, Alma, Lebo, Harveyville, Hiawatha, Topeka, Ottawa, Paxico, 
Seneca, Sabetha, and Garnett
842 PM CDT Thu May 20 2021

...FLASH FLOOD WATCH IS CANCELLED...

The Flash Flood Watch for portions of east central Kansas and 
northeast Kansas, including the following areas, in east central 
Kansas, Anderson, Coffey, Douglas, Franklin, Lyon, Osage, Shawnee 
and Wabaunsee. In northeast Kansas, Brown, Jackson, Jefferson, 
Nemaha and Pottawatomie has been cancelled.

The Flood Watch is cancelled. Flooding is no longer expected to pose 
a threat. Please continue to heed remaining road closures.

$$

Gargan

The office that day

Everything else NWS Topeka, KS issued on the same UTC day.

IssuedProductOfficeCountiesLasted
May 19, 7:46 PM CDTAreal Flood AdvisoryTOPOsage3 hr
May 19, 8:43 PM CDTAreal Flood AdvisoryTOPFranklin3 hr
May 19, 8:49 PM CDTAreal Flood AdvisoryTOPShawnee3 hr
May 19, 9:00 PM CDTAreal Flood AdvisoryTOPDouglas3 hr
May 20, 2:23 AM CDTRiver Flood WarningTOPAnderson36 hr
May 20, 4:53 AM CDTRiver Flood WarningTOPFranklin, Osage45 hr
May 20, 4:53 AM CDTRiver Flood WarningTOPFranklin46 hr
May 20, 4:53 AM CDTRiver Flood WarningTOPFranklin47 hr
May 20, 3:11 PM CDTAreal Flood AdvisoryTOPDouglas, Jefferson3 hr
May 20, 4:30 PM CDTAreal Flood AdvisoryTOPOsage, Shawnee85 min
May 20, 5:24 PM CDTAreal Flood AdvisoryTOPShawnee2 hr

Nearby

Flash Flood Watches in Kansas, 2021Every flash flood watch in 2021

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.