Alert archive / Colorado / Flash Flood Warnings in 2023

Flash Flood Warning 53, NWS Goodland, KS

July 20, 2023Kit Carson County, Colorado

NWS Goodland, KS issued this flash flood warning at Jul 20, 2023, 6:34 PM MDT for Kit Carson County, Colorado. It was in force for 94 min. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued
Jul 20, 2023, 6:34 PM MDT (00:34 UTC)
Expired
Jul 20, 2023, 8:08 PM MDT
In force
94 min
Issued by
NWS Goodland, KS
Area
Storm-based polygon
Flood severity
None

County Kit Carson County, CO

The radar

The Goodland radar (KGLD), 78 km from the middle of the area, began a volume at 00:35 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

Dodge City, (KDDC), launched 00:00Z, 0.6 hours before the alert went out and 291 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, Dodge City, at 00:00Z on 2023-07-21Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1470 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, Dodge City, at 00:00Z on 2023-07-21The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 51 square meters per square second.193958Sfc1 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
1470 J/kg
Mixed-layer CIN
-15 J/kg
Mixed-layer LCL
1272 m above ground
0-6 km bulk shear
42 kt
0-1 km storm-relative helicity
51 m²/s²
0-3 km storm-relative helicity
145 m²/s²
Significant tornado parameter
0.4
Supercell composite
3.4

Open this sounding in Storm Lab

What forecasters said that day

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

NWS Goodland, KS wrote its last area forecast discussion before this flash flood warning went out at Jul 20, 5:15 PM MDT, 1 hour 19 minutes earlier.

Area forecast discussion, Jul 20, 5:15 PM MDT, 1 hour 19 minutes before
Area Forecast Discussion
National Weather Service Goodland KS
515 PM MDT Thu Jul 20 2023

.UPDATE...
Issued at 352 PM MDT Thu Jul 20 2023

A Severe Thunderstorm Watch has been issued for Cheyenne, Sherman,
Thomas, Wallace, Logan, Gove, Greeley and Wichita counties for the
evening hours. A Severe Thunderstorm Watch remains in effect for
Eastern Colorado.

The stronger storms that form near Highway 40 have left the area.
Attention now turns to the storms developing and moving east in
Colorado. While storms north of I-70 have struggled, storms south
of I-70 have been producing severe hail. That severe hail threat
is possible as storms enter far Eastern Colorado, but should
diminish as storms move further east. Still watching for mainly a
flooding and damaging wind gust threat as storms continue to
cluster and move towards the Tri-state area. A tornado or two is
still possible and would favor areas south of I-70 and west of KS
Highway 27.

&&

.SHORT TERM...(This evening through Friday)
Issued at 143 PM MDT Thu Jul 20 2023

For the remainder of today, still looking at an impactful weather
event late this afternoon into the evening. There is a chance, that
the convection earlier this morning may inhibit storm potential
later. But with satellite showing clearing skies in Eastern and
Central Colorado and storms forming along the Front Range, the
forecast largely remains the same with two rounds of storms expected
late this afternoon and evening. Also, a strong storm has developed
in Wallace county where cloud cover has been clearing and a thermal
gradient has developed into Eastern Colorado. This will be the main
focus for storm development until the first round of storms arrives.

The first round should reach Eastern Colorado around 4-6pm MT and is
forecasted to have the most impacts. All severe hazards are possible
with effective shear of 50+, MLCAPE 1000+ J/KG, veering hodographs
and DCAPE generally above 1000 J/KG. But similar to yesterday, these
parameters will limit the hail potential to generally an inch or
less unless a supercell develops in which case 2+" is possible.
While parameters are similar to yesterday for winds, there is the
possibility for linear storm modes and bowing segments which could
produce wind gusts in excess of 75 mph. For tornadoes, a linear mode
is suggesting QLCS tornadoes are possible with low LCLs and high
shear. There could also be a supercell mainly along and south of a
Flagler to Cheyenne Wells where clouds are clearing. If a supercell
develops, a tornado would be possible with it. The main inhibitor is
a lack of 0-1km shear and low SRH.

The big threat is the potential for heavy rainfall and flash
flooding. Most of the area has already seen an inch or two of
rainfall either this morning or yesterday leading to more saturated
soil. Forecasts still call for an additional two to three inches
with the remaining two rounds and there is a low chance for 4+
inches. Between the earlier rain and the forecasted rainfall, the
area should see a couple of instance of flash flooding. The threat
could have been higher if the storms were not forecasted to move so
fast. Corfidi downshear vectors of 40+ kts suggest that storms will
not stay over an area for long. However, the high PWATs will lead to
high rainfall rates which will produce the high rainfall
accumulations.

Tonight, there could be lingering showers and storms along outflow
boundaries, but storm activity should move out of the area around 1-
3am CT. Cloud cover will likely linger through the night, but cold
air advection along with the front will allow lows to drop down to
near 60. Fog is also likely to develop across the area with counties
along the Colorado border favored where higher level cloud cover
could clear and allow for better radiational cooling.

Tomorrow, some showers and cloud cover could linger through the
morning hours, but the area should clear out and have mostly sunny
skies by the afternoon hours. With the colder air from the front,
temperatures will still only warm into the 70's and low 80's.

.LONG TERM...(Saturday through Thursday)
Issued at 1239 PM MDT Thu Jul 20 2023

Upper ridge over the Four Corners to start the period will amplify
and expand eastward across the Rockies through early next week.
This will translate to a hot and dry period of the local area.
High temperatures will be well into the 90s by Sunday with a few
triple digit readings likely. Do not really see any break in the
above normal temperatures through the end of the long term period.
The upper ridge does flatten out a bit towards mid week, which may
allow for a few isolated afternoon and evening storms to move out
of Colorado associated with weak shortwaves topping the ridge.
However, most areas will stay dry through the entire long term
period.

&&

.AVIATION...(For the 00Z TAFS through 00Z Friday evening)
Issued at 515 PM MDT Thu Jul 20 2023

For KGLD and KMCK, a large complex of showers and thunderstorms
are expected to move through the forecast area, impacting the
terminals with showers and thunderstorms from taf issuance through
about 09z-12z. Cigs will bounce in between VFR and sub VFR with
visibilities occasionally falling into sub VFR category due to
heavy rainfall and potentially fog once rainfall ends. Winds will
generally be from the east or east-northeast at speeds up to
12kts. During the daytime hours Friday, cigs slowly improve into
VFR category with winds establishing a light south to southwest
direction, speeds under 10kts.

&&

.GLD WATCHES/WARNINGS/ADVISORIES...
KS...Flood Watch until 2 AM MDT /3 AM CDT/ Friday for KSZ001>003-
     013>015-027>029-041-042.

CO...Flood Watch until 2 AM MDT Friday for COZ090>092.

NE...Flood Watch until 2 AM MDT /3 AM CDT/ Friday for NEZ079>081.

&&

UPDATE...KAK
SHORT TERM...KAK
LONG TERM...024
AVIATION...99
Hazardous weather outlook, Jul 20, 3:50 PM MDT, 2 hours 44 minutes before
Hazardous Weather Outlook
National Weather Service Goodland KS
350 PM MDT Thu Jul 20 2023

COZ090>092-KSZ001>004-013>016-027>029-041-042-NEZ079>081-212200-
Yuma-Kit Carson-Cheyenne-Rawlins-Decatur-Norton-Sherman-Thomas-
Sheridan-Graham-Wallace-Logan-Gove-Greeley-Wichita-Dundy-Hitchcock-
Red Willow-
350 PM MDT Thu Jul 20 2023 /450 PM CDT Thu Jul 20 2023/

This hazardous weather outlook is for extreme southwest Nebraska...
northwest Kansas and east central Colorado.

.DAY ONE...THIS AFTERNOON AND TONIGHT...

A Severe Thunderstorm Watch is now in effect for Cheyenne, Sherman,
Thomas, Wallace, Logan, Gove, Greeley and Wichita counties in Kansas
until 11pm MT or midnight CT. A Severe Thunderstorm Watch remains in
effect for Eastern Colorado until 9pm MT.

A Flood Watch remains in effect for most of the area until
2 AM MDT.

Severe weather is expected this afternoon into the overnight hours.
70+ mph winds, hail up to two inches, and a tornado or two are all
possible with the storms today.

Excessive rainfall is the main threat and could lead to flash
flooding.

Dense fog may be possible for counties along the Colorado border
during the late overnight hours.

.DAYS TWO THROUGH SEVEN...FRIDAY THROUGH THURSDAY...

The Tri-State Area sees heat indices reaching into the lower triple
digits in some locations on Sunday through Thursday. Please consider
making preparations for multiple days of very hot conditions.

.SPOTTER INFORMATION STATEMENT...

Any reports of severe weather or flooding is appreciated!

In the hours before

Special weather statement, Jul 20, 3:18 PM MDT, 3 hours 16 minutes before
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Local storm report, Jul 20, 3:55 PM MDT, 2 hours 39 minutes before
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Special weather statement, Jul 20, 4:06 PM MDT, 2 hours 28 minutes before
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Special weather statement, Jul 20, 4:30 PM MDT, 2 hours 4 minutes before
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Special weather statement, Jul 20, 5:56 PM MDT, 38 minutes before
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Special weather statement, Jul 20, 6:06 PM MDT, 28 minutes before
Special Weather Statement
National Weather Service Goodland KS
606 PM MDT Thu Jul 20 2023

COZ090-091-210030-
Kit Carson County CO-Yuma County CO-
606 PM MDT Thu Jul 20 2023

...A strong thunderstorm will impact portions of southwestern Yuma
and northwestern Kit Carson Counties through 630 PM MDT...

At 605 PM MDT, Doppler radar was tracking a strong thunderstorm over
Cope, or 25 miles north of Seibert, moving southeast at 20 mph.

HAZARD...Half inch hail.

SOURCE...Radar indicated.

IMPACT...Minor damage to outdoor objects is possible. Torrential
         rainfall with this storm and may lead to localized flooding.

This storm will remain over mainly rural areas of southwestern Yuma
and northwestern Kit Carson Counties, including the following
locations... Kirk and Joes.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

A Severe Thunderstorm Watch remains in effect until 900 PM MDT for
northeastern and east central Colorado.

&&

LAT...LON 3957 10280 3982 10280 3962 10245 3936 10284
      3957 10303
TIME...MOT...LOC 0005Z 320DEG 18KT 3966 10287

MAX HAIL SIZE...0.50 IN
MAX WIND GUST...<30 MPH

Vincent

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 20, 7:16 PM MDTFlash Flood WarningGLDSherman, Wallace96 min
Jul 20, 7:57 PM MDTFlash Flood WarningGLDSherman, Wallace95 min
Jul 20, 7:59 PM MDTSpecial Weather StatementGLDWichita31 min
Jul 20, 8:11 PM MDTSpecial Weather StatementGLDWallace34 min
Jul 20, 8:33 PM MDTFlash Flood WarningGLDGreeley, Wallace3 hr
Jul 20, 8:55 PM MDTSpecial Weather StatementGLDGreeley35 min
Jul 20, 9:00 PM MDTSpecial Weather StatementGLDGreeley30 min
Jul 20, 9:14 PM MDTSevere Thunderstorm WarningGLDGreeley, Wichita61 min
Jul 20, 9:21 PM MDTFlash Flood WarningGLDWichita2 hr
Jul 20, 9:36 PM MDTAreal Flood WarningGLDWallace11 hr
Jul 20, 11:41 PM MDTAreal Flood WarningGLDGreeley, Wichita9 hr
Jul 20, 6:06 PM MDTSpecial Weather StatementGLDKit Carson24 min
Jul 20, 6:33 PM MDTSevere Thunderstorm WarningGLDCheyenne, Kit Carson57 min
Jul 20, 6:37 PM MDTSpecial Weather StatementGLDKit Carson38 min
Jul 20, 6:53 PM MDTFlash Flood WarningGLDKit Carson, Yuma89 min
Jul 20, 7:01 PM MDTFlash Flood WarningGLDCheyenne, Kit Carson106 min
Jul 20, 7:05 PM MDTSpecial Weather StatementGLDKit Carson25 min
Jul 20, 7:16 PM MDTSevere Thunderstorm WarningGLDCheyenne, Kit Carson47 min
Jul 20, 7:43 PM MDTSpecial Weather StatementGLDCheyenne32 min
Jul 20, 8:03 PM MDTAreal Flood WarningGLDYuma13 hr
Jul 20, 8:19 PM MDTSpecial Weather StatementGLDCheyenne26 min
Jul 20, 8:59 PM MDTAreal Flood WarningGLDKit Carson12 hr
Jul 20, 9:13 PM MDTAreal Flood WarningGLDCheyenne12 hr

Nearby

Flash Flood Warnings in Colorado, 2023Every flash flood warning in 2023

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.