Alert archive / Colorado / Areal Flood Advisories in 2021

Areal Flood Advisory 4, NWS Denver/Boulder, CO

May 16, 2021Jackson County, Colorado

NWS Denver/Boulder, CO issued this areal flood advisory at May 16, 2021, 1:33 PM MDT for Jackson County, Colorado. It was in force for 87 min.

The area

The counties it named.

The facts

Issued
May 16, 2021, 1:33 PM MDT (19:33 UTC)
Expired
May 16, 2021, 3:00 PM MDT
In force
87 min
Issued by
NWS Denver/Boulder, CO
Area
Storm-based polygon

County Jackson County, CO

The radar

The Cheyenne radar (KCYS), 140 km from the middle of the area, began a volume at 19:35 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

Denver, CO (KDNR), launched 12:00Z, 7.6 hours before the alert went out and 279 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, Denver, CO at 12:00Z on 2021-05-16Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 215 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Denver, CO at 12:00Z on 2021-05-16The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 35 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
215 J/kg
Mixed-layer CIN
-294 J/kg
Mixed-layer LCL
861 m above ground
0-6 km bulk shear
22 kt
0-1 km storm-relative helicity
35 m²/s²
0-3 km storm-relative helicity
-44 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

What forecasters said that day

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

NWS Denver/Boulder, CO wrote its last area forecast discussion before this areal flood advisory went out at May 16, 10:54 AM MDT, 2 hours 39 minutes earlier.

Area forecast discussion, May 16, 10:54 AM MDT, 2 hours 39 minutes before
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Hazardous weather outlook, May 16, 10:00 AM MDT, 3 hours 33 minutes before
Hazardous Weather Outlook
National Weather Service Denver/Boulder CO
1000 AM MDT Sun May 16 2021

COZ030>051-171600-
Jackson County Below 9000 Feet-
West Jackson and West Grand Counties Above 9000 Feet-
Grand and Summit Counties Below 9000 Feet-
South and East Jackson/Larimer/North and Northeast Grand/
Northwest Boulder Counties Above 9000 Feet-
South and Southeast Grand/West Central and Southwest Boulder/
Gilpin/Clear Creek/Summit/North and West Park Counties Above
9000 Feet-Larimer and Boulder Counties Between 6000 and 9000 Feet-
Jefferson and West Douglas Counties Above 6000 Feet/Gilpin/Clear
Creek/Northeast Park Counties Below 9000 Feet-
Central and Southeast Park County-
Larimer County Below 6000 Feet/Northwest Weld County-
Boulder And Jefferson Counties Below 6000 Feet/West Broomfield
County-
North Douglas County Below 6000 Feet/Denver/West Adams and
Arapahoe Counties/East Broomfield County-
Elbert/Central and East Douglas Counties Above 6000 Feet-
Northeast Weld County-Central and South Weld County-Morgan County-
Central and East Adams and Arapahoe Counties-
North and Northeast Elbert County Below 6000 Feet/North Lincoln
County-
Southeast Elbert County Below 6000 Feet/South Lincoln County-
Logan County-Washington County-Sedgwick County-Phillips County-
1000 AM MDT Sun May 16 2021

This hazardous weather outlook is for northeast and north central
Colorado.

.DAY ONE...Today and Tonight

Scattered thunderstorms will develop over the mountains this
afternoon, and spread onto the plains in the late afternoon and
evening hours. Some of the storms on the plains could be severe,
mainly south of Interstate 76 in the early evening. The main
threats are hail up to one inch in diameter and heavy rain. Wind
gusts to 60 mph are also possible. There is a threat of minor
flooding from thunderstorm rains in the foothills burn areas this
afternoon, especially in Boulder and Larimer counties. Sustained
heavy rain is not expected in the burn areas.

.DAYS TWO THROUGH SEVEN...Monday through Saturday

Showers and thunderstorms will be likely on Monday and Tuesday.
The risk for these storms to produce flooding or severe hail or
wind will be low. Showers and storms are possible Wednesday with
less areal coverage. A warm and windy pattern will develop
Thursday into next weekend. There will be a chance for isolated
showers and storms most afternoon and evenings during that
period.

.SPOTTER INFORMATION STATEMENT...

Spotter activation is not anticipated today or tonight.

The office that day

Everything else NWS Denver/Boulder, CO issued on the same UTC day.

IssuedProductOfficeCountiesLasted
May 15, 6:00 PM MDTSpecial Weather StatementBOUDouglas30 min
May 16, 3:58 PM MDTSpecial Weather StatementBOULincoln32 min
May 16, 4:13 PM MDTSevere Thunderstorm WarningBOULincoln32 min
May 16, 4:27 PM MDTSevere Thunderstorm WarningBOULincoln33 min
May 16, 4:43 PM MDTSevere Thunderstorm WarningBOULincoln32 min
May 16, 4:51 PM MDTTornado WarningBOULincoln24 min
May 16, 4:54 PM MDTSevere Thunderstorm WarningBOULincoln36 min
May 16, 5:22 PM MDTAreal Flood AdvisoryBOULincoln113 min

Nearby

Areal Flood Advisories in Colorado, 2021Every areal flood advisory 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.