Alert archive / Colorado / Frost Advisories in 2021

Frost Advisory 2, NWS Denver/Boulder, CO

October 10, 20217 counties in Colorado

NWS Denver/Boulder, CO issued this frost advisory at Oct 10, 2021, 2:04 PM MDT for 7 counties in Colorado. It took effect at Oct 11, 2021, 2:00 AM MDT. It was in force for 6 hr.

The area

The counties it named.

The facts

Issued
Oct 10, 2021, 2:04 PM MDT (20:04 UTC)
In effect from
Oct 11, 2021, 2:00 AM MDT
Expired
Oct 11, 2021, 8:00 AM MDT
In force
6 hr
Issued by
NWS Denver/Boulder, CO

Counties Arapahoe County, CO, Douglas County, CO, Elbert County, CO, Lincoln County, CO, Logan County, CO, Morgan County, CO, Weld County, CO

The nearest sounding before it

Denver, CO (KDNR), launched 12:00Z, 8.1 hours before the alert went out and 69 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 2021-10-10Temperature 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 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Denver, CO at 12:00Z on 2021-10-10The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -33 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
1519 m above ground
0-6 km bulk shear
25 kt
0-1 km storm-relative helicity
-33 m²/s²
0-3 km storm-relative helicity
-26 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

867 
WWUS75 KBOU 102004
NPWBOU

URGENT - WEATHER MESSAGE
National Weather Service Denver CO
204 PM MDT Sun Oct 10 2021

COZ041>044-046>048-111200-
/O.NEW.KBOU.FR.Y.0002.211011T0800Z-211011T1400Z/
Elbert/Central and East Douglas Counties Above 6000 Feet-
Northeast Weld County-Central and South Weld County-Morgan County-
North and Northeast Elbert County Below 6000 Feet/North Lincoln
County-Southeast Elbert County Below 6000 Feet/South Lincoln
County-Logan County-
Including the cities of Wiggins, Fort Morgan, Elbert, Hugo,
Roggen, Forder, Larkspur, Fondis, Briggsdale, Sterling, Pawnee
Buttes, Crook, Raymer, Fort Lupton, Matheson, Peetz, Kiowa,
Grover, Eaton, Agate, Kutch, Castle Rock, Goodrich, Stoneham,
Karval, Greeley, Punkin Center, Brush, Limon, and Merino
204 PM MDT Sun Oct 10 2021

...FROST ADVISORY IN EFFECT FROM 2 AM TO 8 AM MDT MONDAY...

* WHAT...Temperatures in the lower to mid 30s will result in frost 
  formation.

* WHERE...North and Northeast Elbert County Below 6000 Feet/North 
  Lincoln County, Southeast Elbert County Below 6000 Feet/South 
  Lincoln County, Central and South Weld County, Elbert/Central and 
  East Douglas Counties Above 6000 Feet, Logan County, Morgan County 
  and Northeast Weld County Counties.

* WHEN...From 2 AM to 8 AM MDT Monday.

* IMPACTS...Frost could harm sensitive outdoor vegetation. Sensitive 
  outdoor plants may be killed if left uncovered.

* ADDITIONAL DETAILS...The coldest temperatures will occur across 
  the Palmer Divide area, as well as low lying areas across the 
  northeast plains. This includes the South Platte River Valley 
  northeast of Denver.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Take steps now to protect tender plants from the cold. Bring them 
indoors or cover them with blankets.

&&

$$

For more information from the National Weather Service, visit 
https://weather.gov/bou

Barjenbruch
2 follow-up statements
504 
WWUS75 KBOU 110926
NPWBOU

URGENT - WEATHER MESSAGE
National Weather Service Denver/Boulder CO
326 AM MDT Mon Oct 11 2021

COZ041>044-046>048-111400-
/O.CON.KBOU.FR.Y.0002.000000T0000Z-211011T1400Z/
Elbert/Central and East Douglas Counties Above 6000 Feet-
Northeast Weld County-Central and South Weld County-Morgan County-
North and Northeast Elbert County Below 6000 Feet/North Lincoln
County-
Southeast Elbert County Below 6000 Feet/South Lincoln County-
Logan County-
Including Castle Rock, Elbert, Fondis, Kiowa, Larkspur, 
Briggsdale, Grover, Pawnee Buttes, Raymer, Stoneham, Eaton, 
Fort Lupton, Greeley, Roggen, Brush, Fort Morgan, Goodrich, 
Wiggins, Agate, Hugo, Limon, Matheson, Forder, Karval, Kutch, 
Punkin Center, Crook, Merino, Sterling, and Peetz
326 AM MDT Mon Oct 11 2021

...FROST ADVISORY REMAINS IN EFFECT UNTIL 8 AM MDT THIS MORNING...

* WHAT...Temperatures in the lower to mid 30s will result in 
  frost formation.

* WHERE...North and Northeast Elbert County Below 6000 
  Feet/North Lincoln County, Southeast Elbert County Below 6000 
  Feet/South Lincoln County, Central and South Weld County, 
  Elbert/Central and East Douglas Counties Above 6000 Feet, 
  Logan County, Morgan County and Northeast Weld County Counties.

* WHEN...From 2 AM to 8 AM MDT Monday.

* IMPACTS...Frost could harm sensitive outdoor vegetation. 
  Sensitive outdoor plants may be killed if left uncovered.

* ADDITIONAL DETAILS...The coldest temperatures will occur 
  across the Palmer Divide area, as well as low lying areas 
  across the northeast plains. This includes the South Platte 
  River Valley northeast of Denver.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Take steps now to protect tender plants from the cold. Bring them
indoors or cover them with blankets.

&&

$$
104 
WWUS75 KBOU 111421
NPWBOU

URGENT - WEATHER MESSAGE
National Weather Service Denver/Boulder CO
821 AM MDT Mon Oct 11 2021

COZ041>044-046>048-111530-
/O.EXP.KBOU.FR.Y.0002.000000T0000Z-211011T1400Z/
Elbert/Central and East Douglas Counties Above 6000 Feet-
Northeast Weld County-Central and South Weld County-Morgan County-
North and Northeast Elbert County Below 6000 Feet/North Lincoln
County-
Southeast Elbert County Below 6000 Feet/South Lincoln County-
Logan County-
Including Castle Rock, Elbert, Fondis, Kiowa, Larkspur, 
Briggsdale, Grover, Pawnee Buttes, Raymer, Stoneham, Eaton, 
Fort Lupton, Greeley, Roggen, Brush, Fort Morgan, Goodrich, 
Wiggins, Agate, Hugo, Limon, Matheson, Forder, Karval, Kutch, 
Punkin Center, Crook, Merino, Sterling, and Peetz
821 AM MDT Mon Oct 11 2021

...FROST ADVISORY HAS EXPIRED...

Temperatures have warmed above freezing this morning so the frost
advisory has expired.

$$

The office that day

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

IssuedProductOfficeCountiesLasted
Oct 10, 2:43 PM MDTFire Weather WatchBOUArapahoe, Douglas, Elbert, Lincoln37 hr

Nearby

Frost Advisories in Colorado, 2021Every frost 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.