Alert archive / Colorado / Freeze Warnings in 2021

Freeze Warning 2, NWS Denver/Boulder, CO

October 13, 2021Arapahoe County, Douglas County, Elbert County, Colorado

NWS Denver/Boulder, CO issued this freeze warning at Oct 13, 2021, 2:50 PM MDT for Arapahoe County, Douglas County, Elbert County, Colorado. It took effect at Oct 14, 2021, 2:00 AM MDT. It was in force for 6 hr. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued
Oct 13, 2021, 2:50 PM MDT (20:50 UTC)
In effect from
Oct 14, 2021, 2:00 AM MDT
Expired
Oct 14, 2021, 7:55 AM MDT
In force
6 hr
Issued by
NWS Denver/Boulder, CO

Counties Arapahoe County, CO, Douglas County, CO, Elbert County, CO

The radar

The Denver radar (KFTG), 41 km from the middle of the area, began a volume at 20:48 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, 8.8 hours before the alert went out and 117 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 2021-10-13Temperature 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 2021-10-13The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 8 square meters per square second.1939587897117Sfc1 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
1982 m above ground
0-6 km bulk shear
43 kt
0-1 km storm-relative helicity
8 m²/s²
0-3 km storm-relative helicity
146 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

371 
WWUS75 KBOU 132050
NPWBOU

URGENT - WEATHER MESSAGE
National Weather Service Denver/Boulder CO
250 PM MDT Wed Oct 13 2021

COZ042-048-050-051-132200-
/O.CAN.KBOU.HW.W.0006.000000T0000Z-211014T0000Z/
Northeast Weld County-Logan County-Sedgwick County-
Phillips County-
Including Briggsdale, Grover, Pawnee Buttes, Raymer, Stoneham, 
Crook, Merino, Sterling, Peetz, Julesburg, Ovid, Sedgwick, 
Amherst, Haxtun, and Holyoke
250 PM MDT Wed Oct 13 2021

...HIGH WIND WARNING IS CANCELLED...

Winds have dropped below High Wind Warning criteria this afternoon
and will only get weaker as the day progresses towards sunset. The
High Wind Warning has been cancelled. 

$$

COZ041-140500-
/O.NEW.KBOU.FZ.W.0002.211014T0800Z-211014T1500Z/
Elbert/Central and East Douglas Counties Above 6000 Feet-
Including Castle Rock, Elbert, Fondis, Kiowa, and Larkspur
250 PM MDT Wed Oct 13 2021

...FREEZE WARNING IN EFFECT FROM 2 AM TO 9 AM MDT THURSDAY...

* WHAT...Sub-freezing temperatures as low as 28 expected.

* WHERE...Palmer Divide including Castle Rock, Elbert, and 
  Larkspur.

* WHEN...From 2 AM to 9 AM MDT Thursday.

* IMPACTS...Frost and freeze conditions will kill crops, other
  sensitive vegetation and possibly damage unprotected outdoor
  plumbing.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Take steps now to protect tender plants from the cold. To prevent
freezing and possible bursting of outdoor water pipes they should
be wrapped, drained, or allowed to drip slowly. Those that have
in-ground sprinkler systems should drain them and cover above-
ground pipes to protect them from freezing.

&&

$$
4 follow-up statements
578 
WWUS75 KBOU 132240
NPWBOU

URGENT - WEATHER MESSAGE
National Weather Service Denver CO
440 PM MDT Wed Oct 13 2021

COZ041-140400-
/O.CON.KBOU.FZ.W.0002.211014T0800Z-211014T1500Z/
Elbert/Central and East Douglas Counties Above 6000 Feet-
Including the cities of Elbert, Fondis, Kiowa, Castle Rock, and
Larkspur
440 PM MDT Wed Oct 13 2021

...FREEZE WARNING REMAINS IN EFFECT FROM 2 AM TO 9 AM MDT THURSDAY...

* WHAT...Sub-freezing temperatures as low as 28 expected.

* WHERE...Palmer Divide including Castle Rock, Elbert, and 
  Larkspur.

* WHEN...From 2 AM to 9 AM MDT Thursday.

* IMPACTS...Frost and freeze conditions will kill crops, other
  sensitive vegetation and possibly damage unprotected outdoor
  plumbing.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Take steps now to protect tender plants from the cold. To prevent
freezing and possible bursting of outdoor water pipes they should
be wrapped, drained, or allowed to drip slowly. Those that have
in-ground sprinkler systems should drain them and cover above-
ground pipes to protect them from freezing.

&&

$$

COZ038>040-042>045-048>051-140400-
/O.NEW.KBOU.FR.Y.0003.211014T0800Z-211014T1500Z/
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-Northeast Weld County-Central and
South Weld County-Morgan County-Central and East Adams and
Arapahoe Counties-Logan County-Washington County-Sedgwick County-
Phillips County-
Including the cities of Wiggins, Pawnee Buttes, Roggen, Arvada,
Byers, Julesburg, Briggsdale, Leader, Boulder, Fort Morgan, City
of Denver, Cope, Aurora, Littleton, Amherst, Akron, Last Chance,
Raymer, Brighton, Sterling, Highlands Ranch, Fort Lupton, Ovid,
Loveland, Peetz, Grover, Eaton, Deer Trail, Longmont, Sedgwick,
Denver International Airport, Haxtun, Goodrich, Golden, Parker,
Lakewood, Stoneham, Fort Collins, Greeley, Bennett, Otis, Crook,
Holyoke, Nunn, Brush, Hereford, and Merino
440 PM MDT Wed Oct 13 2021

...FROST ADVISORY IN EFFECT FROM 2 AM TO 9 AM MDT THURSDAY...

* WHAT...Low temperatures between 33 and 36 degrees will result in 
  frost formation.

* WHERE...Plains of north central and northeast Colorado.

* WHEN...From 2 AM to 9 AM MDT Thursday.

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

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Take steps now to protect tender plants from the cold.

&&

$$

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

Rodriguez
387 
WWUS75 KBOU 140324
NPWBOU

URGENT - WEATHER MESSAGE
National Weather Service Denver CO
924 PM MDT Wed Oct 13 2021

COZ041-141200-
/O.CON.KBOU.FZ.W.0002.211014T0800Z-211014T1500Z/
Elbert/Central and East Douglas Counties Above 6000 Feet-
Including the cities of Elbert, Fondis, Kiowa, Castle Rock, and
Larkspur
924 PM MDT Wed Oct 13 2021

...FREEZE WARNING REMAINS IN EFFECT FROM 2 AM TO 9 AM MDT THURSDAY...

* WHAT...Sub-freezing temperatures as low as 28 expected.

* WHERE...Palmer Divide including Castle Rock, Elbert, and 
  Larkspur.

* WHEN...From 2 AM to 9 AM MDT Thursday.

* IMPACTS...Frost and freeze conditions will kill crops, other
  sensitive vegetation and possibly damage unprotected outdoor
  plumbing.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Take steps now to protect tender plants from the cold. To prevent
freezing and possible bursting of outdoor water pipes they should
be wrapped, drained, or allowed to drip slowly. Those that have
in-ground sprinkler systems should drain them and cover above-
ground pipes to protect them from freezing.

&&

$$

COZ038>040-042>045-048>051-141200-
/O.CON.KBOU.FR.Y.0003.211014T0800Z-211014T1500Z/
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-Northeast Weld County-Central and
South Weld County-Morgan County-Central and East Adams and
Arapahoe Counties-Logan County-Washington County-Sedgwick County-
Phillips County-
Including the cities of Wiggins, Pawnee Buttes, Roggen, Arvada,
Byers, Julesburg, Briggsdale, Leader, Boulder, Fort Morgan, City
of Denver, Cope, Aurora, Littleton, Amherst, Akron, Last Chance,
Raymer, Brighton, Sterling, Highlands Ranch, Fort Lupton, Ovid,
Loveland, Peetz, Grover, Eaton, Deer Trail, Longmont, Sedgwick,
Denver International Airport, Haxtun, Goodrich, Golden, Parker,
Lakewood, Stoneham, Fort Collins, Greeley, Bennett, Otis, Crook,
Holyoke, Nunn, Brush, Hereford, and Merino
924 PM MDT Wed Oct 13 2021

...FROST ADVISORY REMAINS IN EFFECT FROM 2 AM TO 9 AM MDT THURSDAY...

* WHAT...Low temperatures between 33 and 36 degrees will result in 
  frost formation.

* WHERE...Plains of north central and northeast Colorado.

* WHEN...From 2 AM to 9 AM MDT Thursday.

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

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Take steps now to protect tender plants from the cold.

&&

$$

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

Rodriguez
267 
WWUS75 KBOU 140901
NPWBOU

URGENT - WEATHER MESSAGE
National Weather Service Denver CO
301 AM MDT Thu Oct 14 2021

COZ038>040-042>045-048>051-141800-
/O.NEW.KBOU.FZ.W.0003.211015T0600Z-211015T1500Z/
/O.CON.KBOU.FR.Y.0003.000000T0000Z-211014T1500Z/
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-Northeast Weld County-Central and
South Weld County-Morgan County-Central and East Adams and
Arapahoe Counties-Logan County-Washington County-Sedgwick County-
Phillips County-
Including the cities of Wiggins, Pawnee Buttes, Roggen, Arvada,
Byers, Julesburg, Briggsdale, Leader, Boulder, Fort Morgan, City
of Denver, Cope, Aurora, Littleton, Amherst, Akron, Last Chance,
Raymer, Brighton, Sterling, Highlands Ranch, Fort Lupton, Ovid,
Loveland, Peetz, Grover, Eaton, Deer Trail, Longmont, Sedgwick,
Denver International Airport, Haxtun, Goodrich, Golden, Parker,
Lakewood, Stoneham, Fort Collins, Greeley, Bennett, Otis, Crook,
Holyoke, Nunn, Brush, Hereford, and Merino
301 AM MDT Thu Oct 14 2021

...FROST ADVISORY REMAINS IN EFFECT UNTIL 9 AM MDT THIS MORNING...
...FREEZE WARNING IN EFFECT FROM MIDNIGHT TONIGHT TO 9 AM MDT 
FRIDAY...

* WHAT...Frost is expected this morning. A Freeze is expected 
  tonight with lows in the upper 20s.

* WHERE...Portions of north central and northeast Colorado.

* WHEN...For the Freeze Warning, from Midnight tonight to 9 AM MDT 
  Friday. For the Frost Advisory, until 9 AM MDT this morning.

* IMPACTS...Frost and freeze conditions could kill crops, other 
  sensitive vegetation and possibly damage unprotected outdoor 
  plumbing.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Take steps now to protect tender plants from the cold.

&&

$$

COZ041-141500-
/O.CON.KBOU.FZ.W.0002.000000T0000Z-211014T1500Z/
Elbert/Central and East Douglas Counties Above 6000 Feet-
Including the cities of Elbert, Fondis, Kiowa, Castle Rock, and
Larkspur
301 AM MDT Thu Oct 14 2021

...FREEZE WARNING REMAINS IN EFFECT UNTIL 9 AM MDT THIS MORNING...

* WHAT...Sub-freezing temperatures as low as 28 ongoing.

* WHERE...Elbert/Central and East Douglas Counties Above 6000 Feet 
  County.

* WHEN...Until 9 AM MDT this morning.

$$

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

Hiris
719 
WWUS75 KBOU 141355
NPWBOU

URGENT - WEATHER MESSAGE
National Weather Service Denver CO
755 AM MDT Thu Oct 14 2021

COZ041-141500-
/O.CAN.KBOU.FZ.W.0002.000000T0000Z-211014T1500Z/
Elbert/Central and East Douglas Counties Above 6000 Feet-
Including the cities of Elbert, Fondis, Kiowa, Castle Rock, and
Larkspur
755 AM MDT Thu Oct 14 2021

...FREEZE WARNING IS CANCELLED...

Temperatures have warmed into the mid 30s.  Given the hard freeze 
that has occurred, we will not issue any more frost/freeze products 
for Douglas and Elbert Counties this Fall.

$$

COZ038>040-042>045-048>051-150400-
/O.CAN.KBOU.FR.Y.0003.000000T0000Z-211014T1500Z/
/O.CON.KBOU.FZ.W.0003.211015T0600Z-211015T1500Z/
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-Northeast Weld County-Central and
South Weld County-Morgan County-Central and East Adams and
Arapahoe Counties-Logan County-Washington County-Sedgwick County-
Phillips County-
Including the cities of Wiggins, Pawnee Buttes, Roggen, Arvada,
Byers, Julesburg, Briggsdale, Leader, Boulder, Fort Morgan, City
of Denver, Cope, Aurora, Littleton, Amherst, Akron, Last Chance,
Raymer, Brighton, Sterling, Highlands Ranch, Fort Lupton, Ovid,
Loveland, Peetz, Grover, Eaton, Deer Trail, Longmont, Sedgwick,
Denver International Airport, Haxtun, Goodrich, Golden, Parker,
Lakewood, Stoneham, Fort Collins, Greeley, Bennett, Otis, Crook,
Holyoke, Nunn, Brush, Hereford, and Merino
755 AM MDT Thu Oct 14 2021

...FREEZE WARNING REMAINS IN EFFECT FROM MIDNIGHT TONIGHT TO 9 AM 
MDT FRIDAY...
...FROST ADVISORY FOR THIS MORNING IS CANCELLED...

* WHAT...A Freeze is expected tonight with lows in the upper 20s.

* WHERE...Portions of north central and northeast Colorado.

* WHEN...From Midnight tonight to 9 AM MDT Friday.

* IMPACTS...Frost and freeze conditions could kill crops, other 
  sensitive vegetation and possibly damage unprotected outdoor 
  plumbing.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Take steps now to protect tender plants from the cold.

&&

$$

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

Schlatter

The office that day

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

IssuedProductOfficeCountiesLasted
Oct 12, 9:53 PM MDTFreeze WarningBOUAdams, Arapahoe, Boulder, Broomfield, Denver, Douglas and 8 more10 hr
Oct 13, 4:40 PM MDTFrost AdvisoryBOUAdams, Arapahoe, Boulder, Broomfield, Denver, Douglas and 8 more15 hr

Nearby

Freeze Warnings in Colorado, 2021Every freeze warning 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.