Alert archive / Colorado / Tornado Warnings in 2023

Tornado Warning 2, NWS Denver/Boulder, CO

April 25, 2023Weld County, Colorado

NWS Denver/Boulder, CO issued this tornado warning at Apr 25, 2023, 2:42 PM MDT for Weld County, Colorado. It was in force for 33 min. 2 reports came from inside the area while it was in force.

The area

The outline as issued, with what was reported inside it.

The facts

Issued
Apr 25, 2023, 2:42 PM MDT (20:42 UTC)
Expired
Apr 25, 2023, 3:15 PM MDT
In force
33 min
Issued by
NWS Denver/Boulder, CO
Area
Storm-based polygon
Tornado
Observed
Hail
0.75 in

County Weld County, CO

The radar

The Denver radar (KFTG), 37 km from the middle of the area, began a volume at 20:43 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.

What was reported inside it

TimeReportWhereRemark
Apr 25, 2:45 PM MDTTORNADO4 Sw Prospect Valley, COCORRECTS PREVIOUS TORNADO REPORT FROM 4 SW PROSPECT VALLEY.
Apr 25, 2:50 PM MDTTORNADO4 Sw Prospect Valley, CO

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The nearest sounding before it

N. Platte/Lee Bi, NE (KLBF), launched 12:00Z, 8.7 hours before the alert went out and 344 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, N. Platte/Lee Bi, NE at 12:00Z on 2023-04-25Temperature 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, N. Platte/Lee Bi, NE at 12:00Z on 2023-04-25The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -86 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
947 m above ground
0-6 km bulk shear
18 kt
0-1 km storm-relative helicity
-86 m²/s²
0-3 km storm-relative helicity
-135 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

295 
WFUS55 KBOU 252042
TORBOU
COC123-252115-
/O.NEW.KBOU.TO.W.0002.230425T2042Z-230425T2115Z/

BULLETIN - EAS ACTIVATION REQUESTED
Tornado Warning
National Weather Service Denver CO
242 PM MDT Tue Apr 25 2023

The National Weather Service in Denver Colorado has issued a

* Tornado Warning for...
  South central Weld County in northeastern Colorado...

* Until 315 PM MDT.

* At 242 PM MDT, a confirmed tornado was located near Keenesburg, or
  27 miles southeast of Greeley, moving south at 20 mph.

  HAZARD...Damaging tornado.

  SOURCE...Weather spotters confirmed tornado.

  IMPACT...Flying debris will be dangerous to those caught without 
           shelter. Mobile homes will be damaged or destroyed. 
           Damage to roofs, windows, and vehicles will occur.  Tree 
           damage is likely.

* The tornado will be near...
  Prospect Valley around 245 PM MDT.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

To repeat, a tornado is on the ground. TAKE COVER NOW! Move to a
basement or an interior room on the lowest floor of a sturdy
building. Avoid windows. If you are outdoors, in a mobile home, or in
a vehicle, move to the closest substantial shelter and protect
yourself from flying debris.

&&

LAT...LON 4018 10454 4017 10433 4001 10427 4001 10455
TIME...MOT...LOC 2042Z 357DEG 16KT 4008 10448 

TORNADO...OBSERVED
MAX HAIL SIZE...<.75 IN

$$

AD
2 follow-up statements
274 
WWUS55 KBOU 252054
SVSBOU

Severe Weather Statement
National Weather Service Denver CO
254 PM MDT Tue Apr 25 2023

COC123-252115-
/O.CON.KBOU.TO.W.0002.000000T0000Z-230425T2115Z/
Weld CO-
254 PM MDT Tue Apr 25 2023

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 315 PM MDT FOR SOUTH
CENTRAL WELD COUNTY...
    
At 254 PM MDT, a confirmed tornado was located 4 miles southwest of
Prospect Valley, or 30 miles southeast of Greeley, moving south at 20
mph.

HAZARD...TORNADO.

SOURCE...Weather spotters confirmed tornado.

IMPACT...Expect damage to mobile homes, roofs, and vehicles.

This tornadic thunderstorm will remain over mainly rural areas of
south central Weld County.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

To repeat, a tornado is on the ground. TAKE COVER NOW! Move to a
basement or an interior room on the lowest floor of a sturdy
building. Avoid windows. If you are outdoors, in a mobile home, or in
a vehicle, move to the closest substantial shelter and protect
yourself from flying debris.

&&

LAT...LON 4012 10453 4013 10431 4001 10427 4001 10455
TIME...MOT...LOC 2054Z 357DEG 16KT 4003 10448 

TORNADO...OBSERVED
MAX HAIL SIZE...<.75 IN

$$

AD
850 
WWUS55 KBOU 252114
SVSBOU

Severe Weather Statement
National Weather Service Denver CO
314 PM MDT Tue Apr 25 2023

COC123-252123-
/O.EXP.KBOU.TO.W.0002.000000T0000Z-230425T2115Z/
Weld CO-
314 PM MDT Tue Apr 25 2023

...THE TORNADO WARNING FOR SOUTH CENTRAL WELD COUNTY WILL EXPIRE AT
315 PM MDT...
        
The storm which prompted the warning has moved out of the area.
Therefore, the warning will be allowed to expire.  However small hail
is still possible with this thunderstorm.

Remember, a Severe Thunderstorm Warning still remains in effect for 
Weld and Adams counties including cities such as Prospect Valley and 
Keenesburg.

LAT...LON 4012 10453 4013 10431 4001 10427 4001 10455
TIME...MOT...LOC 2113Z 357DEG 16KT 3995 10447 

$$

AD

The office that day

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

IssuedProductOfficeCountiesLasted
Apr 25, 1:51 PM MDTSpecial Weather StatementBOUAdams39 min
Apr 25, 2:27 PM MDTSpecial Weather StatementBOUAdams48 min
Apr 25, 2:32 PM MDTTornado WarningBOUAdams, Weld14 min
Apr 25, 3:11 PM MDTSevere Thunderstorm WarningBOUAdams, Weld34 min
Apr 25, 3:19 PM MDTSpecial Weather StatementBOUBroomfield26 min
Apr 25, 3:20 PM MDTSpecial Weather StatementBOUAdams, Denver40 min
Apr 25, 4:30 PM MDTAreal Flood AdvisoryBOUWeld3 hr

Nearby

Tornado Warnings in Colorado, 2023Every tornado warning in 2023Tornadoes 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.