Alert archive / Colorado / Severe Thunderstorm Warnings in 2002
Severe Thunderstorm Warning 59, NWS Denver/Boulder, CO
NWS Denver/Boulder, CO issued this severe thunderstorm warning at Aug 23, 2002, 6:11 PM MDT for Logan County, Sedgwick County, Colorado. It was in force for 64 min. 1 report came from inside the area while it was in force.
The area
The counties it named, with what was reported inside it.
The facts
- Issued
- Aug 23, 2002, 6:11 PM MDT (00:11 UTC)
- Expired
- Aug 23, 2002, 7:15 PM MDT
- In force
- 64 min
- Issued by
- NWS Denver/Boulder, CO
- Area
- Counties, with a storm outline in the text
Counties Logan County, CO, Sedgwick County, CO
The radar
The Cheyenne radar (KCYS), 179 km from the middle of the area, began a volume at 00:13 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
| Time | Report | Where | Remark |
|---|---|---|---|
| Aug 23, 6:30 PM MDT | Hail 0.75 | Crook, CO |
NCEI Storm Data entries that began inside the alert's area while it was in force. Before 2003 the local storm report archive is thin, so this is the record of what happened rather than what was phoned in.
Did it verify
Not verified. The Iowa Environmental Mesonet's Cow found no qualifying storm report inside this severe thunderstorm warning while it was in force. That is not proof nothing happened: reports are thin where few people live.
Cow counts a report within 15 km of the polygon while the warning was in force: a tornado for a tornado warning; hail of 1 inch or more, a gust of 58 mph or more or wind damage for a severe thunderstorm warning; a flash flood report for a flash flood warning.
The watch it was issued in
The SPC watch in force over the same counties when this warning went out.
| Issued | Product | Office | Lasted |
|---|---|---|---|
| Aug 23, 5:55 PM MDT | Severe Thunderstorm Watch | SPC | 6 hr |
The nearest sounding before it
Denver, CO (KDNR), launched 00:00Z, 0.2 hours before the alert went out and 112 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.
- Mixed-layer CAPE
- 167 J/kg
- Mixed-layer CIN
- -77 J/kg
- Mixed-layer LCL
- 3250 m above ground
- 0-6 km bulk shear
- 42 kt
- 0-1 km storm-relative helicity
- 21 m²/s²
- 0-3 km storm-relative helicity
- 113 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.2
What forecasters said that day
The local office's own words before this severe thunderstorm warning 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 severe thunderstorm warning went out at Aug 23, 3:25 PM MDT, 2 hours 46 minutes earlier.
Area forecast discussion, Aug 23, 3:25 PM MDT, 2 hours 46 minutes before
NORTHEAST AND NORTH CENTRAL COLORADO AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DENVER COLORADO 325 PM MDT FRI AUG 23 2002 SHORT TERM DISCUSSION: DRIER AIR AT THE SFC HAS MOVED OUT OF THE FOOTHILLS AND ONTO THE ADJACENT PLAINS WHILE LOW LVL MSTR CONTS ON THE EXTREME EASTERN PLAINS. TWO SHOWER COMPLEXES HAVE DVLPD SO FAR...ONE OVR NEB PANHANDLE AND THE OTHER ACRS STRN WASH AND NERN ELBERT COUNTIES. FM THIS IT PPRS THE EVENING CONVECTIVE ACTIVITY IS GOING TO BE FOCUSED ALG AND E OF A LINE FM LOGAN...WASHINGTON AND LINCOLN COUNTIES. A FEW SHOWERS ARE ALSO POPPING UP OVR THE HIGH COUNTRY. WITH UPR LVL JET MOVG OVR THE STATE...CONVECTION THAT GET ORGANIZED ON THE PLAINS COULD BECOME LONG-LIVED. ON THE OTHER HAND...IT WONT BE IN OUR FCST AREA FOR VERY LONG. THE STRONGEST STORM...WHICH IS OVER SRN WASH CNTY IS ALSO MOVG SLOWLY...SO LOCALLY HEAVY RAIN IS ALSO A THREAT. BY MIDNIGHT...THE SHOWER ACTIVITY SHOULD BE DISSIPATING WITH SKIES GRADUALLY CLEARING. LONG TERM DISCUSSION: AFTER TONIGHTS CONVECTION...LOW LVL MSTR WL REMAIN ACRS THE ERN PLAINS AS RETURN FLOW FM THE DEPARTING THUNDERSTORMS DRIVE LOW LVL ELY-SELY WINDS. EACH OF THE MODELS SHOW HEALTHY AMOUNTS OF LOW LVL MSTR ACRS NERN CO THRU SAT AFTN. 700 MB SPEC HUMIDITIES ARE PROGGED TO BE ARND 6 G/KG. JET STREAM IS STILL FCST TO BE ACRS NRN CO SAT AFTN. UPR LVL RDG WL BE BLDG THE AREA...BUT THE INCRSG NWLY FLOW ALOFT COULD PRODUCE ENOUGH SHEAR FOR ORGANIZED CONVECTION TO DVLP. THE RIDGE ALOFT SHOULD BE STRONG ENOUGH ON SUNDAY FOR WARMER TEMPS AND LESS SHOWER ACTIVITY. DRY WX SHOULD CONTINUE INTO MON...BUT THEN A PASSING TROUGH FM THE PAC NW MON NITE WILL PROBABLY BRING BACK THE CHANCE OF PCPN FOR TUES THRU THE END OF THE WEEK. TEMPS SHUD BE ABV NORMAL ON SUN AND MON...OTHERWISE TEMPS WILL BE SEASONAL. KDRBY .DEN...NONE.
In the hours before
Local storm report, Aug 23, 6:05 PM MDT, 6 minutes before
LOCAL STORM REPORT
NATIONAL WEATHER SERVICE DENVER CO
605 PM MDT FRI AUG 23 2002
...PRELIMINARY STORM REPORT FOR AUGUST 23 2002...
TIME(MDT) .....CITY LOCATION.....STATE ...EVENT/REMARKS...
....COUNTY LOCATION....
0605 PM 13 NE STERLING CO 1.75 INCH HAIL
08/23/02 LOGAN
RAYThe office that day
Everything else NWS Denver/Boulder, CO issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Aug 24, 12:02 AM MDT | Severe Thunderstorm Warning | BOU | Lincoln | 43 min |
| Aug 24, 3:08 PM MDT | Tornado Warning | BOU | Sedgwick | 52 min |
| Aug 24, 5:04 PM MDT | Tornado Warning | BOU | Logan, Weld | 41 min |
| Aug 24, 5:40 PM MDT | Tornado Warning | BOU | Logan, Washington | 50 min |
| Aug 24, 5:45 PM MDT | Tornado Warning | BOU | Logan | 45 min |
Nearby
Severe Thunderstorm Warnings in Colorado, 2002Every severe thunderstorm warning in 2002
Sources
The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; verification from NCEI's Storm Data; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.