Alert archive / Colorado / Severe Thunderstorm Warnings in 2000
Severe Thunderstorm Warning 48, NWS Grand Junction, CO
NWS Grand Junction, CO issued this severe thunderstorm warning at Sep 29, 2000, 2:21 PM MDT for San Miguel County, Colorado; San Juan County, Utah. It was in force for 39 min. 2 reports 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
- Sep 29, 2000, 2:21 PM MDT (20:21 UTC)
- Expired
- Sep 29, 2000, 3:00 PM MDT
- In force
- 39 min
- Issued by
- NWS Grand Junction, CO
- Area
- Whole counties; the outline is the Mesonet’s reconstruction
Counties San Miguel County, CO, San Juan County, UT
The radar
The Grand Junction radar (KGJX), 159 km from the middle of the area, began a volume at 20:24 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 |
|---|---|---|---|
| Sep 29, 2:40 PM MDT | Hail 0.75 | Monticello, UT | |
| Sep 29, 2:45 PM MDT | Hail 0.75 | Egnar, 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.
The nearest sounding before it
Grand Junction, CO (KGJT), launched 12:00Z, 8.4 hours before the alert went out and 155 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
- 14 J/kg
- Mixed-layer CIN
- -243 J/kg
- Mixed-layer LCL
- 1516 m above ground
- 0-6 km bulk shear
- 33 kt
- 0-1 km storm-relative helicity
- 52 m²/s²
- 0-3 km storm-relative helicity
- 100 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
The text of this product is not in the archive. The NWS text archive before 2002 is incomplete.
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 Grand Junction, CO wrote its last area forecast discussion before this severe thunderstorm warning went out at Sep 29, 2:00 PM MDT, 21 minutes earlier.
Area forecast discussion, Sep 29, 2:00 PM MDT, 21 minutes before
WESTERN COLORADO & EASTERN UTAH AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GRAND JUNCTION CO 200 PM MDT FRI SEP 29 2000 THUNDERSTORM ACTIVITY SUBSIDED ONLY SLIGHTLY DURING THE MORNING HOURS. LINE REDEVELOPED OVER CENTRAL UT BY LATE MORNING AND IS NOW STRETCHED ACROSS CWA...FROM CENTRAL MOUNTAINS IN CO TO ABAJO MTS IN UT. AND CONVECTION CONTINUES TO DEVELOP OVER CENTRAL UT. LINGERING INSTABILITY FROM OVERNIGHT ACTIVITY BEING ENHANCED BY JET SPEED MAX WORKING UP FROM AZ...CATCHING CWA UNDER LEFT FRONT QUAD. SATELLITE WATER VAPOR IMAGERY SHOWS LOW OFF SOUTHERN CA COAST SENDING A NARROW STREAM OF MOISTURE WITH SOME EMBEDDED DISTURBANCES INTO CWA. PRECIPITABLE WATER ANALYSIS SHOWS VALUES BETWEEN 0.50 AND 0.75 INCHES ACROSS CWA WITH HIGHER VALUES OVER EXTREME SOUTHWEST CO. SO...TYING THIS ALL TOGETHER...HAVE LEFT THE MENTION OF THUNDERSTORMS TONIGHT. HOWEVER AM NOT CONFIDENT ACTIVITY STRICTLY DIURNAL IN NATURE DUE TO THE MANY FACTORS MENTIONED ABOVE...AND HAVE TAKEN OUT EVENING WORDING. DYNAMICS NOT OVERLY IMPRESSIVE SATURDAY...BUT WILL HAVE SOME LINGERING LOW LEVEL MOISTURE AND INSTABILITY. WILL KEEP MENTION OF AFTERNOON ACTIVITY. SUNDAY...WILL HAVE DISTURBANCES EMBEDDED IN WESTERLY FLOW SKIRTING THE NORTHERN BORDER OF THE CWA...AND GRADIENTS BEGIN TO TIGHTEN. WILL PUT IN SHOWERS OR THUNDERSTORMS NORTH AND OVER THE MOUNTAINS ALONG WITH BREEZY CONDITIONS. FOR EXTENDED...MRF SHOWING GOOD RUN TO RUN CONSISTENCY...WESTERLY FLOW TO MOST ENERGY FROM INCOMING SYSTEMS NORTH OF CWA THROUGH TUESDAY. LATEST RUN SHOWS MORE AMPLIFICATION IN TROUGH DUE IN WEDNESDAY. OTHER EXTENDED MODELS ON SAME PAGE WITH UKMET SLIGHTLY MORE PROGRESSIVE. WILL MAKE ONLY MINOR CHANGES TO MONDAY AND TUESDAY. THICKNESSES ALL FALL WEDNESDAY AND GRADIENTS TIGHTEN. WILL SEPARATE OUT WEDNESDAY FOR COOLER TEMPERATURES AND WINDY CONDITIONS. GL .GJT...NONE.
The office that day
Everything else NWS Grand Junction, CO issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Sep 29, 3:03 PM MDT | Severe Thunderstorm Warning | GJT | San Miguel | 42 min |
| Sep 29, 3:45 PM MDT | Severe Thunderstorm Warning | GJT | San Miguel | 45 min |
Nearby
Severe Thunderstorm Warnings in Colorado, 2000Severe Thunderstorm Warnings in Utah, 2000Every severe thunderstorm warning in 2000
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.