Alert archive / Nebraska / Severe Thunderstorm Warnings in 1999
Severe Thunderstorm Warning 106, NWS Cheyenne, WY
NWS Cheyenne, WY issued this severe thunderstorm warning at Sep 2, 1999, 7:26 PM MDT for Morrill County, Nebraska. It was in force for 29 min. No storm report in the archive falls inside the area while it was in force.
The area
The counties it named.
The facts
- Issued
- Sep 2, 1999, 7:26 PM MDT (01:26 UTC)
- Expired
- Sep 2, 1999, 7:55 PM MDT
- In force
- 29 min
- Issued by
- NWS Cheyenne, WY
- Area
- Whole counties
County Morrill County, NE
The radar
The Cheyenne radar (KCYS), 162 km from the middle of the area, began a volume at 01:25 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 watch it was issued in
The SPC watch in force over the same counties when this warning went out.
| Issued | Product | Office | Lasted |
|---|---|---|---|
| Sep 2, 5:45 PM MDT | Severe Thunderstorm Watch | SPC | 5 hr |
The nearest sounding before it
Denver, CO (KDNR), launched 00:00Z, 1.4 hours before the alert went out and 206 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
- 761 J/kg
- Mixed-layer CIN
- -45 J/kg
- Mixed-layer LCL
- 1907 m above ground
- 0-6 km bulk shear
- 41 kt
- 0-1 km storm-relative helicity
- 99 m²/s²
- 0-3 km storm-relative helicity
- 293 m²/s²
- Significant tornado parameter
- 0.1
- Supercell composite
- 3.2
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 Cheyenne, WY wrote its last area forecast discussion before this severe thunderstorm warning went out at Sep 2, 1:49 PM MDT, 5 hours 37 minutes earlier.
Area forecast discussion, Sep 2, 1:49 PM MDT, 5 hours 37 minutes before
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE CHEYENNE WY 149 PM MDT THU SEP 2 1999 TODAY'S FORECAST VERY SIMILAR TO YESTERDAY. STALLED FRONTAL BOUNDARY ACROSS WY. STORMS DEVELOPED TO THE WEST OF CYS AND REPORTS AT THIS TIME ARE OF HEAVY RAIN NO HAIL. ALOFT LONG WAVE TROF TO THE WEST GIVING STRONG SW FLOW TO THE CWA. EMBEDDED SHORT WAVES WILL KICK OFF CONVECTIVE. AS USUAL TIMING OF WAVE ACROSS THE AREA WILL BE PROBLEM. MONSOONAL FLOW NOT AS STRONG TODAY BUT DEW POINTS STILL IN THE 60S IN ERN CWA. UPPER FEATURES SIMILAR ON ALL THE MODELS BUT NGM MOVES SFC LOW MORE QUICKLY TO THE EAST THAN ETA/AVN. THE RESULT IS NGM COMES AROUND TO A W/NW FLOW AND CUTS OFF THE PRECIP WHILE ETA/AVN ARE SLOWER AND THIS KEEPS THE CWA IN MORE UPSLOPE FLOW AND HENCE RAIN AND CLOUDS PERSIST INTO THE WEEKEND. PREFER THE ETA/AVN SO WILL KEEP WITH THE ATYPICAL WET PATTERN THROUGH SATURDAY. UPPER TROF PASSES AREA BY SUNDAY SO WILL PROBABLY GO DRY IN THE .EXTENDED. .CYS... WY...NONE. NE...NONE. GRIFFITH
The office that day
Everything else NWS Cheyenne, WY issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Sep 2, 6:15 PM MDT | Severe Thunderstorm Warning | CYS | Scotts Bluff | 30 min |
| Sep 2, 6:45 PM MDT | Severe Thunderstorm Warning | CYS | Morrill | 40 min |
| Sep 2, 7:55 PM MDT | Severe Thunderstorm Warning | CYS | Morrill | 30 min |
| Sep 2, 10:13 PM MDT | Severe Thunderstorm Warning | CYS | Cheyenne | 32 min |
| Sep 3, 4:51 PM MDT | Severe Thunderstorm Warning | CYS | Laramie | 34 min |
| Sep 3, 4:55 PM MDT | Tornado Warning | CYS | Converse | 35 min |
| Sep 3, 5:02 PM MDT | Severe Thunderstorm Warning | CYS | Platte | 33 min |
| Sep 3, 5:29 PM MDT | Severe Thunderstorm Warning | CYS | Goshen, Laramie | 61 min |
Nearby
Severe Thunderstorm Warnings in Nebraska, 1999Every severe thunderstorm warning in 1999
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.