Alert archive / Nebraska / Severe Thunderstorm Warnings in 1999
Severe Thunderstorm Warning 224, NWS North Platte, NE
NWS North Platte, NE issued this severe thunderstorm warning at Sep 1, 1999, 5:49 PM MDT for Sheridan County, Nebraska. It was in force for 56 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 1, 1999, 5:49 PM MDT (23:49 UTC)
- Expired
- Sep 1, 1999, 6:45 PM MDT
- In force
- 56 min
- Issued by
- NWS North Platte, NE
- Area
- Whole counties
County Sheridan County, NE
The radar
The North Platte radar (KLNX), 163 km from the middle of the area, began a volume at 23:49 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 1, 6:00 PM MDT | Hail 0.75 | Antioch, NE | |
| Sep 1, 6:35 PM MDT | Hail 0.88 | Ellsworth, NE |
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
Rapid City, SD (KUNR), launched 12:00Z, 11.8 hours before the alert went out and 178 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
- 0 J/kg
- Mixed-layer CIN
- No buoyant parcel
- Mixed-layer LCL
- 1658 m above ground
- 0-6 km bulk shear
- 39 kt
- 0-1 km storm-relative helicity
- 155 m²/s²
- 0-3 km storm-relative helicity
- 303 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 North Platte, NE wrote its last area forecast discussion before this severe thunderstorm warning went out at Sep 1, 11:43 AM MDT, 6 hours 6 minutes earlier.
Area forecast discussion, Sep 1, 11:43 AM MDT, 6 hours 6 minutes before
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NORTH PLATTE NE 1240 PM CDT WED 1999 ...FORECAST CHALLENGE CONTINUES TO BE POPS AND TEMPS... SCT MID-LVL INSTABILITY AND -SHRA OVER MUCH OF CWA FROM IML TO VTN AT 15Z. LOW CIRC CENTERED OVER LBF AT 15Z IN ASSOC WITH SFC TROF. SFC FRONT FM NR IML TO ANW. ETA SEEMS TO BE FAIRLY ON TRACK WITH PREVIOUS RUNS. NGM PRECIPITATION FIELDS LOOK OVERDONE (AS THEY DID YESTERDAY AS WELL...AND PROVED TO BE SO.) ALL MODELS (INCLUDING RUC AND MESOETA) HOLD PRECIPITATION BACK TO THE NORTHWEST OF LBF UNTIL TONIGHT. ETA VORTICITY REMAINS FAIRLY CHANNELIZED UNTIL THIS AFTERNOON...BUT SENDS VORT MAX AFTER VORT MAX THROUGH THE FLOW THRU PD. DELINIATION BETWEEN AREAS THAT GET WEATHER AND THOSE THAT DONT MAY BE SHARP DUE TO AMPLIFICATION...AND TIGHT GRADIENT ALOFT. WE ARE NEAR THE INFLECTION POINT...SO EASTERN ZONES WILL HAVE GREATEST AMOUNT OF UNCERTAINTY. SWODY1 INDICATES AREA WILL BE IN THE RRQ OF JET. MORNING SOUNDING PRECIPITABLE WATER LOOKS ABOUT AVERAGE FOR LBF AT .96 INCHES. CAP STRENGTH STRONG OVER LBF...BUT IS TO ERODE WITH FROPA. CONVECTION TO BEGIN ALONG FOOTHILLS AND SPREAD FROM WEST TO EAST SEEMS GENERAL CONSENSUS. WILL GO WITH HIGHER POPS (IF PCPN ISNT ALREADY GOING BY ZONE ISSUANCE TIME) FOR WESTERN ZONES. LOWEST POPS FOR ONL GROUPING THIS EVE/TNT. 2ND/3RD PERIOD...ROUND TWO OF CONVECTIVE WEATHER THURSDAY AFTERNOON. NEARLY STATIONARY FRONT SHIFTS SOMEWHAT NORTHEAST. ALMOST ENTIRE CWA IN DAY 2 SLIGHT RISK AS UPPER LEVEL TROF SHIFTS EAST. AM NOT GOING TO STRAY FAR FROM FWC GUIDANCE WHERE ABLE TO USE. MRF GUIDANCE LOOKS TOO COOL. WILL GO WITH 30 OR 40 POPS MOST AREAS AGAIN FOR THURSDAY. FRIDAY IS SORT OF A BIG QUESTION MARK WITH THE MRF RUNNING COLD. THINK ILL LEAVE POPS OUT FOR NOW EXCEPT FOR MAYBE MENTION IN NORTHWEST COUNTIES...WORDED LATE AFTERNOON. IN THE EXTENDED...MODELS CANT DECIDE IF THE TROF OVER THE WEST WILL CUT OFF AFTER SATURDAY OR NOT. MRF CUTS OFF THE LOW AND LIFTS IT NORTHEAST. ECMWF BRIEFLY CLOSES THE LOW FRIDAY BUT THEN OPENS IT UP AGAIN BY SATURDAY MORNING...GIVING IT A NEGATIVE TILT WHILE LIFTING IT NORTHEAST. PROBABLY THE SAFEST THING TO DO IS GO WITH CHANCES EACH DAY. EVEN IF THE MRF WERE TO VERIFY...I HAVE A HARD TIME BELIEVING THE 64 DEGREES FOR A HIGH SATURDAY AT LBF SINCE THE MRF ALSO HAS SFC RIDGING TAKING PLACE AT THAT TIME. FEEL HIGHS IN THE UPPER 70S TO MID 80S WILL LIKELY COVER IT...WITH LOWS IN THE 50S AND 60S. .LBF...NONE. SLM
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; verification from NCEI's Storm Data; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.