Bryon C. Miller
National Weather Service Forecast Office
|2.||SYNOPTIC ENVIRONMENT AT 0000 UTC|
Figure 1. 0000 UTC Saturday 2 September 1995 NMC Surface Analysis. Note that the thunderstorms developed east of the stationary front.
Figure 2. 0000 UTC Saturday 2 September 1995 ETA model 500 hPa height and vorticity analysis using PC-GRIDDS. Heights indicated by the solid lines (dm), absolute vorticity (10-5S-1)-dashed, and shortwave trough axis - heavy dashed.
Figure 3. 0000 UTC Saturday 2 September 1995 ETA model Q-Vectors and divergence of Q (10-19m Pa-1m-2s-1) initialization. The Q-Vectors and divergence are a layer mean from the 850 hPa to 700 hPa levels. The area of strongest convergence was over south central and southwestern Nebraska.
Figure 4. 0000 UTC Saturday 2 September 1995 ETA model 6 hour forecast of the 312 K isentropic surface valid at 0600 UTC. Solid lines are pressure (hPa) and barbs are in kts. Note that the storm development occurred in the area between the 800 hPa and 750 hPa levels.
These parameters were obtained from the 0000 UTC September 2, 1995 rawinsonde observations from North Platte, NE and Valley, NE.
|CAPE (surface based)||2920 J/kg||88 J/kg|
|Tropopause||50,100 ft||42,800 ft|
|Precipitable Water||1.32 in||0.91 in|
|Wet Bulb Zero height||10,800 ft||9,700 ft|
|SREH (0-3 km)||317 (m/s)2||52 (m/s)|
|3.||MESOSCALE STORM ENVIRONMENT|
These parameters show indices derived from the proximity sounding near the thunderstorm development area.
|Parameter||Estimated Storm Environment sounding|
|CAPE (lifted from 800 hPa)||2343 J/kg|
|Precipitable Water||1.56 in|
|Wet Bulb Zero height||10,102 ft|
|SREH (0-3 km)||308 (m/s)2|
|4.||STORM CHARACTERISTICS AND DOPPLER RADAR OBSERVATIONS|
Figure 5. 0539 UTC 2 September 1995 Storm Relative Velocity Map (SRM) from the KOAX WSR-88D. Note that the circulation is displaced west of the main line of storms.
Figure 6. 0655 UTC 2 September 1995 Reflectivity Cross Section through the storm from the KOAX WSR-88D. Note the large area of greater than 65 dBZ that extended from 8,000 to 28,000 feet.
Figure 7. 0706 UTC September 1995 Vertically Integrated Liquid (VIL) from the KOAX WSR-88D. The area northwest of Lincoln, NE (LNK) has five pixels of 70 dBZ or greater.
This is a chronological summary of storm reports received in the Omaha county warning area on 2 September 1995.
|Storm Reports from 2 September 1995 in the NWSFO Omaha CWA|
|3N Ulysses||0530 UTC||Hail 1.00||Unknown|
|Garland||0650 UTC||Hail 2.75||$100,000|
|3N Malcolm||0657 UTC||Hail 1.75||Unknown|
|Malcolm||0700 UTC||Hail 2.00||$20,000|
|6W Lincoln||0715 UTC||Hail 4.50||$20,000|
|Lincoln||0717 UTC||Hail 1.00||Unknown|
|5.||SUMMARY AND CONCLUSIONS|
The author would like to thank Steve Byrd, Science and Operations Officer at NWSFO Omaha/Valley and Ed Berry, CRH SSD for their careful review of and input to this paper.
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