WMOD00263 ‎(2)‎

• Applicant: CWCB
• Sponsor Name: USBR
• Project Name: Response to RFP
• Title: Numerical Simulations of Snowpack Augmentation for Drought Mitigation Studies in the Colorado Rocky Mountains
• Prepared For: USBR
• Prepared By: Joe Busto, CWCB
• Date: 8/20/2003
• Weather Modification - Doc Type: Application

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More recent cases in which ETA upper air and surface analysis data plus ETA soil
moisture data provide the best agreement with observations.

. Even in cases where the maximum simulated precipitation amounts are in close
agreement with observations, the actual scenario of convective evolution is often
different from that observed. In other words, owing to the inability of upper air,
and surface data, as well as land-surface parameters (especially soil moisture) to
represent completely the real world, the model climatology differs from actual
climatology. These data are more poorly observed in the older convective cases so
that the model climatology of those events varies more from the observed storm
behavior, than in the more recent storms.

. Sensitivity tests reveal that simulations of heavy convective events are highly
sensitive to the specification of initial soil moisture fields.

. Precipitation maxima occurring at higher elevations have significant contributions
from hail, which reduces surface runoff rates due to prolonged melting.

The PMP estimates that we have made should be viewed as a demonstration of concept
only. The data used for our estimates are too limited to provide useful quantitative PMP
estimates. We had to limit our analysis to recent storms because we found that the NCEP
reanalysis data were inadequate for the purpose of extreme precipitation simulations.
Higher resolution ETA-based reanalysis data may overcome this deficiency and permit
more reliable PMP estimates in the future.

3) Contact person for this project would be:

Mr. Jack Byers, Asst. State Engineer
Dept. of Natural Resources
Division of Water Resources
1313 Sherman Street, Rm. 818
Denver, CO 80203
[phone]

8.2 CWCB and WWC

Please see Section 6.2 on page 25 in this Technical Proposal.

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