Why isn't moist "upper-level" south or south-southwest flow favorable for convective precipitation at Cheyenne, Wyoming?

Details

• Personal Author:
  Weiland, Michael S. ; Berry, Edward K.
• Corporate Authors:
  United States. National Weather Service. Central Region
• NOAA Program & Office:
  NWS (National Weather Service) ; CR (Central Region)
• Description:
  Most forecasters at WSPO Cheyenne, Wyoming are familiar with the situation of middle and upper tropospheric flow from the south or south-southwest. Given there is adequate moisture, lifting, etc., the flow results in minimal convective precipitation at Cheyenne. All things considered, most other parts of the U.S. usually receive substantial rainfall with these events, especially the Plains Station records at the WSPO and other climatological information indicate that what happens (especially when daytime heating is a factor) is north to south banded moist convection occurs generally east and west of the city. One quasi-stationary line of showers and thunderstorms occurs over the Laramie Range west of the city, with another line across the Plains to the east. The frustrating result is that Cheyenne may get no rainfall. The purpose of this paper is to only acquaint the reader with the "mesoscale" dynamics of this situation. The authors hope to stimulate research and modeling efforts to quantifiably explain this unique meteorological problem. The case of September 20, 1989 will be discussed.
• Series:
  Central Region Technical attachment ; 90-1
• Document Type:
  Technical Attachment
• Place as Subject:
  Cheyenne (Wyo.)
• Rights Information:
  Public domain
• Compliance:
  Library
• Download URL:
  https://repository.library.noaa.gov/view/noaa/33825/noaa_33825_DS1.pdf
• File Type:
  [PDF - 5.41 MB]
• Collection(s):
  National Weather Service (NWS)
• Main Document Checksum:
  urn:sha256:4fa021ebec0304e0a39c98a69df8b21f3f92248c789ac404dcf48b51020325ce