Climate Commons^™

Improving Projected Potential Evapotranspiration Estimates Using National Weather Service Forecasts, Steven J. Meyer, Kenneth G. Hubbard, Donald A. Wilhite

National Drought Mitigation Center: Faculty Publications

In a recent survey conducted by the University of Nebraska's Center for Agricultural Meteorology and Climatology of Agricultural Network (AGNET) users, the results of potential evapotranspiration (ET_p) projections (calculated using the Blaney-Criddle approach, which employs "normal" climatic data to project ET_p estimates up to three days into the future) were labeled "unrealistic." To improve these projections, National Weather Service (NWS) forecast variables were used as input into the Blaney-Criddle and Penman equations. ET_p projections calculated according to the Penman equation, with data measured by automated weather stations as input, were assumed to represent the "best" …

The Nebraska Agricultural Climate Situation Committee, R. E. Neild, K. G. Hubbard, Donald A. Wilhite

National Drought Mitigation Center: Faculty Publications

The Nebraska Agricultural Climate Situation Committee consisting of an interdisciplinary group of extension specialists provides up-to-date information and advice on seasonal changes in crop/ weather conditions. The committee meets each Monday during the growing season to review:

1. Maps and tabular data developed by a computer program CIS /Crop Weather Information System/ that is linked to a network of weather stations and computer terminals in county agent offices.

2. Insect, plant disease and weed surveys.

3. Weekly weather and crop reports from the State/Federal System.

4. Weather outlooks from the National Weather Service.

5. Climate probabilities.

Situation reports and advisories …

J. P. Finley: The First Severe Storms Forecaster, Joseph G. Galway

National Oceanographic and Atmospheric Administration: Technical Reports and Related Materials

During the 19th century, while others were debating about the theory and morphology of tornadoes, Finley set out to prove that tornadoes, like other weather phenomena, could be forecast. He developed forecast rules and made experimental forecasts. His forecasting and analysis activities made him the center of controversy during most of his professional life and led to open debate in the literature, but he set precedents in meteorological forecasting that are still valid today. His career as a meteorologist started while he was a private in the United States Army. His interest continued even when he had achieved the rank …

Government Response To Drought In The United States: With Particular Reference To The Great Plains, Donald A. Wilhite

National Drought Mitigation Center: Faculty Publications

Drought relief has become an expected response of the federal government to periods of widespread drought in the United States. A wide range of emergency, short-term and long-term drought programs were formulated to deal with the extreme drought of the 1930's. By 1977 there were 40 separate programs administered by 16 different federal agencies. This paper traces the development of federal drought relief bureaucracy, including drought designation criteria and procedures.

Two obvious deficiencies of past drought relief efforts in the United States are noted. First, drought relief organizations and programs have been hastily assembled during periods of crisis. This has …

Changing Fields: Agricultural Land Use Changes In Nebraska 1925-1974, Donald A. Wilhite

National Drought Mitigation Center: Faculty Publications

The series of graphs and maps which follow illustrate agricultural land use changes in Nebraska from 1925 to 1974. With these graphs and maps, the major agronomic crops of corn (dryland and irrigated), wheat, sorghum and soybeans are analyzed. The purpose of this analysis is to provide a pictorial history of Nebraska's ever-changing cropping system and, hopefully, to stimulate ideas and discussion with regard to trends and future directions. The Nebraska Water Resources Center is deeply interested in both the past and the future of Nebraska's agriculture because of the demands which agriculture places on the state's water resources. An …

Turbulence Spectra Above A Vegetated Surface Under Conditions Of Sensible Heat Advection, Raymond P. Motha, Shashi B. Verma, Norman J. Rosenberg

National Drought Mitigation Center: Faculty Publications

Spectra of vertical and horizontal velocity, air temperature and humidity fluctuations were analyzed from measurements made over a well-watered alfalfa crop under conditions of sensible heat advection. Vertical velocity and air temperature spectra as well as cospectra of momentum, sensible heat and water vapor were found to be dependent on atmospheric thermal stratification. These spectra and cospectra were shifted toward higher frequencies under advective as compared to lapse conditions. These results indicate that the predominant eddy sizes are relatively smaller under advective conditions. Humidity spectra, on the other hand, were independent of daytime thermal stratification conditions but were influenced by …

Extreme Evapotranspiration By Irrigated Alfalfa: A Consequence Of The 1976 Midwestern Drought, Norman J. Rosenberg, Shashi B. Verma

National Drought Mitigation Center: Faculty Publications

The rate of evapotranspiration by irrigated alfalfa at Mead, NE (41°09'Nj 96°30'W, elevation 354 m) reached record levels in 1976. Evapotranspiration was measured with precision weighing lysimeters in a field 1.9 ha in size. Evapotranspiration ranged during the growing season from 4.75 to 14.22 mm day^-l and exceeded 10 mm day^-I on one-third of the days studied. On each day of study the ratio of latent heat flux density (LE) to the sum of the net radiation and soil heat flux densities (Rn+S) was such that LE/ (Rn+S) > 1, indicating the occurrence of significant …

Solar Energy And Sunshine In Nebraska, Norman J. Rosenberg

Nebraska Agricultural Experiment Station: Historical Research Bulletins

Weather Bureau records of measured solar radiation useful in interpreting the solar energy regime in Nebraska are available from Lincoln-Omaha, Nebraska; Dodge City, Kansas; Laramie, Wyoming and Rapid City, South Dakota. Pertinent records of sunshine duration (percent of possible sunshine) are available from Lincoln, Omaha, North Platte and Valentine, Nebraska; from Concordia and Dodge City, Kansas; from Cheyenne, Wyoming; from Rapid City and Huron, South Dakota and from Sioux City, Iowa. These records have been subjected to statistical summarization and analysis.

Thunderstorms And Tornadoes Of February 1, 1955, Jean T. Lee

National Oceanographic and Atmospheric Administration: Technical Reports and Related Materials

The purpose of this paper is to describe and illustrate some of the features that are of particular interest in the forecasting of one of the most death-dealing series of convective storms of the 1950s that occurred during the afternoon and evening of February 1, 1955. This series of severe storms included tornadoes, destructive winds, hail, and heavy rain that first struck near Marianata, Arkansas, then roared through Commerce Landing, Mississippi and northern Mississippi. then moved on to near Huntsville, Alabama.

Includes features at the surface, at 850 mb, 700 mb, and 500 mb, and upper air conditions, along with …