New Tools for Forecasters: Real-Time Cross Sections Produced in the Field

Abstract

Objective analyses on vertical cross sections are presented as examples of the type of real-time product available on the Penn State, Department of Meteorology, on-line minicom-puter. The analyses are not new, but their real-time availability is. Our experience has been that such products improve forecaster diagnosis and understanding and suggest that the "man-machine mix" concept, extended to other types of analyses and diagnoses, may be as appropriate to small machines as to large ones.

A Scheme for Short-Term Prediction of Hydrometeors Using Advection and Physical Forcing.

“…These schemes are interactive, and their successful implementation requires a man-machine mix. We have developed these schemes on the Penn State minicomputer system (Cahir et al, 1976;, although they could also work on the AFGL interactive system (Chisolm and Jackson, 1984 For example, the regression equations for short-term count change prediction implicitly include the effects of translation because certain LFM forecast quantities, such as 6-hour relative humidity change, account for system movement. The ACTIVEX Scheme for nocturnal thunderstorm forecasting incorporates system movement in two ways: (1) by using trajectories which, in combination with the diurnally-changing latent instability, may allow convective regions to move; (2) by requiring the forecaster to interactively enter a phase speed which accounts for movement of the low-level jet or front which would cause the zone of anabatic flow to translate.…”

focus on forecasting

“…With mesoscale numerical models still in the development stage, forecasters are required to diagnose and forecast mesoscale and subsynoptic weather patterns in gaps of time between the observations and the availability of National Meteorological Center (NMC) Limited Area Fine Mesh (LFM) 12 h forecasts. Recently several real-time interactive minicomputer systems have been developed (Klein, 1976;Cahir et al, 1976Cahir et al, , 1978Thormeyer, 1978) possessing the flexibility and data access capability to observe the weather-producing mesoscale, to aid the forecaster in diagnosing often complex situations, and to implement forecast techniques for short-range forecast guidance.…”