Coupled Jet-Front Circulation Systems

This online reference on the topic of jets and fronts is meant to be used by advanced undergraduate meteorology students and operational weather forecasters. The objective is to provide a conceptual basis for helping to properly interpret numerical weather prediction forecast fields and satellite and radar imagery, in order to improve forecasts of the timing, intensity, and duration of frontal precipitation events.

The material herein consists of the relevant fundamental dynamics, conceptual models, and applications of these principles to real cases using a combination of mesoscale numerical weather prediction model fields and satellite and radar imagery. The basic premise used throughout the theoretical discussion is that the vertical circulations are the primary factor in explaining the cloud and precipitation distributions. Of course, other factors including the distribution and depth of moisture, instability fields, and terrain should also be considered in making an appropriate weather forecast.

This web page is broken into three main sections:

1. Basic principles of how vertical circulation systems arise in association with upper-level jet streaks and in association with low-level fronts.

2. The 2 November 1996 case: An application of the coupled upper-level straight jet/low-level jet/anafront model to an actual case.

3. The 8 November 1996 case: An application of the coupled upper-level curved jet/low-level jet/anafront model to an actual case.