The intention is to periodically (time permitting) post details related to the coming evening's weather prospects for astronomical observing.
For a starter, here's a quick look at prospects for Wednesday July 10, 2013 (more than 24 hours away).
A quick look at a surface forecast chart shows a high pressure ridge building over the Great Lakes region, fiollowing passage of a cold front across southern Ontario:
This generally means winds from the NW bringing cooler, less humid air, and often clearing skies. Here is a chart showing humidity through a large column of the atmosphere:
At a glance, it shows a significant patch of humidity remaining over southern Ontario at 00 UTC (20:00 EDT Wednesday evening). The presence of an upper level trough (in the image below for the 500 hPa pattern) often means that there will be significant upward motion that may cause the humidity to exist as clouds. Many more details need to be considered to give some confidence to predicting cloudy or clear skies, but just at a glance, it may be reasonable to expect some scattered clouds in an otherwise clearing sky.
No comments:
Post a Comment