The figure above indicates the forecasted high in orange (with error bar denoting the range of ensemble forecast members), average high for this time of year in orange (dashed line), forecasted low in blue (with error bar), average low this time of year in blue (dashed line), and forecasted wind speed in purple. Note that the wind speed forecast is sustained wind (not gusts), and it is based on only one model (not an ensemble).
A unique weather pattern will set up this week, leading to the possibility for showers or thunderstorms Tuesday – Friday. The same trough that moved through Arizona and Utah last week has cut off from the jet stream to form a closed low pressure system. This system is currently located over Northwestern Mexico and is retrograding (i.e. moving from east to west). It will turn northwestward into southern California by Wednesday until it weakens and opens up in in response to a stronger trough moving onto the Northwest Coast later this week.
The low will direct moist subtropical air back into Arizona tonight – Friday from the south and east, for a possibility of showers and possibly thunderstorms each day Tues-Friday morning. Expect also some breezy conditions, especially today and tonight as pressure gradients strengthen on the north side of the low.
By this weekend, the flow aloft will shift to a more southwesterly direction and dry out the atmosphere once again, bringing temperatures back to near normal for this time of year and skies will become mostly clear. The weather should be nice for Octoberwest weekend at Embry-Riddle.
Met Mail is an unofficial weather discussion and forecast transmitted once or twice a week via e-mail by the Embry-Riddle Department of Meteorology (http://meteo.pr.erau.edu/). Embry-Riddle offers an undergraduate bachelor-of-science degree program in Applied Meteorology. Please spread the word to all potential qualified candidates!
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Official National Weather Service forecast