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).
With high pressure to our north, the wind in the middle atmosphere will be from the east much of this week, with southwesterly wind in the upper levels and at the surface. This wind shear profile will create lines of afternoon or evening thunderstorms propagating into the Prescott area from the northeast each day through Wednesday. Expect some storms to become strong and capable of heavy rain, hail up to 1” diameter, and frequent lightning.
On Wednesday and Thursday, we may see slightly drier and warmer conditions as the high pressure shifts a bit more to the west and the wind becomes more northeasterly and descends over Arizona a bit. The probability for thunderstorms will be less on Wed-Thurs, but will increase over the weekend as the monsoon circulation becomes more favorable once again.
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!
ERAU Applied Meteorology degree program
Official National Weather Service forecast