A large upper trough off the West Coast will direct a series of shortwave troughs from the west or northwest across Arizona during the next week. The first upper air trough will move into the Western U.S. tomorrow, along with a large surface low pressure system moving into the West. The low will direct a jet of moist, relatively warm air across the terrain of northern and central Arizona on Wednesday night through Friday, producing lifting and the potential for anywhere from 0.5” to 1.5” of rain. There may be some isolated snow showers at the onset of the event Wednesday evening, but the temperatures will rise into Thursday and Friday, with snow levels topping out above 9,000’. No snow accumulation expected, as this first system will be too warm.
Another weak shortwave will move across the state on Saturday, but at this time it appears that most of the precipitation on Saturday will remain to the north of Prescott.
After Saturday, there is considerable uncertainty in the forecasts, though it appears that the main axis of the trough will shift across Arizona on Sunday afternoon to Tuesday. The cold core of the upper trough moving across the Southwest will allow the snow levels to drop back down below 5,000’ by Monday with the potential for accumulating snow. The timing and amount of possible snow on Sunday – Tuesday remains questionable, but the potential is there.
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