One of the wettest storms of a rain-soaked winter is headed the Valley’s way.
The storm should bring much rain late Thursday and Friday, even to northern Arizona where warm rains could erode snowpack.
The National Weather Service is predicting about 2 inches of rain for the East Valley, and up to 3 inches for mountains north and east of the Valley.
High temperatures in the Valley should be in the mid-60s with lows only in the 50s for the tropical storm.
"Many things appear to be coming together for this to be one of the wettest events of this already wet winter season," said National Weather Service meteorologist Bill Estle in his Tuesday morning forecast.
One of those factors is the Pineapple Express, a phenomenon describing storms that draw moisture from the Hawaiian islands region. These storms have the potential for heavy precipitation but less snowfall because of the warm air they draw on, said state climatologist Andrew Ellis.
Heavy rainfall means the weather service will likely issue small-stream flood advisories and possibly watches or warnings on Friday.
The Salt River Project anticipates runoff boosted by snowmelt from the warm storm, said spokesman Jeff Lane. SRP increased its release from Bartlett Dam from 1,200 cubic feet per second to 1,800 cfs on Tuesday to prepare. More small increases will probably be necessary later this week as the agency gauges the storm, Lane said.
Lane said SRP has released 480,000 acre feet of water into the Salt River so far this year — enough to cover an area the size of Mesa in 6 feet of water. An acre foot is the amount of water it takes to cover one acre in one foot of water.
And water is what most of the state will see with this upcoming storm: Snow should fall only in elevations above 8,500 feet at the beginning, with that level falling to 7,000 feet by the time the storm leaves late Saturday.
Though snowfall will only hit the highest country, that means Arizona Snowbowl, with elevations between 9,300 to 11,500 feet, will get some, said general manager J.R. Murray.
Murray said even warm storms can’t hurt a ski season he expects to last through the first week in April. Skiers should aim to arrive midweek, when slopes are less crowded, to enjoy the ample snow, he said.
"It just doesn’t get any better than what it is," Murray said.