As a low-pressure system moves through the region, rain may finally arrive in the Valley, potentially ending the 157-day dry spell.
A slow-moving low-pressure system is expected to bring below-average winter temperatures and precipitation across Arizona starting Monday.
“It’s going to be widespread rain. Not everyone in the Valley will see it,” said Matt Salerno, chief meteorologist at the National Weather Service office in Phoenix. “However, there is still a chance for measurable rain that could break Sky Harbor’s dry spell.”
The dry spell, which lasted 157 days as of Sunday afternoon, was the second longest on record in Phoenix. The longest dry day of 160 days was in 1972.
To beat the drought, the weather station at Phoenix Sky Harbor International Airport would need to record at least 0.01 inch of rain. If there is no measurable rain in Phoenix by Thursday, a new record will be set for 161 consecutive days of rain.
Monday’s chance of precipitation is between 40 and 50 percent, starting around 9 a.m., peaking around 1 p.m., and ending by the evening commute. Tuesday and Wednesday also have a chance of showers, with afternoon and evening chances ranging from 50 to 60% Tuesday and 60% Wednesday.
“This is a low-pressure trough. It’s a slow-moving system known as a cutoff low,” Salerno said. “It is separated from the mainstream jet stream, which will slow its progress considerably across Arizona. Multiple periods of rain and snow are possible into Wednesday.”
Rain and snow are more likely in Flagstaff and the highlands. Flagstaff is expected to see 3 to 6 inches of snow on Monday, with more snow expected Tuesday and Wednesday.
“We’re forecasting more snow on Monday night alone than we’ve had all winter so far,” said meteorologist Justin Jondrou of the National Weather Service office in Flagstaff.
This is one of the driest winters on record for Flagstaff, with only 2.8 inches of snow since October 1st.
The low pressure system is expected to bring winter temperatures below normal across the region. High temperatures in Phoenix will be in the low 60s to low 50s through midweek, with temperatures increasing as we move away from the region towards the end of the week.
Clouds and moisture will cool the valley, but the city of Salerno doesn’t expect any freeze warnings or major power outages this week.
“We want to emphasize that this is not going to be a high-impact storm system,” Salerno added. “The weather will move slowly as the rain comes on and off. Overall, precipitation is expected to be likely up to 0.1 to 0.2 inches Monday through Wednesday.”
Hayley Evans writes about extreme weather for The Arizona Republic and related topics. azcentral.com. Email her your story tips. hayleigh.evans@arizonarepublic.com.
