Monsoon conditions in the US Southwest are in full effect. Several large haboobs, accompanied by hurricane-force wind gusts, hail and heavy rain, have already been recorded sweeping through Arizona on July 8, 9 and 10, 2018. Several rainfall records were broken, leading to localized flash flooding. NWS warns that coverage of showers and thunderstorms will increase across the Southwest through the end of the week.
Winds in and around Phoenix gusted over 112 km/h (70 mph) on Monday, July 9, downing power lives and bringing traffic to a standstill while heavy rain flooded streets. More than 94 000 customers were left without power as of 20:30 local time, July 9.
Monday's rain in Phoenix officially ended its streak of 118 days without rain recorded at Sky Harbor Airport where the city's official records are tallied. The last rain there was officially recorded on March 11.
This tied for the sixth-longest dry streak in Phoenix, tying the one recorded in 1904.
The airport received 12.2 mm (0.48 of an inch) as of early Monday evening, July 9, breaking the previous record of 11.2 mm (0.44") in 1996. By the end of the day, Phoenix recorded 14.2 mm (0.56").
On the same day, Las Vegas recorded 14.5 mm (0.57"), breaking the old record of 2.28 mm (0.09") set in 1953, while Tucson recorded 25.6 mm (1.01"), breaking its previous record of 18.8 mm (0.74") set in 1932.
Heavy rain from a monsoon storm has caused a train derailment in Marana, southern Arizona on July 10. Northwest Fire District officials say about 20 cars went off the rails as a strong storm was going through the Marana area near Interstate 10.
They say there's no indication any hazardous material spilled from the derailment, but debris is scattered across train tracks and a frontage road.
Update video to train derailment. Follow this feed for updates pic.twitter.com/uZa3wgisQC— Northwest Fire (@NorthwestFire) July 10, 2018
Coverage of showers and thunderstorms will increase across the Southwest through the end of the week as monsoonal moisture surges north, NWS meteorologist Campbell noted today, adding that heavy rainfall along the terrain could lead to flash flooding in addition to flood-prone areas.
By Thursday, heavy rainfall will continue in the Southwest but also begin to spread into the southern and central Rockies. There is a slight risk of flash flooding in the Southwest today with the slight risk shifting eastward by Thursday along the Rockies.
Meteorologists also warned that rain on the burn scars from recent fires could cause debris falls.
While flash flooding is possible and residents should exercise caution, the rain will be beneficial for the drought-stricken region.
Featured image credit: StormChasingVideos