A weakening but still potent upper level low pressure system continued to push east across Arizona during the day on March 13th, and the atmosphere across the central deserts was still very humid and a bit unstable. As the system moved across the greater Phoenix area, scattered afternoon thunderstorms developed over the greater Phoenix area. Some of the thunderstorms generated very heavy rains; a trained spotter near the town of Surprise measured 0.7 inches of rain within a 10 minute period. The heavy rain resulted in episodes of street flooding as well as flash flooding. At about 1700MST flash flooding on Cave Creek near 7th Avenue and Greenway Road. Water 6 inches deep was flowing across 7th Avenue as reported by the public. Heavy rain 3 miles south of Deer Valley caused flash flooding at the Interstate 17 and Greenway underpass to flood. Water 1 to 2 feet deep filled up the underpass resulting in at least one stalled car. A Flash Flood Warning was issued and in effect at the time of the underpass flooding. There were no reports of injuries due to the flooding.

Flash Flood in MARICOPA, ARIZONA
From 13-MAR-20 15:30:00 to 13-MAR-20 21:00:00 (MST-7)
Location: PALO VERDE
Flood cause: Heavy Rain
Property damage: 30.00K
Crop damage: 0.00K
Reported by: Broadcast Media

Scattered showers and thunderstorms, some with heavy rain, occurred during the afternoon hours across the deserts to the west of Phoenix on March 13th. The heavy rain caused washes, streams and rivers to flow very heavily, posing significant danger to motorists. According to local broadcast media, at 1930MST a motorist became trapped in his vehicle at Baseline Road and 319th Avenue due to the Hassayampa River flowing swiftly across the road. The Hassayampa was swollen and flowing heavily due to the earlier heavy rain in the area. About 20 minutes later, a water rescue was needed for the motorist; the rescue occurred to the west of the town of Buckeye. There were no reports of injuries to either the motorists or the rescuers. There was no flash flood warning in effect at the time of the water rescue.

Flash Flood in MARICOPA, ARIZONA
From 13-MAR-20 15:30:00 to 13-MAR-20 18:30:00 (MST-7)
Location: PHOENIX TURF ARPT
Flood cause: Heavy Rain
Property damage: 20.00K
Crop damage: 0.00K
Reported by: Broadcast Media

Scattered thunderstorms developed across the northern portion of the greater Phoenix metropolitan area during the afternoon hours on March 13th. Some of the stronger storms produced intense rain with peak rain rates well in excess of one inch per hour. The heavy rain resulted in some flash flooding which affected the Interstate 17 corridor to the south of the community of Deer Valley. According to a report from local broadcast media, flash flooding along the Interstate resulted in the flooding of the Greenway Road underpass; one to two feet of water filled up the underpass leading to at least one stalled vehicle. A Flash Flood Warning was issued for the area at 1530MST and it was in effect at the time of the flooding. There were no reports of any injuries fortunately.

Heavy Rain in MARICOPA, ARIZONA
From 13-MAR-20 12:00:00 to 13-MAR-20 15:00:00 (MST-7)
Location: ENNIS
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Scattered showers and thunderstorms, some with intense rain, developed across western portions of the greater Phoenix metropolitan area during the early afternoon hours on March 13th. Some of the heavy rain occurred in communities such as Surprise and Sun City West. According to a trained weather spotter located in Sun City West, or about 1 mile southeast of Surprise, at 1235MST 0.70 inches of rain fell within a ten minute period near the intersection of Bell Road and North R H Johnson Boulevard. The heavy rain resulted in some street flooding in the area.

Heavy Rain in MARICOPA, ARIZONA
From 13-MAR-20 12:30:00 to 13-MAR-20 15:00:00 (MST-7)
Location: BEARDSLEY
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Scattered showers and thunderstorms, some with intense rainfall, developed across the northwest portion of the greater Phoenix area during the early afternoon hours on March 13th. The heavy rain affected communities such as Sun City West and Surprise, and resulted in some local street flooding. According to a trained weather spotter located about 1 mile northwest of the town of Surprise, at 1300MST heavy rain resulted in curb to curb flooding in Sun City West along R H Johnson Boulevard. A local storm runoff canal was running with water almost 2 feet deep at the time.

Heavy Rain in MARICOPA, ARIZONA
From 13-MAR-20 14:00:00 to 13-MAR-20 17:00:00 (MST-7)
Location: GLENDALE
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Scattered showers and thunderstorms, some with intense rainfall, developed across the western and central portions of the greater Phoenix area during the afternoon hours on March 13th. Some of the stronger storms occurred around the community of Glendale and resulted in episodes of flooding, including street flooding. According to a trained weather spotter located 2 miles to the southeast of Glendale, heavy rain caused street flooding along Grand Avenue between 43rd Avenue and 51st Avenue. The flooding was reported at 1528MST. The water depth in the curb lane was approaching the top of the curb. A few minutes after the report, a Flash Flood Warning was issued for much of the central and northern portion of the greater Phoenix area.

Flash Flood in MARICOPA, ARIZONA
From 13-MAR-20 15:30:00 to 13-MAR-20 18:30:00 (MST-7)
Location: PHOENIX TURF ARPT
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Afternoon thunderstorms developed across the northern portions of the greater Phoenix metropolitan area on March 13th and some of the stronger storms generated very heavy rain with peak rain rates well in excess of one inch per hour. The heavy rain led to an episode of flash flooding about 3 miles to the southeast of Deer Valley, between Bell Road and Thunderbird Road. At roughly 1650MST, the public reported flash flooding on the east fork of Cave Creek near 7th Avenue and Greenway Road. Water was seen flowing 6 inches deep across 7th Avenue. A Flash Flood Warning had been issued for the area at 1530MST. No reports of accidents or injuries were received  due to the flash flooding.

Flash Flood in MARICOPA, ARIZONA
From 13-MAR-20 15:00:00 to 13-MAR-20 18:30:00 (MST-7)
Location: VALENCIA
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

An exiting but still potent upper level disturbance acted upon a still wet and unstable air mass to produce scattered afternoon thunderstorms across portions of the greater Phoenix metropolitan area on March 13th. Some of the stronger storms generated locally heavy rain with peak rain rates well in excess of one inch per hour. Portions of the heavy rain fell in the community of Buckeye resulting in an episode of flash flooding. According to a trained weather spotter located about 3 miles north of the town of Buckeye, at 1605MST flash flooding resulted in flowing water 6 inches deep covering a 20 foot wide swath across Miller Road, just south of lower Buckeye Road. Despite the quickly flowing water there were no reports of any accidents due to the flash flooding.