Afternoon clearing on the backside of an upper disturbance led to rapid destabilization of the atmosphere across south-central AZ and the development of strong slow-moving storms. A few storms became severe and produced up to one inch diameter hail. The slow storm motion also allowed for minor flooding and accumulating smaller hail, enough to cover some major roadways around the metro. Additionally, multiple reports and photos were received of funnel clouds with a few of the stronger storms.

Hail in MARICOPA, ARIZONA
From 09-DEC-19 15:35:00 to 09-DEC-19 15:35:00 (MST-7)
Location: PHOENIX DEER VLY ARP
Magnitude: 0.88 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

A strong storm produced up to nickel-sized hail and accumulating hail near Loop-101 and 51st street in northwest Phoenix. No injuries or damage was reported.

Hail in MARICOPA, ARIZONA
From 09-DEC-19 14:54:00 to 09-DEC-19 14:54:00 (MST-7)
Location: VELDA ROSE ESTATES
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

A couple trained spotters reported quarter-sized hail fell from a strong thunderstorm near McDowell Rd and Lindsey Rd in northeast Mesa. Accumulating hail was also reported in the area. A severe thunderstorm warning was in effect at the time. No injuries or damage was reported.

Hail in MARICOPA, ARIZONA
From 09-DEC-19 14:40:00 to 09-DEC-19 14:40:00 (MST-7)
Location: APACHE WELLS
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Public mPing report of quarter-sized hail near Las Sendas Golf Club in northeast Mesa. A severe thunderstorm warning was in effect at the time. No injuries or damage were reported.

Hail in MARICOPA, ARIZONA
From 09-DEC-19 15:57:00 to 09-DEC-19 15:57:00 (MST-7)
Location: HIGHTOWN
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

A strong storm produced hail up to 1-inch in diameter near Loop-101 and Warner Rd in Chandler. Accumulating hail was also reported in this area. A severe thunderstorm warning was in effect at the time. No injuries or damage were reported.

Funnel Cloud in MARICOPA, ARIZONA
From 09-DEC-19 15:31:00 to 09-DEC-19 15:31:00 (MST-7)
Location: HELENA
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Multiple public and trained spotter reports, with photos and videos, confirmed a brief funnel cloud developed over Chandler and south Tempe near Loop-101. The funnel extended at most a quarter of the way down from the cloud base to the ground.

Funnel Cloud in PINAL, ARIZONA
From 09-DEC-19 16:26:00 to 09-DEC-19 16:26:00 (MST-7)
Location: CASA BLANCA
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

A funnel cloud developed over northwest Pinal county west of SR-347. The funnel was confirmed via multiple social media photos observing the funnel from near SR-347 and Riggs Rd in Maricopa county. The funnel was reported to have reached about three quarters of the way to the ground.

Hail in MARICOPA, ARIZONA
From 09-DEC-19 14:15:00 to 09-DEC-19 14:15:00 (MST-7)
Location: PHOENIX DEER VLY ARP
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

A strong storm produced quarter-sized hail near the Loop-101 and SR-51 highway interchange in north Phoenix. A severe thunderstorm warning was in effect at the time. This storm also produced accumulating smaller hail and was enough to cover much of the highway interchange. This was observed on multiple ADOT webcams and led to major traffic delays. No injuries or damage were reported.

Funnel Cloud in MARICOPA, ARIZONA
From 09-DEC-19 15:00:00 to 09-DEC-19 15:00:00 (MST-7)
Location: PARADISE VLY
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

A funnel cloud observed over central Phoenix and Paradise Valley generated a lot of attention on social media and the news with many photos and video. The funnel was even observed from the Phoenix Sky Harbor airport and reported in the remarks of the KPHX METAR. The funnel extended roughly half way down from the cloud base to the ground.