A brief period of severe thunderstorm winds and flooding occurred over the Marianas.

Thunderstorm Wind in GUAM, GUAM
From 23-NOV-20 10:00:00 to 23-NOV-20 22:00:00 (GST10)
Location: ANDERSEN AFB
Magnitude: 49.00 MG
Property damage: 100.00K
Reported by: Official NWS Observations

Morning scatterometer data depicted a surface trough just to the east of the Marianas. Upper-level analysis also showed an upper low and trough just to the west of the islands.
The combination of the two casued an area of scattered to numerous showers and
isolated thunderstorms to develop on the trough east of the islands. The scatterometer data did depict higher winds associated with the trough near Tinian and Saipan. By 449 local time winds gusted to 29 knots (33 mph) at the Saipan airport. Gusty winds in the upper 20 to mid 30 knot range persisted across Saipan until 1000 local time with a gust to 36 knots (41mph) at 955.
Further south the thunderstorms along the trough collapsed and produced a outflow
boundary. This boundary headed west towards Guam. While winds were also gusty across Guam just before noon, the outflow boundary produced strong wind gusts at a few locations over the island. Andersen AFB saw a wind gust to 44 knots (51mph) at 154 local time and at the National Weather Service Office the highest wind gust was 49 knots (56 mph) a 1202.
The winds caused some damage to trees on Guam. Power outages did occur in a areas over Guam and was reported in Yigo, Dededo, and Yona.

Flash Flood in GUAM, GUAM
From 23-NOV-20 11:00:00 to 23-NOV-20 22:00:00 (GST10)
Location: UMATAC
Flood cause: Heavy Rain
Property damage: 25.00K
Crop damage: 10.00K
Reported by: Official NWS Observations

As an outflow boundary generated from collapsing thunderstorms east of Guam passed over the island low-level convergence produced an area of brief heavy showers and thunderstorms, mainly over the southwest section of the island.
Rainfall varied over much of the island with 24 hour amounts at the National Weather
Service Office (Central Guam) totaling to 1.08 inches. Andersen AFB saw 2.23 inches
for the day. A USGS rain gage over the southwest section of the island (Alamagosa
Rain Gage near Santa Rita) recored 3.16 inches between 1145 and 1530. Another USGS Gage (Umatic) saw 2.40 inches between 1215 and 1500. A rain gage owned by a private individual (Casa Davis - ISANTA194) just south of Agat recorded 7.90 inches between 1124 and 1359 Guam time. This would equate to 3.06 inches per hour. The accuracy of the gage is uncertain, but it certainly indicates that rainfall was heavy for a short period of time.
USGS stream gages saw a rapid rise of a few streams over the southern section of Guam.  A stream gage on the Ugum River above Talofofo Falls, rose from a stream height of 1.24 feet at 1150 to 9.98 feet at 1350 which is a 8.74 foot change. A USGS gage on the Imong River near Agat rose from a height of 9.42 feet at 1150 to 17.57 feet at 1305 which is an 8.15 foot change and a gage on the La Sa Fua River
near Umatac rose from a height of 10.8 feet at 1150 to 17.16 feet at 1305L a 6.36 foot change.
Flooding was observed in Umatic as the river in the village rose quickly. There was a report of a cow being washed out to sea (althogh video of the event seemed to show that the animal may have been a horse). The animal did die from the ordeal.
USGS Rain gage reading
Umatic 						                1215 to 1500	2.40 inches
Almagosa Rain Gage nr Santa Rita, Guam 		1145 to 1530 	3.16 inches
Fena RG at Res. Pump Station, 			        1200 to 1500	0.97 inches
Windward Hills Rain Gage near Talofofo, Guam 	1145 to 1515 	0.41 inches
Mount Chachao Rain Gage near Piti, Guam 	        1145 to 1515 	1.46 inches
Dededo Rain Gage at Dededo, Guam 		        1030 to 1445	1.45 inches
Mt. Santa Rosa Rain Gage, Guam			1100 to 1500	1.39 inches
Geomag Observatory Rain Gage, Andersen AFB,Guam 1015 to 1530 	1.67 inches
WUnderground  Rain gage reading for the day
Cantrellhaus - IYIGO6  			        2.37 inches wind gust to 36.5 mph at 1334
Pacific Amusement Guam - KBARRIGA2  	1.36 inches wind gust to 30.0 mph at 1500
Perezville - KGUTAMUN1 			        1.06 inches wind gust to 39.0 mph at 1200
Maite - KGUMAITE2  			                0.93 inches wind gust to 36.0 mph at 1209
Ordot Closure Facility - IHAGTA2   	        0.26 inches wind gust to 28.0 mph at 1500
Casa Davis - ISANTA194 (south of Agat)      7.95 inches wind gust to 27.3 mph at 1309
Apra Heights - ISANTARI8 		                1.27 inches wind gust to 40.0 mph at 1244.