Torrential Rains/Flooding/Wet Microburst

Thunderstorms developed across the Triangle area this afternoon around 3pm. This activity basically sat over the same area for over an hour dumping heavy rains over areas near I-540 and RDU. Then it appeared that outflow boundaries and a shortwave trough ( disturbance in the atmosphere) swept across the south central portions of NC enhancing thunderstorm activity. The showers/storms over NW Wake county intensified into a possible severe thunderstorm that dumped upwards of 3-4 inches of rain in some areas. Hail was also reported in the 4:51 observation at RDU. The storms appeared to have trouble moving south into the area where I live but just up the road near Buck Jones Road and Nottingham drive in Cary near 1.50 to 2 inches of rain fell from 5-7pm. At around 6:15 a wet microburst occurred. The rain was so heavy that you could not see in front of you and the winds were howling blowing the rain sideways. Luckily the winds were not strong enough to knock trees down but I would guess we had 35-45 mph gusts for about a 2 minute period with the incredible rain. The rest of the time was characterized by heavy downpours and some occasional intense cloud-to-ground lightning. Below is the storm total product from the National Weather Service Doppler Radar. It clearly shows the locations where the heaviest rain occurred with one area over 5 inches just southeast of RDU off of I-40. I have marked my home location in with a yellow plus and my location during the storms with a red square. Also of note is the location of RDU airport with the runaways drawn in yellow and to markers labeled FFL. These are locations where flash flooding was reported from trained spotters. The area of yellow colors to the south of my home location was from the surprise thunderstorms that occurred at 4am on Friday. Tonight I would estimate that only .10 to .20 inches of rain fell in southeast Cary. The storms really had a hard time making it past US1/US64.


Here are some totals from around the area at various observation sites.

RDU: 1.18 in.
WRAL: 0.95 in.
NWS: .54 in.
Cardinal Gibbons High School: .95 in.
Greenwood Forest, Cary: 1.95 in.
Holloway, Cary: 1.67 in.