Warm, muggy air sat over the Northeast for most of this week.
While temperatures were not unusually high, the dewpoints were. Dewpoint temperatures in the upper 60s °F made for very sticky air and also meant that there was plenty of available moisture in the air for rainfall.
An approaching cold front was the trigger for a potent line of Thunderstorms that moved through the Portland area at around 2:30pm. This line of storms resulted in the highest rain rate yet recorded at WeatherMaine in South Portland.
The rain rate at 3:00pm was an amazing 12.52" per hour. In just 10 minutes, WeatherMaine's rain sensor recorded 0.40" of rain! Below is the matrix of the rainfall rates and 10-minute totals for this event.
|
Time
|
10min Rainfall
|
Rain Rate
(in/hr) |
|
2:40pm
|
0.02"
|
0.53
|
|
2:50pm
|
0.11"
|
6.26
|
|
3:00pm
|
0.40"
|
12.52
|
|
3:20pm
|
0.01"
|
0.35
|
|
3:30pm
|
0.00"
|
0.05
|
|
3:40pm
|
0.01"
|
0.05
|
In addition, a new record was set in Portland during this event:
...RECORD DAILY MAXIMUM RAINFALL SET AT PORTLAND...
A RECORD RAINFALL OF 1.63 INCHES WAS SET AT THE PORTLAND
INTERNATIONAL JETPORT YESTERDAY. THIS BREAKS THE OLD RECORD OF 1.42
SET IN 1991.
