Saturday, October 22, 2016

Wicked Rains Overwhelm SNE

Over 3" of rain fell in less than hour last night as a cold front and subtropical low pressure system combined to produced drought denting rains.  The drought helped contribute to the flash floods as the rain came down so fast none was absorbed by the dry ground.  Water rain right into streets and overwhelmed storm drains that were covered in leaves.   Another round of rain will move through between 11 AM- 4 PM.  Then winds will pick up with gusts approaching 45-50 MPH tonight before lessening slightly Sunday.

The Aftermath
You can check out all the flooding reports here.  All of the rainfall reports can be found here but I wanted to highlight a few.  I expected a few 3" rain amounts but what happened in Worcester County is ridiculous.
Rainfall in inches 
Some isolated showers moved through the region yesterday morning and early afternoon.  Around 4 PM the heavy torrential rain bands began to rotate into Central MA with rainfall coming down at over an inch per hour.  The first whack lasted for about 20-25 minutes.  The main event began around 6 PM with driving tropical rains and thunder and lightning.  This is a video via 7 News of Worcester.
The Worcester Telegram & Gazette has a nice collection of stories and videos.  Many people were stranded on 290 or under bridges as the rain rate was just too fast for the drainage to keep up.  This tweet sent by Worcester Buzz captures the astonishment of residents on Elm Street as waters rise to the front porch.  I feel for everyone who had to deal with feet of water in the basement or cars that were ruined.
Tweet by Worcester Buzz via T&G
For my visual followers here is the precipitation analysis plotted for the last 24 hours.
NWS precipitation analysis 10/21/2016 (image Weatherbell)
When we see flooding pictures from North Carolina, West Virginia, or Louisiana its hard to image the amount of rain and water that actually fell.  Image rain like we had last night for a day (or more).  High winds and big snowstorms are sexy but its the water that always causes the most death and destruction.  Thankfully I haven't see any reports of causalities from the flooding.  The awful situation in Boston was not caused by these rains.

Short Term Forecast
We have another round of rain ready to rotate across our region.  The main rain band is already to Hartford but some showers have fired out ahead of this.
NWS Northeast Regional Radar 
 Here is the surface chart for the Northeast.  The low is going to back into Maine pulling the moisture east and then north.  So we won't get most of that precipitation in Upstate New York.  But the tail around NJ will rotate across Southern New England.  Rain within this band will be heavy at times.  I don't see a lightning signature as of now which is good news but that could change.  The atmosphere is unstable (though not as bad as last night).
WPC Northeast Surface Analysis 8 AM
The latest futurecast does show a fairly strong thunderstorm between 1-2 PM before a brief dry slot works into RI/CMass between 3-5 PM.  Showers will resume this evening.
14z HRRR Simulated Radar 2 PM (image Weatherbell)
Here is the 4 PM simulated radar.  This is concerning for the North Shore/NE MA/NH/S ME.  This band looks like what hit Central MA last night.
14z HRRR Simulated Radar 4 PM (image Weatherbell)
If you happen to live in this region or have to travel this way please check the radar.  Flooded roads are no joke.  Oh and yes that is snow in New York.  I doubt any makes it to SNE unless is in the Worcester Hills as flurries overnight.  Of bigger concern is the winds after this system clears.  The National Weather Service has posted a *Wind Advisory*  from 8 PM tonight to 2 PM Sunday.
NWS Boston Headlines
As the storm pulls away it will gain strength in the Canadian Maritimes.  High pressure will settle into the region bringing a Canadian air mass with mid week temperatures barely making 50 (more on that tomorrow).  In the meantime the large difference in atmospheric pressure to our north and south will force strong winds to squeeze between the two right over New England.  As a result frequent gusts of over 35-45 MPH are likely tonight with a few 50+ gusts likely.

Temperatures this afternoon will also crash.  Can you tell me where the cold front is?
14z HRRR 2 m temps 11 AM (image Weatherbell)  
By 5 PM the 40's come calling
14z HRRR 2 m max temp 5 PM (image Weatherbell)
We drop into the 30's tonight.  I'll discuss next week's weather tomorrow.

-Zack Green

No comments:

Post a Comment

National Weather Service Issues Winter Storm Warning

T he National Weather Service Boston office has issued a * Winter Storm Warning * for most of Southern New England, except for the South Sou...