Flooding Rains, Flash Freeze: What To Expect And When
BOSTON (CBS) - We have a multi-faceted, highly impactful 24 hours of weather ahead with flooding rains followed by a flash freeze.
Here are the headlines:
- There is a high likelihood of significant urban street flooding, most notably where storm drains remain clogged.
- Most larger rivers should stay within their banks, however, some smaller rivers and streams may flood.
- Best chance of strong, damaging winds will be over the South Coast, Cape Cod and Islands, likely within some of the heavier downpours/convection
Any untreated surfaces will quickly ice over during Saturday as a rapid drop in temperatures occurs. The main concern isn't from sleet/freezing rain (most of the precipitation will be ending as the cold air arrives), but instead from any standing water which will instantly freeze and potentially create hazardous roads/walkways.
TIMELINE
Friday:
A wet and warm day. Rainfall will be showery and not all that heavy until the evening. Temperatures will make a run at the records (which were set last year in both Boston and Worcester).
Rapid and significant snow melt continues and some street flooding begins.
Friday Night:
The heaviest rain falls Friday night into Saturday morning across eastern and southeastern Mass.
The combination of very mild temperatures and some torrential downpours will cause widespread urban/street flooding. A total of 1-to-3 inches of rain with pockets up to 4 inches is expected. Winds will gust 40-to-50 mph within some of the downpours over southeastern Mass.
Saturday:
As the rain continues to pour down Saturday morning, a temperature crash will be arriving from west to east. Around dawn on Saturday we will have temperatures near 60 over parts of southeast Mass. and in the 20s in western Mass.
That cold air will quickly spread eastward Saturday morning, changing the rain over to a mix of ice and snow. The good news is that the precipitation will be coming to an end by midday Saturday so there shouldn't be much chance for any significant ice or snow accumulation. The main concern during the day on Saturday is for a flash freeze. Any standing water (and there will be a lot of it) will freeze up quickly.
FLASH FREEZE TIMING
7 a.m: Springfield, Mass. to Fitchburg to Nashua, NH
10 a.m: Providence to Boston to Cape Ann
1 p.m: All areas west of the Cape Cod Canal now below freezing (the entire state except the Cape and Islands)
4 p.m: All areas below 32
PATRIOTS GAME
if you're going to Gillette Stadium Saturday evening, the precipitation will be over but the temperatures will be dropping.
Any standing water in the parking lots or on the roads early in the day will have turned to ice. Temperatures will drop from the upper 20's for tailgaters to the low 20's by the time that Pats are celebrating their victory. Winds 10-15 mph will make it feel like 10-to-15 degrees.
WHAT'S NEXT?
The cold that arrives on Saturday will stick around a while (again). While not nearly as harsh as our last cold outbreak, we are likely in for another stretch of several days below freezing (Sunday into next week). So any ice left on your driveway from the flash freeze won't be melting anytime soon.
Then, we will be watching for a potential snow storm around the middle of next week, stay tuned for more on that!
And finally, it appears that a prolonged January thaw is likely from later next week through most of the rest of the month!
The weather pattern will likely shift into a ridge on the East Coast and trough in the West Coast (the opposite as it has been recently).
So clearly a lot of weather to go through in the coming days and weeks!
As always, we will keep you updated on WBZ-TV and CBSBoston.com.
Follow Terry on Twitter @TerryWBZ
