Friday/Saturday Storm – 3-1-2018 AM Update

Good morning!

There’s a lot to get to, so let’s just get this part out of the way: Today will be partly cloudy and 55, with a light northwest wind.

Let’s go timeframe by timeframe with this storm since there is a lot to digest here.

Tonight/Early Friday (Midnight – 6 AM):
Precipitation Type – Rain
Overall Confidence – High
Forecast Low – 35
Wind – Northeast 5-10 mph, gusts to 35 mph
More Info – Rain should begin early in this time frame. Lows in the mid 30s but precipitation should stay as all rain. Wouldn’t rule out a flake or two but that’s a very long shot. Winds will be on the increase.

Friday Daytime (6 AM – 5 PM):
Precipitation Type – Rain
Overall Confidence – High
Forecast High – 40
Wind – Northeast 15-25 mph, gusts to 50 mph
More Info – Rain for the entire day, and heavy rain for most of it. Strong winds out of the northeast over 20 mph with gusts to 50 mph at times, meaning isolated power outages are possible. Street flooding could be an issue with a few inches of rain expected. Any travel is going to not be fun during this timeframe, including the morning commute and start of the evening commute.

Friday Evening (5 PM – Midnight):
Precipitation Type – Snow and Rain
Overall Confidence – Very Low
Wind – Northeast 15-25 mph, gusts to 50 mph

More Info – Strong winds continue to the same magnitude stated above. A wide variety of scenarios are in play for this time period, and it depends on when exactly rain flips to snow and how quickly temperatures cool off (and how much they cool). Travel is going to be a mess during this period with either heavy rain or heavy snow, but that and the winds are the only things settled with this part of the forecast. If snow falls during this time frame, it would significantly increase the snow total, as well as the risk for power outages as any snow will be very heavy and wet. Impacts from rain would continue with minor urban and street flooding if this time frame is mainly rain. With that in mind, right now the odds favor a flip to snow somewhere near the middle of this time period. There is still a LOT of uncertainty, though.

Early Saturday (Midnight – 8 AM):
Precipitation Type – Snow
Overall Confidence – Low
Forecast Low – 32
Wind – Northeast 15-25 mph, gusts to 50 mph

More Info – Snow will fall – heavily at times – during this time frame. The exact amount is a big wild card, however, with a major spread in exactly how much precipitation falls in this time period. Minor accumulations of up to 3″ are likely at a minimum, unless temperatures are warmer than expected and rain mixes in (a mix is not looking likely during this time frame, though). Even a moderate snow event in the 3-6″ range – which is my going forecast right now – could be quite impactful because of the weight of the snow. A warning-level snow (6″ or more) is less likely, but possible if enough snow falls Friday evening or this period is heavier in terms of overall precipitation but just as cold or a little colder compared to the going forecast. A warmer time frame would obviously result in cut back snowfall amounts, and that is a scenario that is very possible, but a colder Friday night is a more likely wild card scenario though, as heavy precipitation could result in dynamic cooling. Temperatures will be hovering right around freezing. Strong winds continue, which would obviously exacerbate power outage potential. Stay tuned for more on this time period.

Saturday Daytime (8 AM – 4 PM):
Precipitation Type – Snow to Rain
Overall Confidence – Medium
Forecast High – 40

More Info – Snow changes to rain early in this time period, but the jury is still out on exactly when that happens. Rain winds down during the early afternoon. Strong winds continue, at rates a touch weaker than Friday and Friday night.

Regional Snowfall Map
As I pointed out this is the most uncertain part of the forecast. Particularly in the 0-3″ and 3-6″ zones, this could bust significantly in either direction. The 5-9″ further west is a little safer, but is by no means infallible, and could also be too low or too high.

Slide2.PNG

Saturday Night and Beyond: Lows either side of 30 and highs in the low to mid 40s for Sunday and Monday.
Slide1.PNG
Slide3.PNG

I’ll have more later. Have a good day!
-Nathan

Advertisements

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s