Winter Storm Jonas Forecast – Some Questions Still
Snow Storm (Blizzard for some) Jonas is arriving! Here is a snowfall map, we think this looks pretty good after discussing for many hours about what it would look like, and what to forecast. *Let me make it clear that the gradient of snow on this storm in terms of amounts is EXTREMELY tight. 10-20 miles could mean the difference between 6″ and 18″, this is ESPECIALLY true for the Northern Suburbs of NYC up to Orange, Putnam, Rockland and Westchester Counties. We truly believe this will be the snowfall we are looking at, however if we feel we need to change it in either direction (+ or -) we will issue a new map.
The storm is currently sitting over the SE with two lows, the primary is over the Tennessee/NC border, while the secondary low that the NRG is currently being transferred over to is sitting over the SC/NC Coastal Border. The Low should pass West (inside) of Cape Hatteras in the next 3-4 hours.
Radar currently showing snow signature just to the south of NYC, and we should start seeing flakes come down between 11pm and midnight, although it will really kick off after midnight. As you get further north, the later it will start. Anything that falls in Boston will not start until early to mid morning tomorrow, maybe even later.
The HRRR shows snow really beginning here in the Rivertowns around 12:30am…but again, some flakes before that definitely possible.
Snow lasts throughout the entire day tomorrow, the BIGGEST thing to watch here besides the snow which may be heavy at times is the WIND. No, we do not have a Blizzard warning or watch, HOWEVER, winds will SURELY be up there 25-35mph with gusts possibly to 50mph, higher on the coastal areas.
HRRR shows the winds ramping up in the morning. Off the Delmarva those are 80-85kt wind gusts, up near us it is around 35-45kts (40-50mph).
This is where I DISAGREE with NWS, they have LI and NYC on a Blizzard watch that will likely become a warning, and RIGHTFULLY SO, HOWEVER, they leave us out of the blizzard category….I am telling you, winds will be high, blowing snow possible, and limited visibility with winds 25-35mph gusting close to 50mph as you see in the image above. This will only get worse as the day goes on and the system gets closer.
Now, one last thing before I sign off – The key to this storm, and the hardest part of the forecasting for it, is how far north do those HEAVY bands and snow get…Does it get to NYC and leave us with less snow? Or does it get up to us and give us more? This will dictate our snow totals, and the EXTREMELY tight gradient that I have drawn on the snow map. ANY movement in the overall track of the storm 10-20 miles North could give us a 12-18″ snowfall, and NYC 14-18″+, but ANY CHANGE 10-20 Miles south COULD EASILY leave us with 1-3″ and NYC with 6-9″+….SO, this is why we waited so long to issue our forecast, BUT, the models have come into much more agreement this afternoon/evening, and we are much more confident.
Again, any changes that we feel are needed will be shown with an update from here. We will be posting on twitter as well live updates, PLEASE PLEASE follow us @weatherinthehud on twitter. If you do not have twitter, we URGE you to sign up on our site with an email so the second we update you get it by email. And finally, our posts will be shared on Facebook.
Please be safe, and ENJOY THE SNOW!