Wednesday, February 8, 2017

Major Winter Storm Thursday

I mentioned yesterday that there was still some wiggle room with this storm.  The computer guidance wiggled, shimmied, and shook its way to a general 12-18" snowfall regionwide.  Low pressure will pass south and east of New England that will deliver a major snowstorm to the region.  The way my brain works (I admit, it's a scary thing) a minor snowstorm is less than 6", a moderate snowstorm is 6-12", a major snowstorm is 12-18", and a blockbuster is 18"+.   The storm will move quickly.  Most communities will see 12 hours of less of snowfall.  At times the snow will be falling 2-3"/hr.   If you don't have anywhere to be tomorrow try and stay home.  The National Weather Service has added a *Blizzard Warning* to Eastern Plymouth County and the Cape/Islands.  A *Winter Storm Warning* remains in effect for the rest of Southern New England.
NWS Early PM Headlines
Meteorological Fail This AM
The signs were there that temperatures were going to be colder than we thought this morning.  I don't know what happened in NE MA but the communication between meteorologists and decision makers needs to improve. How is the public supposed to know that low pressure in the Gulf of Maine was re-enforcing cold air last night?  It was unexpected initially, but there was still 6-12 hours of advance notice.  Here is the 2 AM High-Resolution Rapid Refresh model temperature forecast for 7 AM.  It had been showing this all evening.
07z HRRR 2 m temps Wednesday 7 AM (image Weatherbell)
Meteorologists had this by 330 AM.   Truth be told the guidance showed this around 9-10 PM last night.  The recently upgraded American high-resolution short range model (the NAM) also predicted below freezing temperatures overnight.  Mistake happen often in meteorology; we are trying to predict the future.  More than once I've looked up and said: "Why the hell is raining"?  I've even told a bride it would be mostly sunny for the 415 PM wedding and at 4 PM there was a downpour (sorry Corrine).  Just last year I advised people to "put the plows away" only to watch in horror as computer guidance began to trend north.  We ended up with 8".  I will screw up again, probably tomorrow!  

55 car pile up 128 Wakefield, MA (image via WCVB)

But this morning, we get 55 car pile ups on 128.  It's fortunate no one died.  Governor Baker addressed the problem this morning.   I think if it is your job to alert the DOT/DPW when they need to treat the roads, you have to be watching guidance like a hawk on days like yesterday.  The call has to be made before 5 AM.  

Snow Breakdown
By 1 AM the low will be nearing the Mid-Atlantic coast.  Snow will be overspreading PA and NY by this time.
WPC Surface Fronts/Precipitation Thursday 1 AM
By 7 AM the snow will probably be near Worcester and Providence.  It will get to Boston by 8 AM.
18z HRRR Simulated Radar Thursday 7 AM (image Weatherbell)
Temperatures will be in the low 20's in Worcester by this point.  At the same time, we are in the low 30's in SE MA.  
18z HRRR 2 m temps Thursday 7 AM (image Weatherbell)
Once the snow starts it will come down fast and furious.  The atmosphere is primed to produce snow tomorrow.  It will be light and fluffy where temperatures remain in the 20's.  This should be most areas outside of the Cape by the middle of the storm.  At 1 PM the low will be blasting SE MA with wind and everyone with heavy snow.
WPC Surface Fronts/Precipitation Thursday 1 PM
Winds will be gusting 40-50 mph where Blizzard Warnings are posted.  Elsewhere expect 20-40 mph wind gusts out of the north.  By 7 PM some snow still lingers in Eastern MA but everyone else is just left with a fresh blanket of powder and bitterly cold temperatures.
12z NAM 3km sim radar Thursday 7 PM (image Weatherbell)
By then temperatures are likely in the teens, upper single digits even!
12z NAM hires 3 km 2 m temps Thursday 7 PM (image Weatherbell)
The NWS is up to 12-16" for most.  I agree with that.
NWS Total Snowfall Forecast through 54 hours (image Weatherbell)

 Enjoy the storm!

-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...