home

Friday, March 10, 2017

Seriously?

Big Kahuna 2 years in a row? 

11:00 AM ET SAT 3/11 UPDATE
  • No major changes to current storm forecast ideas noted below. Some computer models have shifted tracks a distance east or west, as is expected and customary in the days prior to a major event. 
  • Confidence remains high for accumulating snow across the region, however finer details of how much falls in which locations is not yet fully established due to changes in liquid amounts.
  • Cold air to remain in place prior to and after the event, enhancing impact to roads in all areas regardless of starting or ending precipitation type. 


If computer models stay on target with current ideas, many of us may 
have some heavy lifting to do soon. If not, this picture can stay in your memories.
  • SIGNIFICANT WINTER STORM MAY AFFECT PORTIONS OF MID-ATLANTIC REGION EAST OF I-81 TO WASHINGTON-BALTIMORE-PHILADELPHIA METRO REGIONS MONDAY NIGHT INTO WEDNESDAY MORNING.
  • LIQUID EQUIVALENTS OF 1.0-2.0 INCHES MAY PRODUCE INTENSE SNOWFALL RATES EARLY TUESDAY MORNING.
  • SNOW AMOUNTS OF 5" OR MORE MAY BE COMMON THROUGHOUT THE REGION, WITH HIGHER AMOUNTS IF THE STORM SHIFTS WEST.
  • TEMPERATURES IN TEENS OVERNIGHT INTO WEDNESDAY AND THURSDAY, IMPACTING SCHOOLS AND COMMUTERS DUE TO EXTENSIVE REFREEZING OF SNOW MELT RUNOFF.

SURFACE MAP: 8 AM TUESDAY MORNING: 
Looks like a Big Kahuna to us.


LATEST STORM SCENARIOS

SCENARIO A - 60%: Big Kahuna significant accumulating snow event across the Mid-Atlantic region with up to 5" common by Tuesday morning.

SCENARIO B - 20%: Some But Not A Lot due to a westward shift in track that moves axis of heaviest snow into morthern & western MD and southern to central PA, leaving 95 corridor with 5" or less.

SCENARIO C - 20%: Big KaNONa with a last minute pull to the East, bringing heaviest snow to coastal Eastern shore and leaving 95 corridor and interior areas with flurries. 


12:00 PM THU 3/9 UPDATE BELOW


Think of it as an early April fools.
  • CONFIDENCE GROWING FOR A SIGNIFICANT LATE WINTER STORM TO AFFECT THE MID-ATLANTIC & NORTHEAST REGIONS MONDAY NIGHT INTO WEDNESDAY.
  • NEAR-BLIZZARD CONDITIONS POSSIBLE ALONG COASTAL & BAY AREAS.
  • OVER 1.0" OF LIQUID SUGGESTS HEAVY WET SNOW A PROBABLE OUTCOME, ACCUMULATIONS OF 5" OR MORE LIKELY FOR AREAS WEST OF I-95.
  • AM TEMPS 15-20 F WED-FRI TO BRING EXTENSIVE REFREEZING & ROAD ICE.
  • IF NOT HAPPY ABOUT THIS, NEITHER IS THE SNOWCAT. 
5:00 AM ET Fri 3/10  - Now that the word is getting around you will have snow next week, no doubt there will be lots of questions for details. For Winter's last hurrah, we invite you to join the Insiders for direct access to our forecasts via app, notifications and text alerts. 
FANTASTIC SNOW IS COMING BACK, AND WE KNOW WHERE TO FIND IT. Visit the Insiders portal for details, and be a true Powderhound for the grand finale you've been waiting for all season!

How much? Let's just say...more than you've seen in March for a long, long time. Many areas in the Mid-Atlantic are likely to see 5 inches or more, if the most probably scenario plays out as expected. Below is a short version in 3 steps to how your snow dreams may come true next week in the Northeast U.S., especially if you are a teacher, student or Powderhound-at-large.

Remember last time the European model locked onto to a major storm solution 5 days out?
You guessed it, January 2016. Here's the map for 8 AM Tuesday 3/14 (Known as Pi Day)

  • STEP 1: FRIDAY.  A fast-moving clipper on Friday unlocks the gates to Canada, and much colder air. What you get: The chance to watch wet snow fall in the daytime from your office, home or classroom window, and not stick much.
  • STEP 2: SATURDAY-SUNDAY. Truly Arctic air rushes in behind that southern system we discussed in the previous "You may fire when ready" article. What you get: Highs in the 30s, lows in the teens. That's serious cold for March. 
  • STEP 3: MONDAY-TUESDAY. Now the fun part. Since the southern system this weekend would have been pushed SOUTH, you thought that means the Mid-Atlantic escapes, right? In reality, leftovers from that system interact with Gulf and Atlantic moisture, which starts riding back north. By Monday, a fast moving upper level disturbance is expected to "activate" that moisture and develop it into a surface Low near the Carolinas. What you get: A potentially significant coastal winter storm with some similarities to the December 19, 2009 storm. A multi-day event that would "interfere" with next week with accumulating snow starting Monday night.


VISUAL EVIDENCE FROM NOAA & THE MODELS THUS FAR ?
  • Snowfall Probability for the Northeast Corridor, already at 30-50% six days out, which in our book is very high this early.
  • U.S. Hazards Outlook for early next week. Now let's consider some new vocabulary we haven't yet learned this year. Think of a word you could use to describe weather that contains a) heavy precipitation; b) high winds and c) much below normal temperatures? ;-)

  • Mid-Atlantic Liquid Precipitation by next Wednesday. Let's pretend that liquid is falling out of the sky where temperatures are less than 32 F, and come to think of it, the ground will be also! If that liquid reached the ground, gosh, something might happen. Now, what if that liquid amount is, say 2 inches. Have your multiplication tables ready? Remember, 1 inch of rain = 10 inches of snow! Ok, here we go: (Liquid amount, 2.0") x (Snow ratio, 10) = ________. (Your answer) Wouldn't that be fun!
The light purple area are 2.0" of liquid or higher.

"DON'T MINCE WORDS, BONES-- WHAT DO YOU REALLY THINK?" - Capt. Kirk
  1. Favorable long range conditions indicate a significant snow event is increasingly possible across the Mid-Atlantic and Northeast starting by late Monday and may continue into Wednesday 3/15.
  2. Factors that normally limit snow accumulation in March in areas south of PA, such as sun angle, road temperature and low moisture amounts are not expected to affect this potential system-- due to overnight onset of snow, January-like temperatures and 4 days of roads at sub-32 F overnight. 
  3. Changes in the amount of moisture, arrival and departure of cold air, and onset of precipitation will have major effect on outcome of the storm. A delayed onset would mean rain/snow mixed for 95 corridor from Baltimore to DC, Richmond and east. An earlier onset late Monday or  by 12 AM  Tuesday could produce widespread high impact to commutes and schedules Tue and Wed.
  4. Near-blizzard conditions are possible for coastal areas from New Jersey to Maine from Tuesday night into Wednesday.
WHAT'S THE BOTTOM LINE PROBABILITIES FOR TUE 3/14?
  • 40% chance of major coastal and inland impact from the Atlantic to the 95 and 270 corridor westward to I-81, including heavy snow, wind and coastal beach erosion. With temperatures of 25-30 F several days after, schedules and events would be impacted due to multi-day refreezing of snowmelt.
  • 40% chance the system gets pushed East or south and out to sea, snowfall limited to the MD/VA Eastern shore.  
  • 20% chance of an inland cutter, bringing strong winds and windswept rain to the 95 corridor, with extremely heavy wet snow in the interior, and blizzard conditions from NYC to southern New England. 
We shall see how it all shakes out over the next few days.  But we can say, this is not a joke nor a drill, and in the timeless words of actor Leslie Neilsen, "Yes I am serious and don't call me Shirley."



Contributors to this report:
  • Winter Stormcaster Forecaster Connor Meehan (team member since Dec 2010)
  • Winter Stormcaster Troy Arcomano (member since Fall 2013)
  • Meteorologist Jolene Wagner (member since April 2011)
  • Executive Director Keith Krichinsky (member since Dec 2010)
  • Founder and CEO Rich Foot (member since 2004)