Saturday, January 21, 2017

Marching through January

WHY COOLER PACIFIC WATERS BRING LESS SNOWY WINTERS, AND WHAT ARE THE CHANCES OF A "SNOW DAY" THIS SEASON?


6:00 AM 1/21 - In stark contrast to last year at this time, skiers, students and snow lovers alike face another week to 10 days of non-winter conditions, as a March-like pattern has temporarily replaced traditional January weather. The NOAA 6-10 day temperature outlook below shows no help in sight for those yearning to see just one little snow day. But alas Powderhounds, all is not lost. Looking ahead, there is hope in the red letters.

WHERE DID THE SNOW GO? One year ago, the region was buried under the largest snowstorm in decades, courtesy of an equally powerful El Nino-fueled transport of Pacific moisture. Now, it's the hazy, sullen, fog-filled days that result from the wishy-washy influence of cooler-than-normal east Pacific waters. (Relive the storm in our posts leading up the storm: Tue 1/19, Wed 1/20. Thu 1/21, Fri 1/22. The comments also a fun look back.)

For the normal snow addict, It's a very strange and frustrating pattern indeed but one we have come to expect would happen. We are all dealing with the consequences of the old rule that "what goes up" (the 2016 El Nino of +2.3 C) has turned into the "must come down" Nina of -0.5 C). 

THE SHORT ANSWER is simply that when sea surface temperatures of the East Pacific start the winter at a level slightly cooler than normal, this influences the overall pattern in adjacent land surfaces. The climate cannot support the west AND east BOTH being cold at the same time, so if they get it first, we get the scraps. If you want snow, you're on the wrong side of the coast right now!


SO, THE NEXT SNOW DAY IS...? The most efficient way to access our specific projections is to join the Insiders for 2017. You get straight-on reports without fluff or social media distraction, specialized alerts and early AM update via the Insider App, plus text notifications before / during major events. It's a lot of valuable info for a very nominal fee and it's one way of supporting our operations. Image left: Results of all those calories we all burned last winter, captured in this reader photo from College Park, MD



LOTS OF COLD, JUST NOT HERE: A cooler east Pacific is inducing a cooling trend in the western U.S., and in part, occasionally shifting the jet stream's path coming East into a more spring- and sunmer-like pattern. What usually is a big dip south in the jet stream over the East, allowing coastal storms and interior snow, has turned into an opposite pattern:
Most of the significant cold is being dumped into the West first, with little left over for the East. 

If the jet stream is riding northward into Eastern Canada, it's going to bring with it all that warmer subtropical air from the Gulf of Mexico and Caribbean. 

WARM PACIFIC = SNOWY EAST? WHAT GIVES? Remember all those catastrophic precipitation events in 2015-16? The 20 inches of rain in South Carolina? The Midwest and Texas flooding? The 36" blizzard in the East? That's El Nino for you.

If the east Pacific waters are 7-10 degrees warmer than normal (= to 2.3 degrees above normal) much more moisture than is usual can more consistently be evaporated from the sea surface. We mean a LOT of moisture-- so much that anytime this moisture interacted with just enough Arctic air, the result was either a crippling blizzard or a Day After Tomorrow-like deluge. (Image right: El Nino in Winter 2015-16). This moisture transport was so significant last season, we surmise that on Thursday January 21, 2016 - Baltimore County Public Schools must have been so concerned blizzard conditions would arrive during the day on Friday 1/22, that they pre-emptively announced the closing of schools a day early. That's the power of a strong El Nino, kids.


LAST YEAR VS. THIS YEAR: Contrast the "Super El Nino" of 2015-16 as shown above with the current status of a La Nina Watch.

  • The cooler sea surface temperatures of a Nina induces a High pressure system over the northern & eastern Pacific. 
  • Instead all that juicy Pacific moisture riding up the East coast. and dumping on I-95 and ski resorts as snow-- it's being redirected into the California and Oregon coasts. 
  • With little moisture left to cross the Rockies, and little snow cover to encounter once it does, Easterners get scraps of Lake Effect squalls, A "March in January" pattern with fake ice storms or nothing at all.



COME ON FOOTS, TELL ME THERE'S SOME HOPE. 


The election notwithstanding, there is some hope in the Long Range, which we are discussing in detail with issuance of the Weekend Insider Update for subscribers. The quick version is that one target period is on the table over the next 2-3 weeks during which time the pattern can re-orient to favor accumulating snow in the Mid-Atlantic and the East. 

If you have been following this site or our Facebook pages for some time, the team invites you to become an Insider for the full details - so you'll always be in the know, before the snow.


No comments: