The battle for winter begins
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| NOAA Projection from 1/31 for 11:00 PM EST Saturday shows the freezing line at 2 meters right along the Mason-Dixon Line. |
11:30 AM EST 1/31/12 | After a highly variable winter of storms that have been decidedly "out-of-season" the pattern may be shifting toward a more traditional cycle of cross-country events followed by Arctic outbreaks. Given that temperatures are heading into the 50 and 60s today for the East, we know many PowderhoundTM readers are beyond bewilderment as to how this winter can deliver at least one traditional Mid-Atlantic snowstorm. All we can say is, take heart friends, the battle for a Fabulous February is about to begin.
The breakdown on this storm. A fast and clean overview if you're short on time:
- Snowcover in the Great Lakes and eastern Canada is finally building up;
- Computer models place a high in the classic "upstate New York" spot by this weekend. This is crucial prior to a traditional I-95 snowstorm;
- An ample fetch of moisture from the Gulf of Mexico will be available;
- If this scenario plays out, a snow/sleet/freezing rain mix could begin by daybreak Sunday in the I-95 corridor between Richmond and Baltimore.
The "Long Range Cycle" rationale. If we examine the pattern starting with Hurricane Irene in August 2011, the 45-60 day cycle appears to have played out in a possible A vs. B pattern. A-events noted in this example occurred generally within a 60-day cycle, while B-events noted generally took place in the 30 days following the A-event. This 60-day Long Range Cycle concept, also known as Lezak's recurring cycle, was developed by Gary Lezak, the Chief Meteorologist for NBC's Action News in Kansas City, MO. We applied the basics of his forecasting technique to our projections for winter 2010-11 and this year.
| Nine inches of rain in one day inundate Ellicott City, MD during Tropical Storm Lee |
Is the pattern compressing?
The hypothesis under consideration by our Winter Stormcast Team follows the observation that in recent years, as a traditional winter storm pattern gets underway, the cycle of storminess appears to compress into a higher frequency of events toward mid-winter. We hypothesis that the time compression is bookmarked by one or two major events, before "unraveling" to a lower frequency of occasional events on a regional scale. When events seems to align toward one cycle, as in a merger of the 30-45 pattern with the 60-day pattern, the identifier is an "AB" event as shown below.
The hypothesis under consideration by our Winter Stormcast Team follows the observation that in recent years, as a traditional winter storm pattern gets underway, the cycle of storminess appears to compress into a higher frequency of events toward mid-winter. We hypothesis that the time compression is bookmarked by one or two major events, before "unraveling" to a lower frequency of occasional events on a regional scale. When events seems to align toward one cycle, as in a merger of the 30-45 pattern with the 60-day pattern, the identifier is an "AB" event as shown below.
Consider these observations of recent high-impact events:
- (A) August 26-28 Irene traverses the East coast
- (B) September 9-11 Tropical Storm Lee's flooding rains in the East
- (A) October 29-30 Halloween Weekend snowstorm in the Northeast
- (B) November 28-30 Surprise early snowstorm in the Mid-South
- (A) December 19-21 Pre-Christmas Blizzard in the Central Plains
- (B) January 18-19 Snow & ice storm in the Pacific Northwest
- (AB) January 21-23 Southeast severe weather/Northeast snow event
- (AB) February 5-8 Possible winter weather event in the East?
So the battle has begun?
The cropped image above from NOAA's Global Forecast System model for February 5 shows three important features which suggest the winter pattern may be heading toward a major event on the East coast. The blue line is 0 degree celsius at 2 meters, (or 6 feet above the ground) at 11 PM Eastern Time on 2/4/2012, this Saturday. Any precipitation (shown in green) that is inside the blue 2 meter line generally falls as snow or ice. The reason we suspect the beginning of a wintry period in the East centers on these factors:- This map arrangement places an Arctic High in southeast Ontario for the first time since the October snowstorm; current snowcover shows this region is also well-supplied, another pre-storm requirement.
- Computer models show a "battlezone" forming in the Mid-Atlantic this weekend between the cold Arctic air nosing out in front of the approaching Ohio Valley Low.
- Concurrently, the Arctic Oscillation is set to trend negative in this period, which suggests ample cold air may position East of the Appalachians prior to arrival of the eastward advancing Low.
Tell me it's possible! While temperatures Tuesday and Wednesday may approach 60 at some eastern U.S. airports, all that glitters is not gold. Those yearning for snow should find comfort in the fact that just days before the March 1993 Superstorm, temperatures were in the mid-50s in Baltimore harbor. Three days later, fourteen inches lay on the ground from Atlanta to Maine. It's happened before, it will happen again...it's just a question of when.
(Forecaster Foot, Meteorologist Berk and the Winter Stormcast Team)
