Pattern/Storm Summary
It was quite the April storm turning spring back to winter. It is unbelievable how the weather repeats and nobody knew until the 40’s when Jerome Namias discovered the Pattern before there were computers. Then that discovery was lost, until Gary Lezak rediscovered it 25 years ago. Now, we get to bring this exclusive technology to the ski industry.
The Trifecta is a 3-wave storm over spanning about 7 days. The Pacific Northwest kicked off the Trifecta with modest numbers: Crystal Mountain 19, Mt Hood 22. Dropping to the Sierra: Tahoe’s Palisades 78, Kirkwood 46. Over to Utah: Alta 47, Snowbird 45. Finally, Colorado: Breckenridge 13, Arapahoe Basin 18.
The next Pattern storm is due April 28-29 and is looking good on the models, the question this time of year is, will it be cold? Right now, it is cold enough on the back side of the storm, so we’ll see what the timing is like when we get a little closer.
That storm is followed by the Tahoe atmospheric river (AR) system, that in cycle 1, came through October 24th, dropping 39″ in 24 hours. It returned in Cycle 2 with 53″ in 3 days. Cycle 3 was the outlier, with double barrel high pressure in the Pacific and Nevada, the storm was blocked and went well north. This cycle is behaving like cycles 1 and 2, so we will see if it hits 3 out of 4. This storm is showing up on the models, but is way out there (282 hours).
Thanks for reading! Mike The list of pattern storms for the rest of the season below
Upcoming Pattern Storms through June
Below are storms in the pattern that are significant and have repeated at least twice. We have a long cycle length of 64 days, that is the second longest length in the last 20 years. The average cycle length, over the last 20 years is 53 days. The shortest was 38 days and the longest was 75. The long cycle length has a possible connection to the following years El Nino Southern Oscillation (ENSO). Sixty four percent of the time, after a significant jump in cycle length, the following year was an El Nino year.
April 28-29 This storm hit in Cycles 1 and 2 and was 2 days late in Cycle 3. Cycle 2 had rain for the PNW
May 5 (Tahoe AR Oct 25) Epic 100″ week in Cycle 2 with 39″ 1-day total in Cycle 1.However, in Cycle 3 the storm was caught up in the double-barrel high and that pushed the storm up in Canada.
May 7-8 Good storm all three cycles for Colorado and Utah with double-digit totals for all 3 Cycles with Cycle 2 the winner. If you are looking for a powder day in May, this is the one to watch. Arapahoe Basin time?
May 13-14 Storm hit Colorado all 3 cycles and missed to the north of Utah, in Cycle 1
May 17 Missed Utah and Colorado to the north in Cycle 1, but hit in both Cycle 2-3
May 20-21 Last storm of Active West Small system due to the weakening Active West pattern and transition to the Northern Pattern. Hit in all 3 cycles for Utah and Colorado
June 5-6 AR 4th Straight for Seattle?
Updated Prediction Chart
