A note from NWS Joe Ramey about the approaching storm…
“To use some techno speak, this looks like a biggy. A component of this storm is a Kelvin wave associated with the first major Madden Julian Oscillation of the season. San Juans are currently favored with… 4 feet? Trust in important details is still low but the overall picture is impressive. It will have immediate impacts (impossible travel, structure damage in Durango Pagosa area?), near term impacts (weeks of heightened avalanche danger), seasonal impacts (increased potential for spring flooding) and longer term impacts (decreased potential for fire danger).”
Colorado winter snowpack is made or broken by the presence or absence of just a few strong storms. The Christmas storm was the first big one of the season. This will probably be the second.
A storm currently brewing in the Gulf of Alaska is dropping south on it’s usual path and coming onshore along Wash/Ore coast bringing a weekend of snow and potentially more through mid-week. We’ll see continued dry weather through Friday then what looks like a major Pacific storm will arrive in the San Juans late Saturday or early Sunday. The storm has a NW to SE flow so we’ll wait for the brunt of the energy to kick in on Sunday through Tuesday if it all works out. With this storm path direction by the time it reaches us it could be a bit modified with a rain/snow mix due to warm valley temps.
Several models show 1-2 inches of liquid H20 equivalent in this 4 day period which translates to a lot of snow (24-36″ up to 4 feet), but let’s not get too excited just yet, these projections are only projections and by the time it happens reality is always a little different. Two of the three models i’m following show a rowdy storm period although one of them can be overly enthusiastic.
The jet stream plays a big part of this storm beginning Friday night as it picks up copious moisture from the Pacific then moves over the mountain terrain of Colorado. A surface low forms on Monday should keep the storm going into Tuesday/Wed. which might be Prime Time for the San Juans. Lot of uncertainties associated with the various model runs and forecasts…… how warm are the storm temps, where does the surface low migrate, is the moisture overdone? Guess we should just watch it unfold and hope to see the more robust models pan out. Confidence for this storm is scattered and uncertain…which makes it a great storm to observe…
Check out the moisture plume being pulled into the coast by this low pressure trough..!! A BIG Pineapple Express being drawn from west of Hawaii!!
Same information as above only H20 vapor… Impressive!
Watch the loop Sunday-Tuesday with the closed-low forming over SW Colo/N.M.