We continue to experience March dumps in May. Flow pattern has been pretty consistent, with SW flow bringing lows up into the Co. Plateau and Four corners, where they wander slowly along the S.Colorado border, eventually ejecting into the plains.
Then NW flow brings a trough or two down from the great basin. These haul their own moisture and unseasonably cool temps down over the Continental Divide, but invade the San Juans on backdoor flow as they drop S and slowly rotate off to the E.
This pattern has been repetitive since late April, reminiscent of March patterns from back in the olden days.
Any how, the coming week is quite similar. A SW low is spinning through the 4 corners as a cold front sags down the divide from the NW. This front will drag a low from the Great Basin into N. Arizona by tomorrow…
Then a repeat through Wed. or more likely Thursday. Lapse rates, water vapor, and flow point towards a solid precipitation event for most of next week. These transiting lows will put the San Juans in the R exit region of the jet and counter rotation of the lows. Snow levels will be above 9,000′ at least, with intermittent rain below. Intermittent, due to orographic forcing wringing out moisture, then redeveloping.
The good news is this pattern is adding to the existing pack and preventing rapid melt off. Pack is holding well at 60″- 70″ @ tree line