Saturday, November 19, 2016

// // Leave a Comment

Nasty Shadowing Today, Weak Spillover Begins This Evening

Sure is a blustery one on the leeside of the Sierra Nevada today! Look at those gusts in the valley! 49mph at the airport!

This is a classic rain shadowing case. The radar and satellite confirms it.
Beautiful shadowing along the crest!

Confirmed. Awesome.

Note the inversion between 690 hPa and 660 hPa. This is the ideal mountain wave/downslope windstorm setup. Not shown, but some serious vertical windshear as well from 850 to 600 hPa. Flights are likely cancelled at KRNO/KTRK. Trashcans are migrated about the neighborhood.

As the upper level jet dips equatorward, it weakens, but this will bring the precipitable water plume into the central Sierra and lead to enhanced precipitation due to the more favorable orientation. Check out the difference in PDub from tha RightThRRR model output from this morning to early Sunday morning:
Snow levels should come down somewhat in the next 18 hours, but still likely will not fall below pass level (at least that's what Chingy's output sez!):
Plot on right shows time series of freezing elevation (in feet) for the gold dot (Tahoe Basin) at right. Currently, snow levels are pretty high!

The waves keep rolling in over the next week, a very nice active early winter pattern to at least get some sort of base going. Moisture tends to be rather anemic with the shorter overwater trajectories and lack of deep coupling with the subtropics/tropical moisture reservoir, but we'll take it!


Post a Comment