After digging out of 12 -19 inches of snow in the Carson City area and several feet in the Sierra over the last couple of days, the weather will remain tranquil through Tuesday. Highs will range in the mid to upper 40s and lows in the upper teens to upper 20s depending on cloud cover under generally light winds. With abundant low level moisture and cold overnight temperatures, areas of fog and low clouds may develop over the next two mornings in a areas. The limiting factor is the amount of high clouds moving over the area that may limit fog and low cloud development.
Looking at the current synoptic pattern, the latest GFS analysis shows a quasi-rex block closed low pattern at 250mb extending down to 500mb near 140W. The latest IR satellite image shows this very well as this low develops well off the California coast. This low is currently disconnected from a deeper feed of subtropical moisture south of the low in the more zonal flow pushing to toward the southern California coast.
Looking ahead to the next storm, as this low develops off the west coast, forecast simulations are suggesting that subtropical moisture associated with the subtropical jet combining with northern polar jet to allow cyclogenesis to develop as it moves closer to the coast. Latest IVT values according to the 18Z GFS simulation suggests that a moderate atmospheric river will develop as a result of both streams combining to pull in significant moisture over the west. Current forecast simulations suggest that the highest moisture content will be directed more toward southern California, but some shift has been noted that may bring this further north toward the central Sierra toward Lake Tahoe south to Mammoth Lakes area. At any rate, there is a lot of potential for change over the next few days to trend north or south.
Looking at the precipitation potential, it’s too early to get into forecast specifics, but the dynamical forecast simulations are suggesting this may be another significant storm especially over the Sierra. There is some bust potential, so let’s break this down with some of the of the accumulated liquid precipitation totals expected through late next weekend. The GFS currently shows 5 – 7 inches with some greater amounts through next weekend. The GEFS is typically drier, but still shows significant amounts of 3 – 5 inches. The ECMWF is closer to the GFS with slightly lesser amounts, but solidly in the 5 – 7 inch range. The folks at WPC show 4 – 7 amounts, but the focus is mainly over the far northern Sierra and in the Mammoth area leaving Lake Tahoe with a bit lesser amounts, with an almost split look to the precipitation.
So there you have it, the forecast simulations generally agree at this time that another strong storm is expect to affect the area over a 5-day period beginning Tuesday night through at least Saturday, possibly into Sunday. While this is expected to be a warmer storm initially, with snow levels starting out around 7,000 to 8,000 feet, they will lower to the valley floors likely by Friday. A couple more disturbances Friday night through Sunday may bring accumulating snow to the Carson City area and other valleys. It’s too early to determine how much snow may accumulate, but there is the potential for another round of snow next weekend if the forecast verifies.
If you are getting tired already of rain/snow, you may be in luck, some forecast simulations suggest we will return to a drier and mild pattern for the last week of March into early April. We will certainly welcome the added water content for the season as we can since this has been a dry year so far.
As always, more updates as the details become more focused.
Graphics are courtesy of NOAA WPC, WeatherBell Analytics and Tropicaltidbits.com