A heavy winter storm predicted for Tuesday evening has been downgraded and much of the moisture expected to hit the Sierra may stay west of the crest.
As much as 16 to 20 inches of snow was forecast for the crest of the Sierra above Mammoth by Wednesday morning, but a recent update by Mammoth’s amateur weather forecaster is pulling back from that.
“Apparently…the models were wrong in the placement of the upper low as it is verifying too far west,” Howard Sheckter wrote on his website Tuesday evening.
“As a result, the focus and bulk of the precipitation is over the San Joaquin Valley. Heavy down pours and thunder are currently rumbling south of Mammoth in the foothills of the Sierra, east of Hanford and Fresno. Sierra crest updated amounts are now in the three to six inch range for the upper elevations and possibly just enough for a plow in town.
“Lots of hopes tonight being lowered as mother nature just not ready for a good ol’ fashioned snow storm quite yet.”
However, the Reno office of the National Weather Service, in its latest update at 3:30 Tuesday afternoon, was still calling for 16 to 20 inches on the Mammoth crest area.
Beyond Wednesday, the weather is expected to remain unsettled, breaking a six-week long high-pressure ridge pattern that has plagued the Sierra since early January.
“By Wednesday, as low pressure drops over southern Nevada, wraparound showers and upslope flow in Mono County will decrease by midday. North to northwest flow will keep ridges across the region fairly breezy through early Thursday and the pattern in the extended will feature a series of quick moving shortwave troughs that will provide periods of stronger winds, snow showers and below normal temperatures.”
A series of similar storms will hit the region throughout the coming weekend and into next week, according to the weather service.
What is not known is the amount of moisture in the systems, said Edan Lindaman, a meteorologist with the Reno office of the National Weather Service.
“After every other small storm system, we have seen a large high pressure ridge build up quickly,” she said. “We are not seeing that this time, we are not going into a stagnant high pressure system this time.”
“But the details are messy,” she said. “We aren’t sure of what will happen during each of these smaller storms.”
There is no identified big pool of moisture, no left over hurricane moisture waiting to be tapped now that the high-pressure ridge pattern is broken, she said.
It will, however, be cold for the next week or so, more like the normal temperatures for the region than the shorts and shirt weather in Mammoth and Bishop for the past few weeks, she said.