8:30 AM SUNDAY, FEBRUARY 7, 2010

Month to date precipitation for February is 0.21 inches.  Year to date precipitation for water year 2009-2010 beginning October 1 is 6.90 inches.  For the most current weather observations in Carson City, NV, updated every 15 minutes, CLICK HERE.

SHORT TERM:

A low that developed over Western Nevada last evening has moved southeast into Southern Nevada.  Precipitation totals ranged from 1/4 to 1/2 of an inch of rain in the valleys with up to 8 inches of snow above 6000 in the mountains.  For the rest of today, expect a few isolated rain or snow showers under mostly cloudy skies.  Winds will be out of the northeast at 5-10 mph.  Highs today will be in the mid to upper 40s.  Skies will become partly cloudy tonight and Monday under a weak ridge with no precipitation.  Lows tonight will be in the mid to upper 20s and highs on Monday will be in the upper 40s to around 50.

Another compact closed low will move down the California coast Monday night into Tuesday, then into Southern Nevada Tuesday night.  The exact track of this low could have significant impacts on the local weather in Western Nevada.  A further west track down the California coast would favor light precipitation with only minimal amounts of snow on the range of just a few inches in the Sierra and little if any precipitation in the valleys.  A track of the low a bit further east over the Sierra would favor much more in the way of snowfall even in the lower valleys.  Most forecast models are on board with a track to the west down the coast so that will be the favored forecast at this time.

Another weak ridge will build into the area by Wednesday ahead of yet another weak low to affect the area Thursday into Friday.  This system looks to mostly move north of our area but a few showers are possible.  Another ridge looks to build into the west for mostly dry weather for the weekend.  For now, the split flow pattern with weak systems moving in every 24-36 hours looks to continue for the time being.

LONG RANGE:

Looking out further, the overall pattern does not change much from the short term.  Systems will continue to weaken and split over the west coast, but latest models suggest some slight progression of the pattern may occur by the third week of February.  This may allow for better organized storm systems to affect the area at that time.  With the current El Nino and MJO phase space, conditions remain favorable for a significant west coast precipitation event. The limiting factor at this time continues to be the zonal flow over the Pacific with little moisture tap and little amplification in the progressive pattern.  Short waves moving off the Asian continent have rather weak so far this cold season, so the potential isn't being realized at this time for atmospheric coupling. As has been the case much of this winter, these systems appear to be favoring the desert southwest, typical of an El Nino year.  It may be that we will have to wait for increased storminess in the Northern and Central Sierra as we go into March and April to see anything more significant as the Pacific jet begins it's seasonal shift to the north at that time.  The 2002-2003 El Nino of similar strength provided us with a wet April as noted with the season shift of the jet stream.  Hopefully once that window of opportunity arrives, we don't end up with an amplified ridge over the west as has been the case over the recent years leaving us in another drought situation over Northern and Central Nevada.

CONTACT INFO:  carsonspotter@earthclimate.info

Satellite image courtesy of NOAA Satellite Information Service.  For the latest loop, click here.