Southwest Drought Eases With Monsoon
October 21,2014
Northern California should see some precip in the next week according to forecasters. Here is the 7 day totals according to NOAA.
As you can see heavy rain is expected in the extreme north part of the state while the Shasta area should get over half an inch.Light rain could reach as far south as San Luis Obispo County by Saturday says PG&E forecaster John Lindsey,who has predicted an above average wet winter.
Meanwhile the just completed Southwest Monsoon season in Arizona and New Mexico could bring more water into the Colorado river system as the summer storms were active this year.
The Climas (University of Arizona) recap of the season that ended Sept 30 reported “much of Arizona and New Mexico receiving well above-average rainfall.” Indeed “Most of Arizona received well above-average monsoon rainfall—200 to 400 percent of average—and many areas in the state registered 150 percent of their seasonal total or higher.”
“ New Mexico saw a similarly strong, if not stronger, monsoon, with most areas of the state receiving more than 200 percent of their seasonal average and large swaths of southern New Mexico recording between 300 and 400 percent of their seasonal average.”
The upshot – the Bureau of Reclamation Lower Colorado Water Supply Report for October 20 says Lake Powell’s inflow that was at 97% of normal April-July jumped to 125% inflow in September and is expected to reach 146% of normal in October.
Will the strong Monsoon season mean a stronger El Nino than expected? Opinions vary.
The US Climate Prediction Center has been forecasting the likelihood of a weak El Nino winter event that raises the chance of rain in parts of California. The forecast shows the likelihood of above average rain in the southern part of the state.
But as you can see from the above map storms continue to knock at the door on the northern end of the state, a more typical pattern. The issue has been whether these storms are strong enough to reach down to the state’s extensive hydrological infrastructure starting in Shasta as well as the snowpack in the Sierra starting around Tahoe south.
Tahoe snow watcher Bryan Allegretto in an Oct 19 posting suggests much of the state will get wet in November and offers this map of the Winter forecast by Accuweather.
Ag forecaster Alan Fox paints a mixed picture.
“For northern and central California, along with the northern Sierra Nevadas, expect warmer than normal conditions and near normal rainfall in December. This will be followed by some good strengthening of the sub-tropical westerlies in January. The bottom line is that Sierra Nevada snow fall will be below normal at least through January.”