Old Advisory Events
The information herein is NOT intended for use as a weather forecast. The Air District DOES NOT forecast but solely compiles information from both the Phoenix and San Diego National Weather Offices to relay information concerning potential changes in ambient air concentrations that may impact the public.
|February 9, 2018 to February 12, 2018|
|High wind levels have the potential to suspend particulate matter into the air. High levels of PM10 may pose an impact to public health. It is recommended that active children and adults, and people with respiratory disease, such as asthma, limit their outdoor activities.
Potential increases in PM10 concentrations may increase to moderate or unhealthy level.
|Imperial County Weather Synopsis|
A dry cold front will move into the Southwest Saturday night and produce a very dry offshore flow. Although a short duration event, the combination of low relative humidity and strong offshore winds over the Northern Inland Empire and along the slopes and foothills could generate red flag conditions early Sunday morning through early Sunday afternoon. Conditions will rapidly improve Sunday night into Monday as onshore flow kicks in, in advance of the next trough. Consult the fire weather watch for more details.
DISCUSSION FROM THE SAN DIEGO OFFICE
A low-pressure shortwave and trailing dry cold front moving through the interior west will put a dent in our giant ridge. That will help a coastal eddy develop tonight, which will help the marine layer to deepen. Coastal clouds will get into far western valleys Saturday morning with onshore flow not fully clearing Saturday. The energy from that shortwave will boost winds, mainly in the mountains and deserts during the afternoon and evening.
Winds quickly turn offshore (northeast) Saturday night and strengthen behind that shortwave. That will bring somewhat strong offshore winds to Southern California, and somewhat chilly air to the high desert and mountains. Top wind gusts in the favored areas forecasted to exceed 50mph between midnight and midday Sunday.
By midday Sunday, offshore winds will begin to decrease. A new shortwave follows a cutoff low just off the coast on Monday and Tuesday. That allows it to dip into the Pacific air and grab some moisture that could bring us showers.
DISCUSSION FROM THE PHOENIX OFFICE
A blocked atmospheric flow pattern will persist over much of the country the next couple of days. However, several shortwaves will crest a highly amplified east Pacific ridge and carve out a notable negative height anomaly affecting the forecast area next week. In the near term, height aloft will only gradually become depressed as the first positively tilted wave descends towards the four corners region. Negligible impacts on temperatures today with slight reduction in temperatures as the weekend continues.
Overall, high pressure continues to hold in place for the remainder of the week. The first in a series of weather disturbances will sweep by the region early next week with better chances of rain arriving during the middle of the week.
Phoenix Fire Weather
A cold front will slide into the region Sunday yielding windy conditions through much of SE California and lower Colorado River Valley. While the strongest winds will occur early Sunday morning when humidity levels are higher, an enhanced fire danger will exist solely on the gusty north winds.
|Weather Story Phoenix Station||Weather Story San Diego Station|