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.
|October 24 2017|
|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|
|HOT & DRY AGAIN TODAY WITH COOLING AHEAD
SYNOPSIS FROM THE SAN DIEGO OFFICE
Stronger and gusty Santa Ana winds will become more widespread this morning…then become less widespread…more easterly…and not quite as strong for tonight into Wednesday. Near record setting heat will continue today from the coast into the western valleys with slight cooling for Wednesday and greater cooling near the coast on Thursday. Onshore flow for Friday through Monday will bring slow cooling with a gradual return of night and morning coastal low clouds and fog. SHORT TERM (Today through Thursday) Gusty Santa Ana winds continue early this morning near the coastal foothills and below passes and canyons with strongest gusts between 50 and 60 mph. The strongest gust overnight so far has been 59 mph at Fremont Canyon in the coastal foothills of the Santa Ana Mountains and Sill Hill in the San Diego County Mountains. Where mixing from the winds continues. Temperatures have remained quite warm with temperatures still in the 90s in portions of the western Inland Empire and inland portions of northern Orange County.
There was record setting heat Monday…mostly in coastal and western valley areas. The mostly likely areas to be hotter than Monday are areas toward the coast as stronger offshore flow pushes the hotter temperatures for inland coastal areas closer to the coast with high temperatures in some coastal areas around 25 degrees above average.
Stronger and gusty Santa Ana winds will continue today becoming More widespread in the morning with east to northeast winds with gusts to 55 mph and isolated gusts to 65 mph. Winds will become less widespread more easterly and not quite as strong for tonight into Wednesday. Not quite as hot for Wednesday as slow cooling begins to spread slowly inland. Even with the slight cooling the heat may still be sufficient to extend the Excessive heat Warning into Wednesday for some coastal and valley areas. Weak onshore flow will return on Thursday with greater cooling for coastal areas into the western valleys.
SYNOPSIS FROM THE PHOENIX OFFICE
Well above normal temperatures will persist Tuesday as strong high pressure prevails across the western states. This high pressure system will slowly weaken through the rest of the week, resulting in a gradual cooling trend, though temperatures will continue to remain above normal. Dry conditions will also persist with no chance of rain through the end of the month. A rather balmy morning (for late October) across the region this morning, under clear skies and very strong ridging aloft. The combination of strong subsidence aloft and locally gusty northerly winds mixing warmer air down to the sfc has resulted in some locations in the Lower Colorado River Valley and at foothill locations in South-Central AZ seeing temperatures in the 80s at this hour. More sheltered lower desert locations, in contrast, are seeing temperatures in the 60s and low 70s. Latest global model output continues to show 500 mb heights remaining in the 591-594dm range this morning across the region, which is at near-record values from this time of year. The combination of this very warm air aloft and downslope easterly flow near the surface will once again allow temperatures to rise well up into the 90s at many lower desert locations, with a few spots perhaps even reaching 100 degrees. However, the very dry airmass (dewpoints in the 20s and 30s) and some afternoon breeziness will keep things from feeling quite as hot as it could be.
|Weather Story Phoenix Station||Weather Story San Diego Station|