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.
|August 25 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|
| MAJOR HEAT RETURNS THIS WEEKEND.
EXCESSIVE HEAT WATCH IN EFFECT FROM SUNDAY MORNING THROUGH SUNDAY EVENING...
The National Weather Service San Diego and Phoenix offices have issued an Excessive Heat Watch for a wide swath of southern California and SW Arizona which is in effect from Sunday morning through Sunday evening.
Lower desert highs up into the 111-114 degree range across SW AZ and SE CA, which is 6-8 degrees above normal for this time of year. These well-above normal highs combined with lows in the mid-upper 80s are expected to push Heat Risk levels into the high-very high range across that region.
SYNOPSIS FROM THE SAN DIEGO OFFICE
High pressure aloft over the Great Basin will bring a warming trend with hottest temperatures for Sunday through Tuesday. This will create very hot weather over the mountains and deserts. The ridge, combined with weak offshore flow, will make it hot even over the valley and coastal locations. Sunday looks to be the hottest day in the mountains and deserts, then Monday and Tuesday will be the hottest over the valleys and coast. Most areas will be 5 to 10 deg F above normal, however portions of the coast could be as high as 15 deg F above normal Monday and Tuesday. Monday looks like the best chance for breaking or tying high temperature records. An Excessive Heat Watch remains in effect for all areas through various times from Sunday through Tuesday.
Weak offshore flow will expand the heat towards the coast for Monday and Tuesday. The marine layer will become shallower...but still keep areas near the beaches cooler. A small amount of mid level moisture could bring a slight chance of afternoon thunderstorms to the mountains for Monday and Tuesday. A weak trough of low pressure may develop off the California coast next week bringing slight cooling for Wednesday into next weekend.
SYNOPSIS FROM THE PHOENIX OFFICE
Quiet but hot weather is expected this weekend across the Southwest. Dry and fairly stable air will remain in place through the weekend [with] building heat this weekend. A sprawling anti-cyclone anchored over the Great Basin will envelope the entire western US this weekend. The greatest height and temperature anomalies will be found further to the north/west, but we`re now expecting temperatures to get hot enough to increase the Heat Risk into the High category on Sunday. Therefore, we will issue an Excessive Heat Watch for portions of southeast California and southwest Arizona in effect Sunday. A modest increase in moisture levels early next week will mean a return of slight rain chances, possibly stretching into southeast California. Temperatures will also cool a few degrees in response to the moisture return.
|Weather Story Phoenix Station||Weather Story San Diego Station|