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.
|September 1 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|
|….Continued VERY HOT Inland through Saturday
….Moisture from Lidia to Bring Increasing Shower/Tstorm Chances Saturday Night through Monday
….Gusty Easterly Winds Developing Saturday Night-Sunday
SYNOPSIS FROM THE SAN DIEGO OFFICE
Very hot conditions will continue across the area through Saturday with a slight chance of thunderstorms over the mountains and deserts. Tropical Storm Lidia near the southern Baja peninsula will track north then eventually west off the central to northern Baja coast while dissipating.
The remnant moisture from this system will move from south to north across Southern California Saturday night through Monday, bringing an increasing chance of showers and thunderstorms to the area. Winds will increase out of the east Saturday night through Sunday and become quite gusty, especially on east facing mountain slopes.
SYNOPSIS FROM THE PHOENIX OFFICE
Thunderstorm chances will remain limited today, however increasing moisture and humidity over the weekend will lead to better chances of showers and thunderstorms. The best chance of accumulating rainfall will occur over the southwest Arizona and far southeast California deserts. After a cooler and mostly cloudy weekend, warmer conditions will return next week along with more typical isolated afternoon thunderstorms.
Through the weekend, Lidia will track northwest along the Baja peninsula eventually being steered west as a remnant low into the colder Pacific around the building Great Basin ridge. While this blocking high will keep the central circulation of Lidia well from Arizona and California, moisture will continue to be shed along the northern periphery of the storm.
As with any approaching tropical system, there are a couple of competing signals affecting rainfall chances and coverage. Moisture increase is certainly a positive and most models output indicates a substantial jump in Pwats through Yuma/El Centro areas by Saturday afternoon (Pwats forecast 2.0 to 2.2 inches). There will need to be a better deep layer ascent associated with a vorticity band from the remnant tropical system to release the moisture content.
The potential for heavy, flooding rain is present, but with most ensemble member (and virtually all operational output) packed into the lower end of the distribution curve, confidence is low that amounts will exceed the ensemble mean
|Weather Story Phoenix Station||Weather Story San Diego Station|