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.
| November 21 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
|DISCUSSION FROM THE SAN DIEGO OFFICE
An upper level ridge has seized control of the region bringing warming. Today will be the first day of a late season heat wave that will affect the region through Thanksgiving. Outside of the warmth, today will be defined by light winds and decreasing high-level clouds.
The ridge is expected to peak Wednesday making Southern California the warmest place this Thanksgiving. Weak offshore flow will accompany the heat Wednesday and on Thanksgiving, bringing local wind gust of 25-40 mph (light Santa Ana winds) to coastal slopes, canyons, and passes. Potential elevated fire concerns, any fires started may spread quickly.
A slow cooling trend will begin over the weekend as the ridge weakens and shifts slowly to the southeast. Days will remain warm over the weekend however; significant cooling is anticipated Monday when a weak trough passes to the north.
DISCUSSION FROM THE PHOENIX OFFICE
Unseasonably strong ridging continues to build into the region with the circulation center off the central Baja Coast and ridge heights lifting the storm track and upper jet well into the Pacific Northwest and western Canadian Provinces. Clearing skies by Wednesday. Forecast temperatures remain unchanged as one of the warmer Thanksgivings on record.
By late week and early weekend, subtle cooling will result for much of the region. Conditions will keep the current dry streak. This is the driest streak since July 2010. Extended forecast lends itself to temperature variability and some periods of elevated winds.
Overall dry northwest flow aloft will persist today into Wednesday and there will be periods of high cloud embedded in the flow with bases mostly at or above 25 feet. Winds will be very light variable or calm for the next 24 hours.
|Weather Story Phoenix Station
||Weather Story San Diego Station
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