EXTREME HEAT TO BE FOLLOWED BY MORE HUMID SUMMER MONSOON PATTERN!
FINALLY! SOME WEATHER TO DISCUSS!
Massive high pressure moving in from the east, accompanied by a sweep of extremely dry easterly winds swept through Southern California today, accompanied by temps approaching 120 not just in the deserts, but in the inland valleys of the rest of Southern California. Temperatures at 4:30p were still 110-118 degrees in many communities, including Palm Springs, Thermal, Riverside, Van Nuys, among many others. Today is historic and record breaking in that the heat was so prevalent and extreme in the areas west of the mountains as well.
The high pressure came in on a bone dry airmass, with humidity down to 3% at times the past few days. HOWEVER - this is going to quickly change.
Higher humidity is surging up the Gulf of California and into Arizona, carried by southeast winds. Observations around 4:00p Friday indicate a large area of high dew points over 70 degrees building up to our southeast, with dew points surging into the 50's and 60's in Arizona and just south of the Mexican border (dew point temps are shown in the blue numbers). East and southeast winds at the surface and aloft, originating from the humid areas along the Gulf of Mexico and the western Mexico coast, are finally making their way northwest into California, Arizona and New Mexico. This annual wind shift to the southeast is known as the "summer monsoon." Here's a current look at the high dew points surging closer:
SATURDAY LOOKS TO BE MORE HUMID AND COOLER THAN TODAY
As the more humid airmass begins to surge northwest the next few days, temps are likely to drop closer to 105-110 instead of 120. However, higher humidity will encourage continued discomfort. A gulf surge of humid air from the Gulf of California is possible Saturday morning, but is more likely Sunday or Monday morning. Such a scenario will bring in southeast gusts, hazy skies to reduce visibility, as well as dew points surging up to or exceeding 70 degrees. It's possible excessive humidity could even suppress temps to 100 degrees or less during the afternoons at some point the next several days. Today may be the last day in awhile in which swamp coolers will function correctly.
INCREASING CHANCE OF RAIN/STORMS
With the increased humidity and instability in the atmosphere, will come an increasing chance of thunderstorms over the next 5 days. For today, the storms were having a late start in the normal "source regions" of northern and central Arizona, as well as NW Mexico. We will watch to see if any of these storms will move across Arizona into California later tonight.
An extended period of easterly flow will leave our area vulnerable to thunderstorms. It will be impossible to pinpoint exactly where storms will pop, but we should be prepared for scattered thunderstorms capable of high winds, heavy rain, lightning, and even an infamous haboob (large dust storm). The highest chances of heavy weather appears in the Monday - Wednesday time frame. If additional clouds and storms are more prolific than currently planned, high temps could even struggle to rise above 100 degrees at some point the next 5 days. Here's a look at the computer models for next Tuesday, showing a continued deep flow of moist air from the east and southeast.
The extended outlook for next week tends to look a bit drier towards the end of the week, but the pattern could still be sufficiently moist for afternoon and evening thunderstorms over the nearby mountains.
Also of note, is ocean temperature trends in the Central Pacific are indicating rapidly increasing water temperatures suggesting the possible development of another El Nino pattern. Scientists will be carefully monitoring this over the next several months. If trends continue at the current rate, it would suggest a rather significant warming event that could create a strong El Nino, which raises the odds for an often significant by-product, above average rainfall for California. Too early to predict anything with certainty though!
Keep an eye on the sky and on National Weather Service warnings, as we enter flash flood and dust storm season.
It's about time there's some weather to write about!