Delightful desert days will transition to a possible HIGH WIND EVENT here in the deserts late Monday through Tuesday.
Low pressure is expected to move southeast from Oregon on Monday, deepening to 998mb and becoming centered in Southern Nevada by Tuesday morning.
This will rapidly increase the onshore flow of air on Monday, with westerly winds increasing during the afternoon and evening hours as the wind funnels through the Banning Pass and down the backside of the Santa Rosa, San Jacinto and San Bernardino Mountains.
Currently, the National Weather Service has issued a High Wind Watch for the Coachella Valley from Monday afternoon through early Tuesday morning. The nearby mountains are also included in this watch.
Current forecast models predict excessive winds: WSW 30-50, G70-80 late Monday afternoon and night. This has the POTENTIAL to be one of the strongest wind events of the past 6 months. As is normal with desert windstorms, predicting exactly when and where the winds may hit is a tough science - so don't be surprised if not all areas see this type of weather. However, we should be prepared for the POSSIBILITY of a significant windstorm.
A look at the forecast models shows the expected placement of the low pressure system just to our north by Monday night and Tuesday morning. As the core of the highest upper level winds blow across the nearby high mountain peaks, atmospheric conditions known as "mountain waves" - due to stable temperature inversions present near the tops of our highest peaks - will possibly help funnel the upper level winds at 10,000 feet or so down under these mountain top inversion layers, causing intermittent strong winds to surface on the east slopes, down into the normally calmer areas of the central or southern Coachella Valley. During these conditions, often the strongest winds are not found along I-10, but instead briefly hit south/west of Palm Canyon/Hwy 111, as localized extreme S or SW gusts. It will be interesting to see if this materializes this time around.
Gusts of this magnitude could create extreme blowing sand and dust. All areas have the possibility of strong gusts. Central Palm Springs may experience rotors, with the possibility of shifting winds from NW, to SW, or even E winds at times.
Temps will cool from the high 80's on Easter Sunday, down to the high 70's Monday, and back to the low-mid 70's on Tuesday and Wednesday. Temps will slowly climb back around 80 by the end of the week.
A very SLIGHT chance of scattered showers exists for the coastal areas to our west, but most desert areas are expected to stay dry, unless the system takes an unexpected turn toward the west.
LONG RANGE OUTLOOK
7-14 day outlooks continue to predict another low pressure system dropping into the Central California area during the following week, causing the subtropical jet stream to become active into Baja California, through Central Mexico, and into the Southeast US. This could bring cooler than average temps to most of California the week after next, with the possibility of additional precipitation in parts of the state. Interesting to note that this is similar to the jet stream setup that was expected earlier this winter to hit Southern California - due to El Nino - but never materialized. Many meteorologists are curious if this rare April pattern will occur, and if it will bring any additional late season snowpack to the Sierras, or rain to the rest of California during the middle of the month. Previous long range forecasts this winter have mostly been off!