Marine Weather and Tide Forecast for Coachella, CA

KEY MESSAGES

- Hot and dry weather is forecast throughout the entire upcoming week with the hottest days expected to be today and Thursday.

- An Extreme Heat Warning is currently in effect through Monday evening for high temperatures ranging from 109 to 115 degrees across the lower deserts.

- Widespread Moderate HeatRisk will be seen from Tuesday through Friday with high temperatures ranging from 107 to 115 degrees across the lower deserts.

DISCUSSION
Continued hot and dry weather conditions will be the main weather story for the upcoming workweek as a strong subtropical ridge of high pressure persists over the region. Latest afternoon objective analysis shows the subtropical ridge centered over southwest New Mexico with 500 mb heights across our area around 593-595 dm (90- 99th climatological percentile). The hottest temperatures so far this year are expected this afternoon as a result, with highs expected to top out around 111-115 degrees for most lower desert locales. In Phoenix, temperatures will flirt with the daily record high of 115 degrees last set in 2021. Given these temperatures, widespread Major HeatRisk will cover much of the lower deserts and into the southern Gila County high terrain today. For Monday, forecast afternoon highs only drop 1-3 degrees with continued areas of Major HeatRisk. An Extreme Heat Warning remains in effect through Monday evening for most of the area.

Going into early Tuesday, a weak shortwave trough is set to move through northern portions of the state and will briefly flatten out the ridge and lower our heights during the first part of the week. Ensemble guidance show 500 mb heights lowering to around 590 dm before rising again going into Wednesday following the passage of the trough. The passage of this weak shortwave will result in daytime highs Tuesday dropping 2-4 degrees compared to Monday.
This "cool down" won't last for long as the subtropical ridge builds back over the region with 500 mb heights rising to around 592-594 dm by Thursday. Temperatures will once again heat up for the middle part of the week, with Thursday expected to be the hottest day as highs push upwards of 110-115 degrees across the lower deserts. Despite technically having a brief break in the Extreme Heat conditions on Tuesday and perhaps Wednesday, we will likely need to either extend the current Extreme Heat Warning through the workweek or reissue again for a day or two later this week. Widespread moderate HeatRisk is expected through much of the workweek, however, temperatures are expected to flirt with Major HeatRisk thresholds throughout the week.

PREVIOUS DISCUSSION
By around Friday into next weekend, ensembles favor a larger Pacific trough diving southeastward across the Pacific Northwest, likely into at least the Great Basin area. For now, guidance suggests this will eventually displace the sub-tropical ridge well to our east late next weekend, likely giving us a reprieve from the above normal temperatures. NBM forecast temperatures for next weekend show highs dropping more into a 102-108 degree range due to the passing trough, as well as partially due a slight uptick in low level moisture. Models have been fairly consistent in showing a gradual moisture increase (at least into eastern Arizona)
during the last week of June, but it barely looks to be enough to bring higher terrain spotty convection.

AVIATION
Updated at 2325Z.

South Central Arizona including KPHX, KIWA, KSDL, KDVT: No aviation weather concerns will exist through the TAF period under clear skies. Winds will follow typical diurnal patterns, with speeds remaining generally AOB 12 kts through tomorrow afternoon and periods of variability during transition periods. An earlier than usual switch to west winds is expected by late Monday morning, with gusts to 15-20 kts becoming common during the afternoon hours tomorrow.

Southeast California/Southwest Arizona including KIPL and KBLH: No aviation weather concerns will exist through tomorrow afternoon under clear skies. Winds will generally follow familiar patterns, favoring S/SE this afternoon into the early evening before shifting SW/W at both terminals. Speeds should remain mostly AOB 10 kts except at KIPL this evening, where a period of WSW'rly gusts to around 15-20 kts looks likely (>60% chance). Another round of gusty SW/W winds 20-25 kts expected to develop tomorrow afternoon at both terminals.

FIRE WEATHER
Strong high pressure will continue to bring hot and seasonably dry conditions before a weak and dry disturbance brushes across northern portions of the region Monday night into Tuesday.
Temperatures will remain above normal with highs near or above 110 degrees each day across the lower deserts. Wind patterns will continue to follow diurnal trends (upslope and downvalley) with afternoon gusts up to around 20-25 mph the next couple of days, particularly across the higher terrain east of Phoenix. Humidities will stay low with MinRHs between 5-10% and overnight MaxRHs only between 15-30%. Afternoon gusts combined with the dry conditions may lead to some elevated fire weather conditions, especially across the higher terrain east of Phoenix. High pressure will remain the dominant weather feature through the rest of the week with temperatures remaining above normal through at least Friday and afternoon MinRHs likely staying between 5-10% each day.

PSR WATCHES/WARNINGS/ADVISORIES
AZ...Extreme Heat Warning until 8 PM MST Monday for AZZ530>544- 546>556-559>562.

CA...Extreme Heat Warning until 8 PM PDT Monday for CAZ562>567-569- 570.