


Area Forecast Discussion
Issued by NWS Phoenix, AZ
Issued by NWS Phoenix, AZ
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280 FXUS65 KPSR 100510 AFDPSR Area Forecast Discussion National Weather Service Phoenix AZ 1010 PM MST Wed Jul 9 2025 .UPDATE...Updated Aviation Discussion && .KEY MESSAGES... - Extreme Heat Warnings are in effect today through tomorrow as lower desert highs reach 112 to 119 degrees and lead to widespread Major Heat Risk. - Temperatures lower a few degrees Friday through this weekend, but will remain above normal, with lower desert high temperatures around 105 to 110 degrees. - Thunderstorm activity will continue to be limited to the Arizona high terrain and southeast Arizona, likely through this weekend. && .SHORT TERM /TODAY THROUGH THURSDAY/... You know it is going to be a very hot day when the temperature reaches 110F before noon and 114F before 1 PM. This was the case today in Phoenix and several other lower desert communities. High temperatures this afternoon will be pushing 114-119F across most of the lower deserts, as strong high pressure remains situated overhead. Phoenix will likely tie or break the daily record high temperature today of 116F, a few other locations may also break records, like in El Centro, CA. This heat is resulting in widespread Major HeatRisk (Level 3 of 4) today, meaning everyone is susceptible to heat health impacts without adequate cooling. An Extreme Heat Warning was expanded today to nearly all of Southern AZ and SoCal. These are dangerous and deadly temperatures. Please limit time outdoors, stay hydrated, and take advantage of air conditioning. Phoenix has free cooling centers across the metro area if needed. The Extreme Heat Warning will continue through tomorrow for most of the same areas. Temperatures are not forecast to be as hot as today, as a shortwave trough passing through the Great Basin flattens and weakens the ridge slightly. High temperatures forecast around 110-116F will again lead to Major HeatRisk for most communities. Plus, there will be limited relief overnight, with lows only in the upper-80s to low-90s. In addition to it already being hot, it will be mostly sunny today and tomorrow, with very limited clouds. Maximizing solar radiation will definitely be draining on the body. With the high pressure overhead and sub-optimal moisture, afternoon thunderstorms will again be limited to high terrain areas northeast of Phoenix and in Southeast AZ. Mesoanalysis is showing moisture levels have actually lowered from yesterday and overall CAPE values are lower. Still, a gusty shower or brief storm, with limited rainfall, may impact parts of southeaster Gila County this afternoon. Moisture levels and instability lower even more for tomorrow, with overall less convection across the state. A tightening of the pressure gradient tomorrow, in response to the passing shortwave trough to the north, will lead to widespread breezier conditions. Afternoon and evening wind gusts are forecast to reach up to 25-35 mph, rather than the 15-25 mph this afternoon. These stronger winds combined with low humidity will create some locally elevated fire weather conditions. && .LONG TERM /FRIDAY THROUGH TUESDAY/... The subtropical high is expected to continue to slowly migrate westward towards the southern CA coastline heading towards the end of the week through the upcoming weekend. This will result in 500 mb height fields to decrease slightly closer to 591-594dm. This will translate to slightly cooler temperatures, but still remain a few degrees above normal as afternoon highs will average around 110 degrees across the lower deserts with widespread Moderate HeatRisk. The convective potential through the weekend will continue to be very limited as the upper-level flow pattern will remain unfavorable for any deep moisture influx. In fact, as the high settles over the southern CA coastline, the flow will turn out of the north, bringing drier air with PWATs dropping below one inch during the weekend. However, enough low-level moisture may still be present for some afternoon convection to materialize, mainly across the vicinity of the White Mountains and the southeastern third of AZ. Heading into next week, model guidance continues to show the high repositioning towards the Four Corners Region, especially by the middle of the week. This would result in a more favorable flow pattern for deeper moisture advection, with convective coverage on the increase across the higher terrain areas initially before chances increase across the lower deserts, more likely by the latter half of the week. && .AVIATION...Updated at 0510Z. South Central Arizona including KPHX, KIWA, KSDL, KDVT: No major aviation concerns are expected during the TAF period. Winds will follow typical diurnal trends, with an earlier W`rly establishment than usual, and familiar afternoon gusts around 20 kts. At KPHX, the usual E`rly shift appears uncertain, but if one were to occur, it will be short lives, otherwise W`rly winds will prevail through the forecast. Besides a FEW clouds over the region, skies should be mostly clear. Southeast California/Southwest Arizona including KIPL and KBLH: No aviation concerns are expected over the next 24 hours. Typical diurnal wind trends will prevail with familiar afternoon and evening breeziness later in the period, especially at BLH. Besides a FEW high cirrus tonight, skies should be mostly clear. && .FIRE WEATHER... Regionally dry conditions and above normal temperatures will persist through the next week as lower deserts highs reach 110-118 degrees today and tomorrow and then 105-110 through this weekend, with temperatures peaking today. MinRH values will range from 15-20% nearly every day, while MaxRH values will be the lowest tonight at 20-40% before increasing up to 30-50% the rest of the forecast period. One exception will be across Imperial and southern Yuma Counties where periodic gulf surges will result in MaxRH values in excess of 50-60%. The overall wind pattern will follow the familiar diurnal trends, with some afternoon/early evening breeziness with 15-25 mph peak gusts. An uptick in the winds is expected tomorrow and Friday afternoons with 25-35 mph peak gusts. This may lead to locally elevated fire weather conditions, primarily on Thursday due to drier conditions. Very minimal rain chances will exist through this weekend, with activity focused mainly across the eastern and southeastern third of AZ, with CWR <10%. && .PSR WATCHES/WARNINGS/ADVISORIES... AZ...Extreme Heat Warning until 8 PM MST Thursday for AZZ530>556- 559>562. CA...Extreme Heat Warning until 8 PM PDT Thursday for CAZ560>570. && $$ SHORT TERM...Benedict LONG TERM...Lojero AVIATION...RW FIRE WEATHER...Lojero/Benedict