


Area Forecast Discussion
Issued by NWS Phoenix, AZ
Issued by NWS Phoenix, AZ
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561 FXUS65 KPSR 150955 AFDPSR Area Forecast Discussion National Weather Service Phoenix AZ 255 AM MST Tue Jul 15 2025 .KEY MESSAGES... - Rain chances will improve over the next couple of days with the best chances over eastern Arizona and at least a 20-30 percent chance expanding into south-central Arizona Wednesday into Thursday. - A few strong storms will be possible this afternoon and evening, likely focused east and southeast of the Phoenix area. - After near normal temperatures today, expect slightly below normal temperatures with plenty of clouds Wednesday and Thursday. && .SHORT TERM /Today through Wednesday/... A complex forecast scenario this week continues to lead to fairly low forecast confidence. The main issues involve discrepancies between models with how much moisture and instability will be available and the positioning and evolution of the upper level low which has just developed over central Baja. The latest thinking is today may present the best chance of a couple strong to marginally severe storms, while Wednesday may now be less active than previously expected. Moisture levels have increased since yesterday and should continue to do so through tonight. Forecast PWATs show readings between 1.4-1.6" later today focused over south-central Arizona with MUCAPEs climbing to between 500-750 J/kg over much of the area to as high as 1000 J/kg across southeast Arizona. Weak difluence aloft is also likely to develop, while mid level winds (600-400mb) become slightly enhanced out of the east up to 20 kts. The latest Hi-Res CAMs show fairly good agreement with shower and storm development by mid afternoon along the Mogollon Rim and much of far southeast Arizona. The most vigorous convection is expected across southeast Arizona with storm induced outflows likely reaching Pinal Co. by early evening. Strong gusty outflow winds may pose some risk of blowing dust southeast of Phoenix early this evening, while additional storm development will be possible. There may be enough instability leftover early this evening for a strong thunderstorm or two across Pinal Co. It may then be possible to get a decaying outflow into the Phoenix metro, but the CAMs really do not show any strong winds. Guidance also suggests the complex of storms over southeast Arizona is likely to induce an MCV which may bring additional showers or a weak thunderstorms during the overnight hours tonight as the MCV gradually lifts to the north northwest through south-central Arizona. If the MCV scenario comes to fruition, it now looks like it may be a determent for additional shower and thunderstorm development across south-central Arizona at least through Wednesday afternoon. There is also model evidence of some drying already beginning to take place across southwest Arizona to as far north and east as the Phoenix area starting Wednesday morning. Because of these potential negative factors, we have lowered PoPs for south-central Arizona on Wednesday. Guidance does still suggest a good deal of shower and weak thunderstorm activity over eastern Arizona on Wednesday and any weak to modest outflows may be enough to help trigger some activity into the lower deserts by Wednesday evening. The potential for any strong storms Wednesday has been reduced largely in part due to warming aloft and weakening instability. Some higher terrain areas should still be able to see a few heavier rain producing cells, but the overall risk for excessive rainfall will be marginal at best. && .LONG TERM /Thursday through Monday/... Forecast confidence for later this week continues to be fairly low as model differences remain. Both the GEFS and EPS show noticeable drying occurring on Thursday, but the uncertainty lies in how quickly we dry out. Models are finally mostly agreeing on bringing the upper level low northward into northern Baja with potential forced ascent still in place over much of Arizona. If there is enough moisture left over, we may be able to see 500 J/kg or so of MUCAPE during the afternoon hours, but that may not occur in a large area as we are still likely to see considerable cloud cover. Just like Wednesday, Thursday may mostly involve scattered showers and weak storms over higher terrain areas with a few isolated storms possible over the Arizona lower deserts. The drying is expected to continue Friday into Saturday with forecast PWATs dropping to between 1.1-1.3" Friday to around 1" Saturday. Rain chances Friday may partially depend on the eventual track of the upper level low which is mostly shown tracking up the CO River Valley or across southern California early on Friday. The eastern Arizona higher terrain should again have afternoon chances for showers and thunderstorms Friday, but we may also have a shot at some isolated convection closer to the upper low, maybe across southwest Arizona. By Saturday, the upper low is likely to have lifted far enough to the north or west that it will become a non-factor on our weather. Enough lingering moisture may still be present across eastern Arizona this weekend for some afternoon scattered convection, but the south-central Arizona lower deserts are likely to remain quiet. Temperatures are expected to cool off a good deal during the middle part of the week with below normal temperatures on Wednesday and Thursday, especially across south-central and eastern Arizona. As we stated yesterday, highs in the Phoenix area on Thursday may struggle to reach 100 degrees. As we really begin to dry out Friday into the weekend, temperatures will begin creeping upward again with readings back into the normal range by around Saturday. Temperatures at or just above normal are likely to persist through early next week as the subtropical ridge is likely to stay just to our east. && .AVIATION...Updated at 0535Z. South Central Arizona including KPHX, KIWA, KSDL, KDVT: The overall wind pattern throughout most of the period will continue to exhibit the typical diurnal tendency. There is uncertainty whether a full easterly shift will materialize at KPHX early Tuesday morning. Otherwise, wind speeds will generally be aob 12 kts with some occasional afternoon/early evening gusts near 20 kts. There is a low chance (10-30%) of a southerly outflow from distant thunderstorm activity affecting the area terminals Tuesday evening, producing some gusty winds. FEW to occasionally SCT clouds above 10 kft will prevail throughout the period. Some slantwise visibility issues will remain possible, especially during sunrise/sunset, as a result of lofted wildfire smoke. Southeast California/Southwest Arizona including KIPL and KBLH: No major aviation weather concerns under clear skies can be expected throughout the TAF period. Winds will generally be out of southeast at KIPL and out of the south at KBLH. Wind gusts upwards of 25 kts will be likely at times at KBLH during Tuesday afternoon/evening. Some slantwise visibility issues will remain possible, especially during sunrise/sunset, as a result of lofted wildfire smoke. && .FIRE WEATHER... Moisture will gradually increase across much of Arizona over the next couple of days providing increased chances for showers and thunderstorms focused across higher terrain areas. Temperatures will drop off from near normal today to below normal Wednesday and Thursday. Afternoon MinRHs will improve with readings around 20% today and 25% Wednesday and Thursday. Expect south southwesterly gusts of 20-30 mph at times over the CO River Valley with more diurnal lighter winds over the eastern districts. Some drying conditions will begin to usher back into the area later this week resulting in more limited shower and thunderstorm chances by Friday. Eventually, high pressure is likely to return to the region by the weekend with RHs dropping back into the teens, temperatures returning to near normal, and rain chances ending for all but the higher terrain. && .PSR WATCHES/WARNINGS/ADVISORIES... AZ...None. CA...None. && $$ SHORT TERM...Kuhlman LONG TERM...Kuhlman AVIATION...Lojero FIRE WEATHER...Kuhlman