


Area Forecast Discussion
Issued by NWS Phoenix, AZ
Issued by NWS Phoenix, AZ
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286 FXUS65 KPSR 142114 AFDPSR Area Forecast Discussion National Weather Service Phoenix AZ 214 PM MST Mon Jul 14 2025 .UPDATE...Updated Short Term & Fire Weather Discussions. && .KEY MESSAGES... - Near to slightly above normal temperatures will last into Tuesday before dropping to slightly below normal later in the week. - Rain chances will gradually improve over the next couple of days, initially confined to higher terrain areas today before descending into the lower deserts as early as Tuesday evening. - Active monsoon weather is expected for Wednesday and Thursday across southern and central Arizona with strong winds and localized heavy rainfall and minor flooding all possible. && .SHORT TERM /Rest of Today and Tonight/... Mid-level water vapor satellite imagery reveals a subtropical high still west of our region, over the Pacific Ocean, but portions of it stretching back into the Great Basin and northern and western AZ. PWAT values have been increasing across southern and eastern AZ today. With the increase in moisture, most of the shower and thunderstorm activity this afternoon and evening will be confined to southeastern and eastern portions of AZ. Early this afternoon, some showers and storms have already started to develop across the Mogollon Rim, White Mountains, and east of Tucson. There remains a 10-20% chance of a few showers and/or thunderstorms reaching into central and northern Pinal County and far eastern portions of the Phoenix Metro. Highs today will reach into the 105-112 degree range across the lower deserts and mid-to-upper 90s and near 100 degrees in the higher terrain. With overnight lows very similar to this morning, with lows in the 80s across the lower deserts and 70s in the higher terrain. There will be a decent Gulf moisture surge into our area this evening, which will help set the stage for a more active monsoon day tomorrow. && .LONG TERM /Tuesday through Sunday/... The weather pattern will become more favorable for monsoon conditions starting Tuesday as the subtropical high splits with a new (fairly weak) center forming over northern Arizona. Additionally, the weak trough to our south will start to become more organized with a closed low forming in the upper levels somewhere just off the coast of central Baja. The recentering of the high will allow for the flow in the low and mid levels to turn more out of the south and southeast, advecting better quality moisture northward into Arizona. PWATs later on Tuesday are forecast to rise to between 1.3-1.5" into south-central Arizona, but low level mixing ratios are still likely to be a bit on the lower side at around 9 g/kg. The latest HREF and the 06Z HRRR do show isolated to scattered thunderstorm activity across southeast Arizona northward into southern portions of the Mogollon Rim Tuesday afternoon. The better moisture should result in MUCAPE of upwards of 500-1000 J/kg, while we also may begin to see some weak difluence aloft from the developing upper low to our southwest. NBM PoPs seem reasonable calling for 50% chances across the higher terrain with 20-40% chances extending into the south-central Arizona lower deserts. However, the lower deserts are still likely to have to contend with some CIN, so an organized outflow or a collision of outflows is likely to be needed for development over the lower deserts. The main threats with any stronger storms Tuesday should be strong wind gusts of 35-45 mph, while blowing dust may also end up being an issue if any organized strong outflows form. Wednesday into Wednesday night may represent our best chances for more widespread showers and thunderstorms as guidance shows the best difluence aloft setting up over Arizona. Moisture levels should also increase further during this time with PWATs reaching anywhere from 1.4-1.7" and low level mixing ratios closer to 11 g/kg. Despite the better moisture, instability may be an issue as forecast MUCAPEs may struggle to break 1000 J/kg due to increased cloud cover and decreasing lapse rates. This may limit the threat for stronger thunderstorms, but the improving forced ascent from the upper level low`s influence should increase the overall coverage of showers and thunderstorms starting Wednesday afternoon and lasting into early Thursday. NBM PoPs increase to 40-60% over the Phoenix area with 20-30% PoPs extending as far west as La Paz and Yuma Counties. Even higher PoPs of 60-80% are seen over the eastern Arizona higher terrain. Given the better moisture, the potential for heavy rainfall is expected to increase starting Wednesday afternoon with WPC highlighting all of south-central and eastern Arizona in a Marginal Risk of excessive rainfall. However, forecast QPF still seems to be on the low side with averages of 0.1-0.3" over the lower deserts to 0.3-0.5" in higher terrain areas. Localized higher amounts are sure to occur with some areas likely seeing over an inch. Model guidance is still unsure on how to handle the ejection of the upper level low and how quickly drier air will spread northeastward into the region. Models have essentially flip- flopped from last night with the GEFS now the drier and faster progressing model, while the EPS is slower with the low ejection and keeps better moisture over our area through all of Thursday. Forecast confidence for rain chances for Thursday is fairly low as it will likely be contingent on how much the atmosphere is worked over from Wednesday`s activity and how quickly to low lifts northward. The NBM is keeping fairly high PoPs of 30-60% on Thursday and this may be fine if moisture sticks around, but with lowering instability potential rainfall amounts are likely to be decreasing. Diminishing rain chances are expected Friday into Saturday with both models finally agreeing on drier air working into the area. As far as temperatures for the rest of the week, the increasing moisture, cloud cover, and lower heights aloft will all help to drop daily highs to around or even slightly below normal for Wednesday and Thursday. In fact, highs on Thursday in the Phoenix area may not even reach 100 degrees if we see rain in the morning and considerable cloud cover through the rest of the afternoon. Temperatures should begin to warm back up by the weekend with highs back to around normal. The subtropical ridge is then likely to rebuild over the Southern Plains by early next week which should in turn raise temperatures a bit higher over our region. && .AVIATION...Updated at 1737Z. South Central Arizona including KPHX, KIWA, KSDL, KDVT: Gusts and elevated wind speeds will be the main aviation concern through the TAF period. Gusts will resume this afternoon with speeds generally around 20kts. A brief lull in winds is anticipated this evening, but a relatively strong gulf surge will lead to a period with winds around 15 kts with potential for gusts between 20-25 kts from 05-09Z. Thunderstorm activity is expected to stay well east of Phoenix today, with easterly outflow winds not expected to reach terminals. FEW to SCT at or above 16K ft AGL expected this evening/tonight. Slantwise visibility impacts remain possible this morning and evening with lofted wildfire smoke. Southeast California/Southwest Arizona including KIPL and KBLH: Periods of lofted smoke creating slantwise visibility issues will continue to be the main aviation impact through this evening, with those issues enhanced during the sunrise and sunset periods. KIPL will primarily be out of the SE, with wind speeds expected to increase into the low teens by this evening, lasting through the overnight period, but look to relax by sunrise. KBLH will develop gusts around 25kt this afternoon, and sustained wind speeds will generally remain in the upper teens. Mostly clear skies through the TAF period. && .FIRE WEATHER... Moisture will gradually increase across Arizona through the middle part of the week providing increasing chances for showers and thunderstorms, especially by Wednesday. Temperatures will drop off from slightly above normal today and tomorrow to below normal Wednesday and Thursday. Afternoon MinRHs should bottom out around 15% today with southwesterly gusts of 20-25 mph at times continuing into the evening. RHs will improve Tuesday into Wednesday with MinRHs between 20-30% as chances for rain increase. Rain chances should mostly be confined to the eastern Arizona high terrain through Tuesday before moving into the lower deserts by Wednesday. Good chances for showers and thunderstorms across south-central and eastern Arizona are likely to last into Thursday before drying begins from the southwest. 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...Berislavich LONG TERM...Kuhlman AVIATION...Ryan/Benedict FIRE WEATHER...Berislavich/Kuhlman