Area Forecast Discussion
Issued by NWS Phoenix, AZ
Issued by NWS Phoenix, AZ
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280 FXUS65 KPSR 162357 AFDPSR Area Forecast Discussion National Weather Service Phoenix AZ 457 PM MST Sun Nov 16 2025 .UPDATE...Updated Aviation Discussion. && .KEY MESSAGES... - Another large Pacific weather disturbance will bring the next opportunity for rain Tuesday and Wednesday with additional chances arriving late in the week. - Temperatures this week will hover below the seasonal normal with readings at least 10 degrees below normal during the middle of the week. && .SHORT TERM /Today through Monday/... Early afternoon WV imagery and objective analysis depicts a deep, closed low over southern California accelerating northeast towards southern NV as jet energy translates to the eastern periphery of the trough axis while expansive, progressive Pacific troughing dislodges this previously slow moving feature. The steep cold front associated with this system has cleared the Phoenix metro, albeit losing definition over the higher terrain as supporting energy becomes separated. Although cyclonic vorticity was still passing over SW Arizona and forced ascent lingers in the CWA, better quality moisture was being shifted east and pinched away from forcing mechanisms. In addition, increasing dry westerly sfc-H8 flow was scouring mixing ratios closer towards 6 g/kg while jet energy quickly lifting north was creating a midtropospheric subsidence inversion further capping off any moist ascent. Thus, other than a stray shower through orographic processes, confidence is good that a period of dry weather will prevail into at least Monday afternoon. However, this tranquil weather period will be short lived Monday as the aforementioned Pacific wave will dig and intensify into the void left by the departing negative height anomaly. Robust H5 height falls will enter the forecast area Monday afternoon as strong jet energy begins to materialize downstream of the cold core incurring broad scale lift juxtaposed with modest sfc-H7 moisture return. Both global scale and high resolution modeling have been consistent in advertising building theta-e advection with broad scale moist, isentropic ascent around the 300K layer. The greatest uncertainty in this evolution is obtaining more precise timing and location as model spread ranges from Monday afternoon over south-central Arizona to late Monday night in western Arizona. NBM POPs appeared shifted too far eastward, possibly tied to the influence from global ensembles as HREF membership has solidly been focusing better chances from the Phoenix metro westward through Monday evening before spreading east Tuesday. && .LONG TERM /Tuesday through Sunday/... Models remain in good agreement showing the next weather system moving into our region Tuesday with the low center moving through southern California and Arizona as it weakens on Wednesday. The best forcing and moisture is likely to align across central Arizona on Tuesday bringing fairly widespread shower activity with chances for embedded thunder. This weather system is likely to bring higher rainfall amounts to southern and central Arizona than this weekend`s system with QPF amounts averaging around 0.25-0.50" for Phoenix to as high as 0.75-1.00" for higher terrain areas north and east of Phoenix. The western lower deserts of southeast California and southwest Arizona will mostly miss out on the best rain this time with amounts generally less than a tenth of an inch. The slow progression of the low should continue to bring some residual shower activity across central and eastern Arizona Wednesday before eventually coming to an end at some point later Wednesday or Wednesday night as the low moves to the northeast of the region. Even cooler air is anticipated Wednesday as the second system will have a colder source region. Forecast highs begin to lower on Tuesday with readings potentially only in the mid 60s before bottoming in the lower 60s on Wednesday and/or Thursday. These well below normal temperatures should also translate to overnight lows well into the 40s across the lower deserts starting Wednesday night. The active weather pattern may bring a third weather system at some point later in the week or the weekend, but there is much more uncertainty with the track of this potential third trough. Model trends over the past 24-48 hours have been leaning more toward a progressive system which may not end up bringing much additional rainfall. The well below normal temperatures during the middle part of the week should moderate by next weekend with the latest NBM showing readings closer to normal. && .AVIATION...Updated at 2355Z. South Central Arizona including KPHX, KIWA, KSDL, and KDVT: No major aviation concerns are anticipated through Monday afternoon under SCT-BKN cloud decks (bases AOA 4-5 kft AGL). Winds will favor W through at least 03Z, with occasional gusts to around 15 kts possible through sunset. Overnight, expect winds to return to typical E/SE drainage directions. SE winds should then prevail through the end of the TAF period. Monday evening and overnight into Tuesday, anticipate VCSH/SHRA conditions to once again develop, with VFR CIGs around 050-060 filling in over the PHX airspace. Scattered lower decks will be possible. The main concerns with this next round of showers will be brief MVFR CIGS (20% chance), the potential for MVFR or lower VIS during rain (20-30% chance), and isolated TS (15-25% chance). Southeast California/Southwest Arizona including KIPL and KBLH: No major aviation concerns will exist through Monday afternoon under FEW-SCT cloud decks AOA 6 kft AGL, with BKN high cirrus decks filling in overnight. Winds will favor a westerly component through at least this evening, with speeds gradually relaxing over the evening hours. Winds will then develop a southerly fetch by late Monday morning and through the afternoon as another weather system approaches the region from the west. && .FIRE WEATHER... A weather system will continue to move through the region today bringing cooler temperatures, increased humidities, and shower activity across the eastern districts. A few isolated thunderstorms will be possible for the eastern districts producing isolated heavier rainfall amounts. Monday will bring quieter weather conditions, but still with a chance of isolated showers. Minimum humidity values will range between 40-70% areawide through Monday with good to excellent overnight recoveries. Locally gusty winds upwards of 25 mph will be possible through this afternoon with overall light winds tonight and Monday. The active weather will continue for a good portion of the upcoming week with another weather system affecting the area Tuesday into Wednesday and another potentially later in the week. Expect below normal temperatures and elevated humidities to last all week. && .PSR WATCHES/WARNINGS/ADVISORIES... AZ...None. CA...None. && $$ SHORT TERM...18 LONG TERM...Kuhlman AVIATION...Whittock FIRE WEATHER...Kuhlman