Area Forecast Discussion
Issued by NWS Phoenix, AZ
Issued by NWS Phoenix, AZ
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416 FXUS65 KPSR 162011 AFDPSR Area Forecast Discussion National Weather Service Phoenix AZ 110 PM MST Sun Nov 16 2025 .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 1725Z. South Central Arizona including KPHX, KIWA, KSDL, and KDVT: The main aviation impact during the TAF period will continue to be lingering VFR CIGs. Over the course of the afternoon, cloud layers will begin to scatter out, but some brief moments of CIGs around 5- 6k ft cannot be ruled out. W`rly winds will prevail through this evening, with some occasional gusts around 15-20 kts through sunset, before we see our typical E`rly shift tonight. Southeast California/Southwest Arizona including KIPL and KBLH: No major aviation concerns are expected over the next 24 hours. Winds at both terminals will contain a W`rly component through much of the period, with some periodic gusts near 20 kts, especially at KBLH this afternoon. FEW-SCT low and high level clouds will be present through the evening with the lowest bases around 8-10k ft. && .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...RW FIRE WEATHER...Kuhlman