National Weather Service Raw Text Product
Displaying AFOS PIL: AFDPSR Product Timestamp: 2022-07-27 20:17 UTC
Previous in Time Latest Product Next in Time
View All KPSR Products for 27 Jul 2022 View All AFD Products for 27 Jul 2022 View As Image Download As Text
000 FXUS65 KPSR 272017 AFDPSR Area Forecast Discussion National Weather Service Phoenix AZ 117 PM MST Wed Jul 27 2022 .SYNOPSIS... A flood watch remains in effect for much of the area. An abundance of moisture will allow any showers and storms that develop to quickly produce copious amounts of rainfall. The highest chances for showers and storms will reside over Arizona's higher terrain today. Shower and thunderstorm chances will increase over the lower deserts late this week and through the weekend as waves of energy interact with humid conditions. High temperatures will generally remain at or below normal, thanks to this monsoon pattern. && .DISCUSSION... Still juicy out there, with this morning's sounding showing 2.04 inches of precipitable water, which is greater than the max moving average for the day. Plenty of daytime heating will keep instability elevated today, with mesoscale analysis showing 1000-1500 J/kg MLCAPE and very little CIN over much of south- central Arizona. Activity across northern Arizona was able to send a pretty decent outflow boundary towards the lower deserts this afternoon, which has been triggering more convection across the northern half of the Phoenix metro. With exceptionally slow steering flow, this activity is barely moving and most of these cells are producing rainfall rates of at least 1-2 inches per hour. Thus, flash flooding will remain the biggest risk for the remainder of the afternoon. We could see strong winds around 30 mph with any storm as well and the HREF has less than a 10% chance of wind speeds exceeding 35 mph today and tonight. We expected scattered coverage of showers and storms, mainly across south-central Arizona and La Paz county in southwest Arizona, to continue until 4 or 5 pm MST this afternoon, before we see quieter conditions. As we’ve seen the past several mornings, there continues to be indications of a lingering MCV overnight into tomorrow morning bringing some additional showers to south-central Arizona. && .PREVIOUS DISCUSSION.... While there are some subtle changes in the pattern over the next several days, you have to look closely to see them. The overall setup is fairly stagnant: a moisture-laden troposphere is stuck in place. Meanwhile, AZ will sit beneath weak cyclonic flow in the mid-levels through at least the first portion of the weekend. Lapse rates are unimpressive above the BL, so MLCAPE values will range from 500-1500 J/kg most of the time. One distinct wave of energy is readily apparent on WV this morning just to the S of ELP. This feature is forecast to slowly churn its way westward along the Intl Border between now and Saturday, enhancing our PoPs from late Thu through Sat. After coordination with neighboring offices, the flood watch has been extended through Thursday night and may eventually be needed beyond that time as well. From Sunday into early next week, confidence is rather undesirable as forcing mechanisms are essentially indiscernible this far out in time. Ridging is forecast to amplify to our north, and ample moisture will still reside across the region. Iso/Sct storms remain in the forecast, and if we can pick up some enhancement to the easterly mid-level flow, storm motions will likely originate over the AZ high terrain before descending into the lower deserts. All monsoon hazards will remain on the table. MaxT's remain near (SE Cali) to below (elsewhere) normal for the time of year through the period. At PHX, NBM probabilities give us a daily 40% - 70% chance of remaining below 100F through Monday. && .AVIATION...Updated 1735Z. South-Central Arizona including KPHX, KIWA, KSDL, and KDVT: After some nearby showers this morning, most of the showers and isolated storms have shifted away from the terminals. Similar to previous days, conditions remain favorable for pop up isolated storms with heavy rainfall again later this afternoon into this evening. Forecast confidence still remains low on whether any storms will impacts the terminals, only around a 20 percent chance right now. Something that will need to be monitored. Anticipating another round of morning showers on Thursday, confidence enough for VCSH late tonight through the morning. Otherwise, mainly scattered mid clouds and scattered to broken high clouds will persist through the forecast period. Southeast California/Southwest Arizona including KIPL and KBLH: Persistent southeast to south winds are expected at both terminals. The terminals will see some scattered to broken high clouds through the forecast period, but most of the storms are currently expected to remain east of the area. && .FIRE WEATHER... MinRH values will feature a gradient from 25-35% over SW AZ and SE CA to 30-45% near Phoenix and points eastward. Overnight recovery will remain good, highest values (55% +) from PHX eastward. Wetting rains will be concentrated mostly over high terrain today. A flood watch is in effect for portions of La Paz and all of Gila, Pinal, and Maricopa Co's through tonight. From Thursday through early next week, rain/storm chances will be highest over the Arizona high terrain (50-70%), lessening to 10-30% chances nearer to the CO Valley and SE Cali. Winds will generally remain light, save for brief gusts near any stronger storms. && .PSR WATCHES/WARNINGS/ADVISORIES... AZ...Flood Watch through late Thursday night for AZZ533-534-537>563. CA...None. && $$ DISCUSSION...Feldkircher PREVIOUS DISCUSSION...Heil AVIATION...Frieders FIRE WEATHER...Heil