Area Forecast Discussion
Issued by NWS Phoenix, AZ
Issued by NWS Phoenix, AZ
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333 FXUS65 KPSR 260535 AFDPSR Area Forecast Discussion National Weather Service Phoenix AZ 1035 PM MST Tue Jun 25 2024 .UPDATE...Updated 06Z Aviation Discussion. && .SYNOPSIS... Enhanced monsoonal moisture across the region will continue to allow thunderstorm chances to persist into the weekend, overall coverage will decrease and be confined mostly to the higher elevations. Temperatures will continue to run several degrees above normal, so hot and humid conditions will persist as well during this period. && .DISCUSSION... The early afternoon radar and satellite imagery showing the usual midday showers and thunderstorms forming over the high country north and east of Phoenix with the exception of an isolated storm across far southern Maricopa County. Visible satellite imagery has been showing a remnant MCV from overnight convection drifting northwest across the SC AZ through the morning. This has resulted in overall increased cloud cover for most areas and keeping conditions more stable. The latest SPC Meso analysis subsequently showing convective inhibition persisting across the Phoenix valley, unlike yesterday when we had full sunshine and eroded the cap. For the rest of today, the latest HRRR convective trends seem reasonable given the aforementioned instability trends. Most of the convection should remain over the high country with a steering flow to the north and away from the Phoenix area. An exception is likely into western Maricopa County into La Paz County ahead of MCV where more insolation has occurred and cap has eroded. Forecasting some convection to develop in these areas into early this evening. Shower and storm potential does try to trend downward as upper level ridge retrogrades into AZ/NM region this week, which should tend to inhibit convection, especially for the lower deserts. HRRR hints at this trend on Wednesday. Also, by Thursday and Friday, watching a stronger trough dig across the northern Rockies, which will break down the ridge over AZ and also shunt deeper moisture to the south with the development of a drier west/southwest flow. This should further inhibit storm potential and confine it to mainly far SE and Eastern AZ into first half of the weekend. After this trough passes to the northeast, ridge builds again across the SE U.S. which will bring back the southerly flow and moisture that is poised to move back north into the region as early as Sunday. This will increase storm chances again into next week. CPC outlooks for 8-14 days (the first week of July) favors higher percentages for above normal precipitation. As for temperatures, readings will remain above normal by several degrees, but nothing on the record/extreme level. This will maintain a consistent moderate HeatRisk across the region through the period. && .AVIATION...Updated at 0535Z. South-Central Arizona including KPHX, KIWA, KSDL, and KDVT: Areas of light rain may continue to move over KDVT over the next hour before fully clearing to the north. Current northwesterly winds with gusts of 20-25 kt will taper off over the next couple of hours. Winds will become light and variable around 08-10Z through the early morning hours. A westerly component will redevelop by mid- to-late morning. Winds may occasionally gust around 20 kt during the afternoon and early evening. FEW-SCT mid and high level clouds will continue through the TAF period and may become broken at times tomorrow afternoon. Southeast California/Southwest Arizona including KIPL and KBLH: Winds will follow their typical diurnal patterns, with speeds generally aob 11 kt with the exception of some gusts near 20 kt in the afternoon and early evening. Skies will remain mostly clear until FEW high clouds move in tomorrow evening. && .FIRE WEATHER... Monsoonal moisture will continue to result in daily chances for shower and thunderstorm activity. The higher terrain areas will see the greatest potential with some locally heavy rainfall with any storms that develop. Best chances for storms are today, with a gradual decrease in chances/coverage through Friday, where chances drop around 15% or lower. Chances for wetting rains will generally remain around 10-20% for the higher terrain areas and 5-10% for the lower deserts of south-central Arizona today, before dropping below 10% across the region starting Thursday. With the elevated moisture in place, MinRH values through the middle of this week will range between 30-40% across the far eastern districts to between 15-25% across the western districts before slowly drying during the latter half of this week. Winds will follow their typical daily tendencies, with gusty outflows from any thunderstorm activity anticipated over the next several days. Temperatures average several degrees above normal through the forecast period. && .PSR WATCHES/WARNINGS/ADVISORIES... AZ...None. CA...None. && $$ DISCUSSION...Frieders AVIATION...Berislavich FIRE WEATHER...Young/Frieders