Area Forecast Discussion
Issued by NWS Phoenix, AZ
Issued by NWS Phoenix, AZ
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452 FXUS65 KPSR 082055 AFDPSR Area Forecast Discussion National Weather Service Phoenix AZ 155 PM MST Sat Jun 8 2024 .SYNOPSIS... Slightly cooler, although above normal, temperatures are forecast through the weekend into Monday. Expect temperatures to heat up by the middle of next week due in large part to high pressure building into the region. Dry conditions will prevail through the forecast period. && .DISCUSSION... For the short term, weak circulation associated with a very weak upper-level low located over the Sonoran Desert region of the northwest corner of Mexico continues to gradually move northward into AZ helping to slightly lower 500 mb heights dropping temps a couple of degrees. Expect low temperatures this evening to dip to the low 80s for the Phoenix Metro and low to mid 70s for the surrounding region. Expect low temps to fall to the upper 60s in higher mountain elevations. Along with the cooler temperatures, the weak upper-level low will also help enhance somewhat the early evening breeziness across the area, with the potential for some gusts exceeding 30 mph at times across portions of western Imperial County. Upper level clouds will continue to build into the eastern portions of the CWA this evening, slightly clearing overnight, building back in tomorrow during the day. Winds will continue to generally favor diurnal tendencies with occasional afternoon gusts of 20-25 mph expected across most of the region tomorrow. Heading into next week, model guidance continues to remain in pretty good agreement in the overall synoptic pattern as another upper-level low is set to cutoff off the coast of southern CA/northern Baja by Monday with a ridge strengthening across the southwestern CONUS. There still continues to be some discrepancies examining the ensemble cluster analysis in the overall positioning/strength of the cutoff low, which will dictate the positioning of the ridge downstream. Latest trend indicates a pretty robust ridge building across NM/AZ by midweek with 500 mb height fields rising above 590dm across most of the region with values as high as 594-597dm across the eastern half of AZ through NM. Therefore, an uptick in temperatures can be expected heading into the Tuesday-Thursday timeframe with another round of excessive heat conditions possible, especially across the south- central AZ lower deserts, as highs will likely once again reach 110+ degrees and potentially necessitating the issuance of new excessive heat products. Ensemble and cluster analysis shows a cutoff low eventually making its way through the region by the end of next week, bringing slightly cooler temperatures. Heading into next weekend, a more potent large-scale trough will approach the Pacific Northwest and traverse the western CONUS. However, there is a large degree of spread amongst the ensembles and large uncertainty in cluster analysis on the overall depth and position of the trough, which will dictate whether or not the Desert Southwest will see any impacts in the form increased winds, further cooling, and potential precipitation. && .AVIATION...Updated at 1800Z. South-Central Arizona including KPHX, KIWA, KSDL, and KDVT; No major aviation weather concerns will exist through the TAF period under FEW-SCT and at times BKN clouds aoa 20 kft. Wind directions will favor typical diurnal tendencies. A southerly cross runway component is expected to prevail for KPHX and KDVT with speeds mostly aob 8 kt sustained until SW winds definitively establish this afternoon between 20-22Z. Late afternoon gusts into the upper teens will be common across all terminals. Hi-Res guidance continues to show the potential for some weak reflectivity signatures (high-based scattered virga showers) over South-Central AZ this evening, mainly to the east, but confidence is very low in this leading to any aviation impacts. Southeast California/Southwest Arizona including KIPL and KBLH: No major aviation weather concerns will exist through the next 24 hours under FEW-SCT high clouds. Winds will favor S to SSW at KBLH through the period with afternoon and early evening gusts upwards of 20 to 25 kt. Directions will favor WSW at KIPL by this afternoon, with gusts to around 25 kt and occasionally up to 30 kt this evening, before calming overnight and returning to SE early tomorrow morning. && .FIRE WEATHER... Hot and seasonably dry conditions will continue to support a high fire danger across the area into late next week. Slightly cooler temperatures, although still remaining above normal, can be expected through Sunday before heating up once again heading into the middle of next week. Winds will continue to generally favor diurnal tendencies with occasional afternoon breeziness of 20-25 mph expected across most of the region. MinRHs ranging between 5-15% with poor to fair overnight recoveries of between 20-45% will be common. && .PSR WATCHES/WARNINGS/ADVISORIES... AZ...None. CA...None. && $$ DISCUSSION...95/Lojero AVIATION...Whittock FIRE WEATHER...95/Lojero