Area Forecast Discussion
Issued by NWS Phoenix, AZ
Issued by NWS Phoenix, AZ
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461 FXUS65 KPSR 130541 AFDPSR Area Forecast Discussion National Weather Service Phoenix AZ 1041 PM MST Sun May 12 2024 .UPDATE...Updated 06z Aviation Discussion. && .SYNOPSIS... Temperatures will remain above normal for the week ahead with the lower desert communities nearing or exceeding 100 degrees most days. Dry conditions will persist with the usual late afternoon breeziness. An exception will be the higher elevations of northern and eastern Arizona which will see a few late day showers each day. These showers could be supportive of some erratic, gusty winds descending into the lower deserts each evening. && .DISCUSSION... Midday water vapor imagery showing upper level low circulation now into SE CO and continuing to move away from the region. Visible imagery still indicating some residual moisture over the high country back into central/eastern AZ with some cumulus forming. Could be a couple showers form in these areas later today, but isolated in coverage and no impact into the lower elevations. Otherwise, ensembles in overall good agreement with heights building slightly over the region into Monday, bringing with it another day of temperatures a few degrees warmer, with highs around 100 degrees. HeatRisk will maximize in the moderate category at best for scattered locations and mainly across SE CA. The weak ridging will be short lived as another upper low moves in from off the SW CA coast. This will produce height falls again across the SW US. Not enough moisture for showers, except for some higher elevations once again to the north of the forecast area. A northerly mid level flow around this low would suggest the potential for some occasional outflow winds dropping south across the deserts, just something to monitor for potential erratic winds and elevated fire weather. The lower heights through the week would suggest keeping temperatures in check somewhat, right around that century mark. Otherwise, typical May weather this week with dry conditions and afternoon breeziness. Cluster analysis out to days 6 and 7 for next weekend, favoring some type of building heights, could bring the warmest temperatures of the season so far. However the overall consensus is that positive height anomalies remain low so not seeing any higher levels of HeatRisk at the moment. && .AVIATION...Updated at 0540Z. South-Central Arizona including KPHX, KIWA, KSDL, and KDVT: No aviation concerns are anticipated through the forecast period under mostly clear skies. Wind directions will favor their typical diurnal tendencies through tomorrow evening with periods of very light and variable winds during direction switches. The west switch will take hold between 18-20z, and though sustained speeds will remain aob 10 kts, gusts into the mid to upper teens may pick up later in the afternoon and last through the early evening tomorrow. Widely scattered, high-based cu are expected to develop again tomorrow over the high terrain to the north and east. Southeast California/Southwest Arizona including KIPL and KBLH: No aviation concerns are expected through the TAF period under passing FEW-SCT high clouds. There is low confidence in the exact wind directions at BLH, though a southerly component will be favored through much of the period. West winds will be favored at IPL through tomorrow morning and late tomorrow afternoon into the evening. Extended periods of light speeds (aob 6 kts sustained) and variability will be common at both terminals. && .FIRE WEATHER... Periodically gusty winds, dry fine fuels, and low humidity levels will yield a locally elevated fire danger this week. Temperatures will maintain at above normal levels with seasonably dry weather persisting across the districts. Minimum afternoon humidity levels around 10% will be common across lower desert elevations with values in the teens over higher terrain areas. Overnight recovery will range widely from poor to fair in a 20-50% range. Afternoon breeziness with gusts 20-25 mph will be common over most areas with some enhancement possible in far eastern districts due to high based showers over mountains. && .PSR WATCHES/WARNINGS/ADVISORIES... AZ...None. CA...None. && $$ DISCUSSION...Frieders AVIATION...Whittock FIRE WEATHER...18/Frieders