NOTE: Some of the data on this page has not been verified and should be used with that in mind. It may and occasionally will, be wrong. The tide reports are by xtide and are NOT FOR NAVIGATION. Privacy and Cookie policy

FXUS65 KPSR 230502 AFDPSR

Area Forecast Discussion National Weather Service Phoenix AZ 1002 PM MST Fri Sep 22 2023

UPDATE
Updated Aviation Discussion.

SYNOPSIS
Increased cloud cover will allow for slightly below normal temperatures today. As conditions begin to dry out Saturday afternoon, mostly clear skies will prevail through at least early next week. High pressure is expected to strengthen heading into next week as well, resulting in a gradual warming trend and above normal temperatures. Temperatures will peak Tuesday- Wednesday before cooling down slightly the latter half of next week.

DISCUSSION
A low pressure system situated over southern Idaho will weaken in the coming days as an upper level ridge continues to dominate the overall weather pattern through the middle of next week.
Southwesterly flow aloft will allow remnant mid to upper level moisture from Post-Tropical Cyclone Kenneth to push into portions of the Desert Southwest today. This will result in increased cloud cover over the region, as depicted on water vapor satellite imagery.
These thick mid to high clouds with ceilings between 12-15 kft will cause temperatures to be slightly below normal today.
Afternoon highs are expected to range between the low to mid 90s across the lower deserts as light, diurnal winds persist.

PWATs are anticipated to continue rising throughout the day, peaking at 1.2-1.3" in southeast California overnight. However, latest ACARS soundings indicate a substantial amount of lower level dry air in place which will make it difficult to produce rainfall. The best chances are mainly over Riverside County, where NBM PoPs reach over 15% and sprinkles/isolated light showers are possible through this evening. Thus far, sprinkles have been shown on radar imagery but no measurable precipitation has been recorded. Otherwise, mainly virga is expected across the region before conditions dry out beginning late Saturday afternoon through at least the middle of next week.

The subtropical high pressure system over Mexico will strengthen and expand this weekend leading to a warming trend and near normal temperatures. H5 heights are anticipated to peak around 590-592 dam during the first half of the week as temperatures reach 4-6 degrees above normal as early as Monday. Highs are forecast to peak Tuesday and/or Wednesday, reaching between 99-103 degrees in south-central Arizona each afternoon. Although Minor HeatRisk will prevail, temperatures will be above the 90th percentile of climatology so continue to stay hydrated.

Ensemble spread increases the latter half of next week due to uncertainty regarding the amplitude and trajectory of a trough originating in the eastern Pacific. Looking at Day 7 cluster analysis, EPS and GEFS members indicate that the trough will deepen and push southward across the western CONUS, while Canadian members favor a more shallow trough solution. Regardless, the trough is expected to bring slightly cooler temperatures and breezy to windy conditions to late next week. Less than 10% of ensemble members also suggest that moisture will increase towards the end of the period, however uncertainty remains high at this time.

AVIATION
Updated at 0500Z.

South-Central Arizona including KPHX, KIWA, KSDL, and KDVT: No major aviation weather concerns are expected through the TAF period. Winds will generally follow light, diurnal tendencies becoming variable at times. By tomorrow afternoon, W/SW winds will increase with sustained speeds around 8-11 kts along with a few gusts upwards of 15-20 kts possible before subsiding in the evening. Isolated virga can't be ruled out Saturday morning, which could create some erratic breezy winds, but expect this to mostly remain confined to the north of the terminals. SCT-BKN clouds aoa 12 kft will continue before clearing out by tomorrow evening.

Southeast California/Southwest Arizona including KIPL and KBLH: No major aviation weather concerns are expected through the next 24 hours. Light W to NW winds are favored at KIPL through the period, while winds at KBLH predominantly favor the SSW with extended periods of variability through tomorrow morning. A few passing virga showers will remain possible through the overnight hours, which could create some erratic breezy winds at times. SCT- BKN mid and high clouds aoa 10 kft will continue before clearing out going into tomorrow afternoon.

FIRE WEATHER
Tranquil weather will prevail through at least the middle of next week as the chances for wetting rain remain neglible. Near to slightly below normal temperatures will warm to slightly above average as early as Monday. The warmest days expected next week are Tuesday- Wednesday, followed by a cooling trend the latter half of the week. Afternoon humidity values will mostly fall into the teens with fair to good overnight recoveries of 30-60% this week, however larger expanses of single digit minimum RH and poor recovery will begin to develop next week. Lighter winds are expected through at least mid week with only daily periodic afternoon upslope breeziness.

PSR WATCHES/WARNINGS/ADVISORIES
AZ...None.
CA...None.

toggle option: (graph/table)

Full Color Weather Map

Link to Loop


Other links: GEOS-West     Contential US     Full GOES-East

Phoenix, AZ,