898 FXUS65 KPSR 031753 AFDPSRArea Forecast Discussion National Weather Service Phoenix AZ 1053 AM MST Fri Oct 3 2025
.UPDATE...Updated 18Z Aviation Discussion.
&&
.KEY MESSAGES...
- Low pressure will brush the Desert Southwest today and bring a dry cold front through the region tomorrow morning leading to breezy to locally windy conditions and cooling temperatures heading into the weekend.
- A gradual warming trend will commence once again for the first half of next week.
- Increasing rain chances late next week with impactful rainfall possible, but forecast confidence is very low at this time.
&&
.SHORT TERM /TODAY THROUGH SUNDAY/... Upper level water vapor satellite imagery and objective analysis early this morning reveal a closed low over northern CA with high pressure over SE AZ. The aforementioned low will slowly move east/southeastward over the next two days and push a dry cold front through the region early Saturday morning. This will lead to lowering heights aloft and thus will lead to a cooling trend across the region. Afternoon high temperatures will be in the mid 90s across SE CA and SW AZ, in the upper 90s to low 100s across south- central AZ, and in the low-to-mid 90s across the higher terrain. Temperatures will cool 5-10 degrees tomorrow, with highs falling into the mid-to-upper 80s to near 90 degrees across the lower deserts and in the low-to-mid 80s across the higher terrain. This morning low temperatures will be in the upper 60s to low 70s across the lower deserts and in the mid 70s in more urban areas (central Phoenix) and in the mid 60s across the higher terrain. Low temperatures will cool into the upper 50s to 60s (near 70 degrees in central Phoenix) tomorrow morning.
In addition to the cooling temperatures the aforementioned low pressure system and associated cold front will bring breezy to locally windy conditions to the region today and tomorrow. WIndy conditions already exist across the far SW corner of Imperial County, where winds of 40-45 mph have already been observed early this morning. Gusty winds will continue for this area through early Saturday morning, where wind gusts up to 55 mph are possible. A wind advisory is in effect for the far SW corner of Imperial County through 5am PDT Saturday morning. Wind speeds will increase elsewhere across the CWA late this morning through this evening. The rest of western Imperial County (just west of Imperial Valley) will be in a Wind Advisory from 3pm PDT this afternoon through midnight PDT tonight, where wind gusts up to 40 mph are possible. Wind gusts of 20-30 mph are expected across central and eastern AZ, with gusts of 25-35 mph are expected across SW AZ and the rest of SE CA. Winds will subside after sunset across south-central and eastern AZ, but will continue into the overnight hours across SE CA and portions of SW AZ. Breezy conditions (20-25 mph) are then again expected across the higher terrain of eastern AZ Saturday afternoon and early evening.
Saturday night into Sunday the closed low will open up and move into the northern Plains as a shortwave trough with a secondary trough digging into the Intermountain West Region. This secondary trough will help to keep temperatures below normal on Sunday. Cooler morning lows will continue on Sunday. Morning lows will range from the upper 50s to mid 60s across the lower deserts, with most areas seeing lows in the low 60s. Higher terrain areas will see Sunday morning lows in the mid 50s. High temperatures on Sunday are forecasted to be very similar to those on Saturday. Lower desert high temperatures are forecasted to be in the upper 80s to low 90s, with higher terrain areas forecasted to be in the mid 80s. Dry conditions will continue into next week.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/... The trough that will be bringing below normal temperatures to the region this weekend will move into the Plains on Monday with broad troughing left in its wake across Western CONUS. A subtropical high will also be trying to build back into the Desert Southwest early next week. This subtropical high will be battling another low pressure system that will be in the Gulf of Alaska at the start of the workweek and will push southward into the Pacific NW by the middle of the week. As the high pressure tries to build into our region heights aloft will rise. This will lead to gradually warming temperatures through the middle of next week. Temperatures are currently forecasted to be in the upper 80s to low 90s across the lower deserts to start the week and warm into the mid 90s by Wednesday. Temperatures across the higher terrain will be in the mid to upper 80s. Morning low temperatures will continue to be in the 60s across the lower deserts, with the exception of some areas of near 70 degree morning lows on Wednesday around the Phoenix Metro. Morning lows in the higher terrain will be in the upper 50s to start the workweek, warming to the low 60s. Dry conditions will also continue through at least the middle of next week.
Heading into the end of next week models start to differ on what exactly will happen. Models are in fairly good agreement that the aforementioned low, that will be pushing into the Pacific NW by the middle of next week, will continue to push southward into northern CA and stall there heading into the weekend. Where the models differ is what to do with the remnants of a tropical system that will be moving northwestward during the same timeframe. If the remnants of the tropical system phase with the trough/low off the Pacific Coast, then an abundance of moisture would be pulled up into our region. Ensembles currently show around 200% of normal PWATs for the end of next week and heading into next weekend. The GEFS and EPS tend to favor this solution. The Canadian Ensemble has a subtropical ridge building across the Baja keeping the remnants of this system well south of our area. Outlying members of the GEFS and EPS bring the circulation associated with the tropical system itself into our region, resulting in really high rainfall amounts. While it is looking more likely that our region will see an increase in moisture by the end of next week, the question though is how much and will there be enough forcing to produce showers and storms to capitalize on the increase in moisture. Impactful rainfall is possible, however with all the uncertainty forecast confidence is low at this time. With all the forecast uncertainty there is a large range of possible temperatures for the end of next week, however it does look like there will be a cooling trend. The question is how cool will temperatures get. Stay tuned for future forecast updates.
&&
.AVIATION...Updated at 1744Z.
South Central Arizona including KPHX, KIWA, KSDL, and KDVT: No major aviation concerns this TAF period. Current S`rly winds will slowly go SSW`rly early this afternoon, then fully settle out of the W by early evening. During this time gusts can be expected between 15-20kts, but will relax by sunset, through the overnight hours where winds will struggle to go E`rly until near sunrise. Skies will remain mostly clear with FEW cumulus clouds with bases aoa 9 kft expected tomorrow afternoon.
Southeast California/Southwest Arizona including KIPL and KBLH: Winds at KIPL will predominantly favor the W. At KBLH, SW to W winds will continue. Gusty winds will develop this afternoon with gusts climbing upwards of 25-30kts at both terminals. At KIPL, gusts may climb up to around 35 kts at times this evening evening, this can lead to restrictions in visibility from blowing dust. Gusty conditions will continue into the overnight hours at KIPL but will start to taper off around 09Z. Gusty conditions at KBLH will start to taper off late this evening ~06Z. Mostly clear skies will prevail through the TAF period.
&&
.FIRE WEATHER... Temperatures will start to cool out west today, but remain above normal across the central and eastern districts, with some south- central AZ lower desert locations seeing tripple digits again today. Further cooling is expected this weekend region wide, thanks to a dry cold front, with temperatures falling below normal. This cold front will bring breezy to locally windy conditions to the region. Gusts of 20-30 mph are expected across south-central and eastern AZ this afternoon and evening. Gusts in excess of 40 mph are possible across western Imperial County, otherwise gusts of 25-35 mph are expected across SE CA and SW AZ. The gusty winds will continue through early Saturday morning across SE CA and SW AZ. Gusty winds (20-25 mph) are expected Saturday afternoon and early evening across the eastern AZ higher terrain. MinRHs will be in the 15-25% range through the middle of next week, with overnight recoveries in the 30-60% range. Gradually warming temperatures and dry conditions are expected for the first half of next week. There is increasing chances for wetting rainfall by the end of next week, however, forecast confidence is low at this time. With the increasing rain chances MinRHs currently look to increase to 30-40% for the end of next week.
&&
.PSR WATCHES/WARNINGS/ADVISORIES... AZ...None. CA...Wind Advisory until 5 AM PDT Saturday for CAZ562.
Wind Advisory from 3 PM this afternoon to midnight PDT tonight for CAZ566.
&&
$$
SHORT TERM...Berislavich LONG TERM...Berislavich AVIATION...Ryan FIRE WEATHER...Berislavich
NWS PSR Office Area Forecast Discussion