FXUS65 KPSR 262106

AFDPSR



Area Forecast Discussion

National Weather Service Phoenix AZ

206 PM MST Thu Jun 26 2025



.KEY MESSAGES...



- Temperatures will gradually heat up into the weekend reaching 

  to above normal levels with widespread Moderate HeatRisk across 

  all areas by Sunday



- Extreme Heat Watch is in effect for the Phoenix metro Sunday

  through Tuesday with areas of Major HeatRisk and high

  temperatures topping 110 degrees



- Dry conditions will prevail through at least the weekend, but a

  gradual increase in moisture next week is likely to lead to

  increasing chances for showers and thunderstorms by the middle

  to latter part of the week

  

&&



.DISCUSSION...

Early afternoon satellite depicts a very dry airmass overhead,

with the favored area of convection well removed to the east

across central to eastern New Mexico. General troughing across the

region continues the dry southwesterly flow, but as this feature

dissipates over the coming days, the strong area of high pressure

that brought oppressive heat to the eastern part of the country

the last few days will meander back westward going into this

weekend. This will lead to seasonable temperatures to warm to 

above normal levels by the end of this weekend, with widespread 

Moderate HeatRisk. Temperatures will be hot enough to reasonably 

have Extreme Heat products out for at least the Phoenix metro 

Sunday-Tuesday as highs warm into the 110-115 range and lows warm

into the mid to upper 80s (probs of KPHX hitting a low of 90 is

around 40-60%). Thus, an Extreme Heat Watch is in effect, with 

additional areas of south-central Arizona included on Monday when

Major HeatRisk is the most expansive across the lower deserts.



The weather pattern evolution becomes much more muddled starting

early next week as a weak trough begins to amplify across the West

Coast. This feature will influence the movement of the subtropical

high overhead the region early next week to retreat near the Four

Corners. This retreat should present the first indication of low 

level southeasterly flow with the first significant moisture 

returns of the season, a typical feature of the monsoon. However, 

large discrepancies are apparent amongst the ensembles on how 

early and how quick this moisture will develop across Arizona. The

GEFS remains much quicker than the ECMWF as the latest means 

depict the high center north of the Four Corners (GEFS), which 

would cause the moisture levels to increase faster than the high 

center positioned further south (ECMWF). Thus, GEFS members show 

an earlier increase to above normal PWAT's as early as Monday 

evening, with the increasing PWAT signal for the ECMWF delayed 

more into the Tuesday-Wednesday timeframe. 



Thus, the timing of moisture increases, dictated by the strength 

of this troughing and subtropical high positioning, will determine

how soon the region could conceivably see convection potential 

increase. The current thinking is convection potential will first

increase across higher terrain areas of south-central Arizona as 

early as Tuesday, with gradual increasing chances into the lower 

deserts going into mid to late week. Prior to higher potential of 

showers/storms into the lower deserts, this transition from dry to

more moist conditions may be preceded by a couple of days of 

gusty winds and blowing dust impacts due to outflows stemming from

periphery convective activity in southeastern Arizona and higher 

terrain areas during the late afternoon and evening hours. We 

also cannot rule out a day or two of a dry lightning threat ahead 

of more robust convection.



&&



.PREVIOUS DISCUSSION...

By late next week, we may even be able to see some deeper 

tropical moisture seep into portions of our area, but this will be

dependent upon what happens with a potential Tropical Cyclone 

south of Baja during the middle part of next week. If we do end up

seeing some tropical moisture at some point late next week, right

now it looks to fall on around next Friday. There are still a lot

of what-ifs, but we can at least point toward the 6-10 day CPC 

outlook which shows a 70-80% chance of above normal precipitation 

late next week. We will hopefully have a better idea on our 

rainfall potential over the next few days. 



&&



.AVIATION...Updated at 1725Z.



South Central Arizona including KPHX, KIWA, KSDL, KDVT: 

No aviation weather concerns are expected during the TAF period.

Another similar pattern today as winds will continue to follow

typical diurnal shifts. Seasonal afternoon sporadic gusts in the 

mid to upper teens will develop during the afternoon hours. Only 

clouds present over the region will be a FEW mid-level clouds to 

the far east of the terminals. 



Southeast California/Southwest Arizona including KIPL and KBLH: 

No aviation concerns are expected during the TAF period. Winds

will continue to follow diurnal trends, with some occasional

breeziness at KBLH in the afternoon. While not directly impacting

sfc visibilities, lofted smoke/haze may occasionally affect

slantwise visibilities during the late afternoon/evening hours at

KIPL. 



&&



.FIRE WEATHER...

High pressure will gradually strengthen across the region through

the weekend leading to a strong warming trend and continued dry

conditions. Temperatures will warm to above normal starting Friday

before peaking early next week. Expect little change in humidity

trends as MinRH values continue to range between 5-15% each day

and overnight recoveries stay between 20-35%. Winds will follow 

familiar diurnal trends with typical afternoon breeziness, gusting

mainly between 15-20 mph. Eventually, the weather pattern should 

become more favorable for increasing moisture and at least some 

scattered high terrain showers and thunderstorms by around next 

Tuesday. This may initially result a day or two of dry lightning 

concerns before moisture and rainfall chances increases later next

week.



&&



.PSR WATCHES/WARNINGS/ADVISORIES...

AZ...Extreme Heat Watch from Sunday morning through Tuesday evening 

     for AZZ537-540-542>544-546-548-550-551.



     Extreme Heat Watch from Monday morning through Monday evening 

     for AZZ534-538-539-552>555-559.



CA...None.

&&



$$



DISCUSSION...Young

PREVIOUS DISCUSSION...Kuhlman

AVIATION...Ryan/RW

FIRE WEATHER...Young/Kuhlman

