


Area Forecast Discussion
Issued by NWS Phoenix, AZ
Issued by NWS Phoenix, AZ
Versions:
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
025 FXUS65 KPSR 021002 AFDPSR Area Forecast Discussion National Weather Service Phoenix AZ 302 AM MST Wed Jul 2 2025 .KEY MESSAGES... - Today is expected to bring isolated to scattered thunderstorms across south-central and eastern Arizona with the potential for strong gusty winds, blowing dust, and localized heavy rainfall. - After lingering chances for a few isolated thunderstorms on Thursday, drier conditions will end any rain chances starting Thursday night. - Near normal temperatures are forecast for today through Saturday, before heating back up by early next week. && .SHORT TERM /TODAY THROUGH THURSDAY/... The main forecast concern continues to be the potential impacts from the anticipated thunderstorms for today. The current synoptic set up shows an unseasonably strong Pacific low centered near Los Angeles and the sub-tropical high slowly retreating to the northeast into Colorado. Southeasterly flow since yesterday continues to feed modestly moist air into Arizona to as far north as southern Nevada with PWATs now up to between 1.0-1.2" over the southern half of Arizona. This moist fetch is expected to last into this afternoon with PWATs likely peaking between 1.2-1.4" and low level mixing ratios mostly between 8-10 g/kg. This amount of moisture would normally not be sufficient for a good amount of monsoon storm activity, but with the help of the incoming (weakening) Pacific low, the moisture should end up being sufficient. Through the rest of the morning hours, we can expect isolated showers and thunderstorms across portions of the area, likely focused west and south of the Phoenix area where there is better forcing. Once the heating of the day kicks in and instability continues to build, we are likely to first see convection firing over higher terrain areas of central and eastern Arizona early in the afternoon. Hi-res CAMs then suggest this would likely be followed by additional development later in the afternoon over the south-central Arizona lower deserts due to steeper than normal lapse rates, MUCAPE upwards of 1000 J/kg, and little inhibition. The CAMs show scattered showers and thunderstorms anywhere east of a line from Wickenburg to Ajo during the late afternoon into the evening hours. The biggest threats from any storms today should be strong gusty winds and the potential for blowing dust given expected DCAPEs of 1200-1400 J/kg. Moisture levels may just be high enough when combining with fairly weak steering flows to allow for some very localized heavy rainfall amounts of greater than 1" and minor flooding of area washes and low water crossings. The activity is likely to linger through the rest of this evening, but with the coverage and intensity weakening as the evening progresses. After midnight, guidance mainly just shows some lingering shower activity possible across the higher terrain east of Phoenix. For Thursday, model guidance continues to show the weakening Pacific trough tracking northeastward through northern Arizona with dry air surging eastward across the state. For the most part, guidance shows only 10-15% chances for any additional showers or thunderstorms across the south-central Arizona lower deserts Thursday morning and early afternoon to as high as 30-35% over Gila Co. Given the drying, any activity will likely be on the weaker side with potential rainfall amounts much less than today. Temperatures for today and Thursday will be noticeably less hot than the past few days with highs at or just below normal. && .LONG TERM /THURSDAY NIGHT THROUGH WEDNESDAY/... As the weather pattern settles back into westerly dry flow over the majority of the region, rain chances are expected to come to an end by Thursday night. PWATs are forecast to drop down to between 0.8-1.0" starting Friday and likely last there through the rest of the 4th of July weekend. Near normal temperatures are likely to continue into Saturday with overnight lows for rural desert areas easily falling into the 70s as moisture decreases, but lows within Phoenix area still likely to stay just above 80 degrees. Model uncertainty increases considerably next week as the GEFS shows an increase in moisture by around Tuesday, whereas the EPS keeps the moisture well to the south. Both generally agree the sub-tropical ridge will again set up over our region by early next week, first centered just to our east before gradually shifting westward through our region during the middle of next week. Heights are also favored to rise during this time as the ridge strengthens, pushing H5 heights from 590-592dm starting Sunday to as high as 595-597dm by the middle of next week. The recent shift for a stronger ridge setting up over our region has abruptly turned conditions noticeably hotter for next week with NBM highs now mostly between 110-113 degrees by Tuesday. If this new scenario of a stronger ridge comes to fruition and moisture stays out of our area, expect forecast temperatures to trend even hotter than the latest forecast. If the GEFS is more correct showing better moisture, than we may see at least a return of monsoon activity for higher terrain areas. However, for now it does not look very promising for any decent monsoon storms through at least the first half of next week. && .AVIATION...Updated at 0600Z. South Central Arizona including KPHX, KIWA, KSDL, KDVT: Spotty storms S and SE of the Phoenix area are expected to gradually diminish over the next few hours. A few brief showers/virga cannot be ruled out in the Phoenix area through 8Z. Winds will maintain an E/SE component through tomorrow morning, with speeds at times up to 10-15 kts. A period of southerly crosswinds are expected again midday Tuesday, but will then veer W/SW by 20-21Z with 10-15kt speeds and ~20kt gusts. Greatest aviation impacts are expected late tomorrow afternoon and evening, with slight chances (30%) for TS and potential for erratic wind shifts and wind speeds. Most favorable direction for outflows will be from the south, but multiple outflows tomorrow may lead to multiple wind shifts. Visibility reductions in BLDU is possible with outflows from the south. Best timing for convection currently looks like 02-05Z, but could start as early as 00-01Z, and current probability for wind gusts >30kts is 50-60%. Southeast California/Southwest Arizona including KIPL and KBLH: No major aviation concerns are expected during the next 24 hours. Both terminals will maintain diurnal trends (W in the evening and overnight, with east to southeast in the morning and afternoon at KIPL, and S`rly at BLH). Winds will mostly remain under 10kts at KIPL and 20-25kt gusts are expected in the afternoon at KBLH. FEW to SCT mid level clouds will pass over the area during the period, with potential for some vicinity virga or a brief shower at KBLH tomorrow morning. && .FIRE WEATHER... Increased moisture along with an incoming weather system is expected to bring an active day today across the eastern districts. Shower and thunderstorm chances today across the eastern districts are between 30-50% with gusty erratic winds likely to occur with the thunderstorm activity. Humidities will continue to improve today with MinRHs of 20-30% for the eastern districts to 15-20% for the western districts. A drying trend will begin Thursday with much more isolated chances for showers and thunderstorms for the eastern districts. MinRHs Thursday will mainly dip to between 15-20%. Even drier air will filter into the region by the weekend with MinRHs falling to 10-15% by Sunday. Temperatures will run near normal through Saturday before heating up again into next week. && .PSR WATCHES/WARNINGS/ADVISORIES... AZ...Blowing Dust Advisory from 3 PM this afternoon to 7 PM MST this evening for AZZ553-554. CA...None. && $$ SHORT TERM/LONG TERM...Kuhlman AVIATION...Benedict FIRE WEATHER...Kuhlman