


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
013 FXUS65 KPSR 152346 AFDPSR Area Forecast Discussion National Weather Service Phoenix AZ 446 PM MST Tue Jul 15 2025 .UPDATE...Updated Short-term and 00Z Aviation Discussion. && .KEY MESSAGES... - Rain chances will improve over the next couple of days with the best chances over eastern Arizona and at least a 20-30 percent chance expanding into south-central Arizona Wednesday into Thursday. - A few strong storms will be possible this afternoon and evening, likely focused east and southeast of the Phoenix area. - After near normal temperatures today, expect slightly below normal temperatures with plenty of clouds Wednesday and Thursday. && .SHORT TERM /Rest of today through Wednesday/... The latest radar imagery as of mid-afternoon depicts thunderstorm activity across the vicinity of the Mogollon Rim through southeast AZ as MLCAPE values range between 500-1000 J/KG across the region. The latest HREF membership continues to show the greatest thunderstorm coverage to remain confined mostly across southeast AZ into the evening hours with the potential for an outflow boundary to move northwestward and affecting portions of south- central AZ later this evening, however, at this time not much in the way of strong wind gusts are expected with the HREF only showing a 10-30% chance of gusts in excess of 30 mph across the Phoenix area while slightly higher probabilities exist southeastward into northwest Pinal County. If the stronger winds materialize in Pinal County, then some blowing dust will likely materialize. Otherwise, not much in the way of thunderstorm activity is expected across south-central Arizona this evening, most likely due to some convective inhibition remaining in place. Guidance suggests the complex of storms over southeast Arizona is likely to induce an MCV which may bring additional showers or a weak thunderstorm during the overnight and early morning hours Wednesday as the MCV gradually lifts to the north northwest through south-central Arizona. If the MCV scenario comes to fruition, it now looks like it may be a determent for additional shower and thunderstorm development across south-central Arizona at least through Wednesday afternoon. There is also model evidence of some drying already beginning to take place across southwest Arizona to as far north and east as the Phoenix area starting Wednesday morning. Because of these potential negative factors, we have lowered PoPs for south-central Arizona on Wednesday. Guidance does still suggest a good deal of shower and weak thunderstorm activity over eastern Arizona on Wednesday and any weak to modest outflows may be enough to help trigger some activity into the lower deserts by Wednesday evening. The potential for any strong storms Wednesday has been reduced largely in part due to warming aloft and weakening instability. Some higher terrain areas should still be able to see a few heavier rain producing cells, but the overall risk for excessive rainfall will be marginal at best. && .LONG TERM /Thursday through Monday/... Forecast confidence for later this week continues to be fairly low as model differences remain. Both the GEFS and EPS show noticeable drying occurring on Thursday, but the uncertainty lies in how quickly we dry out. Models are finally mostly agreeing on bringing the upper level low northward into northern Baja with potential forced ascent still in place over much of Arizona. If there is enough moisture left over, we may be able to see 500 J/kg or so of MUCAPE during the afternoon hours, but that may not occur in a large area as we are still likely to see considerable cloud cover. Just like Wednesday, Thursday may mostly involve scattered showers and weak storms over higher terrain areas with a few isolated storms possible over the Arizona lower deserts. The drying is expected to continue Friday into Saturday with forecast PWATs dropping to between 1.1-1.3" Friday to around 1" Saturday. Rain chances Friday may partially depend on the eventual track of the upper level low which is mostly shown tracking up the CO River Valley or across southern California early on Friday. The eastern Arizona higher terrain should again have afternoon chances for showers and thunderstorms Friday, but we may also have a shot at some isolated convection closer to the upper low, maybe across southwest Arizona. By Saturday, the upper low is likely to have lifted far enough to the north or west that it will become a non-factor on our weather. Enough lingering moisture may still be present across eastern Arizona this weekend for some afternoon scattered convection, but the south-central Arizona lower deserts are likely to remain quiet. Temperatures are expected to cool off a good deal during the middle part of the week with below normal temperatures on Wednesday and Thursday, especially across south-central and eastern Arizona. As we stated yesterday, highs in the Phoenix area on Thursday may struggle to reach 100 degrees. As we really begin to dry out Friday into the weekend, temperatures will begin creeping upward again with readings back into the normal range by around Saturday. Temperatures at or just above normal are likely to persist through early next week as the subtropical ridge is likely to stay just to our east. && .AVIATION...Updated at 2340Z. South Central Arizona including KPHX, KIWA, KSDL, KDVT: Westerly winds will continue through the early evening hours with occasional gusts upwards of 20-25 kts. Thereafter, there is a potential for a decaying southerly outflow boundary to move through the area after 04-05z, resulting in a directional shift out of the southeast. KIWA will have the best chance for some gusty winds in excess of 20 kts from the outflow boundary. Any shower/thunderstorm activity is expected to remain confined across eastern and southeastern AZ. Otherwise, winds out of the east to southeast will prevail through the overnight and early Wednesday morning before shifting out of the west by the mid to late morning hours with speeds generally aob 10 kts. There is a low chance (10-20%) of a few light showers early Wednesday morning. Cloud bases are expected to be around 10 kft AGL throughout the period with coverage increasing to SCT-BKN starting later this evening. Southeast California/Southwest Arizona including KIPL and KBLH: No major aviation weather concerns are expected throughout the TAF period. Winds will generally be out of the east to southeast at KIPL and out of the south at KBLH. Wind gusts upwards of 20-25 kts will be expected at times through this evening and once again Wednesday afternoon/evening, with the strongest gusts mainly at KBLH. Clear skies will persist through tonight with a FEW mid to high-level clouds likely throughout the day Wednesday. && .FIRE WEATHER... Moisture will gradually increase across much of Arizona over the next couple of days providing increased chances for showers and thunderstorms focused across higher terrain areas. Temperatures will drop off from near normal today to below normal Wednesday and Thursday. Afternoon MinRHs will improve with readings around 20% today and 25% Wednesday and Thursday. Expect south southwesterly gusts of 20-30 mph at times over the CO River Valley with more diurnal lighter winds over the eastern districts. Some drying conditions will begin to usher back into the area later this week resulting in more limited shower and thunderstorm chances by Friday. Eventually, high pressure is likely to return to the region by the weekend with RHs dropping back into the teens, temperatures returning to near normal, and rain chances ending for all but the higher terrain. && .PSR WATCHES/WARNINGS/ADVISORIES... AZ...None. CA...None. && $$ SHORT TERM...Lojero/Kuhlman LONG TERM...Kuhlman AVIATION...Lojero FIRE WEATHER...Kuhlman