textproduct: NWS Flagstaff

SYNOPSIS

Isolated showers and thunderstorms will remain in the forecast for the eastern portions of Arizona for the next few days. Otherwise, above normal temperatures and mainly dry conditions will persist. By the weekend and into early next week, a colder and much windier pattern develops, along with the potential for a significant rainfall event, as tropical moisture moves back into the southwest.

DISCUSSION

A weak trough over north-central Arizona this morning will meander southeastward through Thursday. This will keeps the ongoing threat for high-based and isolated convection intact, mainly for the eastern zones.The trough is moving around a ridge that has now been displaced southwestward, but is still close enough to provide us with above normal temperatures for the next few days.

By the end of the week, the ridge moves a bit eastward, before collapsing heading into the weekend as a much stronger trough enters the interior Pacific Northwest. This next trough will then dig south or southwestward, strengthening and possibly cutting off by Sunday or Monday. This will likely allow for significant tropical moisture transport into Arizona, along with the remnants of Hurricane Rachel. The trough does not eject inland until next Tuesday or Wednesday, so this moisture stream could go on for awhile.

There are still many things that could go wrong with this forecast and the phasing of the offshore trough and tropical moisture is not as dialed in as it was yesterday. Nonetheless, this is potentially a very impactful pattern.

For now, there is higher confidence in a windy, colder and wet pattern developing as early as Saturday and lasting well into next week. There is lower confidence in QPF amounts and the potential for intact tropical circulation remnants actually moving into the state.

Stay tuned.

AVIATION...Wednesday 07/12Z through Thursday 08/12Z

Expect mainly VFR conditions. ISOLD-SCT -SHRA/-TSRA, mainly over Apache County. A few showers may produce brief MVFR and gusty outflow winds. Sfc winds are not anticipated to affect flight operations.

OUTLOOK...Thursday 08/12Z through Saturday 10/12Z...Expect VFR conditions. ISOLD -SHRA/-TSRA southern Apache County Thursday and Friday afternoons. Light winds through 18Z Friday, then S10-15kts during the daytime on Friday.

FIRE WEATHER...Wednesday and Thursday

Expect mainly dry conditions and continued seasonably warm temperatures. A slight chance of high-based showers and thunderstorms remains possible for Wednesday and Thursday afternoons, primarily for the eastern zones. Chances for wetting rains are near zero. Daytime winds generally light and variable, trending easterly or southeasterly over higher terrain each afternoon.

Friday through Sunday...Dry and continued warm for Friday Then turning windy and cooler over the weekend, with increasing chances for showers and thunderstorms. Southerly winds 10 to 15 mph Friday becoming southwesterly 15 to 25 mph, with gusts from 30 to 40 mph over the weekend. The windiest day will be Sunday.

FGZ WATCHES/WARNINGS/ADVISORIES

None.