textproduct: NWS Flagstaff

SYNOPSIS

Dry conditions and lighter east wind is expected through this afternoon, then a weather system brings chances for showers and thunderstorms this evening through Sunday. This active pattern continues through most of next week with continued daily shower chances, occasional gusty winds, and below normal daytime temperatures. The highest chance of rain next week is on Wednesday and Thursday.

DISCUSSION

A closed low off the Baja will gradually weaken and drift northeast into our region through Sunday. A very dry air mass is currently in place following a couple days of easterly winds, with precipitable water values ranging from 0.10" in northeast AZ to around 0.40" in southern Yavapai County. There will still be some gusty easterly winds over the higher terrain and locations just downwind through early this afternoon, but much lighter than what was observed Thursday and Friday. As the low off Baja moves closer, we will start to see an increase in moisture, with precipitable water values forecast to rise to 0.60" to 0.90" from about the Mogollon Rim southward by early this evening. Forecast soundings indicate this will be a top down moistening process, with the lower levels remaining pretty dry at least initially. This may limit precipitation coverage/intensity this evening into the pre-dawn hours Sunday, before the low levels moisten further and lift from the approaching low brings more widespread showers. Not expecting heavy rainfall out of this system, with most areas ranging from a few hundredths up to 0.30", and NBM probabilities of over 0.30" are only 20-40% - focused on the higher terrain of the Mogollon Rim.

Monday through Tuesday - the weekend low moves off to the northeast as another stronger low dives southward just off the west coast. Expecting slightly warmer temperatures with only a 10-30% chance of showers during this period. From Wednesday through Friday, the low off the coast is forecast to slowly move eastward across our region. Still some differences in strength/timing of the system, but still expecting another round of showers and a few thunderstorms with the best chances later Wednesday through Thursday. There is a possibility that this system could tap some deeper moisture from the south and bring a threat of some heavier rain, but it's too early for specifics. For now, WPC has placed our region in a marginal risk for excessive rainfall on Wednesday.

AVIATION...Saturday 17/18Z through Sunday 18/18Z

Mainly VFR conditions. SCT -SHRA spread from south to north after 00Z. NE-E winds 5-15 kts with gusts 15-25 kts through 19Z-20Z, then becoming E-SE 5-15 kts with gusts 20 kts through 01Z. Winds become light and variable after 01Z.

OUTLOOK...Sunday 18/18Z through Tuesday 20/18Z...Mainly VFR conditions. ISO-SCT -SHRA/-TSRA brief MVFR possible in heavier SHRA or TS. Best chances are across the higher terrain through Sunday afternoon and again Monday afternoon. Variable winds 5-15 kts on Sunday, becoming S-SW 5-15 kts Monday.

FIRE WEATHER...Today through Sunday

Cool temperatures with east through southeast winds around 10-20 mph today, becoming light and variable on Sunday. Scattered showers moving in from the southwest by this evening, continuing through Sunday. A few thunderstorms possible Sunday afternoon. Minimum RH is 15-30% today, increasing to 40-70% on Sunday.

Monday through Wednesday...Slight chance of showers and thunderstorms Monday and Tuesday, then showers and thunderstorms likely on Wednesday. South winds 5-15 mph on Monday, becoming south 10-20 mph with gusts to 30 mph on Tuesday, then increasing to 15-25 mph with gusts 30-40 mph on Wednesday.

FGZ WATCHES/WARNINGS/ADVISORIES

None.