textproduct: NWS Flagstaff

SYNOPSIS

Activity tapers off a bit today although the higher terrain may see some scattered showers or storms this afternoon. Things begin to ramp back up starting Sunday with daily chances of storms becoming more likely area wide. This pattern will continue through next week.

DISCUSSION

Today should be a bit of a down day for convection as the activity from Friday has worked over most of the atmosphere. Shortwave that was the trigger for this event is also departing to the east, but still enough left over moisture remains that daytime heating and terrain may trigger a few isolated to scattered afternoon storms over the Mogollon Rim and White Mountains. Isolated areas of flash flooding remain possible as heavy rain could fall over areas saturated from yesterday's activity.

The story for this week will be a series of shortwaves moving through the westerlies interacting with monsoon moisture over the state with each wave setting off more showers and thunderstorms. The next such shortwave will arrive on Sunday which will lead to an uptick in storm chances area wide. Each shortwave brings extra shear to the thunderstorm ingredients which could lead to some extra strength, organization and even a few severe cells with damaging winds and larger hail. Will have to evaluate each wave as it passes for that potential. Activity may also vary from one afternoon to the next depending on how much the atmosphere gets worked over from the previous day. At this time this pattern looks to hold true for the rest of the week.

AVIATION...Saturday 12/18Z through Sunday 13/18Z

Mainly VFR conditions forecast, but brief MVFR/IFR conditions possible in heavier SHRA/TSRA. Best chances for showers/storms will be between 18Z-03Z across higher terrain. Gusty/erratic winds likely near storms, with S-SW winds 5-15 kts expected otherwise.

OUTLOOK...Sunday 13/18Z through Tuesday 15/18Z...Daily chances for SHRA/TSRA expected, with coverage across much of central/northern AZ Sunday afternoon and becoming focused along and east of a KPGA-KFLG-KPAN line Monday and Tuesday. Heavier storms will be capable of producing gusty/erratic winds, heavy rain, and hail. Outside of storm driven winds, look for SW winds 10-20 kts.

FIRE WEATHER...Today and Sunday

Today will be a down day as far as showers and thunderstorms are concerned for most of the area, the exception being over the Mogollon Rim and White Mountains where a few scattered afternoon thunderstorms are still possible. Shower and thunderstorm activity will pick up again area wide on Sunday as another disturbance moves into the area. Winds S-SW 10-20 mph each afternoon and daytime temperatures remaining around normal.

Monday through Wednesday...Over the next few days expect daily shower and thunderstorm activity. The amount of activity and coverage may be dependent on how much the atmosphere gets worked over from the previous days storms. Winds S-SW 10-20 mph, with gusts to near 25 mph each day.

FGZ WATCHES/WARNINGS/ADVISORIES

None.