textproduct: NWS Flagstaff

SYNOPSIS

Monsoon moisture will return to the area through the coming week daily storm chances, along with the risk for heavy rainfall and localized flooding. With the added moisture, temperatures begin to trend toward normal today and even below normal by late week.

DISCUSSION

High pressure will remain centered north and northeast of our region through the coming weekend, with continued favorable conditions for monsoon moisture to flow into Arizona. Moisture levels as measured by precipitable water will be on the high side of climatology, in the 85th-95th percentile for mid July. This means that storms that develop will have a potential for producing heavy rainfall and localized flash flooding. East/southeast steering flow the past few days has focused activity over Yavapai/Gila counties as storms move off the Mogollon Rim. This general steering flow is forecast to continue today, though better moisture in northeast Arizona should allow for more storms there compared to previous days. Some of this activity in northeast Arizona may move toward the Mogollon Rim during the evening hours and bring a second chance at rainfall. By Wednesday through Friday, the steering flow becomes more northeasterly as an inverted trough approaches from the east. However, this flow is looking weak (5-10 kts), and this will enhance the potential for storms with heavy rainfall and flash flooding. WPC has placed areas from the Mogollon Rim through Yavapai/Gila counties in a slight risk for excessive rainfall Wednesday, spreading north to include all of our area by Thursday and Friday. Of course factors such as morning cloud cover play a role in how unstable it becomes each day which impacts flood risk, and this is difficult to predict very far in advance. However, the potential will certainly be there for flash flooding, especially for more flood prone areas such as fire scars. We will continue to monitor this potential, and may need Flash Flood Watches for parts of the area in the Wed-Fri time frame. Outside of storm potential, the added moisture and cloud cover will allow for our recent hot weather to ease. Daytime temperatures for most areas will be near normal today, falling to several degrees below normal by the end of the week/weekend.

AVIATION...Tuesday 14/18Z through Wednesday 15/18Z

Mainly VFR conditions. SCT SHRA/TSRA expected through 03Z, with the greatest chances mainly over the higher terrain. Brief MVFR conditions and gusty outflow winds 30-40 kts possible in and around TS. Winds S-W 5- 15 kts, becoming light and VRB after 03Z.

OUTLOOK...Wednesday 15/18Z through Friday 17/18Z...Mainly VFR conditions. SCT-WDSPD SHRA/TSRA each afternoon and evening, potentially lasting into the overnight hours. Brief MVFR conditions and gusty outflow winds 30-40 kts possible in and around TS. Winds S- W 5-15 kts, becoming light and VRB overnight.

FIRE WEATHER...Today and Wednesday

Daily chances for showers and thunderstorms, primarily over the higher terrain. Wetting rains and gusty outflow winds possible with any stronger storm. Outside of storm activity, winds south/southwest 5-15 mph.

Thursday through Saturday...Daily chances for showers and thunderstorms continue, with the best chances over the higher terrain. Heavy rainfall and and gusty outflow winds possible with any stronger storm. Outside of storm activity, winds west through south 5-15 mph.

FGZ WATCHES/WARNINGS/ADVISORIES

None.