textproduct: NWS Flagstaff

SYNOPSIS

Deep monsoon moisture will remain over the area into the coming weekend and well into next week. With this moisture comes the daily threat of thunderstorms, along with the risk for locally heavy rainfall and flooding. With the added moisture and cloud cover, daytime temperatures will largely remain below normal.

DISCUSSION

Really not much change over the next several days and perhaps well into next week. The region is locked in a very moist air mass, both in the vertical as shown by PW and in the boundary layer, as shown by dew points ranging from the mid 50s to over 70 degrees. Northeasterly steering flow will also persist, at least for a few more days, before potentially transitioning to a southerly or southeasterly flow.

The current northeasterly steering flow heavily favors locations just south and southwest of the Mogollon Rim, with a secondary area forming later in the day across Apache and Navajo counties. This secondary area is what supports nocturnal convection, as we are seeing again tonight.

Despite all the favorable mechanisms to produce heavy rain, we are also seeing large areas of rain-cooled ground and extensive debris cloud, due to the overnight convection. These things can prevent stronger convection from forming and therefore limit the amount of storms that can produce Flash Flooding. This and the lack of any clear forcing mechanism will keep any additional FFA issuances at bay for now, perhaps a better chance over the weekend.

AVIATION...Friday 17/06Z through Saturday 18/06Z

Expect SCT-NMRS SHRA/TSRA and ISOLD +TSRA through the period, storms most numerous in the afternoon hours. Any stronger storms will produce brief MVFR. Outside of storms, sfc winds are not anticipated to affect flight operations.

OUTLOOK...Saturday 19/06Z through Monday 20/06Z...Expect SCT-NMRS SHRA/TSRA and ISOLD +TSRA through the period, storms most numerous in the afternoon hours. Any stronger storms will produce brief MVFR. Outside of storms, sfc winds are not anticipated to affect flight operations.

FIRE WEATHER...Friday and Saturday

Expect a medium to high grade monsoon environment, with generally light winds outside of outflow and thunderstorm activity. Most storms will produce wetting rain with stronger storms producing localized Flash Flooding.

Sunday through Tuesday...Chances for showers and thunderstorms continue, generally light winds outside of outflow and thunderstorm activity. Most storms will produce wetting rain with stronger storms producing localized Flash Flooding.

FGZ WATCHES/WARNINGS/ADVISORIES

None.