textproduct: Glasgow

KEY MESSAGES

- A new round of showers and thunderstorms is expected this afternoon and evening. There is a small chance one or two cells could become severe along the far south.

- Expect a slow warm up into Saturday with 80s and 90s for Highs.

- A second wave of showers and thunderstorms is expected Saturday night into Sunday.

DISCUSSION

WEATHER PATTERN OVERVIEW: A shortwave ridge will filter in this morning with partially clear skies ahead of another shortwave trough this afternoon. There is a good shot of thunderstorms occurring from west to east starting around 8-9AM in the southwest and reaching the east by around 3-6 PM. Some of the storms may produce heavy rainfall as precipitable water will be around an inch or slightly higher. Roughly a tenth of an inch of precipitation is expected for most places that do get a hit, but higher totals could easily be possible.

The next shortwave ridge bring dry and warmer weather on Friday. Flow aloft turns southwest on Friday evening so showers are expected to move in after 6 PM Friday. There is potential for another hot day occurring on Saturday in the east depending on the timing of a cold front that will likely move across the region. There is a Day 3 severe weather outlook for the east part of the area, so there is currently a marginal outlook for the afternoon and evening hours.

More concerning will be a prolonged southwest upper flow that sets up this weekend and deep into next week. This time of year could mean higher than normal thunderstorms occurrences that could be severe. Flash flooding is also possible with Precip Water near or above an inch (normal is between 0.50-0.75"). There is low certainty on how long this southwest flow will occur.

FORECAST CONFIDENCE & DEVIATIONS: The only NBM deviation was a few hours of PoPs being interpolated to improve trends slightly during the late morning hours tomorrow as storms move into the west slowly.

There is MODERATE to HIGH confidence in showers occurring today night, and HIGH confidence in scattered thunderstorms on Saturday.

There is HIGH confidence in temperatures through Saturday, with MODERATE confidence on temperatures from Sunday onward.

/GAH

AVIATION

LAST UPDATED: 0630Z

FLIGHT CAT RANGE: VFR

DISCUSSION: A surface low northeast of the area is allowing mid to near MVFR clouds to impact TAF sites as it exits. Some fog may be able to build in along the Montana Canada border from 10 to 15Z but should not reach the Terminals directly. A new round of showers and thunderstorms is expected to impact the terminals in the afternoon and evening today before exiting the area overnight. Some of these storms may have erratic gusty winds.

WIND: Light and variable through tonight. Becoming W at 10 kts or less after sunup through Thursday. Becoming light and variable again Thursday evening. Erratic gusty winds will be possible near any thunderstorm.

GAH

GGW WATCHES/WARNINGS/ADVISORIES

None.