textproduct: Glasgow

KEY MESSAGES

- The next chance for isolated showers and perhaps a lone thunderstorm is across the west this afternoon.

- Above normal temps, low relative humidity, strong nw winds, and pre-greenup fuels has lead to a Fire Weather Watch across the east Friday

- A slightly wetter system arrives Friday night into Saturday with up to a tenth of an inch possible over Petroleum, SW Phillips, and SW Garfield counties.

- Above normal temps with mainly dry conditions expected to return Sunday and run through the work week.

DISCUSSION

WEATHER PATTERN OVERVIEW: Currently a low pressure system lies over the Hudson Bay while a ridge runs up the western North American coast from California to British Columbia. Northeast Montana begins in between these two features under northwest flow aloft.

Today through tonight: A weak shortwave will work its way through the flow pattern and drag some weak afternoon showers and an isolated thunderstorm or two down from the the northwest which may die out along the west in the evening hours. Overall QPF totals look to be around a hundredth of an inch or less with most areas receiving no rain.

Friday and Friday night: Ridge to the west presses harder to the east and drags warmer air over the region with highs in the 70s. Pressure gradient force will strengthen up just prior to a cold front moving through that evening and allow for low RH and strong NW wind. Looking at GOES NDVI most areas across the east are around or below 20-30% greenness and throwing that into the mix means that a Fire Weather watch across the east was necessary for Friday afternoon and early evening.

Saturday: With the cold front moving through the previous night a zone of lift will be associated with the post frontal disturbance across central Montana for about 24 hours. This will have some impact across the southwest including Petroleum, SW Phillips, and SW Garfield counties. QPF totals look to max out at a tenth of an inch or maybe a wetting rain while most other locations look to be dry. Temps should drop about 10 degrees for the day.

Sunday through the work week: Ridge to the west moves across the region, flatten, and then rebounds in the west by Wednesday. Overall temps look to be up to normal or above normal with mostly dry conditions. Forecast beyond Wednesday becomes LOW confidence as sub-synoptic details wash out with either a trough or ridge on any given day depending on the ensemble member.

FORECAST CONFIDENCE & DEVIATIONS: Main NBM deviation was to hourly PoPs through this afternoon raising PoPs across the west slightly, though they are still much lower than the previous forecast.

There is LOW confidence in thunderstorms occurring this afternoon.

There is HIGH confidence of critical fire weather conditions occurring on Friday afternoon for fire weather zones 120 and 122.

There is MODERATE confidence in rain showers up to a tenth of an inch across Petroleum, SW Phillips, and SW Garfield counties Friday night into Saturday.

AVIATION

LAST UPDATED: 1630Z

FLIGHT CAT RANGE: VFR

DISCUSSION: Mainly mid to high clouds today. A few afternoon showers and a possible lone thunderstorm could drift through the area from 20 to 02Z. Chances of a hit are less than 30 percent and therefore not in the TAF directly and overall impacts if they do should not drop below VFR.

WIND: NW at 5 to 15 kts this afternoon. Becoming light and W to variable this evening through tonight. Becoming W and increasing to 10 to 20 kts Friday after sunup.

GAH

GGW WATCHES/WARNINGS/ADVISORIES

Fire Weather Watch from Friday afternoon through Friday evening for Dawson/McCone/Prairie/Richland/Wibaux Counties-Fort Peck Reservation and Daniels/Roosevelt/Sheridan Counties.