Area Forecast Discussion
Issued by NWS Glasgow, MT
Issued by NWS Glasgow, MT
503 FXUS65 KGGW 041046 AFDGGW Area Forecast Discussion National Weather Service Glasgow MT 446 AM MDT Sat May 4 2024 .DISCUSSION... KEY MESSAGES: - Night-time temperatures will drop below freezing in many areas tonight. - Unusually warm conditions are expected on Sunday, but the southeast winds will be quite strong, with gusts into the 40s in many places. - Another round of rain is expected starting Sunday night through at least Thursday. Ranges are looking on track to be around a inch and a half to 2 inches for many locations with moderate confidence(50-70%). WEATHER PATTERN OVERVIEW: Storm system that brought the brisk cool conditions today will pull into eastern Canada from western Ontario and allow winds to go light and variable while skies will clear. This will allow temperatures to fall into the 20s for most places. Sunshine will return Saturday and will be a pleasant day with light winds. However, winds will increase from the southeast as strong low pressure moves in from the Pacific NW. Look for increasing and thickening clouds Saturday Night with rain showers moving in Sunday Night. A steadier rain will move into parts of the area Monday but a dry slot may limit heavy rain potential next week. Models are still not specific on timing and amounts yet. (from previous discussion) There is a small chance (5-20%) that some of these thunderstorms could become severe, but with overnight convection being the main periods of interest there will be no insolation and severe weather will likely not occur. Will need to monitor SKEW- Ts in these periods as they get within CAM model ranges for further scrutiny. Tuesday through Thursday night: Closed low will migrate northeastward and start to cut off from the warm air. However, this just means that most of the convective elements will become mainly stratiform. Main problem here onward is that positioning of the low is in question with a range for its center position from South Dakota all the way up to southern Saskatchewan. The low looks to generate a trowal in most models which will bring a heavy amount of rain to areas directly under or behind it. The majority of the ensembles place this over eastern Montana which could easily generate 1 to 2 inches to the area it hits. This feature has remained consistent over the last 48 hours raising confidence to moderate(50-70%). Friday onward: A new ridge looks to move into the area which will raise temps and dry conditions out. TFJ && .AVIATION... LAST UPDATED: 1030Z FLIGHT CAT RANGE: VFR DISCUSSION: Clouds will diminish this morning with a deck hanging on just northeast of KOLF-KSDY. This afternoon will feature mainly clear skies with increasing high to mid clouds tonight. LLWS: Some low level wind shear will be possible (20-50% chance) across northeast Montana from 07-14Z tonight, but it looks to only impact KSDY and/or KGDV for a couple hours at this time. WIND: Light and variable through the morning. Becoming southerly at 5 to 10 kts this afternoon. Then veering SE to E and increasing to 5 to 15 kts this evening through tonight. GAH && .GGW WATCHES/WARNINGS/ADVISORIES... Lake Wind Advisory from midnight tonight to noon MDT Monday for Central and Southeast Phillips-Central and Southern Valley- Garfield-McCone-Petroleum. && $$ weather.gov/glasgow