Forecast Discussions mentioning any of "ACARS" "MDCRS" "AIRCRAFT" "TAMDAR" "AMDAR" "WVSS" received at GSD on 05/31/22


Area Forecast Discussion
National Weather Service Great Falls MT
638 PM MDT Mon May 30 2022 .SYNOPSIS... Precipitation will continue through the overnight hours across Southwest and portions of Central Montana, especially in north and east facing upslope areas. Accumulating snow is expected above 7000 feet across these areas, which could lead to slippery and slick roadways. Finally, areas of fog will be possible Tuesday morning where recent rains have fallen, and where skies clear out. && .UPDATE... A northerly low level flow continues to move moisture southward across the region. Forecast is performing accurately; therefore, no updates are made, at this time. - Fogleman && .DISCUSSION... Rest of today through tonight...primary forecast concern will be on- going precipitation chances/amounts through Tuesday morning, in addition to the potential for fog developing where recent precipitation has fallen. Broad H500 trough, with multiple closed lows (one over the Northern and Central Plains, and the second over the Pacific Northwest), was in place across much of the Western CONUS/Canada this afternoon. Over Southwest through North Central Montana beneath this large H500 trough, winds throughout the column were predominately out of the north to northeast, which continued to support orographically enhanced precipitation along east and north facing slopes. Expect precipitation (rain below 6000ft, rain/snow mix between 6000-7000ft, and all snow above 7000ft) to persist within the aforementioned upslope areas through the overnight hours tonight, in addition to much of Southwest and into portions of Central Montana where broad synoptic scale lift will also remain. Additional precipitation amounts across these areas of 0.1-0.25" can be expected, with localized amounts of 0.5-0.75" over the higher terrain of Southwest Montana. Snowfall amounts above 7000ft across Southwest and Central Montana of up to 6 inches can generally be expected, with the exception of the Tobacco Root Mtns, Madison Range, and Gallatin Range where amounts could approach 12 inches. Precipitation will gradually wind down from north to south Tuesday morning. Given recent precipitation across the region and decreasing winds, especially over Southwest and Central Montana, areas of fog may develop through Tuesday morning. This will be especially true where any clearing takes place. - Moldan Tuesday through next Monday...A gradual transition from light flow aloft within the broader upper level trough to westerly flow under weak ridging occurs from Tuesday through the rest of the week for overall mainly dry conditions with temperatures returning to seasonal averages. A few afternoon showers and thunderstorms are possible, especially near the mountains, but no organized areas of precipitation are expected. This coming weekend into early next week, a southwest flow is expected with disturbances ejecting east out of of a larger scale trough off the west coast. This will bring an increasing chance for precipitation, including thunderstorms, especially by early next week. Hoenisch && .AVIATION... 620 PM MDT Mon May 30 2022 (31/00Z TAF period) KCTB, KHVR: Expect VFR conditions throughout this TAF period. Periods of gusty north and northwesterly winds up to 35KT are forecast. Expect mountain obscuration along The Great Divide. KGTF, KLWT, KHLN, KBZN, KEKS, KWYS: Periods of MVFR conditions are forecast with conditions improving with time from north to south. KWYS may slip into the IFR range during the overnight/early morning hours in rain/snow and with low ceilings. Mountain obscuration is forecast. Periods of gusty north northwesterly to north northeasterly winds impact light aircraft near mountains and through north-south oriented mountain valleys. Additionally, expect poor visibility through mountain valleys/passes in rain/snow with mist/fog. - Fogleman Refer to weather.gov/zlc for more detailed regional aviation weather and hazard information. && .PRELIMINARY POINT TEMPS/POPS... GTF 39 60 38 68 / 50 0 0 0 CTB 35 60 38 65 / 20 0 0 0 HLN 41 61 40 70 / 50 20 0 10 BZN 38 57 36 65 / 70 30 0 10 WYS 31 50 27 58 / 70 40 20 30 DLN 37 54 35 63 / 60 30 0 10 HVR 39 66 40 70 / 20 0 0 0 LWT 37 57 36 64 / 70 20 0 10 && .TFX WATCHES/WARNINGS/ADVISORIES... None. && $$ http://www.weather.gov/greatfalls