913 FXUS65 KTFX 231824 AFDTFX Area Forecast Discussion National Weather Service Great Falls MT 1124 AM MST Sun Feb 23 2020 ...UPDATED AVIATION DISCUSSION AND MORNING UPDATE... .SYNOPSIS... Mild and breezy conditions are expected through early afternoon, but cooler temperatures and an increasing chance for snow are expected this afternoon through Monday. Warming temperatures and drier conditions return by mid-week. && .UPDATE... The morning update has been published. A vigorous Pacific shortwave and its associated surface cold front is currently moving through Washington and is still forecast to pass through our region roughly from 5 to 9 pm. Gusty westerly winds along with a brief period of snow showers or even snow squalls are expected, especially over Central/Southwest Montana. Forecast remains on track but did add a Winter Weather Advisory for Hill, Blaine, and Fergus Counties, which runs from 5 am through 8 pm Monday. An area of more organized snow along with gusty winds are expected for these locations on Monday. && .AVIATION... Updated 1100 AM MST Sun Feb 23 2020 (23/18Z TAF Period) Northwest flow aloft continues today as a vigorous shortwave trough and its attendant surface cold front approaches from the west. A brief period of gusty westerly winds and snow showers are expected once the front passes through. This will degrade the VFR conditions to MVFR/IFR or even possibly lower during this time. Conditions improve once this initial band of snow moves through and the biggest threat for snow retreats to the mountains but expect intermittent MVFR CIGS for the remainder of the night. More snow showers are expected on Monday, especially for the eastern terminals (KHVR and KLWT), where general light snow and gusty winds are anticipated. There will be low level wind shear this evening and tonight and mountains will be obscured for much for the TAF period. && .PREV DISCUSSION... /ISSUED 342 AM MST Sun Feb 23 2020/ Forecast remains on track for a shortwave trough currently just off the British Columbia coast to sweep into Montana tonight. Generally mild and continued breezy conditions persist across the region today with increasing cloud cover as the system approaches the state. Scattered to numerous snow showers will develop over the western mountains this afternoon, then will spread out over the plains and the lower elevations of southwest Montana tonight. Current Winter Weather Advisories for Marias Pass and Kings Hill Pass appear to be on track at this time. Tonight through Monday evening will also see the possibility for isolated/scattered snow squalls to affect travel at times, especially along Interstate 90 from Butte to Bozeman. The shortwave trough will strengthen and move into the central Great Plains Monday night with residual showers persisting across southern portions of the forecast area through Tuesday morning. Tuesday through Thursday will see the upper trough strengthen into a early spring/late winter storm for the Plains, Midwest, and Great Lakes regions with Montana remaining beneath an unsettled north to northwest flow aloft. Model confidence is generally low during this mid-week period but it appears likely that scattered to possibly numerous showers should be expected over the mountains, with a few showers also moving out over the plains at times. Thursday night through Saturday will see an upper level high pressure trough build over the Northern Rocky Mountain region for mild and dry conditions. Afternoon high temperatures for Friday and Saturday will likely climb into the 50s. Latest diagnostic models, ensemble means, and the National Blend of Models appear to be trending toward developing a fairly significant upper level trough over the western United States for Sunday but confidence remains low at this time. mpj && .PRELIMINARY POINT TEMPS/POPS... GTF 49 27 36 17 / 10 50 50 50 CTB 44 24 32 15 / 30 30 40 30 HLN 49 26 36 17 / 20 70 50 40 BZN 45 21 34 14 / 10 80 60 50 WYS 34 1 24 -7 / 10 90 70 50 DLN 41 20 31 10 / 10 80 20 10 HVR 41 25 32 12 / 20 50 70 50 LWT 42 24 30 12 / 10 70 80 60 && .TFX WATCHES/WARNINGS/ADVISORIES... Winter Weather Advisory from 8 PM this evening to 11 PM MST Monday above 5000 feet for Cascade...Judith Basin...Meagher. Winter Weather Advisory from 5 AM to 8 PM MST Monday Blaine... Fergus...Hill. Winter Weather Advisory from 2 PM this afternoon to 11 PM MST Monday above 5000 feet for Northern Rocky Mountain Front. && $$ http://www.weather.gov/greatfalls |