FXUS65 KTFX 091643 AFDTFX Area Forecast Discussion National Weather Service Great Falls MT 1040 AM MDT Thu May 9 2024 Hydrology section updated .SYNOPSIS... Lingering shower activity will continue to diminish and end heading into the afternoon hours. Much drier and milder conditions are then expected for the weekend, but a passing disturbance will bring some breeziness and a slight chance of a few showers and perhaps a thunderstorm to the plains Saturday night into Sunday. Additional weather disturbances are expected to pass through the Northern Rockies early next week and bring unsettled conditions, but temperatures look to remain at or above average. && .UPDATE... Updated forecast is out. The main adjustment this morning was to increase Pops in the Great Falls area. Light rain is falling along a deformation zone that has set up with the upper level ridge building in from the west and low pressure to our southeast. Precipitation is light, but never the less continues to fall. The forecast models diminish this light precip this evening. Otherwise, temperatures look on track for today, with a nice warming trend expected over the weekend. Brusda && .AVIATION... 550 AM MDT Thu May 9 2024 (09/12Z TAF Period) Overall, a high pressure ridge building into North Central, Central, and Southwest Montana from the northwest will shift the decreasing flow aloft more northeasterly, and surface high pressure will keep winds fairly light through at least 10/12Z. Details: North-central Montana (KCTB, KHVR): VFR conditions will continue through the period as mid-level cloudiness decreases from the north. Central (KGTF, KHLN, KLWT) and Southwest (KBZN, KEKS, KWYS) Montana: Mountain-obscuring low VFR/MVFR conditions with areas of fog and scattered rain and mainly mountain snow showers will continue across the area through at least 18Z, but IFR ceilings will linger at KLWT until around 18Z. Clouds are expected to start lifting and breaking up after then, with a chance of showers and MVFR conditions lingering until 00Z along and south of a KEKS-KBZN-KLWT. Skies should partially clear after 00Z, allowing patchy fog to form after 04Z. -Coulston Refer to weather.gov/zlc for more detailed regional aviation weather and hazard information. && .HYDROLOGY... The flood warning will continue for Clear Creek. The water is receding on the creek, but it will just take a bit more time before the water levels go below flood stage. The areal flood advisory has been replaced with a flood watch for small streams and creeks that flow out of the Bears Paw Mountains this weekend. In talking with emergency managers in this area this morning, most creeks have receded from the recent rainfall. However, warm temperatures are expected to develop on Friday and then continue through the weekend. This could result in small streams and creeks that flow out of the Bears Paw Mountains to come out of their banks once again. Thus a flood watch has been issued for this area for that potential. Additionally, with warm temperatures expected elsewhere over the CWA from Friday through Sunday, expect small streams and creeks that flow out of the mountains of the remainder of North Central and Southwest MT to begin to rise as well. Since many of these streams and creeks are at lower levels, the threat/impact from any flooding that could develop is lower at this time. Never the less, we will continue to monitor the situation and should the potential for flooding increase elsewhere over the CWA additional flood statements might need to be issued over the weekend. Brusda && .PREV DISCUSSION... /ISSUED 550 AM MDT Thu May 9 2024/ Abundant low level cloudiness, areas of showers, and even some patchy fog can be found over North-central and Southwest Montana this morning. Northeasterly flow aloft will more or less hang around for one more day before the responsible low pressure system weakens further and moves away from the region tonight. Scattered showers are expected to be light and will diminish and end in a northeast to southwest fashion as the day progresses. Temperatures begin moderate from the chilly last couple of days, but will still run slightly below average, especially over central and southwestern locations where clouds will linger for much of the day. No significant note worthies for tonight aside from some patchy fog in spots with light winds and lingering moisture in place amid partial clearing. Ridging attempts to build in heading towards the weekend, but there will still be a bit of a northwesterly flow aloft, leaving an opportunity for a weak shortwave and cold front to pass through the plains Saturday night into Sunday. This system will merely bring some breeziness, a few clouds, and lower end shower and isolated thunderstorm chances. The warming trend will generally be uninterrupted with afternoon highs climbing well into the 70s by Sunday. Ensembles remain in fairly good agreement with another more defined shortwave and cold front passing through Monday into Tuesday, bringing more breeziness and scattered showers and isolated thunderstorms to much of North-central and Southwest Montana. Most suites favor a northwesterly flow aloft continuing for the second half of next week, with about two thirds of them favoring ridging to be more dominant and only a minority of guidance leaning towards troughing and unsettled conditions. At this time, there's nothing really out of line from what's normally expected this time of year and temperatures look to run at least near average even with the wetter model solutions. - RCG && .PRELIMINARY POINT TEMPS/POPS... GTF 56 33 66 40 / 80 0 0 0 CTB 59 31 71 44 / 0 0 0 0 HLN 55 36 69 43 / 40 0 0 0 BZN 51 31 65 35 / 50 10 0 0 WYS 50 25 63 28 / 30 10 0 0 DLN 54 33 66 37 / 30 0 0 0 HVR 64 38 70 43 / 20 0 0 0 LWT 49 31 60 37 / 50 10 0 0 && .TFX WATCHES/WARNINGS/ADVISORIES... Flood highlights are in effect for portions of North Central MT. && $$ http://www.weather.gov/greatfalls