Area Forecast Discussion
Issued by NWS Great Falls, MT
Issued by NWS Great Falls, MT
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049 FXUS65 KTFX 271229 AFDTFX Area Forecast Discussion National Weather Service Great Falls MT 628 AM MDT Thu Jun 27 2024 ...Aviation Section Update... .SYNOPSIS... Strong thunderstorms are forecast for today. Some of these storms may become severe, producing strong erratic gusty winds, large hail, frequent lightning and heavy downpours. Temperatures cool through the end of the traditional work week, with a few general thunderstorms developing on Friday. && .DISCUSSION... Note: The forecast area for The National Weather Service Great Falls Weather Forecast Office includes north central, central and southwest Montana. Today...An upper level trof rolls across The Treasure State, today, with the attendant cold front impacting our region. Considering the timing of cold frontal passage, thunderstorms develop early and continue through the day. Some of these storms may become severe. The Storm Prediction Center (SPC) includes, Meagher, Judith Basin and Fergus Counties in an area of Slight Risk for Severe Weather. For this area, there is a 15% to 29% risk for severe wind of >= 58 mph, 15% to 29% risk for large hail of >= 1" and 2% to 4% risk for tornado. Some other portions of our region are included in a Marginal Risk for Severe Weather. Across these areas, there is 5% to 14% chance for severe wind and a 5% to 14% chance for large hail. These probabilities are considered within a 25 mile radius at any given point in the risk area. All of today`s thunderstorms have the potential to produce frequent lightning and heavy downpours. The severe weather threat is forecast to move out of our area by late afternoon. Cooler temperatures, follow. Tomorrow...Low elevation high temperatures range about 10 degrees Fahrenheit below normal. Rainfall impacts north central and central Montana, allowing for some needed moisture. Strong gusty winds are forecast, especially along The Northern Rocky Mountain Front. Considering cold and wet conditions, hypothermia becomes an concern to those working or recreating outdoors. Saturday through next Thursday...An upper level ridge dominates the first part of the weekend favoring warming conditions and a dry day. Low elevation highs return to near normal values. With the approach of the next upper level trof, the weather becomes more active, again, with daily showers and thunderstorms forecast from Sunday through next Thursday. - Fogleman && .AVIATION... 27/12Z TAF Period Note: The NWS Great Falls Weather Forecast Office manages the following TAFs: KCTB, KHVR, KGTF, KLWT, KHLN, KBZN, KEKS and KWYS. KWYS begins this TAF period in LIFR conditons due to low visibility in fog and low ceiling. These conditions are forecast to improve after 27/14Z; otherwise, generally, VFR conditions are forecast. MVFR conditions are included during periods of showers and thunderstorms. Mountain-obscuring conditions are forecast with widespread showers and thunderstorms associated with a cold frontal passage between 12Z and 00Z. Most of these thunderstorms will be capable of producing erratic gusts to 40KT, lightning, small hail, and heavy downpours. Additionally, stronger thunderstorms are forecast to occur along and east of a line from KHVR to KHLN to KBZN, where gusts could exceed 45KT, at times, with large hail and frequent lightning. In the wake of the cold front, showers and storms will decrease, as breezy and gusty westerly winds become more widespread. Overall, the passing shortwave responsible for this thunderstorm activity will keep a moderate westerly flow aloft over the area, which will cause some mountain wave turbulence. Also, a low level core of stronger southerly winds ahead of the shortwave will cause low-level wind shear in far Southwest Montana (KEKS, KWYS) between 11Z and 16Z before the winds translate more down to the surface. -Coulston/Fogleman Refer to weather.gov/zlc for more detailed regional aviation weather and hazard information. && .PRELIMINARY POINT TEMPS/POPS... GTF 71 49 62 43 / 90 10 70 10 CTB 67 46 61 42 / 70 50 90 0 HLN 75 50 70 46 / 80 10 30 0 BZN 77 42 69 41 / 70 10 10 0 WYS 70 34 63 34 / 50 10 10 0 DLN 73 40 69 40 / 60 0 0 0 HVR 73 49 64 43 / 90 20 80 10 LWT 73 44 59 38 / 90 10 50 20 && .TFX WATCHES/WARNINGS/ADVISORIES... None. && $$ http://www.weather.gov/greatfalls