Area Forecast Discussion
Issued by NWS Great Falls, MT
Issued by NWS Great Falls, MT
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218 FXUS65 KTFX 090941 AFDTFX Area Forecast Discussion National Weather Service Great Falls MT 341 AM MDT Tue Jul 9 2024 .SYNOPSIS... Very warm and dry conditions will persist across the area into next week with the hottest temperatures likely to occur on Wednesday and Thursday. Temperatures fluctuate slightly this weekend into next week but are likely to remain well above average. && .DISCUSSION... A strong upper level ridge initially centered over southern NV/CA with axis north through the interior NW US and BC will continue to gradually expand east over the next 2 days with the axis shifting east across the Northern Rockies and MT in the Wed/Thu period. Heat continues to build across the area today with temperatures 1-3 degrees warmer than yesterday with Wednesday and Thursday still looking to see the hottest temperatures as the ridge axis and associated lower level thermal trough shift across the Rockies. Temperature forecasts have changed very little with most lower elevation locations expected to see temperatures reach the lower 90s today and mid to upper 90s Wednesday and Thursday. A subtle weather disturbance crossing the ridge Thursday will slightly moderate temperatures on Friday, but only by a few degrees before heat rebuilds on Saturday as the upper level ridge/high becomes established more directly to our south across the central Rocky Mtn states (UT/CO). Multi-model ensembles all support a continuation of anomalous upper level ridging centered across this area through early next week, but cluster analysis reveals some minor differences in the amplitude of the ridge. In any case, very warm to hot temperatures are likely to persist well into next week under this stagnant weather pattern. Moisture will remain very limited through Wednesday with just some higher level moisture moving over the ridge bringing some mid to high clouds at times. The subtle disturbance moving across the area Thursday and additional disturbances (largely moving by north of the area) this weekend may provide some lift for a slight (5-20%) risk of high-based showers and thunderstorms, primarily across the mountains of central/SW MT. By next week there is some indication of deeper moisture beginning to move around the ridge but chances for meaningful precipitation will remain low. Hoenisch && .AVIATION... 09/06Z TAF Period VFR conditions prevail this TAF period under mostly clear skies and light winds. The greatest concern will be for density altitudes given forecast hot temperatures Tuesday. -AM Refer to weather.gov/zlc for more detailed regional aviation weather and hazard information. && .FIRE WEATHER... Building heat and dryness will accelerate the drying of fuels over the next several days and increase fire danger indices. In addition, overnight moisture recovery will worsen through Thursday, particularly at mid-higher elevations. Winds are relatively light through Wednesday with some increase in afternoon breeziness Thursday through the weekend. This, in addition to the risk for isolated lightning late this week into the weekend will add to the overall increase in fire weather concerns with continued heat and dryness likely to continue into next week. Hoenisch && .PRELIMINARY POINT TEMPS/POPS... GTF 91 61 97 63 / 0 0 0 0 CTB 91 59 96 62 / 0 0 0 0 HLN 96 63 100 65 / 0 0 0 0 BZN 92 56 96 58 / 0 0 0 0 WYS 84 44 87 45 / 0 0 0 0 DLN 89 55 93 57 / 0 0 0 0 HVR 93 61 97 64 / 0 0 0 0 LWT 87 58 91 62 / 0 0 0 0 && .TFX WATCHES/WARNINGS/ADVISORIES... None. && $$ http://www.weather.gov/greatfalls