Area Forecast Discussion
Issued by NWS Great Falls, MT
Issued by NWS Great Falls, MT
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749 FXUS65 KTFX 071438 AFDTFX Area Forecast Discussion National Weather Service Great Falls MT 838 AM MDT Sun Jul 7 2024 .SYNOPSIS... Drier and warmer conditions develop today under a northwest flow aloft. Much warmer temperatures develop by the middle of the upcoming week as strong upper level high pressure moves inland with hottest temperatures likely as the ridge shifts across the region Wednesday and Thursday && .UPDATE... No update is needed this morning as the previous forecast remains on track. -Wilson && .AVIATION... 07/12Z TAF Period Mid level clouds associated with a weak weather disturbance in northwest flow aloft are dissipating this morning. Except for some mountain cumulus development this afternoon, mainly clear skies are expected across the area through most of the TAF period with prevailing VFR conditions and light surface winds. Hoenisch Refer to weather.gov/zlc for more detailed regional aviation weather and hazard information. && .PREV DISCUSSION... /ISSUED 415 AM MDT Sun Jul 7 2024/ The area remains under a somewhat cyclonic northwesterly flow aloft this morning on the western periphery of larger scale troughing across the central US/Canada. A subtle mid-upper level disturbance moving through the NW flow is producing mid-level clouds and widely scattered sprinkles/showers across some areas early this morning, but expect this activity to decrease fairly quickly after 6am as the disturbance exits and drier/warmer air aloft begins to build into the area from the west and northwest. Warming and drying aloft will support more stable conditions today with some terrain generated cumulus this afternoon leading to a very low (<20%) probability of an isolated shower over the central MT mountains with otherwise dry and mainly sunny conditions across the area. A strong upper level ridge with axis currently extending from CA north and just offshore of the Pacific NW will gradually shift inland through the early part of this week. Temperatures will be close to seasonal averages across the area today, warming to 5-15 degrees above seasonal averages Monday and Tuesday. The hottest temperatures are likely to occur as the upper ridge slumps east across the Northern Rockies and MT Wednesday and Thursday with daytime maximum temperatures reaching the mid to upper 90s for many lower elevation areas and near daily records for some locations, particularly on Thursday. There remains a risk for some locations, especially the Helena area, to see max temperatures reach or exceed 100F later this week (see table below). Temperatures may moderate slightly as the upper ridge flattens some Friday into next weekend but are expected to remain well above average with daytime temperatures in the 90s most likely to persist through the weekend across SW MT valleys. Hoenisch Probability of daytime maximum temperatures reaching 100F or higher: Wed Thu Fri Bozeman 15% 20% 20% Cut Bank 2% 3% 0% Dillon 0% 0% 0% Great Falls 20% 20% 5% Havre 5% 20% 0% Helena 65% 55% 20% Lewistown 0% 0% 0% && .PRELIMINARY POINT TEMPS/POPS... GTF 81 55 88 58 / 0 0 0 0 CTB 83 53 89 57 / 0 0 0 0 HLN 87 58 92 61 / 0 0 0 0 BZN 80 51 87 54 / 0 0 0 0 WYS 73 39 80 41 / 0 0 0 0 DLN 78 49 85 52 / 0 0 0 0 HVR 83 54 89 59 / 0 0 0 0 LWT 74 51 83 55 / 10 0 0 0 && .TFX WATCHES/WARNINGS/ADVISORIES... None. && $$ http://www.weather.gov/greatfalls