textproduct: Great Falls

KEY MESSAGES

- Today through Tuesday there will be rain showers in the afternoon and evening.

- It will be warm this afternoon and tomorrow before a brief cooldown occurs on Monday and Tuesday.

DISCUSSION

- Meteorological Overview:

This morning a cold front moved through North-central Montana which has brought slightly cooler temperatures to North-central Montana this afternoon. This afternoon northwest flow moves over North- central, Central, and Southwestern Montana. This will bring isolated showers and thunderstorms to portions of North-central and Central Montana this afternoon and evening. On Sunday northwest flow aloft remains over North-central, Central, and Southwestern Montana. On Sunday temperatures will return to near seasonal averages. Sunday evening/early Monday morning a cold front will move through North- central, Central, and Southwestern Montana. Ahead of this cold front in Southwestern Montana Sunday afternoon/evening isolated showers and thunderstorms will form in Southwestern Montana.

On Monday northwest flow aloft remains over North-central, Central, and Southwestern Montana. This combined with the cold front that moved through will bring below seasonal average temperatures to the area. On Monday due to the northwest flow aloft there will be isolated showers and thunderstorms over North-central, Central, and Southwestern Montana. On Tuesday an upper-level ridge begins to approach Montana and this will bring northerly flow aloft to North- central, Central, and Southwestern Montana. Tuesday afternoon there will be mountain showers and it will be mostly dry at lower- elevations. On Wednesday an upper-level ridge builds in over North- central, Central, and Southwestern Montana. This will allow temperatures to warm up with mostly dry weather. On Thursday and Friday there will be northwest flow over North-central, Central, and Southwestern Montana. This will bring isolated showers and thunderstorms to North-central, Central, and Southwestern Montana. -IG

- Forecast Confidence & Scenarios:

Today there is a 10 - 15% chance for thunder Glacier County down to Cascade County and from Cascade County to Western Fergus County. Today there will be isolated weak thunderstorms in those areas. There is very limited moisture and instability this afternoon which will limit thunderstorm development. Today along the I-15 Corridor between the Canadian Border and Great Falls there is a 20 - 30% chance for a tenth of an inch of rain or greater. On Monday there is a 5 - 30% chance for a tenth of an inch of rain or greater across portions of North-central Montana. On Wednesday there is a 15% chance for thunder across Southwestern Montana. On Thursday there is a 15 - 25% chance for thunder across the majority of North-central, Central, and Southwestern Montana. -IG

AVIATION

02/18Z TAF Period.

Mid-level clouds will start to increase this afternoon with a few isolated showers and possibly a thunderstorm near some north- central MT terminals late this afternoon through this evening. KCTB has the greatest risk (30%) for a thunderstorm in the vicinity with variable/gusty winds late this afternoon/evening with a lower 10-20% risk at KGTF and KLWT after 00z. Hoenisch/thor

PRELIMINARY POINT TEMPS/POPS

GTF 42 74 43 55 / 30 0 30 40 CTB 37 72 40 53 / 40 0 20 20 HLN 43 74 43 54 / 10 0 10 30 BZN 38 71 39 56 / 10 20 10 30 WYS 30 64 30 57 / 10 20 10 30 DLN 40 71 39 61 / 10 10 10 10 HVR 39 76 41 56 / 10 0 30 20 LWT 40 69 38 50 / 40 0 30 50

TFX WATCHES/WARNINGS/ADVISORIES

None.