textproduct: Great Falls

KEY MESSAGES

- Rain continues to slowly exit Central MT throughout the morning.

- Dry conditions and warm temperatures settle in for most of the week.

- Unsettled weather and a cool down in temperatures possible next weekend.

DISCUSSION

- Meteorological Overview:

The vertically stacked low pressure system will continue to slide eastwards throughout the day. With it will also pull the precipitation over Central MT. However, expect light rain to continue over Central MT through at least the morning hours. Isolated showers may linger in eastern Fergus County through Sunday afternoon. As this storm system exits, high pressure moves into the region, creating low level stability. The calm conditions with breaking in the clouds overnight tonight will bring the potential for fog to develop mainly in Southwest MT this morning. Similar conditions set up Monday morning, with the potential for fog development to shift into North-Central MT as well.

A drier weather pattern sets up for most of the week as the current storm system moves east and another shortwave slides south of Montana across the Great Basin. As this shortwave slides across the Great Basin region, areas near the MT/ID border might get clipped with a few rain showers late Tuesday night. For the second half of the week, southwest flow dominates as the next incoming trough builds off of the western U.S. coast. Above normal temperatures are expected through Friday.

Ensembles hint at this upper-level trough moving through next weekend, bringing back chances for precipitation. This trough also pushes temperatures down closer to normal, and may lower snow levels to the higher mountain peaks. -Wilson

- Forecast Confidence & Scenarios:

There still remains some uncertainty in fog development across the Southwest MT valleys this morning. The main uncertainty is forecast soundings also showing low stratus also developing, which could prohibit fog potential. The best chances for fog development will be in the higher Southwest MT valleys. There's a 10-20% chance for fog development this morning. Monday morning, hi-res guidance shows greater probabilities, with a 30-60% chance for fog with less than a mile of visibility along US Highway 2 from Havre to Cut Bank. -Wilson

AVIATION

20/06Z TAF Period

Moisture wrapping around the upper level low tracking across WY will maintain low to mid clouds and mountain obscuration across eastern portions of southwest and central MT tonight with some light precipitation lingering near KLWT. Mid level cloud-cover thins from west to east across these areas overnight, which is likely to allow for low stratus and/or patchy fog development. VFR conditions prevail further north with mainly high cloud- cover, however surface winds remain fairly light and cannot rule out some patchy fog development near KHVR or KCTB early Sunday morning. Expect improvement at all sites by 16z Sunday. Hoenisch

PRELIMINARY POINT TEMPS/POPS

GTF 65 46 74 47 / 20 10 0 0 CTB 68 43 73 43 / 0 0 0 0 HLN 61 45 72 44 / 90 10 0 0 BZN 57 44 66 40 / 90 40 10 0 WYS 57 34 63 29 / 60 60 10 10 DLN 60 42 67 40 / 70 20 0 0 HVR 70 46 74 46 / 10 10 10 0 LWT 60 46 65 44 / 90 80 30 0

TFX WATCHES/WARNINGS/ADVISORIES

None.