textproduct: Great Falls

KEY MESSAGES

- Windy conditions develop later today over portions of North Central MT.

- Mild temperatures are expected across all of North Central and Southwest MT to end the work week.

- A change in the forecast for this weekend, as temperatures will be much cooler, along with a chance for rain and snow.

DISCUSSION

- Meteorological Overview: An upper level ridge is building over the Pacific Northwest today, resulting in warm air advection over Central MT. This warm air advection is producing a few areas of light snow, mostly over Southwest MT. Snow accumulations of a few inches are expected in the mountains of Southwest MT, but for lower elevations, maybe a dusting to a half inch. Windy conditions develop quickly this morning as the warm air moves in. Some blowing snow could occur this morning before temperatures warm enough to crust over the snow over North Central MT. The winter weather advisory for blowing snow remains unchanged for the Browning and Heart Butte areas. Additionally, winds become stronger this afternoon and overnight over portions of North Central MT. There is no change to the current high wind statement as well. Afternoon temperatures will also be quite a bit warmer today for most areas, generally about 20 degrees warmer than yesterday.

For Tuesday the strong winds continue over North Central MT, as the mild air continues to move in.

For Wednesday through Friday it continues to get warmer over the CWA, as the upper level ridge builds over Montana, resulting in the potential for near record high temperatures in many areas. The chance for any precipitation mid week will be really limited, and mostly just over the Rocky Mountain Front. Do expect another period of strong winds by Thursday, with additional high wind statements possible for later this week.

For Saturday through Monday...the forecast has changed a bit, with the models no progging a Canadian cold front to move southward through the CWA on Saturday. Rain/snow will accompany the frontal passage, along with cooler temperatures over the weekend and into early next week.

- Forecast Confidence & Scenarios: There is a 90 percent chance for strong winds in the high wind warning area for later today and Tuesday.

There is a 50 percent chance the high wind warning might need to be expanded into the Great Falls area for Tuesday, but with only a 50 percent probability of warning criteria wind gusts at this time, I held off on expanding the warning.

There is over an 80 percent chance of temperatures reaching record high temperatures later this week over portions of the CWA. Brusda

AVIATION

16/12Z TAF Period

Scattered light snow showers will affect Central and Southwest MT until about 14z. Some blowing snow is possible over North Central late this morning. Windy conditions develop over much of North Central as well this afternoon and will continue to be strong through the night. Mountains/passes will be obscured at times through the period. Brusda

HYDROLOGY

With the recent heavy snowfall in Judith Basin and Fergus counties, there is the potential for some small streams to run high, ponding of water in fields, and even some minor city flooding where storm drains are clogged this week. Overall, any flooding that does develop should be minor, with no flooding expected on any rivers at this time. Brusda

PRELIMINARY POINT TEMPS/POPS

GTF 47 42 58 46 / 20 40 10 10 CTB 49 39 57 42 / 10 10 0 0 HLN 50 39 61 41 / 20 20 10 10 BZN 53 38 64 40 / 30 30 0 10 WYS 42 27 52 26 / 40 40 10 10 DLN 55 39 63 40 / 10 20 0 0 HVR 45 35 63 41 / 10 10 0 0 LWT 43 37 56 40 / 10 20 10 10

TFX WATCHES/WARNINGS/ADVISORIES

Winter Weather Advisory until noon MDT today for East Glacier Park Region-Eastern Glacier, Western Toole, and Central Pondera- Northern High Plains-Southern High Plains-Southern Rocky Mountain Front.

High Wind Warning from 9 AM this morning to 6 PM MDT Tuesday for East Glacier Park Region-Eastern Glacier, Western Toole, and Central Pondera-Northern High Plains-Southern High Plains- Southern Rocky Mountain Front.

High Wind Warning from 3 PM this afternoon to 6 PM MDT Tuesday for Bears Paw Mountains and Southern Blaine-Eastern Toole and Liberty-Fergus County below 4500ft-Hill County-Judith Basin County and Judith Gap-Northern Blaine County-Snowy and Judith Mountains-Western and Central Chouteau County.