Marine Weather and Tide Forecast for Big Sky, MT
March 18, 2024 9:39 PM MDT (03:39 UTC) Change Location
Sunrise 7:27 AM Sunset 7:36 PM Moonrise 11:51 AM Moonset 3:48 AM |
Area Discussion for - Great Falls, MT
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FXUS65 KTFX 190235 AFDTFX
Area Forecast Discussion National Weather Service Great Falls MT 835 PM MDT Mon Mar 18 2024
SYNOPSIS
The mild and dry airmass that has been in place across the region will remain across central and southwest Montana through mid-week while a cooler airmass begins to move south into north-central Montana on Tuesday. Areas of snow and additional cooling develop near the Canadian border on Wednesday with cooler air eventually spreading south across central and southwest Montana later this week before much colder temperatures and unsettled conditions develop this weekend.
UPDATE
Overnight low temperatures and hourly temperatures across the plains were decreased to reflect temperatures cooling off faster than forecasted in those locations. Wind directions across the area were adjusted this evening through tomorrow morning to better reflect current observations and trends. The rest of the forecast is on track. High temperatures across North-central and Central Montana will be about 10 degrees cooler tomorrow due to a dry cold front moving southwest across North-central and Central Montana tomorrow morning. -IG
AVIATION
537 PM MDT Mon Mar 18 2024 (19/00Z TAF Period)
VFR conditions prevail across all terminals for this TAF period. Due to an upper-level ridge in place above North-central, Central, and Southwestern Montana there will be high-level clouds at all terminals until Tuesday around noon at the plains terminals(KCTB, KHVR, KLWT, and KGTF). At the plains terminals some mid-level clouds will move into the area Tuesday around noon and stay through the end of the TAF period. There will be light winds at all terminals excluding the KCTB terminal. At the KCTB terminal Tuesday morning there will be gusts to 20kts for a few hours. Across the plains terminals, winds will become more northerly Tuesday morning due to a front that will move in. -IG
Refer to weather.gov/zlc for more detailed regional aviation weather and hazard information.
PREV DISCUSSION
/ISSUED 537 PM MDT Mon Mar 18 2024/
An upper level ridge of high pressure currently centered across the NW US will gradually weaken through the first half of this week as large scale troughing in central Canada expands to the west and southwest downstream of an amplifying ridge over eastern AK. At the surface, a trough exists to the lee of the Rockies connected with a larger scale trough of low pressure moving southeast from Central Canada through the Northern US plains. This is resulting in breezy west to northwest winds across the area, which will persist into this evening before diminishing and combined with the mild temperatures brings an elevated risk for grassland fires. Meanwhile, high pressure and a colder airmass currently situated across NW Canada is beginning to move south through northern Alberta. The leading edge of this airmass will modify significantly before reaching MT but will bring a shift to north and eventually northeast winds across north-central MT on Tuesday, where daytime temperatures will be about 10 degrees cooler than today, but still above seasonal mid-March averages.
The cold airmass deepens across the Canadian Prairies Tuesday night through Thursday with moisture increasing along an elevated (700MB) frontal zone stretching from SW Alberta through NE MT.
Snow developing along the frontal zone near the Canadian border will initially be light Tuesday night through Wednesday before increasing Wednesday night and Thursday in response to favorable positioning beneath the right entrance of an upper level jet.
Probabilities for snow amounts in excess of 2 inches Wednesday range from around 40% near Havre to 80% across far NE Blaine county with probabilities for 4 inch or higher snow accumulations near Glacier NP ranging from 60% over Marias Pass to above 80% across the higher peaks near the Canadian border. While daytime temperatures cool to the 30s near the Canadian border Wednesday and Thursday, milder temperatures persist Through Thursday for areas from Helena southward.
Medium range model ensembles are in fair agreement on the larger scale pattern developing late this week into the weekend with an offshore upper level trough moving inland beneath the larger scale trough already in place across western Canada. This brings increasing confidence in a turn to more winter-like conditions across the entire forecast area, including the potential for widespread snow and much colder temperatures. Details related to the timing and location of what looks to be several waves of moisture and upper level energy to move though the region are less certain still at this time and will be key to more specific snowfall amounts and timing of winter weather impacts, which may begin as early as Thursday across a larger portion of north-central MT before expanding south to include much of SW MT Friday night through the Weekend. Below are some preliminary snowfall probabilities for the Friday through Sunday period. Hoenisch
3-day Snow Accumulation Probabilities for Friday through Sunday: >2" >4" >8" Havre 90% 70% 30% Great Falls 90% 80% 40% Helena 90% 60% 15% Bozeman 70% 20% 5%
PRELIMINARY POINT TEMPS/POPS
GTF 33 55 30 49 / 0 0 10 10 CTB 31 48 25 38 / 0 0 20 20 HLN 35 61 35 61 / 0 0 0 0 BZN 30 59 30 60 / 0 0 0 0 WYS 19 51 22 49 / 0 0 0 0 DLN 30 58 32 59 / 0 0 0 0 HVR 27 51 25 35 / 0 0 40 60 LWT 31 53 27 49 / 0 0 30 20
TFX WATCHES/WARNINGS/ADVISORIES
None.
Area Forecast Discussion National Weather Service Great Falls MT 835 PM MDT Mon Mar 18 2024
SYNOPSIS
The mild and dry airmass that has been in place across the region will remain across central and southwest Montana through mid-week while a cooler airmass begins to move south into north-central Montana on Tuesday. Areas of snow and additional cooling develop near the Canadian border on Wednesday with cooler air eventually spreading south across central and southwest Montana later this week before much colder temperatures and unsettled conditions develop this weekend.
UPDATE
Overnight low temperatures and hourly temperatures across the plains were decreased to reflect temperatures cooling off faster than forecasted in those locations. Wind directions across the area were adjusted this evening through tomorrow morning to better reflect current observations and trends. The rest of the forecast is on track. High temperatures across North-central and Central Montana will be about 10 degrees cooler tomorrow due to a dry cold front moving southwest across North-central and Central Montana tomorrow morning. -IG
AVIATION
537 PM MDT Mon Mar 18 2024 (19/00Z TAF Period)
VFR conditions prevail across all terminals for this TAF period. Due to an upper-level ridge in place above North-central, Central, and Southwestern Montana there will be high-level clouds at all terminals until Tuesday around noon at the plains terminals(KCTB, KHVR, KLWT, and KGTF). At the plains terminals some mid-level clouds will move into the area Tuesday around noon and stay through the end of the TAF period. There will be light winds at all terminals excluding the KCTB terminal. At the KCTB terminal Tuesday morning there will be gusts to 20kts for a few hours. Across the plains terminals, winds will become more northerly Tuesday morning due to a front that will move in. -IG
Refer to weather.gov/zlc for more detailed regional aviation weather and hazard information.
PREV DISCUSSION
/ISSUED 537 PM MDT Mon Mar 18 2024/
An upper level ridge of high pressure currently centered across the NW US will gradually weaken through the first half of this week as large scale troughing in central Canada expands to the west and southwest downstream of an amplifying ridge over eastern AK. At the surface, a trough exists to the lee of the Rockies connected with a larger scale trough of low pressure moving southeast from Central Canada through the Northern US plains. This is resulting in breezy west to northwest winds across the area, which will persist into this evening before diminishing and combined with the mild temperatures brings an elevated risk for grassland fires. Meanwhile, high pressure and a colder airmass currently situated across NW Canada is beginning to move south through northern Alberta. The leading edge of this airmass will modify significantly before reaching MT but will bring a shift to north and eventually northeast winds across north-central MT on Tuesday, where daytime temperatures will be about 10 degrees cooler than today, but still above seasonal mid-March averages.
The cold airmass deepens across the Canadian Prairies Tuesday night through Thursday with moisture increasing along an elevated (700MB) frontal zone stretching from SW Alberta through NE MT.
Snow developing along the frontal zone near the Canadian border will initially be light Tuesday night through Wednesday before increasing Wednesday night and Thursday in response to favorable positioning beneath the right entrance of an upper level jet.
Probabilities for snow amounts in excess of 2 inches Wednesday range from around 40% near Havre to 80% across far NE Blaine county with probabilities for 4 inch or higher snow accumulations near Glacier NP ranging from 60% over Marias Pass to above 80% across the higher peaks near the Canadian border. While daytime temperatures cool to the 30s near the Canadian border Wednesday and Thursday, milder temperatures persist Through Thursday for areas from Helena southward.
Medium range model ensembles are in fair agreement on the larger scale pattern developing late this week into the weekend with an offshore upper level trough moving inland beneath the larger scale trough already in place across western Canada. This brings increasing confidence in a turn to more winter-like conditions across the entire forecast area, including the potential for widespread snow and much colder temperatures. Details related to the timing and location of what looks to be several waves of moisture and upper level energy to move though the region are less certain still at this time and will be key to more specific snowfall amounts and timing of winter weather impacts, which may begin as early as Thursday across a larger portion of north-central MT before expanding south to include much of SW MT Friday night through the Weekend. Below are some preliminary snowfall probabilities for the Friday through Sunday period. Hoenisch
3-day Snow Accumulation Probabilities for Friday through Sunday: >2" >4" >8" Havre 90% 70% 30% Great Falls 90% 80% 40% Helena 90% 60% 15% Bozeman 70% 20% 5%
PRELIMINARY POINT TEMPS/POPS
GTF 33 55 30 49 / 0 0 10 10 CTB 31 48 25 38 / 0 0 20 20 HLN 35 61 35 61 / 0 0 0 0 BZN 30 59 30 60 / 0 0 0 0 WYS 19 51 22 49 / 0 0 0 0 DLN 30 58 32 59 / 0 0 0 0 HVR 27 51 25 35 / 0 0 40 60 LWT 31 53 27 49 / 0 0 30 20
TFX WATCHES/WARNINGS/ADVISORIES
None.
Airport Reports
EDIT (hide/show)  Help Click EDIT to display multiple airports. Follow links for more data.Airport | Dist | Age | Wind kt | Vis | Sky | Weather | Temp | DewPt | RH | inHg |
KEKS ENNIS BIG SKY,MT | 18 sm | 24 min | calm | 10 sm | Clear | 41°F | 23°F | 48% | 30.18 |
Billings, MT,
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