mt discuss
Office: TFX
FXUS65 KTFX 090000
AFDTFX
Area Forecast Discussion
National Weather Service Great Falls MT
600 PM MDT Wed May 8 2024
.Aviation Section Updated...
.SYNOPSIS...
Snow and rain will end from northeast to southwest by Thursday
morning. Across North-central and Central Montana patchy dense fog
is possible this evening through Thursday morning in areas where
skies clear. North-central, Central, and Southwestern Montana
will dry out and warm up Thursday afternoon through the weekend.
By the middle of next week the weather pattern could change.
&&
.DISCUSSION...
This afternoon through Thursday... Rain/snow will
continue through the evening along the Highway 200 Corridor and
south. Precipitation will end from northeast to southwest by
Thursday morning. There will also be isolated rain showers across
North-central Montana through this evening. Snow will continue
along the Southern Rocky Mountain front through this evening.
Patchy dense fog has formed in Northern and Central Fergus County
and will continue through Thursday morning. At times visibility
will be reduced to a quarter mile or less. Patchy dense fog could
form in other locations of Central and North-central Montana if
skies clear overnight due to all the moisture from this system. A
Winter Weather Advisory has been issued for the Madison River
Valley and Gallatin Valley until midnight due to snowfall reducing
visibility down to a half mile at times. The Blizzard Warning for
the Little Belts and Highwood Mountains has been downgraded to a
Winter Storm Warning due to the strong winds and wind gusts having
ended. The snow has ended for the Highwood Mountains. The Winter
Storm Warning along the Northern Rocky Mountain front has been
cancelled due to the snow having ended. The Winter Storm Warning
along the Southern Rocky Mountain Front has been downgraded to a
Winter Weather Advisory. For more details see the TFX
WATCHES/WARNINGS/ADVISORIES section below. On Thursday an upper-
level trough begins to move out of the area. This will begin to
warm up and dry out North-central, Central, and Southwestern
Montana.
Friday through Sunday... On Friday an upper-level ridge begins to
move over North-central, Central, and Southwestern Montana. This
will warm temperatures up to about seasonal averages across the
area. This upper-level ridge will stay in place above North-central,
Central, and Southwestern Montana through the weekend which will
keep temperatures dry and allow temperatures to warm up to above
seasonal averages across the area through the weekend. Isolated
locations of North-central and Central Montana and the Helena Valley
have a 50 - 65% chance for having temperatures of 80 degrees or
warmer.
Monday through next Wednesday... On Monday cluster analysis
indicates that there will be upper-level zonal flow over North-
central, Central, and Southwestern Montana. This will keep the
area's weather about the same on Monday as Sunday. On Tuesday three
clusters (86% of ensemble members) have a week upper-level trough
over North-central, Central, and Southwestern Montana. One of the
clusters (14% of ensemble members) has an upper-level ridge over
North-central, Central, and Southwestern Montana. This indicates
that the weather pattern could change on Tuesday. Next Wednesday the
ensembles begin to diverge and so the weather over North-central,
Central, and Southwestern Montana is uncertain at this time. -IG
&&
.AVIATION...
600 PM MDT Wed May 8 2024 (09/00Z TAF Period)
North-central Montana (KCTB, KHVR): VFR conditions will prevail
through the TAF period with some vicinity rain showers near KHVR
possible through 09/09Z. Otherwise, the precipitation will continue
progressing southward away from the hi-line. Gusty winds are
expected to continue through around 09/03Z before tapering off below
15kts.
Central Montana (KGTF, KHLN, KLWT): MVFR conditions are expected to
prevail at KGTF and KHLN through at least Thursday morning with the
possibility of IFR or lower in passing rain showers. Mountains and
passes will be obscured through much of the TAF period. Meanwhile at
KLWT, fog and low clouds are expected to prevail through at least
Thursday morning with IFR or lower expected during this time. There
is a possibility of fog developing around KGTF, however, at this
time confidence was not high enough to include it in the TAFs.
Southwest Montana (KBZN, KEKS, KWYS): Rain and snow showers are
expected to impact KBZN and KEKS through most of the TAF period with
IFR or lower possible through the period. KWYS will generally stay
dry and fluctuate between VFR and MVFR through the TAF period.
Mountains and passes will be obscured through at least Thursday
afternoon.
-thor
Refer to weather.gov/zlc for more detailed regional aviation
weather and hazard information.
&&
.HYDROLOGY...
The flood warning will continue for Clear Creek, as the creek has
risen into major stage earlier today.
Additional runoff from the Bears Paw Mountains will continue to
produce minor flood impacts from other small streams and creeks,
such as Big Sandy Creek and Beaver Creek. Areas of minor flooding
have been reported around Beaver Creek, along with locations around
Hays and Lodge Pole. Thus the areal flood advisory will continue for
portions of North Central MT until Thursday afternoon.
For areas further south and west, most of the higher elevations have
had just snowfall recently, thus runoff from the recent snowfall
will begin in a few days as warmer air moves back in. Since most
river levels are currently low, impacts should be minor from any new
flooding that develops. Brusda
&&
.PRELIMINARY POINT TEMPS/POPS...
GTF 34 56 34 64 / 80 40 0 0
CTB 31 59 33 70 / 10 0 0 0
HLN 40 58 37 70 / 60 30 0 0
BZN 34 55 31 64 / 70 50 10 0
WYS 30 53 26 61 / 40 30 0 0
DLN 37 56 34 66 / 50 20 0 0
HVR 41 66 38 70 / 40 20 0 0
LWT 32 48 31 58 / 90 50 10 0
&&
.TFX WATCHES/WARNINGS/ADVISORIES...
Winter Weather Advisory until midnight MDT tonight for Southern
Rocky Mountain Front.
Winter Storm Warning until midnight MDT tonight for Big Belt,
Bridger and Castle Mountains-Gallatin and Madison County
Mountains and Centennial Mountains-Snowy and Judith Mountains.
Winter Weather Advisory until midnight MDT tonight for Gallatin
Valley-Madison River Valley.
Winter Storm Warning until midnight MDT tonight for Little Belt
and Highwood Mountains.
&&
$$
http://www.weather.gov/greatfalls
Office: MSO
FXUS65 KMSO 081716
AFDMSO
Area Forecast Discussion
National Weather Service Missoula MT
1116 AM MDT Wed May 8 2024
.DISCUSSION...Moisture previously encircling the primary low
pressure center in eastern Montana is now gradually receding
eastward as the system progresses eastward today. Radar forecasts
indicate lingering showers persisting along the Divide of west-
central and southwest Montana tonight, potentially bringing
sporadic snow showers that could briefly impact mountain passes
like MacDonald and Homestake.
Looking ahead, model clusters and ensemble forecasts are
converging on the development of a modest Rex block/split flow
pattern over the western U.S. by Thursday. In this scenario, the
Northern Rockies will find themselves under the influence of a
warm high pressure ridge, fostering a steady warming trend through
the weekend. Expect valley highs across central Idaho and western
Montana to range from the mid 70s to mid 80s during this period.
Confidence in this forecast is bolstered by the NBM v4.2, which
projects an 80 percent probability for high temperatures below
4000 feet to exceed 80 degrees on Sunday.
However, as we head into early next week, the ensemble mean
guidance suggests the high pressure ridge will begin to flatten,
initiating a cooling trend. Yet, model clusters diverge
significantly on the specifics of the weather pattern, introducing
notable uncertainties in temperature and precipitation forecasts.
This variability translates to a wide spectrum of possibilities,
ranging from continued warmth and dry conditions to a 40% chance
of cooler, showery weather by Wednesday.
&&
.AVIATION...Moisture wrapping around a surface low over central
Montana will continue to spread light valley rain showers across
region, sporadically lowering ceilings at all aviation sites. The
surface low will slowly move eastward, reducing showers across
the Northern Rockies. Shallow fog may develop early tomorrow
morning for KGPI, KMSO and KHRF, along with a low stratus deck.
&&
.MSO WATCHES/WARNINGS/ADVISORIES...
MT...None.
ID...None.
&&
$$
Office: BYZ
FXUS65 KBYZ 081936
AFDBYZ
Area Forecast Discussion
National Weather Service Billings MT
136 PM MDT Wed May 8 2024
.DISCUSSION...
Rest of Today through Thursday Night...
Moisture. Is. Everywhere.
While the upper low supplying all the weather we've seen the past
few days is now located in western South Dakota and slowly progged
to move east over the next day, wrapping around it is still an
abundance of moisture flowing in to southern and central Montana.
Upslope into the foothills and mountains is deep as well, and
with a lot of moisture still available upstream, the current rain
over the lower elevations and snow in the higher foothills and
mountains will persist through tonight at it's current rate. The
Livingston area (not including Bozeman Pass) will see their snow
slowly switch to rain this afternoon and evening, then likely
seeing low clouds and fog roll in overnight through tomorrow
morning, reducing visibilities along I-90.
Across the lower elevations, rain will persist through the
afternoon with the aforementioned moisture upstream continuing
to move south into southern MT with it's upslope flow. While rain
should slowly diminish tonight, a persistent upslope through
Thursday could keep light to moderate rain continuing along the
foothills south of Billings. Despite all of the rain over the past
couple days and today, streams are expected to remain below any
potential flood stages. Only streams that may get close and have
some minor flooding of low-lying areas will be focused in the area
between Billings, Sheridan, WY, and Miles City, as those areas
have reported 3-4" of rain so far over the past 72 hours. While
those are very high amounts, the fact that the soil out there was
very dry and had room to soak up a lot of water, and that it fell
over a 2-3 day period assisted in preventing any major flooding
concerns.
On Thursday, one last, small push of moisture and rain showers
will occur across the area, but accumulation potential from this
will be much lower than yesterday or today, and little impacts are
expected from it. By the evening, winds will become westerly and
officially shut off the moisture from the area, ending this
weather system impacting us once and for all.
Vertz
Friday through Wednesday...
Building ridge aloft will bring dry and warmer weather Friday thru
the weekend. We should see temps in the 60s Friday then 70s
Saturday and Sunday. By Sunday afternoon the ridge will flatten
enough such that weak energy emerging from southwest Canada may
induce a few diurnal showers.
Above normal temps (70s to near 80F) will continue Monday, but
with an increasing chance of showers & t-storms in response to
lowering heights and a stronger shortwave emerging from the
developing WNW flow aloft. This energy will be associated with a
surface cold front, so there is potential for gusty winds by late
in the day as well.
Tuesday & Wednesday look more active and cooler as a couple of
additional waves drop thru an amplifying NW flow aloft. There is a
good chance (30-50%) of showers on each of these days, and
freezing levels will fall enough to produce some accumulating
snowfall over the mountains, above 7kft or so.
One final note. The upcoming warmer temps will melt much of the
wet snow that is currently falling at elevations between
6000-8000 feet. Do not see a flood risk, but rivers/streams
emerging from the foothills will likely see some rises this
weekend. Any higher elevation snow melt will end by Tuesday when
cooler temps arrive.
JKL
&&
.AVIATION...
A slow-moving storm system will continue to bring frequent showers
(especially west of KMLS & K00F) thru tonight and much of
Thursday. MVFR to IFR can be expected, with poorest flying weather
(possibly to LIFR in fog) along the foothills tonight into early
tomorrow. Mountains will remain obscured in snow, especially the
N-NE facing slopes. Brisk NW-NE winds (gusts 25-35kts from KBIL
eastward) will decrease tonight and be lighter Thursday. JKL
&&
.PRELIMINARY POINT TEMP/POPS...
Thu Fri Sat Sun Mon Tue Wed
-----------------------------------------------------------
BIL 044/058 041/066 043/076 047/078 050/078 050/072 046/065
97/W 30/U 00/U 01/U 22/T 35/T 33/T
LVM 038/054 036/063 037/073 043/078 046/077 045/068 042/064
+7/W 20/U 00/U 01/U 22/W 24/T 33/T
HDN 042/061 041/067 039/077 045/079 047/080 048/073 045/065
97/W 30/U 00/U 01/U 22/T 44/T 33/T
MLS 041/063 041/067 042/075 048/077 050/079 049/071 045/064
44/W 10/U 00/U 01/U 12/W 33/T 22/T
4BQ 039/060 043/066 041/074 046/076 049/078 049/071 045/062
44/W 20/U 00/U 01/U 12/T 34/T 23/T
BHK 036/064 039/067 041/075 045/075 047/079 047/069 040/063
23/W 10/U 00/U 01/U 12/T 33/T 22/T
SHR 036/056 038/064 037/074 043/076 045/078 045/070 041/061
95/W 31/B 00/U 12/W 23/T 45/T 44/T
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...Winter Storm Warning remains in effect until noon MDT
Thursday FOR ZONES 67-68-171.
WY...Winter Storm Warning remains in effect until noon MDT
Thursday FOR ZONE 198.
&&
$$
weather.gov/billings
Office: GGW
FXUS65 KGGW 082018
AFDGGW
Area Forecast Discussion
National Weather Service Glasgow MT
218 PM MDT Wed May 8 2024
.DISCUSSION...
KEY MESSAGES:
- Steady rain becoming scattered, with wind less of a concern
through late Thursday afternoon.
- Flooding concerns remain minimal as the ground has efficiently
absorbed the rainfall we have observed. Stream and creeks have
risen slightly, but not enough to cause any flooding concerns.
- There is high confidence for warmer than normal conditions
this weekend into much of next week.
WEATHER PATTERN OVERVIEW:
Today through Thursday night: Northeast Montana is on the
periphery of a low pressure system that continues to provide
enough forcing, along with daytime heating today and tomorrow, for
scattered showers to move through until late Thursday afternoon.
There is high (70 percent) confidence for locations in the
southwest portion of the GGW CWA to receive over one tenth of an
inch of rain, with the rest of the area likely to remain below
this threshold.
Friday onward: A warm up will occur this weekend as a positively
tilted ridge builds into the area. Although there is high (70
percent) confidence of dry weather occurring through early next
week, the GFS ensemble is hinting at a slight chance of showers
and thunderstorms occurring from Sunday into early next week.
CONFIDENCE AND POTENTIAL DEVIATIONS FROM BASE FORECAST:
High confidence exists on a warming trend this weekend, as
deterministic forecast highs in the 70s and lower 80s are
currently on the lower end of the ensemble ranges. There is low
confidence on the timing of precipitation probabilities late this
weekend.
-Stoinskers/Zanker
&&
.AVIATION...
LAST UPDATED: 2030Z
FLIGHT CONDITIONS: Low VFR/MVFR/IFR
DISCUSSION: MVFR and scattered IFR conditions due to low clouds
and scattered showers from the departing low pressure system are
expected to last through 03Z as ceilings begin to rise tonight.
The exception is KGDV, where there is low to moderate (30 to 50
percent) confidence of LIFR ceilings overnight before these
ceilings rise to VFR Thursday afternoon. Scattered showers will
continue through Thursday afternoon before ending, so there is
moderate (40 percent) confidence of MVFR conditions occurring
within rain showers.
WINDS: Northeast 15 to 20 kts with gusts to 30 kts, becoming
north at 5 to 10 kts after 03Z, increasing to 10 to 15 kts after
15Z.
&&
.GGW WATCHES/WARNINGS/ADVISORIES...
Lake Wind Advisory until 6 PM MDT this evening for Central and
Southeast Phillips-Central and Southern Valley-Garfield-McCone-
Petroleum.
&&
$$
weather.gov/glasgow
