998
FXUS65 KBYZ 111611
AFDBYZ

Area Forecast Discussion...Updated
National Weather Service Billings MT
1011 AM MDT Tue Mar 11 2025

.KEY MESSAGES...

- Warm Wednesday and Thursday with highs in the 50s and 60s (near
  70 possible); showers increase over mountains Thursday
  afternoon.

- Turning colder, a period of rain and wet snow, and brisk north
  winds Thursday night and Friday; greatest chance of snow
  accumulations over the mountains and foothills.

- Unsettled weather pattern with seasonable temperatures for the
  weekend.

&&

.UPDATE...

Combination of warm front over the NE zones, weak vorticity over
the N and some upper divergence over the NW zones...was generating
some light precipitation across the N zones this morning. Kept low
PoPs over the N per the HRRR thru the day. Increased wind speeds
by nudging them toward the NBM 90th percentile, as good mixing
will be over the area today as temps warm up with time. Added
patchy fog thru 18z over Carter County where web cams and
satellite showed persistent fog this morning. Arthur

&&

.DISCUSSION...
Through Wednesday afternoon...

Currently, a weak band of frontogenesis is bringing light showers
(most likely virga) to portions of east central MT. These showers
will dissipate over the next few hours. A weak wave will pass
through northern MT today, bringing an increase in cloud cover,
with less than a ten percent chance of showers for east central
MT. Conditions will be breezy for the Livingston area today with
model soundings and high res models showing 700 mb winds (~35
kts) mixing down to the surface. Gusts in the 30s (mph) are most
likely. High temperatures today will be in the 50s to low 60s.
Into Wednesday, ridging will begin to take place, allowing for dry
conditions and continued above average temperatures. Mid to high
clouds will moderate temperatures in the west with highs in the
50s, with central and eastern zones into the 60s. The areas with
the best chance of reaching 70 degrees F will be Yellowstone, Big
Horn and Rosebud counties with up to a 50-75% chance. TS


Wednesday night through Monday...

Wednesday night to Thursday morning will be mostly dry, with a
deepening surface low east of the mountains, Pressures are
noteworthy here as all models show near 990mb by afternoon. Expect
temps in the 60s to near 70F on Thursday, warmest in the central
and east where the probabilities for reaching 70F are 20-40%.
Daily record highs at Billings & Sheridan could be challenged.
More interestingly on this day...height falls with approaching
trof, increasingly diffluent southerly flow and diurnal
instability (lifted indices of zero to -1) may yield a few
rumbles of thunder as showers should develop over western areas.

Models seem to be painting a more consistent picture of what to
expect Thursday night and Friday. Splitting Pacific trof will have
strong energy moving out of the southern Rockies intensifying a
low over western KS/OK. This is too far south to be a real player
in our region so we will have to contend with ascent from the much
weaker northern portion of the trof. Pwats expected to rise to
near a half inch is pretty good for March, 1-2 standard deviations
above normal, so we will have moisture to work with. Focus of
precip should be along mid level baroclinic zone as it moves west
to east from Thursday evening thru midday Friday. Northerly winds
will bring upslope enhancement in our south as well. There remain
model issues that need to be resolved, however. The GFS and its
ensembles continue to be wetter than the EC, especially in our
east on Friday, as it shows a bit sharper trof passage. If the GFS
is correct, eastern areas may see a gusty wind/wet snow combo on
Friday. Though snow accumulations would be limited by warm surface
temps, there could be a roughly 6-hour window of hazardous
conditions for young livestock. Otherwise, this is looking like a
rain to wet snow event with greatest precip (0.30-0.50") in
southern upslope areas. Mountains should see a 4-8" snowfall, with
up to 1-2" possible along the immediate foothills. Elsewhere,
temps will remain too warm for much of any snow accumulation. The
probability of at least 0.25" of precip is 10-20% over the north
and east, 30-50% central areas including Billings, and 50-75% over
mountains and foothills.

As far as Billings goes, wet bulb zero heights to near 3500` by
12Z Friday suggest a brief period of wet snow is possible in the
metro area from late Thursday night to early Friday. If
frontogenesis is strong enough and precip heavy enough, some wet
snow could briefly accumulate a bit on the grass. That looks like
the most that can be hoped for in Billings.

Drying arrives by Friday afternoon but below normal heights linger
through Saturday, bringing at least a chance of snow showers over
the mountains. There may be enough diurnal instability for
afternoon snow showers over the western lower elevations Saturday
afternoon/evening.

The consensus is for a brief period of ridging Sunday, thus a
drier and somewhat warmer day. There are hints of enhanced winds
along the foothills and this needs to be watched.

By Monday, models are in fair agreement in showing another Pacific
trof and cold front, and the next chance of rain/snow.

Regarding temperatures, after the warm Thursday, Friday & Saturday
should see highs in the upper 30s to mid 40s (slightly cooler than
normal). As already mentioned, Sunday looks warmer (mid 40s to mid
50s) before cooling arrives Monday.

JKL


&&

.AVIATION...


VFR conditions will be in place across all taf sites. Breezy SW
winds will top out at about 35 kts at KLVM today, decreasing into
the evening. TS

&&

.PRELIMINARY POINT TEMP/POPS...

    Tdy Wed     Thu     Fri     Sat     Sun     Mon
-------------------------------------------------------
BIL 063 034/068 041/065 034/047 027/045 029/052 035/050
    0/B 10/B    02/T    84/S    12/J    21/B    44/W
LVM 055 034/057 040/055 028/040 024/039 025/043 029/041
    2/O 01/N    16/T    93/S    15/J    34/W    65/J
HDN 063 030/067 035/068 033/046 024/045 026/052 032/052
    0/U 10/B    01/B    86/O    12/J    21/B    34/W
MLS 058 032/065 036/067 035/042 019/038 021/050 031/049
    2/R 00/B    00/B    35/O    00/B    10/B    21/B
4BQ 061 031/066 035/067 034/042 020/040 024/050 032/050
    0/U 00/B    00/B    36/O    10/B    10/B    11/B
BHK 056 028/062 032/066 030/039 013/033 015/045 024/047
    2/O 00/B    00/B    15/O    10/U    10/U    11/B
SHR 061 029/065 032/068 031/041 018/040 021/048 027/048
    0/U 00/B    01/B    68/S    12/J    20/B    24/W

&&

.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...None.
WY...None.

&&

$$
weather.gov/billings