553
FXUS65 KBYZ 150022
AFDBYZ

Area Forecast Discussion...Updated
National Weather Service Billings MT
622 PM MDT Tue May 14 2024

.UPDATE...
Short wave trough axis is pushing through our CWA at this time.
Leading edge of trough is signified by line of thunderstorms
extending from near Roundup to Pryors at this time. Pea size hail
has been reported within this line with gusts to around 30-35
mph.

Pops have been updated for rest of evening and overnight hours.
BT

&&

.DISCUSSION...

Tonight through Wednesday night...

Radar showed isolated to scattered showers and thunderstorms, some
with moderate rainfall over much of the area this afternoon.
Mesoanalysis depicted trough over the region with two main
vorticity maximums circulating through it. One vort max was over E
WY moving E into SD/NE and the other was elongated from W MT S
into SE ID. CAPE and shear were minimal, but low-level lapse rates
were steep. PWAT`s were .5-.8 inches. This activity will continue
through the evening, before diminishing from N to S later tonight.
Highest precip. chances (60-80%) will be from KBIL S and over and
near the mountains. Snow levels will be from 8000-9000 ft, so
high elevations could pick up several inches of snow, although
probability of accumulations over 2 inches was less than 10
percent through Wed. morning. HRRR suggested patchy fog over much
of the area so carried some fog through early Wednesday.

Slightly anticyclonic flow with energy in the flow will be over
the area on Wednesday. Soundings were inverted-v and CAPE/shear
were minimal. A warm front develops over the central zones late in
the day and moves into the E for Wed. night. Decent PWAT`s
continue through the period. Not much QPF expected Wed. and Wed.
night so went with 20-30% PoPs, mainly into Wed. evening. Temps
will be slightly above normal on Wednesday and RH will not be low.
Winds are not expected to be very strong either, except in
thunderstorms due to inverted-v soundings. Arthur

Thursday through Monday...

A zonal/NW flow upper level flow pattern will persist through much
of the week. General troughing over the mountain west will allow
for several shortwaves and upper lows to make their way through
the region during the extended forecast. Rounds of showers and
thunderstorms will be possible with cold fronts accompanying the
shortwaves, 15-50% chance of precip possible. Brief shortwave
ridging tries to build in Thursday-Friday, bringing warmer
temperatures before general troughing and NW flow returns through
the weekend.

Highs in the 70s to 80F Thursday and Friday, dropping back into
the 60s, up to 70F over the weekend and into Monday.

Matos
&&

.AVIATION...

Rain showers with embedded weak thunderstorms will continue
across portions of the area this evening before diminishing from
NW to SE late this evening into tonight. Localized MVFR/IFR
conditions are possible within the precipitation, along with gusty
winds and small hail where thunderstorms form. With this,
mountain obscurations will persist into tonight. Otherwise, patchy
fog may limit visibility later tonight behind the precipitation,
but overall confidence is too low to introduce into the TAFs.
Arends

&&

.PRELIMINARY POINT TEMP/POPS...

    Wed     Thu     Fri     Sat     Sun     Mon     Tue
-----------------------------------------------------------
BIL 047/070 051/077 051/077 045/065 042/067 044/066 046/065
    62/W    23/W    34/T    44/W    23/W    24/T    34/T
LVM 042/069 046/076 048/073 040/062 038/065 039/063 041/061
    31/B    13/W    23/T    43/W    24/T    24/T    35/T
HDN 046/070 047/077 047/080 044/065 041/070 043/068 044/068
    82/W    23/W    44/T    54/W    23/W    24/W    34/T
MLS 046/069 049/074 049/077 045/063 042/068 044/067 044/066
    32/W    23/T    43/W    44/W    22/W    23/W    23/W
4BQ 048/067 047/075 050/080 044/065 042/070 044/068 045/067
    52/W    22/T    31/U    33/W    22/W    23/W    33/W
BHK 041/068 045/073 048/075 041/064 039/068 041/064 041/064
    20/U    13/T    23/W    43/W    22/W    23/W    23/W
SHR 044/066 044/074 046/079 041/066 039/069 041/066 042/065
    73/W    12/T    32/T    34/T    22/T    34/T    44/T

&&

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

&&

$$
weather.gov/billings