Area Forecast Discussion
Issued by NWS Billings, MT

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FXUS65 KBYZ 260333

Area Forecast Discussion...Updated
National Weather Service Billings MT
933 PM MDT MON JUL 25 2016


Fairly vigorous upper level short wave seen on water vapor
imagery is currently moving across the central portions of the
state. Although some thunderstorm activity occurred late this
afternoon/early this evening across Carter County, the main action
has and continues to be from Yellowstone County and areas north
and west. Scattered showers and thunderstorms across these areas
have been producing mainly heavy rain and gusty winds. Another
batch of showers and thunderstorms are approaching Park and
Wheatland Counties. Activity this evening is slowly moving
east/northeast. Latest short range models keep scattered activity
through the night mainly along and north of a Miles City-
Billings-Livingston line. As a result, the only main update this
evening was to increase pops into the higher chance category and
extend them a bit further east. Updated forecast has been sent.


.SHORT TERM...valid for Tue and Wed...

Short wave on satellite imagery to our west looks fairly sharp.
Thus, I fully expect to see thunderstorms develop as this feature
crosses the divide into the plains this evening. Lower levels
will initially be on the dry side...thus CAPE is limited in the
west so we expect mainly generic storms. As storms track eastward
through the evening they should be wetter with a strong storm
possible. Models all suggest convection will continue through the
night in the east as short wave moves across the area.

Best chance of any strong to severe storms is primarily in
southern Carter County where good shear/helicity and CAPE values
will support sustained deep updrafts. CIPS analogs also support
the idea of severe storms being limited from the Black Hills into
the SE corner of Montana. So we will continue to mention severe
for the early evening in this location.

For Tuesday...another short wave plows through our region. This
time though the low level moisture and instability factors will
be higher. Precip water values will be pushing one inch across
much of eastern Montana. So with better MUCAPE and increasing
shear we expect more areal coverage of thunderstorms. Hail and
heavy rain are more likely with some cells as well.
Otherwise...temps will be a bit cooler for Tuesday. BT

.LONG TERM...valid for Thu...Fri...Sat...Sun...Mon...

Active pattern continues through at least the beginning of the
extended, though model differences grew in regards to the
handling of Thursday`s shortwave. GFS looks to have slowed down
the wave a little bit and thus has much higher temperatures
compared to the EC, which moves it through during peak heating. EC
run also had a little bit more moisture and cooler easterly and
northeasterly flow. For now took an even blend of the two which
put temperatures in the mid 80s on Thursday. While the chances for
a wetting rain will be better across the area, storms will also
produce more lightning. With dry conditions in place over much of
southeastern Montana, this could encourage a few new lightning
fire starts. Some storms east of Miles City and Broadus could be
strong or severe on Thursday.

West-northwest flow aloft will preside over the region Friday
with east and northeast surface winds. This will keep
temperatures near average and in the upper 80s as drier air aloft
works in from the west. Upper level flow begins to veer to the
southwest by the weekend which will cue a warmup back into the low
to mid 90s. Deep mixing will allow mostly dry conditions though
some monsoonal moisture working in from the southwest will
increase fire concerns with high based dry thunderstorms late in
the weekend into next week. Dobbs.



Showers and thunderstorms are spreading across western routes this
evening...and are expected to spread eastward through the early
overnight hours. Otherwise...VFR conditions will prevail through
the TAF period. AAG



    Tue     Wed     Thu     Fri     Sat     Sun     Mon
BIL 063/093 063/089 062/084 060/087 062/094 065/095 062/090
    33/T    32/T    33/T    31/B    11/U    12/T    22/T
LVM 054/093 054/090 054/086 052/088 056/092 057/093 053/089
    22/T    22/T    33/T    31/B    12/T    22/T    22/T
HDN 060/094 061/090 059/086 057/088 059/095 064/096 061/092
    23/T    32/T    23/T    31/B    11/U    12/T    22/T
MLS 067/095 066/089 064/084 061/086 061/094 066/097 066/091
    34/T    43/T    23/T    32/T    11/U    12/T    22/T
4BQ 065/095 063/091 062/084 059/087 061/093 064/098 065/093
    24/T    23/T    24/T    41/B    11/U    12/T    22/T
BHK 062/092 061/085 058/079 057/083 058/088 061/093 062/090
    24/T    45/T    34/T    42/T    11/U    12/T    22/T
SHR 056/094 057/091 057/085 055/087 056/092 058/095 059/091
    12/T    22/T    24/T    41/B    21/U    12/T    22/T




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