Area Forecast Discussion
Issued by NWS Billings, MT

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FXUS65 KBYZ 290255

Area Forecast Discussion...Updated
National Weather Service Billings MT
855 PM MDT Sun May 28 2017

Inherited PoP trends are still intact for the evening. Drier air
behind back door front is taking over and diminishing most of the
convection over the plains. Scattered showers and maybe a lonely
thunderstorm may linger over the western mountains and foothills
through the rest of the evening. Only made a few tweaks for the
evening update. BT


.SHORT TERM...valid for Mon and Tue...

Scattered showers and thunderstorms will continue into this
evening. Some of these thunderstorms could produce some gusty
winds as the dewpoint spreads are fairly large. Most of the
convection so far this afternoon has been generally short lived
without much strong development. While CAPE values 200 to 500 J/kg
will remain over the area into early evening, shear is very
border line for supporting stronger development. While some small
hail is possible, the main hazard will just the winds from the low
level dryness.

The ridge will continue to build into the area tomorrow, but the
area will be on the edge of the ridge. Some energy will be able to
work into the area, but the rising heights will suppress
thunderstorm activity to mainly just the higher terrain. Tuesday will
be similar with even more limited convection. By Tuesday
temperatures will be in the mid to upper 70s as the ridge really
begins to settle into the area. Reimer

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

Models start off in fairly good agreement in the long term with
an upper ridge over the Northern Rockies shifting east on Thursday
as an upper trough moves into the Pacific Northwest. An
associated shortwave will swing through the area during the
afternoon allowing for showers and thunderstorms to develop.
Beyond Thursday, models continue to struggle with diverging
solutions. Kept pops mostly unchanged through the long term to
account for the high level of uncertainty. Regardless, afternoon
showers and thunderstorms look to be possible most days, with the
best chances over the higher terrain.

Temperatures will warm from the 70s and into the 80s during the
second half of this week and into the weekend. With the above
normal temperatures, an increase in snowmelt is expected, causing
flows to increase on area waterways by the end of the week. Will
continue to monitor this closely as the week progresses. STP



Scattered showers and thunderstorms continue over central and
western routes, but should diminish overnight. Main threats from
the thunderstorms are gusty winds and some small hail. In general,
VFR conditions will prevail, although MVFR conditions are
possible near heavier showers or thunderstorms. Mountains will be
partially obscured through the evening. Northwest winds gusting up
to 30 kts across eastern areas will decrease through the evening.



    Mon     Tue     Wed     Thu     Fri     Sat     Sun
BIL 047/073 047/077 050/084 055/084 054/080 053/081 051/079
    21/U    10/U    01/U    11/B    22/T    22/T    22/W
LVM 040/070 040/076 044/082 047/080 046/076 044/076 042/077
    31/U    11/U    11/U    13/T    22/T    22/T    22/T
HDN 046/072 042/077 047/085 051/086 051/081 049/082 048/079
    20/U    00/U    01/U    11/B    22/T    22/T    22/T
MLS 044/069 042/074 047/084 055/087 056/081 052/081 051/079
    00/U    00/U    00/U    01/U    22/T    22/T    21/B
4BQ 043/068 041/073 046/084 052/086 054/080 051/080 049/077
    10/U    00/U    00/U    01/U    22/T    22/T    21/B
BHK 040/064 037/069 041/079 049/082 052/076 048/075 046/075
    00/U    00/U    00/U    01/U    23/T    32/T    22/T
SHR 042/067 040/073 044/082 048/083 050/078 047/079 046/077
    21/U    11/U    11/U    11/B    22/T    22/T    22/T




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