Area Forecast Discussion
Issued by NWS Billings, MT

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FXUS65 KBYZ 181747

Area Forecast Discussion...Updated
National Weather Service Billings MT
1147 AM MDT Thu May 18 2017

Precipitation winding down. Canceling the Winter Storm Warning and
Snow Advisory for Beartooth area. BT


.SHORT TERM...valid for Tdy and Fri...

Precipitation has decreases over the past 6 hours and will
continue to diminish from north to south today as the strong upper
low centered over northern Utah tracks further southeast. Low
level northeast winds continue to advect drier low level air that
is helping to bring an end to precipitation. Foothills areas will
continue to see at least a chance of precipitation into this
evening but additional accumulations past this morning will be
insignificant. Dropped Winter Storm Warning for the lower
elevations of Park county as temperatures have warmed up turning
most precipitation to rain in addition to downward precipitation
trends. Beartooth Foothills and area mountains will continue to
see snow into this morning before foothills transition to rain,
and mountain snow will taper off this afternoon. Kept winter
highlites for those areas going.

This afternoon looks mainly dry outside of the mountains and
foothills as that low level dry air will work against weak forcing
over the area. Temperatures will bump into the 60s for most
locations with 40s and 50s in the foothills where clouds persist.

Upper low begins to work northeast toward the Dakotas on Friday
and will bring a chance of showers to SE MT as it does so. Bulk of
energy stays well away from the area so precipitation amounts will
be light with this activity, but it will hold down temperatures

Hydrology...2 to 3 inches of precipitation fell in the foothills
and mountains since yesterday morning. Tie Creek SNOTEL in
the Bighorn Foothills reported 3.6 inches, and Fishtail RAWS in
the Beartooth Foothills shows 3.24 inches in the past 24 hours.
The rainfall runoff is currently working through small creeks and
streams causing significant rises. The snowfall containing this 2
to 3 inches of water will melt later today (as it fell at
temperatures near freezing) sending additional water into these
smaller waterways. Expect some minor flooding along small creeks
and streams in the foothills today into tomorrow due to this
runoff and have issued flood advisories for those areas. Thinking
most larger rivers have plenty of room to absorb this runoff as
snowmelt has diminished over recent days with cooler
temperatures in the mountains. But will keep a close eye on the
smaller rivers such as the Shields and Tongue over the next 36
hours. Chambers

.LONG TERM...valid for Sat...Sun...Mon...Tue...Wed...

Not a whole lot of changes to the long term portion of the
forecast. Saturday morning, a surface low moves over the northern
Plains. In its wake, northwest flow will reign into next week.
This means continued periods of showers with isolated
thunderstorms during the afternoon as various impulses move
through the region.

The first upper-level wave moves through the northern Rockies on
Saturday night and Sunday which will bring isolated to scattered
showers for areas mainly west of a line from Sheridan to
Billings. By Monday morning, a backdoor front slides in bringing
scattered showers and thunderstorm to most of the region.
Temperatures will generally range from the 60s to low 70s with
lows in the 40s through the period. Walsh



CIGS near airport minimums at LVM and IFR to MVFR at BIL/SHR will
begin to improve as storm system shifts southward today. MLS will
remain dry and CIGS should improve this morning. BT



    Tdy Fri     Sat     Sun     Mon     Tue     Wed
BIL 053 038/060 039/066 045/068 046/066 045/069 048/073
    1/E 11/B    11/B    22/T    34/T    31/B    13/T
LVM 046 028/055 036/063 039/065 041/065 040/069 042/072
    2/R 11/U    13/T    33/T    34/T    41/B    23/T
HDN 055 039/060 037/067 042/071 044/067 043/069 046/074
    1/E 11/B    11/U    12/T    34/T    31/B    13/T
MLS 059 039/060 038/065 043/072 047/067 044/069 047/072
    0/B 01/E    11/U    01/B    23/T    31/B    23/T
4BQ 056 038/053 034/061 039/069 044/065 041/066 044/070
    0/B 23/O    21/B    01/B    34/T    31/B    23/T
BHK 056 037/055 034/059 036/069 042/063 040/065 041/068
    0/U 12/W    22/W    11/U    34/T    32/W    22/T
SHR 046 034/050 033/060 038/064 041/061 038/063 041/068
    2/R 53/O    31/U    13/T    34/T    31/B    12/T




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