Area Forecast Discussion
Issued by NWS Billings, MT

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FXUS65 KBYZ 200851

Area Forecast Discussion
National Weather Service Billings MT
251 AM MDT Tue Jun 20 2017

.SHORT TERM...valid for Tdy and Wed...

Today will be by far the hottest day during the next week. The
upper level ridge that has been dominating the weather over the
last several days will break down as a shortwave trough moves
across the Northern Rockies. Ahead of the associated cold front,
temperatures will climb into the lower 90s with the aid of pre-
front warming. Winds will generally be out of the west which
will also help with the warming as the downsloping winds will
warm and dry the area. The NAM is continuing to show dewpoints
that are much higher than reality.

As the cold front moves through the area late this afternoon and
into the evening, still expecting some thunderstorms to develop.
The NAM solution is more favorable for the development of some
stronger storms. The GFS solution is much more limited with the
CAPE, which seems to a slightly more realistic solution given how
it has been tracking with the observations. Given the fairly dry
low-levels, the main issue will be the winds that will be able to
develop and move away from any storms that form. There is some
support for some stronger updrafts and thus some potential for
larger hail.

Wednesday will generally be dry behind the cold front. However,
some stronger northwest winds will be able to mix down during the
day. This will produce more breezy conditions across the area.
Temperatures will be around 10 degrees cooler.

Hydrology concerns will remain elevated through the short-term as
more snowmelt works through the rivers from several days of warm
temperatures. Rivers will continue to run higher than they have
been over the last week, but should remain within their banks. The
increased flows will increase bank erosion. Reimer

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

Forecast remains consistent this morning. Dry zonal flow on
Thursday transitions to cyclonic northerly flow Friday as upper
low drops south out of Canada. This will bring an increasing
chance of showers and thunderstorms Thursday night into Saturday
morning, though with PW values remaining below 0.75 inches kept
precipitation chances in the 20 to 40 percent range.Temperatures
for Friday and Saturday look well below normal in the 60s to lower
70s, while overnight temperatures drop into the 30s in the
foothills and 40s elsewhere. Dry Northwest flow takes over on
Saturday with ridging bringing a warming trend into early next
week. Chambers



VFR conditions will prevail for the next 24 hours. Isolated
thunderstorms will accompany a cold front through the area late
today into tonight. These will be high based storms with strong
wind gusts and small hail the main threat. Chambers



    Tdy Wed     Thu     Fri     Sat     Sun     Mon
BIL 092 063/083 052/077 046/068 044/067 044/075 050/083
    1/U 20/U    01/U    13/T    42/T    11/U    00/U
LVM 089 054/081 042/074 038/066 037/064 036/074 043/080
    3/T 20/U    01/U    23/T    42/T    11/U    01/U
HDN 094 063/084 051/078 047/069 045/068 043/076 049/084
    1/B 30/U    11/U    13/T    42/T    11/U    00/U
MLS 092 066/083 052/077 047/069 044/068 045/076 049/083
    0/B 30/U    11/U    12/T    22/T    11/U    00/U
4BQ 093 064/083 053/077 047/069 044/065 042/073 047/082
    0/B 20/U    11/U    12/T    43/T    21/U    10/U
BHK 088 061/081 048/074 044/067 042/064 041/072 046/080
    0/B 20/N    01/U    12/T    23/T    21/U    10/U
SHR 089 059/080 050/075 044/067 041/063 038/071 044/079
    2/W 31/U    21/U    13/T    43/T    21/U    10/U




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