Area Forecast Discussion
Issued by NWS Billings, MT

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FXUS65 KBYZ 170318

Area Forecast Discussion...Updated
National Weather Service Billings MT
918 PM MDT Wed Aug 16 2017

Another update to refine skies and winds based on latest trends,
and to remove PoPs for all areas except NE Bighorns through 06Z.
Shortwave seen on water vapor imagery was moving through the area
and caused a few showers and storms earlier in the evening. The
showers were all but dissipated at 03Z. 850 mb temperatures in the
lower 20s C, supported lows in the 50s overnight. Arthur


.SHORT TERM...valid for Thu and Fri...

Zonal to weakly northwest flow across the area tonight. A weak
wave will move through western and southern zones this afternoon
and evening. A few showers and thundestorms have formed over
mainly over the mountains and foothills. High resolution, short
range models, keep the activity in this general area this evening,
so will keep low PoPs going there.

A cold front will cross the area Thursday, but cooler air will
hold off until evening, despite northwest winds by afternoon.
Therefore, temperatures will be very warm with humidities falling
into the teens for many location. West to northwest winds will
increase behind the front as mixing increases in the afternoon
with some gusts to 30 mph expected over central and eastern zones.
Have upgraded the Fire Weather Watch to a Red Flag Warning for
Thursday afternoon and evening. Isolated thundestorms are possible
along and behind the front, but cape was looking weak with a dry
atmosphere, so not expecting much in the way of activity.

Flat ridging moves back in for Friday and this will keep the very
warm temperatures in place. Humidities will be low again, but
winds should be weaker, with the exception of some gusts to 20
mph in the afternoon for a couple of hours with mixing. Moisture
and lack of energy moving through, will lead to a dry forecast
for Friday. TWH

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

Westerly flow pattern will dominate over the region through the
weekend with ridging beginning to build back over the Northern
Rockies by the early part of next week. A weak cold front crossing
the area on Saturday may bring fire weather concerns with gusty
northwest winds and low RH during the afternoon. Ridging then
looks to remain over the region through the rest of the extended.
Monsoonal moisture working north under the ridge will bring
chances for afternoon/evening showers and thunderstorms most days,
highest over the mountains.

High temperatures will generally be in the 80s across the area
through the extended, with a few locations approaching the lower
90s ahead of the cold front on Saturday. STP



Expect VFR conditions to prevail. Winds will increase as a cold
front moves through between 15z and 20z from northwest to
southeast. Winds gusting to 25 kts are possible. Reimer


    Thu     Fri     Sat     Sun     Mon     Tue     Wed
BIL 059/086 056/091 059/088 058/085 058/084 058/087 059/088
    00/U    00/U    00/U    11/U    10/B    11/U    11/B
LVM 050/085 048/090 050/088 049/084 049/085 049/087 051/086
    00/U    00/U    00/U    11/U    11/U    11/U    12/T
HDN 057/089 054/093 057/089 057/088 057/087 056/090 058/090
    00/N    00/U    00/U    11/U    11/B    11/U    11/U
MLS 060/090 056/092 060/090 060/088 059/086 058/088 060/089
    00/B    00/U    00/U    11/B    11/B    11/U    11/U
4BQ 056/088 054/091 058/091 058/090 058/087 057/089 058/088
    02/T    10/U    00/U    11/U    11/B    11/U    11/U
BHK 056/088 052/088 057/090 056/084 055/083 054/085 056/085
    02/T    10/U    00/U    12/T    21/B    10/U    01/U
SHR 055/084 050/089 053/088 053/086 053/084 052/086 054/087
    02/T    10/U    00/U    11/U    11/B    11/U    11/B


MT...Red Flag Warning in effect from noon to 9 PM MDT Thursday FOR
      ZONES 117-127>133.


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