Area Forecast Discussion
Issued by NWS Billings, MT

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FXUS65 KBYZ 270240
AFDBYZ

Area Forecast Discussion...Updated
National Weather Service Billings MT
840 PM MDT Wed Jul 26 2017

.UPDATE...

Current forecast is in good shape. Monsoonal flow will continue
to move over the forecast area tonight. However, very little in
the way of dynamics and shear. As a result, the few thunderstorms
that have formed have been short-lived with very little if any
movement as they have been having a difficult time maintaining an
updraft. We will continue a slight shower/thunderstorm chance for
the remainder of the evening and overnight hours across the entire
forecast area. However, the best chances will be over the
mountains and adjacent foothills. The only changes made this
evening was to decrease coverage of thunderstorm activity as they
are expected to be more isolated in nature. Hooley

&&

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

Minor perturbations in southwest flow with a weak cold pool in the
mid levels tracking into the CWA this afternoon and producing
convection over the high country. Some of this will continue to
drift east through the evening and affect lower elevations with
isolated storms and maybe a pocket or two of scattered showers.
Low level jet develops over southeast Montana later tonight which
could unzip the atmosphere and lead to some mid based convection
late tonight and into Thursday morning over mainly Carter and
Fallon Counties. The impulses in the monsoonal flow tomorrow
also look stronger with a little better CAPE, but still weak
shear. Precipitable Water values are progged higher Thursday as
well with the eastern two thirds of the CWA around an inch or
greater. So wetting rain and some isolated heavy downpours are
certainly possible. Low level convergence and parameters are
pointing to areas from Rosebud County eastward as having the
strongest convection and best shot of any severe or borderline
severe threats tomorrow.

Another round of convection for Friday looks likely. Coverage and
intensity are difficult to ascertain due to the nature of
monsoonal flow which models do not often handle well. So we will
simply go with a broad brush of the usual isolated to scattered
for now.

Temperatures will remain seasonal for the short term future. BT

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

Not much change in the extended. Persistent ridge over the west
and monsoonal moisture advecting over the region will continue to
bring chances for afternoon and evening showers/thunderstorms.
Weak shortwaves moving across southern Canada will suppress the
ridge from time to time, although models differ in the timing of
these waves. Storms will be on the wetter side with PWATs ranging
from 0.75 to 1.25 inches through the extended. Temperatures will
range from the upper 80s to lower 90s across the lower elevations
most days. STP

&&

.AVIATION...

Isolated showers and mainly weak thunderstorms will impact the
region tonight. Local erratic wind gusts are possible, otherwise
VFR will prevail. Thunderstorms will increase in coverage across
eastern areas from KMLS-KBHK Thursday afternoon and evening, with
local MVFR possible. JKL

&&

.PRELIMINARY POINT TEMP/POPS...

    Thu     Fri     Sat     Sun     Mon     Tue     Wed
-----------------------------------------------------------
BIL 066/091 065/092 064/091 064/091 065/092 064/091 064/090
    22/T    21/B    21/U    12/T    21/U    12/T    21/U
LVM 057/087 056/088 055/087 057/088 057/087 055/090 054/089
    23/T    32/T    21/U    12/T    22/T    22/T    22/T
HDN 064/093 063/094 062/093 065/092 063/094 063/093 062/093
    22/T    21/B    21/U    12/T    22/T    21/U    11/U
MLS 070/095 068/095 067/093 068/093 068/094 066/095 065/093
    22/T    31/U    22/T    22/T    22/T    21/U    11/U
4BQ 066/092 065/093 064/092 065/090 065/091 064/093 062/092
    23/T    32/T    21/U    12/T    23/T    32/T    21/U
BHK 064/090 063/091 063/090 064/088 064/089 061/092 060/088
    23/T    32/T    31/U    12/T    22/T    21/U    11/U
SHR 058/089 058/089 058/087 060/087 058/087 058/090 056/088
    33/T    32/T    22/T    22/T    22/T    22/T    21/U

&&

.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...None.
WY...None.

&&

$$
weather.gov/billings



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