000
FXUS63 KBIS 181134
AFDBIS

Area Forecast Discussion
National Weather Service Bismarck ND
634 AM CDT Fri Aug 18 2017

.UPDATE...
Issued at 625 AM CDT Fri Aug 18 2017

Showers becoming numerous across east central North Dakota
associated with a mid level circulation. Will adjust POPs to
followthe trends for the next few hours. Otherwise the
precipitation chances will decrease with time east. Added widely
scattered showers across the southwest through the mid morning.

&&

.SHORT TERM...(Today and tonight)
Issued at 244 AM CDT Fri Aug 18 2017

Forecast concerns for the short term include thunderstorms over
central and southeast sections of the forecast area this morning.
Thunderstorms formed Thursday evening along a surface trough with
an associated shortwave aloft. Shear and instability are somewhat
marginal for significant thunderstorms at this time of the night but
the storms definitely are sustaining themselves. Used the HRRR
time lag ensemble to provide short term guidance. The trends
suggest the convective activity will exit end/exit the region by
noon Friday.

This will leave Friday afternoon and night mainly clear. Highs
today will be in the 70s to middle 80s.

.LONG TERM...(Saturday through Thursday)
Issued at 244 AM CDT Fri Aug 18 2017

The extended period begins with very warm temperatures associated
with a short wave ridge moving through the region Saturday. GEFS
plumes of 2 meter temperatures support upper 80s to mid 90s
for highs on Saturday which is above Superblend guidance by 2 to
4 degrees. To warm the temperatures used the maximum of all
guidance temperatures with the current SB forecast to provide the
warmer forecast. This gave upper 80s northwest to mid 90s
central. Felt this was reasonable with the mixing associated with
an approaching cold front. As a result there are fire weather
concerns for Saturday afternoon west.

This will be followed by a Pacific cold frontal passage cooling
the region back into the 70s and lower 80s Sunday through Tuesday.
The next significant chance for showers and thunderstorms Sunday
and Sunday night. Broad ridging develops aloft by early to middle
of next week suppressing convection and returning warmer, but near
normal temperatures to the region.

&&

.AVIATION...(For the 12Z TAFS through 12Z Saturday morning)
Issued at 625 AM CDT Fri Aug 18 2017

Main hazard to aviation will be thunderstorms in the vicinity of
KJMS this morning. Otherwise as a surface trough moves east the
chances for showers and thunderstorms will decrease across the
James river valley. VFR conditions will prevail at all TAF sites.

&&

.FIRE WEATHER...
Issued at 244 AM CDT Fri Aug 18 2017

Have issued a Fire Weather Watch for Saturday for low humidity and
sustained west winds around 20 mph. Very warm temperatures in the
upper 80s to mid 90s across southwest and west central North
dakota Saturday will produce low humidity as low as 15 percent. An
approaching cold front saturday morning will pass through and
bring west winds by noon. Afternoon winds should increase to 20
mph behind the cold front.

&&

.BIS WATCHES/WARNINGS/ADVISORIES...
Fire Weather Watch from Saturday afternoon through Saturday
evening for NDZ017-018-031>033-040-041-043-044.

&&

$$

UPDATE...WAA
SHORT TERM...WAA
LONG TERM...WAA
AVIATION...WAA
FIRE WEATHER...WAA