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Area forecast discussion 
National Weather Service Bismarck ND
1249 PM CDT Wednesday may 6 2015

Update...
issued at 1241 PM CDT Wednesday may 6 2015

Quick update to capture latest trends. Only minor adjustments to
precipitation chances were made.

Latest radar trends continue to follow closely with the high-res
models. A dry slot is forming across south central North Dakota.
This area will likely see a break from the rain for the next
couple of hours. However...another round of showers...and even
some thunderstorms...are likely to form and move into southern and
central North Dakota this afternoon.

Update issued at 931 am CDT Wednesday may 6 2015

Latest radar imagery indicates the heaviest rain band stretches
from southwest North Dakota (bowman and hettinger)...north and
east through Bismarck and Jamestown. This band of rain will
continue to push off to the north and west through the morning
hours. Latest high-res models indicate this band of rain Will Park
over western North Dakota through the rest of the day...bringing
light to moderate rain to areas including
Crosby...Williston...Watford City...New Town...Killdeer and
Dickinson. Further to the east...across central and eastern North
Dakota the high-res models indicate afternoon heating will produce
some instability...leading to scattered thunderstorms. Rainfall
could be heavy at times for locations impacted by these afternoon
thunderstorms.

Update issued at 615 am CDT Wednesday may 6 2015

Latest water vapor and radar imagery show the initial shortwave
pushing into north central North Dakota...with the next shortwave
generating precipitation up along the southern border and moving
north with time. Current forecast with likely probability of precipitation transitioning
to categorical remains on track...no updates to current forecast.

&&

Short term...(today and tonight)
issued at 341 am CDT Wednesday may 6 2015

Focus in the short term remains on incoming precipitation and the
chances for thunderstorms.

The first wave of scattered showers moved into the south central
shortly around 07 UTC. The hrrr did a decent job of timing this
line of showers and thunderstorms and has it diminishing as it
progresses north. A few lightning strikes have been observed with
the line and have kept with isolated thunderstorm chances through
the morning hours. Surface observations at Linton showed heavy
rain while a shower went over and reported 0.20 inches. At first
glance it appears this system may well bring the much needed
rainfall forecasted.

Frontal boundary shifts eastward into western ND around 18 UTC
Wednesday and into central ND later in the afternoon. This will
coincide with 2-3 more embedded impulses lifting north across the
Dakotas before the main wave moves through Wednesday night. Widespread
rainfall should be experienced in the morning and afternoon with
higher amounts in proximity to the frontal boundary as it moves
slowly from west to east across the state...with storm total
amounts still depicted from 0.5-1.5 inches. With both the 00z
GFS/European model (ecmwf) generating 900-1200 j/kg of MUCAPE over central and east
along to east of the frontal passage...locally heavier rainfall (greater
than an inch) with convection will be very possible considering
precipitable waters around 1.25".

Long term...(thursday through tuesday)
issued at 341 am CDT Wednesday may 6 2015

Exiting system Thursday/Thursday night will leave behind below
average temperatures for most of the long term period. Another
round of precipitation possible over the weekend into early next
week for mainly southern North Dakota.

Precipitation will gradually wane Thursday/Thursday evening from
west to east as a strong cold front will be exiting the James
River Valley Thursday morning. However a chance of showers will
remain across the southern James River Valley into Thursday night
before ending after midnight. Cold air advection ensues Thursday
with northwest winds of 20 to 35 miles per hour.

Friday through Tuesday...850mb temperatures remain around +1c from
Friday through Monday. Expect highs in the 50s with overnight lows
in the middle 30s. Areas of frost still appear likely during the late
night and early morning hours Friday through Tuesday. Highs will
reach into the lower 60s Tuesday. Dry but cool for Friday...then
the next closed upper low will eject out from the southwest Continental U.S.
And into the northern High Plains by Monday. The latest GFS keeps
the precipitation confined to the southwest and just along and
south of the border Friday night through Saturday night. The European model (ecmwf)
also follows this idea through Saturday night...but then pushes
the precipitation back into south central North Dakota Sunday into
Monday morning. The superblend advertises a European model (ecmwf) solution during
this period. If this does come true...850mb temperatures of -2c may yield
some wet snow. Any shift further north with this system will need
monitoring as precipitation types and chances would change. Drier
weather slated for late Monday into Tuesday.

&&

Aviation...(for the 18z tafs through 18z Thursday afternoon)
issued at 1241 PM CDT Wednesday may 6 2015



MVFR and occasional IFR conditions are expected at all taf sites
through tomorrow morning. Widespread showers and isolated
thunderstorms are expected of and on through the next 24 hours.
Confidence that thunderstorms will impact any one individual
terminal is minimal. Therefore...only mentioned thunderstorms in
the vicinity of kbis/kmot/kjms as those areas are the most likely
to see thunderstorms nearby this afternoon.



Otherwise...a cold front will approach kisn around 21z and will
progress slowly east through the afternoon and overnight. Behind
the front...winds will become gusty out of the northwest.



&&

Bis watches/warnings/advisories...
none.
&&

$$

Update...aj
short term...mm
long term...Kansas
aviation...aj

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