363
FXUS63 KBIS 131945
AFDBIS

Area Forecast Discussion
National Weather Service Bismarck ND
245 PM CDT Mon May 13 2024

.KEY MESSAGES...

- There will be daily chances for showers and thunderstorms
  through the week. A few storms may become strong this
  afternoon and evening in the west.

- Near average temperatures are expected this week, with highs
  in the mid 60s to upper 70s and lows in the 40s.

&&

.DISCUSSION...
Issued at 245 PM CDT Mon May 13 2024

This afternoon, the progression of a shortwave disturbance down
the overall ridging pattern is pushing an associated surface
low and cold front across the northern Plains. Along this front,
a a modest corridor of instability of around 500 to 1000 J/KG
MUCAPE will be present through the late afternoon. However, this
instability has become increasingly incongruous with the
promised development of widespread showers and thunderstorms
over the past few days, with the most recent model runs delaying
it later into the evening. This, along with the instability
axis being fairly disconnected with the area of highest bulk
shear across the north central this afternoon, limits
expectation to see not much more than scattered showers and some
isolated thunderstorms across the west this afternoon. There
may be a brief period late this afternoon that could see a
stronger storm over the west with some small hail and some gusty
winds, but overall the potential for severe weather is low
today.

Otherwise, some lingering smoke from Canadian wildfires remains
aloft over the forecast today. Near surface smoke has mainly
drained away to our south by this time, but enough remains for
the horizon to remain hazy at times. Winds remain out of the
south southeast today at 10 to 15 mph, with some locations
gusting up to around 25 mph at times. Highs are broadly in the
upper 60s east to upper 70s west. Lows tonight are forecast in
the 40s and lower 50s.

Late Monday into early Tuesday, a slow moving 500-700mb trough
will progress east across the northern Plains, promoting 50 to
80 percent chances for showers across forecast area through
Wednesday afternoon. Modest instability with model CAPE values
of a few hundred J/KG will allow isolated thunderstorm
development (15 to 35 percent chance) through this period,
though limited shear means the potential for strong to severe
storms is low at this time. By Wednesday, portions of central
North Dakota have around a 30 to 45% chance of exceeding 0.50"
of total rainfall. Highs on Tuesday and Wednesday are expected
to remain in the mid 60s to lower 70s range, with overnight lows
dropping into the 40s and lower 50s.

As the shortwave progresses past the forecast area late
Wednesday morning, a brief ridging pattern will diminish PoPs
Wednesday afternoon and early evening. By this period another,
more modest shortwave will begin to dig across the northern
plains that will continue to promote ongoing chances for showers
(10 to 20 percent) and isolated thunderstorms (15 to 25%)
through the early weekend as clusters favor it developing into
an upper level low by the end of the workweek. By late Saturday
into early Sunday this newly developed low will progress off
toward the northern Great Lakes region, allowing more sustained
ridging to push across the area and keeping us relatively dry
through early next week. High temperatures through this period
will be around seasonable normals, forecast to broadly be in the
mid 60s to lower 70s. Lows are forecast in the 40s and lower
50s.

&&

.AVIATION /18Z TAFS THROUGH 18Z TUESDAY/...
Issued at 245 PM CDT Mon May 13 2024

VRF conditions are present at the start of the 18Z TAF period. A
deck of mid level clouds is currently progressing southeast
across the forecast area. Late this coming afternoon and
evening, a cold front will bring increasing chances for showers
and thunderstorms across the west before spreading eastward to
most terminals throughout the period, though it may not reach
KJMS until later Tuesday afternoon. Where these showers and
thunderstorms do develop, MVFR conditions along with gusty and
erratic winds are expected. Southeasterly winds are expected to
increase and strength through this afternoon and evening to 10
to 15 knots with gusts up to 25 knots, then beginning to
diminish and turn toward the south overnight and through Tuesday
morning.

&&

.BIS WATCHES/WARNINGS/ADVISORIES...
None.

&&

$$

DISCUSSION...Adam
AVIATION...Adam