300
FXUS63 KBIS 191950
AFDBIS

Area Forecast Discussion
National Weather Service Bismarck ND
250 PM CDT Sat Oct 19 2024

.KEY MESSAGES...

- Near-critical fire weather conditions are expected across
  western and parts of north central North Dakota the rest of
  this afternoon into the early evening.

- Above normal temperatures will continue into early next week,
  with highs in the 70s Sunday and Monday.

- Low to medium chances for only light amounts of precipitation
  early next week, mainly in the northwest Monday night and
  across the south Tuesday night.

&&

.DISCUSSION...
Issued at 250 PM CDT Sat Oct 19 2024

Split flow dominates the upper air pattern across the CONUS
today, with a deep, closed cutoff low across the Desert
Southwest, while mostly zonal flow was in place across North
Dakota. Tightened surface flow is producing breezy to strong
southwest winds, as the forecast area is in between high
pressure well to our southeast, and multiple low pressures in
the Canadian Prairies. A weak surface trough was analyzed near
the MT/ND border, with winds in Montana having a slightly more
westerly component to surface winds, compared to our
southwesterly winds on the east side of the trough. Scattered
high clouds have been slowly diminishing through the afternoon,
with forecast highs in the 60s.

Main forecast concern today is still near-critical fire weather
conditions across western and parts of north central North
Dakota this afternoon, although thinking the risk is just a bit
lower than initially expected due to dew points not dropping
quite as low as forecast. However, with the breezy to strong
winds continuing, will keep mention of near-critical through the
rest of the afternoon. The tight surface pressure gradient will
keep winds from fully relaxing through the night, staying in the
10 to 15 mph range. This, combined with warmer 850mb temps
moving in, will produce seasonably mild overnight lows in the
upper 30s to mid 40s.

Much warmer than average both Sunday and Monday, with shallow
ridging building in to start the week while the previously
mentioned cutoff low ejects into the Central Plains. Expect
widespread max temps in the 70s on Sunday and Monday, with high
confidence in this forecast due to extremely low spread in NBM
percentiles. Winds are expected to generally be up to 10 mph
these days.

Precipitation chances return Monday night a deep trough over the
western CONUS pushes a cold front into the forecast area, while
the deep low to our south could extend low POPs into our
southeast counties. As the cold front sweeps through the
forecast area overnight, blended guidance produces rain chances
of 30 to 50 percent across the northwest and north central.
Cluster analysis shows that ensemble members are in much
stronger agreement on the main swath of precipitation staying
north of the forecast area, with only low chances of at least
0.10" of liquid in areas that have a chance of rain. NBM winds
on Tuesday have increased which was expected, as deterministic
guidance has been consistent on strong cold air advection and
pressure rises behind the front, although the overnight timing
is not quite as favorable for stronger winds. This is the only
day that is highlighted for elevated winds, but with cooler
temps and higher relative humidity, fire weather concerns
should remain low.

We are also advertising a slight chance of rain across the
southern half of the state Tuesday night as a jet streak moves
over the region, although latest guidance continues to shift
this further south. Current NBM probabilities only have a low
chance for any measurable precipitation, so not expecting much
to come from these chances at this point.

For the back half of next week, ensemble spread is larger,
although there is a general pattern for continued seasonably
mild temperatures and no significant chances for precipitation.
Extended outlooks favor warmer than normal temperatures through
the end of the month, when average highs are down into the upper
40s across the forecast area.


&&

.AVIATION /18Z TAFS THROUGH 18Z SUNDAY/...
Issued at 1235 PM CDT Sat Oct 19 2024

VFR conditions expected at all terminals through the TAF period,
with only a scattered MVFR cloud deck in parts of the James
River Valley this afternoon. Breezy southwest winds will
continue through the afternoon, strongest in northwest North
Dakota where gusts could be around 30 knots. Winds will diminish
this evening, although will stay around 10 knots through the
night before shifting to become more westerly on Sunday.

&&

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

&&

$$

DISCUSSION...Jones
AVIATION...Jones