Scientific Forecaster Discussion
fxus63 kbis 120308
Area forecast discussion
National Weather Service Bismarck ND
908 PM CST Mon Nov 11 2019
issued at 906 PM CST Mon Nov 11 2019
Clear skies and light winds having there impact on temperatures
this evening. Lowered mins to around 11 below south central to
around zero north.
Update issued at 556 PM CST Mon Nov 11 2019
Clear skies this evening with the Arctic high pressure departing
the region. This will allow the evening temperatures to fall
initially, followed by some non-diurnal temperature trends later
tonight as strong warm advection begins in return flow around the
Temperatures will be the most uncertain tonight. Will monitor
closely but have little confidence we can pick a winning
temperature trend at this time. Current forecast looks OK.
Short term...(this evening through tuesday)
issued at 224 PM CST Mon Nov 11 2019
The center of surface Arctic high pressure was over the western
Dakotas this afternoon. Winds over the western half of ND were
lessening and were westerly. The lake effect light snow/flurries
will likely be confined to areas mainly east of Lake Sakakawea and
the Missouri River late this afternoon into early evening.
The high center will slide southeast into the Central Plains
tonight, and our surface winds will become light...then become
southerly later tonight. Our low temperatures tonight could occur
this evening or just after midnight, then begin rising towards
daybreak as southerly winds begin to mix the lower atmosphere. On
Tuesday, we can expect fairly decent warm advection behind a warm
front, allowing temperatures to rise into the 20s over north central
ND and the James River basin...and temperatures are expected to
reach into the mid and upper 30s for a brief time Tuesday afternoon
in southwestern ND.
Long term...(tuesday night through monday)
issued at 224 PM CST Mon Nov 11 2019
An upper level shortwave over the Pacific northwest on Tuesday
progresses east/southeast across the Dakotas Tuesday night and
Wednesday. The surface warm front Tuesday will be followed by a cold
front Tuesday night with the passage of the upper level shortwave.
This system will induce light snow, arriving Tuesday evening over
western North Dakota, spreading quickly into central ND before
tapering off from north to south by Wednesday afternoon. The 12z
models suggest western and south central ND would receive some light
snow...with far west and much of southwestern ND having the best
chance for an inch of snow. Thus, minor snow amounts with this fast-
moving clipper-type system. There may be a period of freezing
drizzle Wednesday morning as we may lose our mid-level clouds as the
light snow is tapering off. BUFKIT soundings support this scenario.
The cold air behind this clipper will be associated with another
high pressure system sliding down the Lee side of the Canadian
rockies. Look for highs Wednesday in the 20s to lower 30s, but lows
Wednesday night ranging from around 10 to 15 above over central ND
and in the lower 20s in the southwest.
A more persistent warm-up ensues Thursday through early next week. A
progressive overall upper level pattern, with zonal flow being
interrupted by shortwaves in the flow. Look for highs mainly in the
30s and lower 40s...and lows mainly in the 20s. The quick-moving
shortwaves will bring a slight chance of light snow Friday
night/Saturday...and another chance of light snow Sunday
Aviation...(for the 00z tafs through 00z Tuesday evening)
issued at 556 PM CST Mon Nov 11 2019
High pressure will maintain VFR conditions across the region at
the taf sites.
We expect some low level wind shear at kdik between 12-16z due to
a strong low level inversion and increasing winds through 2000