National Weather Service Raw Text Product

878 
FXUS63 KBIS 051241
AFDBIS

Area Forecast Discussion
National Weather Service Bismarck ND
641 AM CST Thu Nov 5 2020

.UPDATE...
Issued at 641 AM CST Thu Nov 5 2020

No changes needed with this update. Temps running mainly in the
30s early this morning with calm to light southerly winds. 

&&

.SHORT TERM...(Today and tonight)
Issued at 436 AM CST Thu Nov 5 2020

Current 500mb pattern shows nearly zonal flow along the
International Border region with slight troughing over the 
Northern Plains. A strong 150kt was coming inland at 250mb near 
the Pac NW supporting a surface low over southwest Canada that 
will progress eastward placing our region in the warm sector with 
southwest flow reinforcing the warm, breezy weather. Continued to 
go above guidance for forecast highs today with highs getting into
the mid 70s at many locations. Record highs will be within reach 
at several locations, including Bismarck (76 is record), Dickinson
(76), Minot (74) and Jamestown (74). 

Breezy southwest winds are expected as well, generally 15-25mph
with higher gusts. With regard to fire weather concerns,
dewpoints and relative humidity were trended downward closer to
RAP and HRRR guidance, which resulted in far southwest ND having
minimum RH in the 15-20% range and 20-25% for adjacent areas south
and west of the Missouri River. The strongest winds are not
totally in synch with the lowest humidities, which should lessen
fire weather concerns somewhat. However, near critical fire
weather conditions are still expected, especially over western ND. 

Winds should diminish by late afternoon and early evening. With
mostly clear skies expected overnight, expect lows in the mid 30s
to low 40s.

.LONG TERM...(Friday through Wednesday)
Issued at 436 AM CST Thu Nov 5 2020

The main story is the strong storm system approaching the region
over the weekend with the main impacts on Sunday and Monday.
Models are in good agreement with deepening upper level trough
over the west coast on Thursday night and Friday. Trough will
continue to deepen with 130kt upper jet streak diving through and
eventually ejecting in southwest flow toward our region.
Latest deterministic runs of the ECMWF and GFS, as well as 00Z
GEFS and ECMWF ensemble mean surface pressure continue to show
relatively good agreement, placing an approximately 990mb surface
low over western ND at 18Z Sunday. Not much change from earlier
ensemble data either, with the GEFS still slightly farther east
with higher probabilities for 3"+ compared to ECMWF ensemble
guidance, though still relatively low. So northwest ND continues 
to look to have the best opportunity for accumulating snow. One 
noteworthy observation is seen on the GEFS plumes at Williston for
QPF. The ensemble mean and operational run are in close agreement
with a little over half an inch of liquid equivalent, but the 
individual members show a wide range of solutions ranging from 0.1
inches to 1.3 inches on the high end. So there continues to be 
greater uncertainty with precipitation/snow potential in the 
northwest, but much higher confidence with the other expected 
impacts of strong winds Sun/Mon and a significant cool down. 

&&

.AVIATION...(For the 12Z TAFS through 12Z Friday morning)
Issued at 641 AM CST Thu Nov 5 2020

VFR conditions expected through the forecast period. Breezy
southwest winds expected to develop this afternoon at all sites,
but will diminish by late afternoon or early evening.

&&

.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

UPDATE...JNS
SHORT TERM...JNS
LONG TERM...JNS
AVIATION...JNS