Area Forecast Discussion
Issued by NWS Bismarck, ND

Home | Current Version | Previous Version | Graphics & Text | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
FXUS63 KBIS 250537

Area Forecast Discussion
National Weather Service Bismarck ND
1237 AM CDT Sun Sep 25 2016

Issued at 1229 AM CDT Sun Sep 25 2016

Updated clouds and pops to better account for the latest satellite
and radar trends.

UPDATE Issued at 856 PM CDT Sat Sep 24 2016

The surface low over central ND has remained nearly stationary
over the past few hours, while the upper low in the southwest is
starting to track northeast. This is producing a narrow band of
weak instability combines with strong shear across portions of
northwest and far north central ND. due to the surface low not
moving, will have to extend the mention of thunder back to the
west, into northwest ND this evening, and will keep a chance in
the far north central late this evening. Otherwise no significant
changes. Wind advisory is now in effect over the southwest.

UPDATE Issued at 637 PM CDT Sat Sep 24 2016

Surface and upper level low pressure will lift northeast across
the forecast area tonight into Sunday morning. Currently the
surface low is situated over west central ND with the upper low in
far southwest ND. Cold front has made it through northwest ND and
should move across the southwest this evening as the surface and
upper low finally begin to lift northeast.

For the early evening update we adjusted pops/weather based on the
latest radar and satellite analysis. Basically a slower trend
through the night. Day shift had delayed the start of the wind
advisory in the southwest until 7 pm MDT and this looks reasonable
as winds are beginning to move into the northern portion of the
advisory. Will send out updated hazard and text products shortly.


.SHORT TERM...(This evening through Sunday)
Issued at 253 PM CDT Sat Sep 24 2016

Deep cut off upper level low was centered around southeastern
Montana at 18Z with the associated surface low over southwestern ND.
Dry slot of system was supporting mostly dry conditions across
south central ND Saturday afternoon with low level southerly flow
in the warm sector helping increase instability. Dew points in
this area were mainly in the mid/upper 60s and SB CAPE around 1500
J/Kg. High res models show convection developing after 20Z, with
the HRRR showing the stronger cells just outside our area. Any
severe threat should be relatively short lived and over by 00Z
Sun. Also expect showers and stratiform precip to spread from west
to east overnight as upper low progresses across the state,
reaching southern Manitoba as an open trough by 18Z Sun.

Expect strong winds to develop behind the system as the surface
low reaches northcentral ND this evening. Wind advisory that is
in effect tonight for the extreme southwest will be expanded to
the north and east. Will also make some adjustments to the
starting time as winds will be a little slower to strengthen than
originally thought. GFS depicts strongest BL winds around 40 kts
over this area. 0.5 km AGL winds also max at around 50 knots near
Adams/Sioux counties at 09Z.

On Sunday, precip will end from west to east and should be
completely out of the area by late afternoon. Breezy to windy
northwest winds will continue through the day as the low pushes away.

.LONG TERM...(Sunday night through Saturday)
Issued at 253 PM CDT Sat Sep 24 2016

A longwave upper level ridge will build over the Plains during the
week leading to mostly dry weather along with a warming trend. High
temps initially in the 60s on Monday will warm to the low 70s on
Tuesday, with similar highs through Friday.


.AVIATION...(For the 06Z TAFS through 06Z Sunday evening)
Issued at 856 PM CDT Sat Sep 24 2016

MVFR to IFR cigs with scattered showers bringing areas of MVFR/IFR
vis will spread east through the area early this morning as a
cold front pushes through. Conditions will improve late to mid
morning as the low cigs push east, with most locations returning
to VFR by mid-day. Gusty northwest winds will develop behind the
front, which will continue through the day before diminishing
towards evening.


Wind Advisory until 6 PM CDT /5 PM MDT/ this evening for



AVIATION...JJS is the U.S. government's official web portal to all federal, state and local government web resources and services.