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Area forecast discussion 
National Weather Service Grand Forks ND
1142 PM CDT Tuesday Sep 30 2014

issued at 1137 PM CDT Tuesday Sep 30 2014

Surface/500 mb low just southeast of Minot moving north. Showers
mostly concentrated just west of dvl region on edge of forecast area
with only spotty light rain reported over forecast area (mainly
sprinkles). Dry slot (at least in terms of low level moisture)
moving into southeast ND and this will move into the central Red River overnight
per ceiling forecasts from latest hrrr model. Threat for showers
diminishing further overnight with mainly dry south with isolated
showers north and northeast.

Update issued at 717 PM CDT Tuesday Sep 30 2014

Tweeking probability of precipitation this evening. Main band of showers that moved into
the Red River late this afternoon has since weakened and mostly fallen apart
as it rain into dry air over northwest Minnesota. Upper low west of Bismarck
with surface low in similar location moving north as expected. Brief
clearing in dry slot in the Aberdeen-Huron South Dakota area middle afternoon lead
to a narrow band of T-storms southeast of Bismarck to west of
Aberdeen and these are moving north-northeast around the upper low
but with much more stable air in southeast ND they are weakening. Hrrr
seems to have a good handle on hourly precipitation and has the remaining
shower band drying up as it moves into southeast ND toward Fargo by 03z.
This would leave much of the Red River/northwest and west-central Minnesota dry overnight.
Did tweek probability of precipitation to indicate that idea but did leave in some low
probability of precipitation perhaps a bit longer than otherwise would due to
uncertainities. Better bet for showers in dvl basin so kept higher
probability of precipitation there.


Short term...(this evening through Wednesday night)
issued at 330 PM CDT Tuesday Sep 30 2014

Forecast for this period focuses on precipitation chances
associated with the latest low pressure system. The 995 mb low is
currently located in western South Dakota and is forecast to lift north-
northeastward across central ND and into southwestern Manitoba overnight
tonight. A band of showers associated with the upper level low
currently arcs from Bottineau to Fargo and is forecast to lift
northward through the late afternoon...reaching Pembina by the early
evening hours. This band is expected to diminish through the
evening hours. Isolated surface based thunderstorms will be
possible south of this band...primarily near the South Dakota border...late
this afternoon. A storm or two could reach severe limits in the
far south. Its looking like most of the forcing with this system
will be in central ND have trimmed probability of precipitation downward
somewhat. cover looks to remain in the area for much of the
day. However...precipitation chances will be limited to the far
north and east. Despite the cloud cover...temperatures should be able to
reach the middle 60s to lower 70s across much of the area.

Long term...(thursday through tuesday)
issued at 330 PM CDT Tuesday Sep 30 2014

Wednesday night to Friday night...another potent wave enters area
bringing showers and possibly embedded thunder to the County warning forecast area by
Thursday PM. GFS differs significantly with its 12z solution of this
system and used a blend of the Gem/ec/NAM with its 500mb
placement...timing and track...all of which bring the upper low to
the South Dakota/ND/MN border area by 12z Friday. Ahead of this system 850mb
temperatures reach into the 5 to 9c range with and favorable warming SW
surface winds allowing surface temperatures to reach into the middle 60s. Cold front
will move quickly across the region Thursday afternoon with
slightly negative showalters and strong 925mb cold air advection. Strong winds
will continue overnight into Friday with the NAM showing 40kts or
better to mix during the daytime. 850mb temperatures drop to minus 4c or
so with 925mb temperatures near 0c so will lower Friday maximum temperatures into
the low to middle 40s. Showers slowly depart west to east Friday.

Saturday to Tuesday... northwest flow aloft dominates the period with
baroclinic zone oriented northwest to southeast across the northern plains which
will allow any weak wave in the flow to produce showers this
weekend. Will maintain chance/slght chance probability of precipitation Sat and sun with blended
guidance giving low 50s for maximum temperatures. Thicknesses increase as the
northwest flow weakens and becomes more west northwest early next week.
Temperatures moderate some as a result and slght chance probability of precipitation are
limited to the eastern County warning forecast area.


Aviation...(for the 06z tafs through 06z Wednesday night)
issued at 1137 PM CDT Tuesday Sep 30 2014

Widespread MVFR ceilings over most of the forecast area with the exception
of far eastern areas such as Baudette-Bemidji-Wadena where VFR ceilings
remain. Issues this forecast is affect of dry slot in clearing out the
MVFR ceilings into Fargo area overnight and possibly into tvf/gfk as
well. Then MVFR ceilings likely to spread back in as upper low/surface low
moves into southwestern Manitoba. Winds will remain strong
overnight in the 15 to 30 knots range from the south-southeast
turning southwest and then eventually closer to west Wednesday afternoon.


Fgf watches/warnings/advisories...


short term...knutsvig
long term...jk

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