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Area forecast discussion 
National Weather Service Grand Forks ND
1240 PM CDT sun Apr 19 2015

issued at 1240 PM CDT sun Apr 19 2015

Previous updates are on track so only minimal updates are needed
for today. Water vapor imagery indicates base of 500mb trough
beginning to turn to the northeast...which should propagate the
forcing into southern Manitoba by late afternoon...and current
probability of precipitation in good shape for timing. Cold pool aloft showers across
central North Dakota expected into eastern North Dakota by late
afternoon as cold pool aloft shifts east. Bismarck received very
small hail with one weak that will be possible given
the very low freezing levels (although thunder not expected).

Update issued at 947 am CDT sun Apr 19 2015

Radar imagery indicates an area of showers from the Devils Lake
basin into the northern valley. The northern upper wave is a tad
slower than expected...and will raise probability of precipitation across this current
rain area...and slow down their exit. Water vapor imagery
indicates the main energy of this upper wave will swing to the NE
today...inducing 700mb warm air advection/frontogenesis. This
forcing will propagate NE today...and anticipate the current area
of showers will gradually diminish from the southwest. Given the
above thinking...and current model guidance...areas across the
northern valley should receive 0.20-0.40 inches of rainfall (12z-
00z). Isolated-scattered instability showers this afternoon possible
most areas with cold pool aloft moving into the region. It is also
going to get windy along and west of the valley...but with speeds
just under advisory criteria.


Short term...(today through monday)
issued at 356 am CDT sun Apr 19 2015

Upper level trough over eastern Montana will move across the forecast
area this afternoon and tonight. Open trough will close off today,
slowly drift east of ls, and expand to cover much of the northeast
part of the US by the end of the period. Upper level jet will
develop on east side of the trough. Another jet will dive south on
the west side of the trough on Monday. The jet on the west side of the
trough will remain over the western zones or farther west through
the period.

Highest precipitable water in the southeast zones now and will shift
east today. Most of the frontogenesis with the system is expected
with the cold front over central ND. Low level jet was over central
and southern Minnesota and is forecast to shift east/northeast today.
Precipitation currently over Minnesota should also shift north and east today.
Upper level divergence expected mainly over the northern Red River
valley in right entrance region of upper jet.

Middle level dry air over South Dakota will move northeast today and restrict
amount of rain expected with this system. With low level jet
shifting east/northeast and frontal boundary farther west,
ingredients not coming together for significant precipitation. Will trim
back quantitative precipitation forecast.

Long term...(monday night through saturday)
issued at 356 am CDT sun Apr 19 2015

Wednesday to Saturday night...a quiet period weatherwise with northwest
flow aloft and cool Canadian surface high pressure. Some uncertainty
towards the end of the week with how quickly 500mb ridging tries to
build into the northern plains and with it there is potential for
warm air advection precipitation. Thus have some light probability of precipitation in for
Saturday. High temperatures in the forties will moderate to low
fifties by weeks end.


Aviation...(for the 18z tafs through 18z Monday afternoon)
issued at 1240 PM CDT sun Apr 19 2015

Will continue to have gusty northwest winds during the daytime
hours. Should lose some of the gustiness during the evening but
sustained winds will stay up. Then expect the same gusty winds again
during the day Monday. Ceilings are a little tougher call. May see
some rise into the low end of VFR criteria this afternoon but then
models suggest they may lower back into at least MVFR criteria again
tonight. Area of steadier rain over the kgfk area should slowly move
east and affect ktvf/kbji during the later afternoon. There is other
shower development occurring over central ND that may slide into
eastern ND later this afternoon too. This showery precipitation should die
off this evening and start up again by late Monday morning. Will not
insert any late Monday morning showers into the they should
get more numerous around 18z or later.


Fgf watches/warnings/advisories...

short term...hoppes
long term...jk

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