Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Grand Forks ND
947 PM CDT sun may 24 2015
issued at 945 PM CDT sun may 24 2015
Upper level trough was located over Wyoming with a short wave over OK.
Trough will move into western Iowa by morning. Upper level jet on the
east side of the trough will move into southern Minnesota tonight then
shift east sun. Low level jet was farther east in the Great Lake
states. Respectable precipitable water around 1 and a quarter
inches over the southeast zones tonight. Most of the thermal ridge
axis and middle level frontogenesis stays to the south and east of
the area. Areas radars indicated rain moving into the south but
was not reaching the ground yet. Will trim back probability of precipitation and quantitative precipitation forecast.
Also will decrease temperatures a bit in the north for tonight.
Update issued at 703 PM CDT sun may 24 2015
Current area radars indicated only precipitation was in the far southern
Red River and the far southeast zones. May tweak probability of precipitation on the next
update. Little change to current forecast.
Short term...(this evening through Monday night)
issued at 310 PM CDT sun may 24 2015
Forecast challenges mainly rain coverage with approaching system.
Operational models in general agreement in shifting surface low to
southeast by Minnesota. NAM looks to be the odd model out with a farther southeast
surface low track and drier forecast. Will follow high resolution
models for near term precipitation trends.
Rain so far has been slow to shift northward however as forcing
with upper low approaches later tonight expect rain to become more
organized and lift northward. Limited probability of precipitation to generally along and
south of Highway 2. Clouds and warm temperatures across the north
will hold temperatures up.
Rain band wrapping around surface low will set up across the
south half of the forecast area tomorrow gradually shifting east later in the
afternoon as the low shifts east. Warmest temperatures will be
along the international border where no precipitation expected along some
filtered solar. With lack of instability went strictly with rain.
Rain should continue to shift east Monday night and should be
clear of the forecast area by morning. Clouds likely to linger good part of
the night holding temperatures up
Long term...(tuesday through sunday)
issued at 310 PM CDT sun may 24 2015
Most areas will be dry Tuesday however with modest instability
and weak boundary across the north will maintain some low probability of precipitation in
the afternoon/evening. With mild column in place temperatures
should range above average most areas.
Next system slower in exiting The Rockies so will now go with a
dry and warm forecast for Wednesday. Exception will again be along
the international border closer to sagging cold front.
(Wednesday night-sunday)...models in general agreement
indicating more or less zonal type flow with an upper trough
affecting the region Thursday/Friday. Rain/thunder chances early in
the period will give way to high pressure and dry conditions for the
weekend. Temperatures will cool behind the late week system...but
slowly climb back to near normal values by the end of the weekend.
Aviation...(for the 00z tafs through 00z Monday evening)
issued at 703 PM CDT sun may 24 2015
IFR conditions over southern Minnesota was moving north and east.
Surrounding the IFR area, VFR conditions were across much of South Dakota and
into central Minnesota and edging into the southern zones. Otherwise VFR
conditions were across much of the forecast area. Look for MVFR
conditions to move north into the southern zones this evening.