Scientific Forecaster Discussion
Area forecast discussion...updated
National Weather Service Twin Cities/Chanhassen Minnesota
709 am CDT sun Mar 16 2014
Short term...(today and tonight)
issued at 329 am CDT sun Mar 16 2014
Surface high pressure over northeast Minnesota and northern
Wisconsin early this morning will slowly slide southeast over the
Great Lakes this afternoon and into New England late tonight. A
clear and chilly day is in store with a polar airmass in place. 925 mb
temperatures ranging from -12c over WI to -3c near the sodak border will
spell highs from the lower 20s to upper 30s respectively.
A warm front will push across the plains tonight as a large area of
low pressure develops. A band of light snow should accompany the
front across mainly central/northern Minnesota and northern WI where the
low levels have the best chance of saturating. Amounts will be an
inch or less...and should last only a few hours. Lows tonight will
be reached in the evening before steady or slowly rising temperatures
accompany the front overnight.
Long term...(monday through saturday)
issued at 329 am CDT sun Mar 16 2014
Long term trends remain light snow event for Monday...mainly over
the northern County Warning Area...and then potential snow storm developing
Tuesday into Wednesday.
Initial band of warm air advection/isentropic lift should move across the eastern
County Warning Area into Monday morning. The namwrf doesnt quite saturate the
boundary layer...but some light quantitative precipitation forecast is generated on the European model (ecmwf) and
GFS Monday morning. Both the European model (ecmwf) and the GFS generate another
area of quantitative precipitation forecast over west central Minnesota during the afternoon. Will
have to monitor this...as it may be a bit fast with the onslaught
of forcing associated with the deepening trough over the Lee of
The Rockies over Wyoming/Colorado region. Will hold onto small
chance probability of precipitation for this into the afternoon. Strong warming ahead of
the trough should warm temperatures into 50s over southwest
portion of the County Warning Area...where no snow cover remains.
This warm trend continues into Monday night and Tuesday as the
surface low moves out into the plains over southern South
Dakota...near fsd by Tuesday morning. All models trended farther
south with the track of the low...with the European model (ecmwf) dropping even a
bit farther south with the low. It was deepest/slowest with the 500 mb
trough as it moved over th rockies. Will follow a GFS/ec
compromise for the moment. This will likely mean a colder solution
overall...with a better potential of accumulating snow over the
County Warning Area into Wednesday. Especially if the system slows a bit/deepens
as the GFS and ec are trying to indicate as the upper trough
becomes more negatively tilted Tuesday/Wednesday. This lifts the
surface low northeast again over southern/eastern Wisconsin on
Wednesday...a more favorable track for snow over eastern Minnesota and
western WI. Will have to monitor later model runs to see it this
At the moment..we have 3-5 inches of snow in the western County Warning Area later
Monday night into Wednesday...with a general 1-3 inches over the
east during Tuesday/Wednesday. There will likely be a mix of
rain/sleet/snow developing out ahead of the system for Tuesday. We
could see some freezing rain as well late Monday night/Tuesday
morning...depending how quickly above freezing temperatures/higher
dewpoints arrive. May need some sort of headline for the event...
mainly for the late Monday night into Tuesday night period.
System exits the area into Wednesday...with the trend toward
cooler conditions returning for next weekend. Small chance probability of precipitation
for the possibility of a weak system moving through the area
Thursday night into Friday night. Otherwise a cooler and drier
Aviation...(for the 12z tafs through 12z Monday morning)
issued at 655 am CDT sun Mar 16 2014
VFR expected through this evening. A warm front will push eastward
overnight and could produce a band of snow across central Minnesota. This
may result in MVFR conditions...but confidence is low. East winds
will veer southerly and increase through the period.
Kmsp...VFR conditions through the period. Any snow tonight is
likely to remain north of the terminal.
/Outlook for kmsp/
Monday...VFR with MVFR and -ra possible late. Winds S at 10g15kts.
Tuesday...MVFR with IFR and -sn/ra/fzra possible. Winds NE at
Wednesday...MVFR with IFR and snow possible early...then VFR.
Winds northwest at 20g30kts.