Scientific Forecaster Discussion
fxus63 kmpx 192340 aaa
Area forecast discussion...updated
National Weather Service Twin Cities/Chanhassen Minnesota
640 PM CDT Thu Apr 19 2018
Short term...(this evening through friday)
issued at 210 PM CDT Thu Apr 19 2018
Regional satellite imagery has shown a slow decrease in the
snowpack on the edges along the Buffalo Ridge, and in central
Minnesota this afternoon. Temperatures reflected the bare ground
in portions of central Minnesota where afternoon readings rose
into the 50s. Compare this area to yesterdays snow storm along the
Iowa, Minnesota border, and temperatures were only in the upper
30s to lower 40s. Due to the snow melt, and a strong ridge
overhead through tonight, fog is likely to form, especially in
west central Wisconsin. I wouldn't be surprised to see areas of
dense fog developing where wind speeds remain nearly calm.
Temperatures on Friday will be a few degrees warmer, but still
below average for late April.
Long term...(friday night through thursday)
issued at 215 PM CDT Thu Apr 19 2018
Very little weather concerns over the next week as a split flow
regime develops, and continues through the extended period. The
main storm track will be across the southern conus, with weaker
and unorganized systems moving across the northern plains and
upper Midwest. There remains a low chance of precipitation early
next week, but current model trends, and the split flow regime,
keeps this system moving further to the south across the plains,
vs. The upper Midwest. Even past next week, model uncertainty
remains due to the split flow regime, and most of the energy with
the weather systems remain across Canada or the far southern Continental U.S..
As temperatures slowly begin to rise with above normal
temperatures possible by Sunday/Monday, the snowpack will melt.
The melting and with some areas still having a frozen ground,
especially in the headwaters of the Minnesota River Valley, most
of the liquid water (from the snow) will runoff into the streams,
and eventually rivers. This will lead to rising streams and
rivers. Earlier today we issued a river Flood Warning for the
Minnesota river near Montevideo, the Redwood river near Redwood
Falls, and the Cottonwood River near New Ulm. This area has nearly
two inches of liquid water (unmelted) still in the river basin.
All of the increasing flows along these rivers will eventually
flow downstream and affect the Minnesota river at Mankato,
Jordan, and Savage. Currently we don't have much precipitation in
the next 7 days forecast. But, if this changes, and especially if
we get heavier rainfall from thunderstorms, these rivers will rise
Aviation...(for the 00z tafs through 00z Friday evening)
issued at 640 PM CDT Thu Apr 19 2018
Some patchy fog is expected overnight, otherwise VFR with light
Kmsp...some light fog/mist is possible late tonight, but
conditions should remain VFR.
/Outlook for kmsp/
Sat...VFR. Light/variable wind.
Sun...VFR. S wind 5 kts.
Mon...VFR. S wind 5 kts.