Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Twin Cities/Chanhassen Minnesota
534 am CDT Sat may 30 2015
Short term...(today and tonight)
issued at 409 am CDT Sat may 30 2015
The cold front has long since cleared the mpx County Warning Area this morning.
Behind the front there is a 1032 high over SW Manitoba. The impact
of this Canadian high has been most evident in the 24 hour
temperature change plot...with the entire mpx County Warning Area 10 to 20 degrees
colder than 24 hours ago. For the rest of today...we will spend the
morning slowly pushing mainly middle and high clouds to the southeast
of the area. We will maintain 5 to 15 miles per hour north wind. Changed
forecast highs little...though mixing to 850 mb on the GFS/NAM would
say we could see highs a few degrees warmer than what we have.
Still...it will be a beautiful late May Day...so long as you Don/T
mind highs being 10 to 15 degrees below normal.
For tonight...the Canadian high will slide over to Lake
Superior...with skies clearing out...save for some high clouds
arriving late in western Minnesota out ahead of shortwave that will be moving
into the Dakotas. Still expecting lows across the area in the 32-42
degree range. In all likelihood...the next shift will have to issue
a frost advisory...just did not do it tonight as Duluth was holding
off on issuing anything in northwest WI until their current headlines in
north central Minnesota expire...so will get those sorts of headlines out
when the rest of northwest WI will get them as well. As of now...most
likely counties for needing an advisory would be Barron...Rusk...and
Chippewa counties in western WI. Will probably see some patchy frost to
the west of there into central Minnesota...but winds look to remain up west
of these three counties /farther from the high center/...which will
make it a bit more difficult to get frost formation going.
Long term...(sunday through friday)
issued at 409 am CDT Sat may 30 2015
High pressure will keep tranquil conditions over much of the
region through Monday night. Aside from any frost potential Sunday
morning...the biggest concern for early in the long term is
whether we can shake out a few showers Sunday afternoon over far
western Minnesota. A disorganized middle level disturbance will track across
the plains around the ridge over The Rockies. Very dry air around
800 mb and a fairly thin stratus deck above 700 mb will greatly
limit chances for rain. Still...there may be a drop or two in
spots so maintained slight chance probability of precipitation for now...but future shifts
may drop them completely.
The rest of next week looks pretty active as a boundary stalls
from the Great Lakes/upper Midwest to the Central High plains in
response to the ridge building east over the MS valley and a
trough digging down the West Coast. Convective development will
depend largely on diurnal instability and longevity will depend on
the nocturnal low level jet. Subtle short waves and potential atmospheric
contamination from earlier rounds of convection make picking out
periods with an enhanced chance for precipitation very difficult...if not
impossible. Thus...maintained medium probability of precipitation in the 40-60 percent
range through most of the middle to latter parts of next week.
Given the synoptic pattern...several inches of rain may fall in
spots next week if we can get multiple periods of convection.
Aviation...(for the 12z tafs through 12z Sunday morning)
issued at 534 am CDT Sat may 30 2015
MVFR ceilings continue to slowly head southeast this morning and will finally
clear eau by 15z and move out of southern Minnesota by 18z. Mainly clear
skies will then prevail as dry high pressure GOES across northern Minnesota.
North winds will continue to gust outside of central Minnesota through
the day before settling down and shifting toward the east
Kmsp...will continue to see north winds gust up around 20 kts
through the day before settling down tonight as they begin to veer
toward the east. VFR ceilings are here to stay until the next chance
for thunderstorms arrives...but that will not be until Tuesday
/Outlook for kmsp/
sun...VFR. Winds southeast 5-10 knots.
Monday...VFR. Winds southeast 10 knots.
Tuesday...VFR. Chance -tsra late. Winds south-southeast 10-15 knots.