Area Forecast Discussion
Issued by NWS Twin Cities, MN

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary Off
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42

000
FXUS63 KMPX 122049
AFDMPX

Area Forecast Discussion
National Weather Service Twin Cities/Chanhassen MN
249 PM CST Mon Feb 12 2018

.SHORT TERM...(This evening through Tuesday)
Issued at 248 PM CST Mon Feb 12 2018

Early this afternoon, a polar high was in place across Minnesota and
Wisconsin, making it a slow recovery from widespread subzero
readings this morning.  Winds were light with the lack of a pressure
gradient as the high moves through.

This evening...the high pressure will continue moving eastward
toward the Great Lakes, which will allow light southeasterly winds
to develop at the surface.  Aloft, a subtle 600-700mb wave will lift
in from the southwest, with some isentropic ascent noted on the 295k
theta surface.  There will be dry air underneath this area of
ascent, and cloud bases will be pretty high for seeing much in the
way of snow.  Still, the 40+ knots of wind on the 295k theta surface
and saturday 7-10k ft above the ground should produce some very
light snow or flurries to the ground across western and parts of
central MN.

Tomorrow will be warmer, but breezy.  As the high moves away,
southerly winds of 10-20 MPH will develop during the day, ushering
in the warmer temperatures from the south.  Highs should reach the
upper 20s tomorrow, exactly normal for mid-February.  This will be
the warmest day since January 31st, when highs reached the low
30s.

.LONG TERM...(Tuesday night through Monday)
Issued at 248 PM CST Mon Feb 12 2018

The long term period will bring a bit of a roller coaster of
temperatures to our area from Wednesday into early next week.  The
best chance of seeing any precipitation will come Thursday, but
would be rather light.

By tomorrow night, a retrograding closed low at 500H will be off the
coast of California and dictate a zonal flow pattern across the
CONUS.  Meanwhile, a strong west to east jet will move into southern
Canada, keeping the arctic air north of there. A trough of low
pressure at the surface will move from southwestern Canada on a
southeastern course, with a warm front lifting into our area with
strong southwest flow on Wednesday.  Temperatures still look to
reach the 40s for most, with 50 not out of the question in southwest
Minnesota due to downsloping off the Buffalo Ridge.

The front will drop through Thursday with highs back below freezing
and a chance for light snow associated with the front.  This would
be a quick-hitting band of snow, which typically produce light
accumulation.  An amplified longwave trough will drop southeast from
the west coast of Canada this weekend as the aforementioned low off
the California coast gets sheared out and ejected east in the
dominant flow of the incoming longwave.  While this process occurs,
the strong jet to our south will shift east and a low pressure
system will develop across northern Montana, ultimately leading to
southwest flow this weekend once again, which explains why the
temperatures bounce back above freezing Saturday and Sunday.

Looking ahead to next week, there is good agreement that the
longwave trough over the western CONUS by late in the weekend will
stay put for at least the first half of next week.  The flow will
become more amplified with the southeast CONUS seeing a very strong
ridge building in response to the amplified troughing to the west.
Our region will be very near the thermal gradient between the
western trough and eastern ridge, which could lead to more active
weather.  For temepratures, the guidance at this time is favoring
the western trough reaching our area, which would lead to below
normal temperatures returning.

&&

.AVIATION...(For the 18Z TAFS through 18Z Tuesday afternoon)
Issued at 1103 AM CST Mon Feb 12 2018

Quiet period ahead with VFR conditions, and the focus being the
wind direction change from today to tomorrow. High clouds will
move through the area today, with a mid cloud deck and very light
snow possible across far western MN tonight. Mentioned the snow in
the AXN TAF, but nowhere else. North winds around 5 knots will
turn to the southeast tonight and south-southwest by tomorrow
morning. Speeds will increase to closer to 10-12 knots by the end
of the TAF period.

KMSP...no additional concerns.

/OUTLOOK FOR KMSP/
Wed...VFR. Winds SW 5-10 kts.
Thu...MVFR. Chc -SN/IFR. Winds NW 10-15 kts.
Fri...VFR. Winds W 5-10 kts.


&&

.MPX WATCHES/WARNINGS/ADVISORIES...
WI...None.
MN...None.
&&

$$

SHORT TERM...SPD
LONG TERM...SPD
AVIATION...SPD



USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.