Area Forecast Discussion
Issued by NWS Twin Cities, MN

Home | Current Version | Previous Version | Graphics & Text | Print | Product List | Glossary On
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 43
FXUS63 KMPX 252130

Area Forecast Discussion
National Weather Service Twin Cities/Chanhassen MN
330 PM CST Sat Feb 25 2017

.SHORT TERM...(This evening through Sunday)
Issued at 301 PM CST Sat Feb 25 2017

Surface analysis this afternoon shows an approaching cold front
from ND with a surface low over far NW MN. High pressure dominates
much of the central CONUS. Aloft, one sharp longwave trough is
exiting into New England while another is developing over Manitoba
into southern Idaho. This trough will produce enough lift in
conjunction with the approaching front to produce isolated to
scattered snow showers in mainly northern and eastern portions of
the WFO MPX coverage area through midday tomorrow. Little to no
accumulations are expected. Cloudy skies will linger through much
of the day tomorrow as the front will settle over central MN into
northern WI while the upper trough shifts into the Great Lakes.
Little in the way of airmass change will take place. Therefore,
high temperatures tomorrow will be rather similar to high
temperatures today, running in the upper 20s to mid 30s. Lows
tonight will be a bit warmer due to the blanket of clouds across
the area. Min temps will drop to the upper teens to mid 20s.

.LONG TERM...(Sunday night through Saturday)
Issued at 301 PM CST Sat Feb 25 2017

The main forecast concern in the extended period is precipitation
chances late Monday night/Tuesday, along with precipitation type as
a warm layer aloft moves overhead.

Weak west-northwest flow aloft will become more southwest early
next week as two storm systems moving east/southeast off the
west coast, combine, and move inland. This will set the stage for
a series of weak shortwaves riding northeast along this southwest
flow aloft until Wednesday as the mean trough moves through the
mid section of the nation.

Ahead of the expect system late Monday night & Tuesday, warmer air
aloft will surge northward ahead of a developing storm system in
the Rockies. An old frontal boundary from today`s system will
linger in the region which will likely be the focal point of
moisture convergence as the storm system begins to move out of the
Rockies, and into the plains. All three models, EC/GFS/GEM
increase boundary layer moisture ahead of this system Monday
night. This may allow for stratus, low clouds and fog to form
before any upper level energy moves into the area. Therefore,
drizzle or freezing drizzle is likely, especially in areas where
the heavy snow fell a couple of days ago. Depending upon the
strength of the low level jet expected to develop Monday night,
will lead to an area of moisture convergence and likely an
expanding area of light precipitation, especially on the nose of
this jet. Although most of the lift is associated with the low
level jet Monday night/Tuesday, as energy from the storm moving
out into the plains Tuesday, precipitation will likely increase in
coverage and intensity. The stronger of the upper level energy
moving out of the Rockies Tuesday is associated with the southern
jet, so as a surface low begins to form in the plains Tuesday,
most of this energy should be south of Minnesota. This scenario is
highly dependent on frontal boundary position and the energy
moving out across the plains. Therefore, chances of precipitation
could either decrease or increase based on these factors.

Past Tuesday, a cool period is expected for a few days before the
mean flow becomes more west/southwest next weekend. This type of
flow will again provide for milder temperatures with 40s not out
of the question this time next week.


.AVIATION...(For the 00Z TAFS through 00Z Sunday evening)
Issued at 301 PM CST Sat Feb 25 2017

An east-west oriented cold front will remain draped over central
MN into northern WI through tomorrow. Mid-level ceilings have
drifted into the area from the west along this front and will
remain in place tonight through much of tomorrow. Occasional MVFR
ceilings are possible around KAXN but otherwise the TAF sites will
have VFR ceilings. A few snow showers are possible this evening
through midday tomorrow, but nothing that is expected to reduce
visibilities lower than VFR conditions. Northwest winds will back
to southwest overnight then veer to northwest again during the day

KMSP...VFR conditions expected throughout this set. Only concern
may be wind directions for tonight into tomorrow, if they go more
southerly than currently advertised. This may put wind speeds more
south than southwest and could pose a problem for 30s versus 12s.

Mon...VFR becoming MVFR. Chance -RASN Mon night. Wind S 5-10 kts.
Tue...MVFR. likely. Chance -RASN. Winds E 5 kts shifting to N.
Wed...MVFR ceilings possible. Otherwise VFR. Winds N 5-10 kts.




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