Area Forecast Discussion
Issued by NWS Twin Cities, MN

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 43 44 45 46 47 48 49 50

FXUS63 KMPX 120456

Area Forecast Discussion
National Weather Service Twin Cities/Chanhassen MN
1056 PM CST Tue Dec 11 2018

.UPDATE...For 06Z Aviation discussion below


.SHORT TERM...(This evening through Wednesday)
Issued at 259 PM CST Tue Dec 11 2018

Main concern in the short term is the shortwave set to move through
just to our south, but potentially bringing a light wintry mix to
portions of the area tonight and tomorrow morning.

Approaching shortwave was evident on satellite this afternoon moving
quickly eastward across western South Dakota.  This wave is set to
deepen tonight and dig southward into Iowa as it begins to take on a
negative tilt.  With the southern path of the wave, most of the
forcing due to vorticity advection will move through Iowa toward
southern Wisconsin.  However, models continue to advertise light
snowfall across western MN this evening prior to the main wave
digging south of the better saturation to our northwest.  Could see
light accumulations out west tonight.  Most of the CWA will likely
remain dry however, with western WI the highest threat for wintry
precip.  As the system progresses eastward, dry air will be an issue
and soundings still suggest a chance for light freezing drizzle in
western WI tomorrow morning.  Drying behind the system will quickly
fill in tomorrow afternoon.

.LONG TERM...(Wednesday night through Tuesday)
Issued at 259 PM CST Tue Dec 11 2018

The long term period still looks quiet, with no threat of any
meaningful precipitation through the next week.  So, the main point
of discussion is the temperatures, which look to warm above
normal this weekend.

From Wednesday night into Thursday, the western jet will dig into
Texas with and an upper level cutoff low will develop. The system
will stay on a southerly track and eventually lift toward the
northeastern CONUS. In the meantime, a front will move through
the local area Thursday, and with moisture in question it could be
dry. An upper level ridge will build over our area while the
aforementioned low is moving through the southern CONUS.
Temperatures in the mid to upper 30s look likely this weekend, but
another dry front looks to move through Sunday afternoon, cooling
temperatures off into early next week.


.AVIATION...(For the 06Z TAFS through 06Z Wednesday night)
Issued at 1057 PM CST Tue Dec 11 2018

Ceilings will continue to degrade to MVFR early in the period as
the stratus deck builds in, and will eventually become IFR at
most sites by daybreak Wednesday. MVFR visibilities are also
expected attendant with BR. Sites could also experience very light
precipitation in the form of snow or freezing drizzle, primarily
at KAXN overnight, and KRNH/KEAU Wednesday morning. Any
accumulations would be minor. Confidence regarding the timing of
improvement to VFR on Wednesday is low. MVFR conditions are
expected through Wednesday morning, with possible improvement
during the afternoon. However, we will most likely see the return
of MVFR/IFR ceilings on Wednesday night.

The chance for light precip still looks better to the east over
Wisconsin. Could see some very light snow during the latter part
of the morning push, but still expect visibility reductions to be
owed to BR.

Thu...MVFR ceilings. Wind lgt and vrb.
Fri...VFR. Winds W 5 kts.
Sat...VFR. Winds S 5-10 kts.




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