Area Forecast Discussion
Issued by NWS Twin Cities, MN

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FXUS63 KMPX 301135
AFDMPX

Area Forecast Discussion
National Weather Service Twin Cities/Chanhassen MN
535 AM CST Wed Nov 30 2016

.SHORT TERM...(Today and tonight)
Issued at 343 AM CST Wed Nov 30 2016

A very homogeneous air mass remains overhead this morning with a
nearly vertically stacked storm system across east central
Minnesota. This system has been cut off from the main storm track
which has allowed for the persistent clouds, light precipitation
and very little temperature change over the past 2 days.

Regional IR satellite imagery which can highlight cloud
temperatures, depicted both supercooled water droplets and ice
in the clouds across Minnesota and Wisconsin. In addition, radar
can also estimate/calculate reflectivity at specific temperatures,
so using both the satellite and radar we can induce that the
precipitation across the area, although light, was a mixture of
both rain, snow and drizzle. Colder cloud temperatures were noted
in the western Dakotas and surface observation noted all snow, vs
the mixture in our region.

The upper low will continue to weaken today as it drifts to the
southeast, and as a short wave moving southward across Manitoba,
will lift this system southeast, and eventually eastward as the
mean flow becomes more west-northwesterly. Specifically,
occasional light rain, drizzle and light snow will continue across
Minnesota and western Wisconsin until drier air from the
aforementioned short wave moves across the area late tonight.
Temperatures will remain nearly steady or rise a few degrees from
morning lows. Any snowfall amounts will be minor as surface
temperatures will be above freezing.

.LONG TERM...(Thursday through Tuesday)
Issued at 343 AM CST Wed Nov 30 2016

Thursday through Saturday...The lasting portion of the low
pressure system impacting the short term will shift into
southwestern Quebec province, with a trailing surface trough
extending westward through the northern Great Lakes into central
MN. A few rain/snow showers in eastern MN and western WI will
remain to start the day Thursday but these will steadily dissipate
by the early afternoon, resulting in dry conditions by sunset.
High pressure will then prevail from Thursday night through
Saturday, maintaining dry conditions across the region. However,
weak wave aloft will maintain cloud cover throughout the rest of
the week so seeing sunshine will be a difficult prospect through
the rest of this week. Temperatures will remain fairly steady
since no significant cold/warm air advection is expected behind
the departing system and H5 heights display little change in
forecast progs. Highs will remain in the low-mid 30s while lows
range through the 20s.

Sunday through Tuesday...A few changes to the pattern are in store
for the early portion of next week but the chances of a
significant system have diminished due to poor agreement between
the GFS and EC along with the placement of the system within each
model. First, for Sunday, a modest surface cold front looks to
swing through the region but it will be a quick-mover and fairly
devoid of moisture so aside from isolated/scattered rain and snow
showers, this system is rather weak. Going into early next week,
there is agreement on the formation of a low pressure system in
the central-northern Rockies late Sunday but now there are much
more northern tracks displayed by both the 30/00z GFS and 30/00z
ECMWF. Both models attempt to deepen the system over eastern MT
and eastern WY Sunday night. Afterwards, the GFS swings it
northeast into Manitoba province by Tuesday morning while the
ECMWF swings it through the Dakotas and into northwest MN by
Tuesday morning. In either scenario, it is a warmer and less
precip-intense system, highlighting precipitation along the cold
front of the the system for Monday night into Tuesday (as opposed
to any warm frontal precipitation which now looks to be shunted
into northern MN, north of the WFO MPX coverage area). In
addition, wrap-around precipitation for Tuesday night into
Wednesday looks fairly unimpressive and the main question is where
the front stalls out mid-week which would determine any persistent
precipitation for the middle portion of next week. Plenty of
uncertainty lurks with how these features evolve for next week,
for sure, but confidence is low on having any storm systems
produce significant precipitation for this area for early
December.

&&

.AVIATION...(For the 12Z TAFS through 12Z Thursday morning)
Issued at 535 AM CST Wed Nov 30 2016

Deep moisture and little mixing today will lead to IFR ceilings
with occasional light precipitation in the form or rain/snow.
Visibilities could drop to 1-2SM in heavier snowfall, but this is
unlikely for an extended period of time. Winds will be light and
variable over east central/west central Wisconsin until noon as
the surface low moves overhead. By the afternoon, winds will
become more west/northwest and increase. Western Minnesota will
continue to see west/northwest winds of 5 to 10 mph with the
stronger winds in the southwest part of the state.

KMSP...

Little change in the current ceilings with IFR, or low end MVFR
ceilings through the taf period. Mixing in the boundary layer
will be limited, so ceilings should remain below 1.7k. Some light
precipitation is likely today, but any snow will be minor and not
accumulate. Winds will slowly become west-northwest during the
morning and increase slightly this afternoon.

/OUTLOOK FOR KMSP/

Thu...MVFR. Wind NW 5-10 kts.
Fri...MVFR. Wind NW 5-10 kts.
Sat...VFR with MVFR possible. Wind W at 10 kts.

&&

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

$$

SHORT TERM...JLT
LONG TERM...JPC
AVIATION...JLT


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