Area Forecast Discussion
Issued by NWS Twin Cities, MN

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840
FXUS63 KMPX 142150
AFDMPX

Area Forecast Discussion
National Weather Service Twin Cities/Chanhassen MN
350 PM CST Sat Jan 14 2017

.SHORT TERM...(This evening through Sunday)
Issued at 350 PM CST Sat Jan 14 2017

The main forecast concern in the near term is temperature trends.

Generally clear through the short term period with perhaps some high
clouds streaming over the southern cwa later tonight into Sunday.
Still have residual ridging over the area and winds should
decouple...mainly to the east closer to the ridge center. We expect
overnight lows similar to last night readings with reading ranging 5
below to 5 above.  The coldest reading expected in west central
Wisconsin.

Temperatures are expected to warm through 20s across the area Sunday
afternoon with plenty of sunshine and winds becoming more
southerly.

.LONG TERM...(Sunday night through Saturday)
Issued at 350 PM CST Sat Jan 14 2017

Here we are less than 48 hours away from a storm system moving
into the region from the far southwest and we are still seeing
major differences between the deterministic solutions with regards
to precipitation type. The crux of the matter is how the
solutions handle the interaction between an upper level low moving
northeast from northern Mexico and a short wave pushing through
British Columbia and the Pacific Northwest.

It is quite evident in the 250mb pattern that some of the
solutions show phasing (ECMWF/NAM) while others have little to no
phasing (GEM/GFS). The former solutions end up with a warmer low
level pattern across eastern/southern MN and western WI with more
potential for ice accumulation while the latter are colder with
mainly snow. An example is right here at MPX. Both the 12z and 18z
NAM have virtually all freezing rain with amounts approaching
0.40 inches while the 12z GFS has the same amount of QPF, but it`s
all snow (4 inches). At this point confidence is quite low on the
outcome for Monday into Tuesday. With blended solutions, one ends
up with minimal snow accumulation (1-3 inches) for the event from
southwest MN through the north Metro along with only a little ice
accumulation (0.05-0.10 inches) across far south central/southeast
MN. Hence, the winter storm watch continues as is due to the
possibility that the ECMWF/NAM are more correct on the warmer
temperatures in the low levels which would result in more
freezing rain over what the current forecast has. Plus, the watch
outlines the freezing rain threat from the NAM quite well with the
potential that you would need an ice storm warning for Monday and
early Monday night.

In the wake of this system, mild pacific air will flow in on
westerly winds setting the stage for a January thaw. There`s great
agreement between the solutions for the latter half of the week as
daytime highs will likely climb into the upper 30s to lower 40s if
not higher. However, a series of storm systems will push into the
western United States during this period with rain becoming an
issue for next weekend and early the following week. In fact,
there could be a lot of rain with both the ECMWF and GFS showing
widespread rains of 1 to 2 inches between Saturday and Tuesday.
Too bad we don`t have this kind of continuity in the early part of
the long term.

&&

.AVIATION...(For the 18Z TAFS through 18Z Sunday afternoon)
Issued at 1105 AM CST Sat Jan 14 2017

VFR through period. Winds light west becoming more southerly as
high retreats to the east into Sunday.

KMSP...
VFR no concerns.

/OUTLOOK FOR KMSP/
Sun night...VFR. Winds S 5 kts.
Mon...MVFR/IFR. -SN likely with chance of -fzra/-IP Monday
morning. Winds SE 4 to 7kt.
Tue...VFR. Winds NW bcmg W 5 kts.

&&

.MPX WATCHES/WARNINGS/ADVISORIES...
WI...None.
MN...Winter Storm Watch from Monday morning through Tuesday morning
     for MNZ051>053-058>063-065>070-075>077.

     Winter Storm Watch from late Sunday night through late Monday
     night for MNZ073-074-082>085-091>093.

&&

$$

SHORT TERM...DWE
LONG TERM...RAH
AVIATION...DWE



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