Area Forecast Discussion
Issued by NWS Twin Cities, MN

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213
FXUS63 KMPX 251031
AFDMPX

Area Forecast Discussion
National Weather Service Twin Cities/Chanhassen MN
531 AM CDT Sat Mar 25 2017

.updated for the 12z aviation discussion below...

.SHORT TERM...(Today and tonight)
Issued at 335 AM CDT Sat Mar 25 2017

Short term concerns are cloud trends today and timing of light rain
chances later this afternoon and overnight.

Low clouds remain over most of the cwa this morning. Moist lower
level flow continues through the day. The HRRR and 0.5km
condensation pressure deficit forecast continues a mostly cloudy
trend for the day. Some indication of some thinning of the moisture
over the northern areas into the afternoon.  We could see some
sunshine develop over that region for a time this afternoon. This
would help temperatures warm close to 50. We will hold onto a more
cloudy trend with temepratures holding mainly in the 40s. Isentropic
forecast at 295K surface shows saturation lifting northwest over the
southeast area of the cwa mainly during the afternoon. Will hold
onto the small chance of light rain for the afternoon there.

The upper circulation  lifts a bit northeast and spreads deeper more
moist early flow over the region. We expect some light rain or
drizzle to work into central MN during the night...with highest pops
in west central Wisconsin. With clouds around again tonight...
lows should remain in the middle 30s.

.LONG TERM...(Sunday through Friday)
Issued at 335 AM CDT Sat Mar 25 2017

Confidence in the model solutions starts high for the Sunday
through Tuesday period, lowers to moderate by midweek and then is
quite low by Friday.

Looking at the big picture, a series of short waves/closed upper
lows will dominate the southern stream during the long term. The
first one will be south of us on Sunday and will lift northeast
across the Great Lakes on Monday. This has been well advertised by
the deterministic solutions with the eastern FA being brushed by
some light rain from Sunday into Monday. Tuesday remains the best
day of the long term as an elongated surface ridge moves through
with plenty of sunshine expected. One concern for Tuesday morning
is the potential for fog, especially eastern areas where it will
have rained. However, lingering mid level cloudiness is
anticipated early on, which should help mitigate the fog
potential.

The next short wave/closed upper low will be moving into the
Southern Plains on Wednesday. The GFS still prefers to shear this
system out to the east-northeast while the EC wants to remain more
closed and begin heading our way due to an upstream kicker.
Although the GFS shears out the southern wave, it now has a much
stronger northern stream wave impacting our area. So, either way
we end up with showers, either coming in from the west with the
northern wave, or from the southwest with the southern stream
feature. Much of the rain chances for Wednesday were confined to
western MN with pops spreading east during the night and
continuing on Thursday.

Things totally unwind by the time Friday arrives. The EC continues
to bring the southern stream feature into the Middle MS Valley
with plenty of showers indicated across our area. We would be in a
northeast low level flow pattern with highs from the EC in the
upper 30s to middle 40s. On the other hand, because the GFS had
sheared out this southern wave to the east, it has a new northern
stream wave approaching along with a pretty strong warm front
moving in. Highs from the GFS are progged in the lower to middle
60s. There was discussion from some of the surrounding offices on
lowering highs to be more in line with the EC. However, just
seeing how these waves have been behaving, we kept our highs in
the middle of the two ranges with lower to middle 50s indicated.
Only small chance pops were used as well.

&&

.AVIATION...(For the 12Z TAFS through 12Z Sunday morning)
Issued at 540 AM CDT Sat Mar 25 2017

Lower clouds should remain over most of the area today...as moist
low level easterly flow will continues. There is a possibility of
the moisture being thin enough to break up some...but believe
this would occur mainly around KAXN and did continue to mention
that this afternoon. The broader flow is expected to lift north
and west during the day as the upper low translates a bit
northeast. This should swing in deeper moisture...affecting mainly
the eastern areas into tonight. Timing looks to be a little later
than sooner...with the rain moving into KEAU after 00z Sun and
toward KMSP by 05z. Any accumulation will be light and will likely
be a combo of -ra/-dz. As this arrives...IFR cigs are expected
which will work east during the night. east/northeast winds will
increase this morning and will be a bit gusty/20kts possible
during the day.

KMSP...Expect MVFR cigs to remain today. timing of -ra/-dz
continues to looks like by 05z with IFR cigs following through
the overnight. Will trend back to MVFR after 15z Sun.

/OUTLOOK FOR KMSP/
Sun Night...MVFR. Chc -ra. Wind NNE 5 kts.
Mon...Chc MVFR Early.
Wind N 5 kts. Tue...VFR. Wind NE 5 kts.

&&

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

$$

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



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