Area Forecast Discussion
Issued by NWS Twin Cities, MN

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FXUS63 KMPX 250343

Area Forecast Discussion
National Weather Service Twin Cities/Chanhassen MN
1043 PM CDT Fri Mar 24 2017

.SHORT TERM...(This evening through Saturday)
Issued at 341 PM CDT Fri Mar 24 2017

Typical March weather underway here with all the summer
temperatures to the southeast. Stratus and northerly flow have
kept temps only in the 30s and 40s, but Chicago managed to reach
the low 80s south of the front. Drier air will work into western
MN this evening and clouds should clear nicely, which is already
evident on satellite. The precip band has weakened and shifted
southeast but the upper low across the southern Plains will eject
northeastward to the Mid Mississippi Valley Saturday/Saturday
night which will bring the clouds and precip band back
northwestward. Amounts will be light and the precip should be
confined to southeast of a Fairmont to Eau Claire line through the

.LONG TERM...(Saturday night through Friday)
Issued at 341 PM CDT Fri Mar 24 2017

The weather pattern that we are currently in is difficult to
predict. That is the bottom line, so thought it best to temper
expectations and acknowledge that there will be little change in
the forecast and not anticipating any drastic uptick in confidence
until this highly amplified, split-flow pattern changes. The
reason being, amplified waves eventually end up breaking and
getting cut off from the main flow. Predicting a cut-off waves
movement is difficult, especially when there are multiple waves
that interact with each other.

Within these upper level lows are areas of enhanced vorticity which
end up producing precipitation. For example, on Saturday night
models indicate a band of light rain lifting northward, but the
positive vorticity advection is weak, the precip is light, and the
confidence in receiving measurable rainfall is low, so only have a
25 to 35 percent chance of rain through Sunday. On Monday a northern
stream wave will move through and subsidence on the back side will
bring an end to the precipitation chances, but forecast soundings
show residual boundary layer moisture, so should see increasing
clouds driven by daytime heating.

Tuesday will end up being the sunniest day of the forecast with
highs in the lower 50s expected. On Wednesday another occluded
cyclone over the southern plains will spread mid level moisture and
clouds over the Upper Midwest. Confidence tapers off considerably
after Wednesday, so continued with the blended guidance and slight
chances for precipitation. One thing is highly likely, and that
is the month of March will once again be above normal at MSP and
STC, possibly at EAU as well.


.AVIATION...(For the 06Z TAFS through 06Z Saturday night)
Issued at 1043 PM CDT Fri Mar 24 2017

We officially have stratus trapped beneath an inversion and with
the moisture associated with the rain field across IA into WI
coming back northwest during the day Saturday, see no reason why
we don`t keep the clouds going through this period. The lone
exception would be at AXN, whose position near the surface ridge
axis may allow the clouds to mix out there, similar to what we saw
Friday. For everyone else, cigs will be pretty steady through the
day, with a bit more of a lowering possible Saturday night as
what is currently to our southeast heads this way. Like the idea
of the GFS with a band of -ra working back northwest into
southeast MN after 18z, reaching EAU between 1z and 3z and MSP
between 4z and 7z. Rain will be pretty light, but may be enough to
bump vis down into the MVFR category while precip is falling.

KMSP...Clouds are here to stay, likely until Sunday night or
Monday morning. Followed the idea of the 00z GFS for bringing a
band of -ra into the Twin Cities around 6z. This will be on a
weakening trend, but enough support from other hi-res models on
this GFS solution to include some light rain to end the TAF

Sun...MVFR. Chc -ra. Wind NNE 5 kts.
Mon...Chc MVFR Early. Wind N 5 kts.
Tue...VFR. Wind NE 5 kts.




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