Area Forecast Discussion
Issued by NWS Twin Cities, MN

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FXUS63 KMPX 170352

Area Forecast Discussion
National Weather Service Twin Cities/Chanhassen MN
1052 PM CDT Sun Apr 16 2017

.Updated for 06Z Aviation Discussion...
Issued at 1047 PM CDT Sun Apr 16 2017


.SHORT TERM...(This evening through Monday)
Issued at 245 PM CDT Sun Apr 16 2017

A pair of upper lows this afternoon could be found along the
international border, with steep mid-level lapse rates resulting in
scattered shower development in northern MN, though this activity is
expected to remain north of us as the cool mid level temps driving
this instability reaches our NE CWA this evening, after we lose
diurnal heating. What these upper lows will do is send a dry cold
front across our area tonight. This front at 3 pm was stretched out
from near International Falls back west to across southern NODAK
between I-94 and SODAK. This front will allow winds to become more
NW/N tonight and Monday.

For precip chances, removed the sprinkle mention we had, with dry
low level air looking to best any attempt at precip generation. The
best chance for sprinkles/light rain though looks to go down along
the I-90 corridor. This is where the RAP shows a band of FGEN in the
h7-h6 layer traversing, with the HRRR and 3 of the 4 HopWRF members
showing some light returns developing around midnight. Again,
soundings show air below h85 remaining dry, so this looks to be
nothing more than a layer of broken to overcast clouds in the 8k-10k
foot layer.

As for temepratures, we will see cooler air filter in behind the
front overnight. Mixing to h85 on the GFS shows our entire are
remaining below 60 for highs Monday, with model blends coming in a
few degrees cooler for highs tomorrow as well. For highs, split the
difference between the cooler 12z guidance and the warmer going
forecast, which knocked highs for Monday back a couple of degrees.
We`ll have pretty much full sunshine tomorrow, so we should be able
to warm a bit more than what the blended guidance has.

.LONG TERM...(Monday night through Sunday)
Issued at 245 PM CDT Sun Apr 16 2017

The long term will feature two systems, one early Tuesday and the
other late Wednesday into Thursday. A gradual warm up will follow
into next weekend.

Models are in good agreement with timing and intensity of a band
of showers moving through late monday night into Tuesday morning.
Instability is minimal with poor lapse rates in place, but
moisture transport is impressive with the 55-65 kt LLJ overhead
which could bring some isolated thunder. The rain should move into
WI by early afternoon and out of the area by late afternoon. Dry
slot moving in behind the rain with gusty southwest winds will
allow temperatures to quickly rebound into the 60s. A narrow
corridor from south central to east central MN could reach the
lower 70s given a favorable placement of the thermal ridge during
mid afternoon.

Cold front will push through during the afternoon with the next
system already taking shape over eastern CO/western KS. Heavy
convection will likely be ongoing along the front Tuesday night
along or south of the I-80 corridor. The front may not be able to
lift back north of that Wednesday, which means the system will
track well south of the CWA. Models have generally shifted south
with this system which is not all that unusual given the
aforementioned setup. Nonetheless, southern MN is likely to see
widespread rain Wednesday afternoon and Wednesday night, it`s just a
question of how far north the rain shield will lift. PoPs trend
downward pretty quick with northern extent across central MN and
northwest WI during this period.

Surface ridging will build south and should keep seasonal
temperatures in the area for late week. A warming trend is
probable ahead of a series of fronts late weekend into early the
following week.


.AVIATION...(For the 06Z TAFS through 06Z Monday night)
Issued at 1047 PM CDT Sun Apr 16 2017

VFR conditions throughout. Clouds with bases around 10kft will
pass overhead. Light northwest winds will become calm on Monday
and eventually take on a southeasterly direction late Monday ahead
of the next system that will spread rain across the region early
Tuesday morning.

VFR conditions throughout. Precip chances will return around 12Z
on Tuesday, but did not include mention in the taf for this

Tue...MVFR and -RA with IFR/TSRA possible in morning. Wind SSW
 bcmg W in afternoon at 10G20kt with dry conditions.
Wed...VFR with -RA/MVFR Cigs likely overnight. Wind NE at
Thu...MVFR Cigs possible early then VFR. Wind NE at 5-10kt.




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