Area Forecast Discussion
Issued by NWS Twin Cities, MN
FXUS63 KMPX 231840
Area Forecast Discussion
National Weather Service Twin Cities/Chanhassen MN
140 PM CDT SUN OCT 23 2016
.SHORT TERM...(Today and tonight)
Issued at 320 AM CDT Sun Oct 23 2016
Early morning water vapor imagery to the north nicely illustrates a
shortwave skirting the International border. This feature will
spread some clouds as far south as central MN/WI today, and spawn a
few showers across the north as well. At this point the forcing and
moisture sufficient for precipitation look to stay mostly north of
the forecast area, although a few early afternoon showers could make
it as far south as Ladysmith, WI. Breezy northwest winds will
develop this morning and afternoon as the associated surface trough
passes. The attendant cool air advection will cause temperatures to
be 5-10 degrees cooler than yesterday, with highs in the lower 50s
to lower 60s anticipated.
Tonight, clouds scatter out and winds become light and variable.
This will make for a chilly night, with Monday morning lows in the
30-35 degree range anticipated.
.LONG TERM...(Monday through Saturday)
Issued at 340 AM CDT Sun Oct 23 2016
Two concerns over the next several days as a strong storm system
begins to organize in the Central Plains and Upper Midwest
First, precipitation onset remains questionable on Tuesday due to
initial dry air mass to the east and how fast moisture builds
northward across the plains. Due to this drier air mass to the
east, the onset of precipitation could hold off across eastern
Minnesota until late in the afternoon, early evening. West central
Wisconsin may not see any precipitation until late Tuesday
evening, or early Wednesday morning depending upon the strength of
isentropic lift and how it will be oriented from southwest to
Secondly, this system is very dynamic and has very high anomalous
water content just to the south of MPX forecast area. Precipitation
water values of 1.0" to 1.2" along the Minnesota/Iowa border are
very rare for late October. Therefore, once this system become
very organized I would expect periods of heavy rainfall once the
setup develops along the nose of the low level jet Tuesday
evening. As with any system, any deviation of this jet and
orientation of the frontal boundary, will shift the heavier
rainfall amounts to the south or north.
Confidence remain very high on a wet period once the
precipitation starts, and will likely not end until the main short
wave moves through Wednesday afternoon/evening.
Further information on how much precipitation could fall is
evident in the latest GEFS QPF ensemble members which have
anywhere from 0.40" to 1.8" for the Twin Cities area by Wednesday
afternoon, with the mean and current operational run (00z/23) of
0.80". Further to the south across Iowa, these ensemble members
increase to 1.0 to nearly 2.4" with a mean and operational run of
Past Thursday, the progressive pattern will continue with a long
wave trough across the west coast, and weak ridging across the
plains. This will lead to several fast moving short waves and
associated frontal boundaries across the Upper Midwest by the end
of next week, and into the weekend.
This mean upper flow regime will hold the near or above normal
temperatures profile through the first part of November over the
Upper Midwest. The orientation of the PNA and AO would also suggest
that the warm pattern will continue through the first week of
November. I don`t see any major cold waves until the PNA becomes
more positive or the AO becomes positive.
.AVIATION...(For the 18Z TAFS through 18Z Monday afternoon)
Issued at 116 PM CDT Sun Oct 23 2016
The stratus clouds that started in northern Minnesota this morning
have made steady progress to the south this afternoon and have
brought MVFR ceilings to most of the TAF sites. The clouds will
hang tough this afternoon as they are being reinforced by cool air
moving across the area. Late this afternoon or early this evening,
we expect a slow thinning of these clouds and some of the
airports under cloud cover now will see the ceilings scatter out.
That being said, we`re getting to time of year where this happens
We think this 2500-3000kft ceilings will be in place for the
remainder of the afternoon and possible early evening. There are
a few thin spots in central MN and this layer where the clouds are
is forecast to slowly dry out with time, but it can happen quite
slowly this time of year.
/OUTLOOK FOR KMSP/
Mon Night...VFR. Winds becoming ESE at 5KT.
Tue...Becoming MVFR with -RA. Chc IFR late. Wind SE at 10G20kt.
Wed...MVFR/IFR with -RA early. Wind ENE at 5-10kt.
Thu...VFR. Wind W 5-10kt.