Area Forecast Discussion
Issued by NWS Twin Cities, MN

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary Off
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44

FXUS63 KMPX 102314

Area Forecast Discussion
National Weather Service Twin Cities/Chanhassen MN
614 PM CDT Tue Oct 10 2017

.UPDATE...For 00z Aviation discussion below


.SHORT TERM...(This evening through Wednesday)
Issued at 346 PM CDT Tue Oct 10 2017

Early afternoon water vapor imagery together with GFS 500 mb
heights and winds identified a compact upper level low across
southern Iowa, with widespread synoptic ascent downstream across
eastern Iowa, southern Wisconsin, and northern Illinois. Regional
reflectivity with surface obs confirmed the precipitation, with a
few lighting strikes across the south where there was some
instability to go along with the forcing.

This precipitation will bring rain to the far southeast part of
the forecast area this afternoon and evening. Meanwhile areas to
the northwest had clear skies and light winds. This will set the
stage for another cool night across western and central Minnesota,
but have decided to discontinue frost/freeze headlines for this
region given that it is mid=October and most locations saw a
freezing temperatures last night.

Looking ahead, southerly winds will develop on Wednesday, and
forecast soundings show mid level clouds by mid afternoon across
eastern MN and western WI. Meanwhile western Minnesota should have
more sun. Highs on Wednesday will be in the upper 50s to near 60.

.LONG TERM...(Wednesday night through Tuesday)
Issued at 346 PM CDT Tue Oct 10 2017

The main focus of the long term remains the west coast trough and
the expected precipitation with it as it progresses eastward through
the weekend.  At this time, Saturday night looks to be our best
chance of appreciable rainfall.

The aforementioned trough will be pushing onshore tonight, and by
tomorrow night it will be over Oregon and Washington.  A surface low
will already begin to develop across Montana/southern Canada by this
time, and locally we can expect increasing southerly winds for
Thursday as the pressure gradient pushes eastward.  Low level
moisture advection looks quite strong tomorrow night into Thursday,
so did include a mention of drizzle across far southern MN.

From Thursday into Friday, the surface low itself will deepen and
move northeast through much of Manitoba.  Meanwhile the west coast
trough will have another reinforcing shortwave form which will take
a more southern route and is the feature to watch for us.  Lead
energy looks to bring rain across our southeast Friday, but the main
system arrives Saturday afternoon/evening and we do anticipate
widespread rainfall Saturday night.

After that system departs, warmer temperatures should return with
the end of the period looking like highs in the 60s are a reasonable


.AVIATION...(For the 00Z TAFS through 00Z Wednesday evening)
Issued at 614 PM CDT Tue Oct 10 2017

VFR conditions expected to prevail through the period with
showers skirting the southern fringes of the area this evening.
-SHRA could clip KEAU between 00z and 06z, but attendant
 conditions should remain VFR. Otherwise, expect an increase in
 mid-level clouds on Wednesday, lowering to low-end VFR during the
 afternoon. Winds will start off light then increase from the
 southeast on Wednesday afternoon. Gusts to 25 knots possible at

Clouds lower throughout the day but the ceiling is expected to
remain VFR through 00z Thu. Northeast winds around 6 knots or less
becomes easterly for Wed morning, then southeast for the afternoon
and increasing to around 10 kts.

Thu...VFR. Wind S 10 kts.
Fri...Mainly VFR. MVFR late with p.m. SHRA likely. Wind N 5 kts
becoming NE.
Sat...Mainly VFR. MVFR late with p.m. SHRA expected. Wind
ENE 5 kts.




AVIATION...LS is the U.S. government's official web portal to all federal, state and local government web resources and services.