Area Forecast Discussion
Issued by NWS Twin Cities, MN

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FXUS63 KMPX 241057

Area Forecast Discussion
National Weather Service Twin Cities/Chanhassen MN
557 AM CDT MON OCT 24 2016

.UPDATE...For 12z Aviation discussion below


.SHORT TERM...(Today and tonight)
Issued at 300 AM CDT Mon Oct 24 2016

The surface ridge of high pressure that settled into the area
overnight will bring a dry and mild day with light winds and mostly
sunny skies. With little in the way of mixing, temperatures will max
out right around seasonal normals, with readings in the low to mid
50s this afternoon.

This evening clouds will be on the increase as the aforementioned
high slides off to the east and isentropic lift ensues ahead of the
approaching wave. There could be a few showers developing between
09z and 12z Tuesday, although the majority of the precipitation
should hold off until after daybreak.

.LONG TERM...(Tuesday through Sunday)
Issued at 315 AM CDT Mon Oct 24 2016

Confidence remains high for widespread precipitation to develop
Tuesday, and continue through Tuesday night, early Wednesday. As
with previous forecast concerns, timing with the onset of
precipitation Tuesday, especially across eastern Minnesota and
western Wisconsin, remains problematic. This is mainly do to
initial dry air mass across the Great Lakes advecting drier air
westward across the our region Tuesday. Overall, models have
depicted heavy QPF amounts with the system, but have tapered off
across central Minnesota over the past several runs. This decrease
or tapering off of the heavier QPF amounts is related to a slight
shift southward of the surface low across Iowa. There is no
question that all of MPX forecast area will get wet, the main
question is where the heaviest QPF amounts develop. The best time
frame for heavy rainfall will occur Tuesday evening as the best
lift and moisture advection resides across southern Minnesota.
This axis of heavier rainfall will shift to the east late Tuesday
night, early Wednesday, with a general tapering off of the light
rainfall Wednesday morning from eastern Minnesota, into west
central Wisconsin.

Past Wednesday, model spread increases as the mean upper flow
becomes slightly west-northwest across the Upper Midwest. The
larger spread of the ensembles means that confidence in the
forecast is low.

Overall, the 50H /5-day mean of the GFS, EC, CMC/ model run has
the upper level pattern continuing to depict a long wave trough
over the eastern Pacific and eastern Canada through next weekend.
In between, a weak ridge dominates the southern Plains, and desert
southwest. As mentioned before, the Upper Midwest has a slight
west-northwest flow later this week, and into the weekend. This
type of flow does support weak short waves riding southeast across
the Upper Midwest, and some of the model solutions do support
light precipitation late this week, and next weekend.

Although confidence remains low on temperatures past Wednesday,
based the mean upper pattern and the core of the coldest air
remaining across Canadian, no significant cool down is expected
through the first week of November. Even the CFSv2 /Climate
Forecast System Ensemble/ supports the warmer temperatures across
the Upper Midwest through the first week of November. Beyond the
first week of November, the CFSv2 shows some cooling over the
central part of the U.S. with the core of the warmest air holding
across northern Canadian.


.AVIATION...(For the 12Z TAFS through 12Z Tuesday morning)
Issued at 557 AM CDT Mon Oct 24 2016

After the areas of fog lift this morning, prevalent VFR conditions
are expected as surface high pressure yields light winds and
fleeting few-sct cirrus clouds. Precipitation will likely arrive
early in the next period (Tuesday morning).

High confidence in VFR through period.

Tue...Becoming MVFR with -RA. Chc IFR late. Wind SE at 10G20kt.
Wed...MVFR/IFR with -RA early. Wind ENE at 10kt.
Thu...VFR. Wind VRB 5kts.


.MPX Watches/Warnings/Advisories...


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