Area Forecast Discussion
Issued by NWS Twin Cities, MN

Home | Current Version | Previous Version | Graphics & Text | Print | Product List | Glossary On
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
FXUS63 KMPX 132100

Area Forecast Discussion
National Weather Service Twin Cities/Chanhassen MN
300 PM CST Tue Feb 13 2018

.SHORT TERM...(This evening through Wednesday)
Issued at 245 PM CST Tue Feb 13 2018

After two weeks, temperatures have finally risen above normal.
Upper 20s, to lower 30s were widespread across central and
southern Minnesota, as well as west central Wisconsin. The main
concern tonight, and into Wednesday is the possibility of fog, and
stratus forming as some of the snow has melted and moisture near
the surface increases. The main issue is that humidity levels in
the boundary layer remain very dry this afternoon, or at least
drier than expected for the formation of fog/low clouds and
stratus. Therefore, kept clouds/fog to a minimum, and kept close
to previous highs in the 30s, and mid 40s across the region.
However, some of these readings could be a few degrees cooler if
the cloud cover is much greater.

.LONG TERM...(Wednesday night through Tuesday)
Issued at 255 PM CST Tue Feb 13 2018

The extended period continues to be uncertain in terms of
precipitation as the split flow regime remains over the CONUS.
Temperatures will be a roller coaster as highs drop back into the
teens on Thursday, but rebound into the 30s over the weekend. This
is due to the wavy pattern and a quasi-zonal flow aloft. Not until
late in the weekend, and into early next week does the flow
become more southwest aloft and the split flow regime abates some.

Confidence is high that a strong upper ridge will hold across the
Gulf of Mexico for later this week, and into the first part of
the weekend. This mean upper ridge will begin to move across
Florida, and over the Bahamas next week and strengthen. Thus, the
wavy pattern will become more southwest aloft across the southeast
1/3 of the nation. This southwest flow is a milder flow for our
region, and more unsettled in terms of getting more chances of
precipitation. In addition, with the milder flow aloft,
precipitation type may become an issue next week. This is
dependent on where the surface boundary is established and how the
mean flow around 5k becomes.

Even though the pattern from Wednesday night, through the upcoming
weekend is not conducive on anything widespread in terms of
precipitation, there are a few weak systems that may provide light
snowfall. One will occur Thursday as the interaction of the upper
jet and weak forcing develops briefly, and a slightly better
chance Sunday as a more pronounced surface boundary moves across
the area. Confidence remains low on either case, but depending
upon the orientation of the upper jet this weekend, and as the
flow slowly becomes more southwest, may allow for better
organization of precipitation.


.AVIATION...(For the 18Z TAFS through 18Z Wednesday afternoon)
Issued at 1120 AM CST Tue Feb 13 2018

Not much change from the previous TAFs issued at 12z with a chance
of MVFR cigs developing in central Minnesota this afternoon. It
will only affect KAXN/KSTC airport sites. Otherwise, the main
concern overnight is whether stratus/fog develops as moisture in
the boundary layer should continue to increase. Some melting of
the snow pack across Nebraska, Iowa should allow for the boundary
layer to moisten up, but will clouds form? Confidence remains low
on the development of lower cigs, but something to keep in mind
for the evening. South/Southwest winds of 10-15 kts, gusts of
20-25 kts will continue this afternoon, but abate this evening but
remain from the south during the next 24 hours.


No additional concerns, still low confidence on stratus developing


Wed Night...VFR. Chc MVFR late. Winds SW 5-10 kts, bcmg W.
Thu...MVFR. Chc -SN/IFR. Winds NW 15G20 kts.
Fri...VFR. Winds W 5-10 kts.




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