Scientific Forecaster Discussion
fxus63 kmpx 241754
Area forecast discussion
National Weather Service Twin Cities/Chanhassen Minnesota
1154 am CST Fri Nov 24 2017
Short term...(today and tonight)
issued at 345 am CST Fri Nov 24 2017
It is going to be a warm day with record temperatures possible.
Readings this morning are already in the 40s over much of the area,
with some mid 50s near the Buffalo Ridge. Msp has been knocking on
the door of 50 degrees and is near the warmest it's been all month.
Cloud cover is scant early this morning, except along the Canadian
border. A fair amount of sun is expected early this morning, but
increasing mid level clouds should begin mid to late morning
followed by a frontal passage this afternoon. A few showers or
sprinkles are possible near the front along and north of I-94. The
atmosphere is pretty dry below about 15,000 feet which should limit
the extent of the shower activity. Reduced pops into the low chance
range and kept them north of I-94.
Warm air aloft will remain in place throughout today, even several
hours behind the frontal passage. 925 mb temps of +10 to +13c will
reach as far northeast as the WI border. We should be able to mix up
to 850 or 800 mb per forecast soundings as mixing deepens and some
sun reemerges this afternoon behind the front.
Dry adiabatic mixing to those temperatures aloft signals low to mid
60s. The GFS is even warmer along the Minnesota river.
The following are records for today:
msp: 59 (2011, 1990)
stc: 56 (1990)
eau: 61 (1931)
Long term...(saturday through thursday)
issued at 345 am CST Fri Nov 24 2017
Little concern in the longer term with rather fast more zonal
west/east flow pattern to continue. Mild and dry weather for the
most part expected to continue. There are a couple of precipitation
threats for mid week but they appear minimal.
Degree of cooling behind the departing Friday trough is the real
question. Appears best shot of cooler air will drift to the east
with the southwest a bit cooler, but still mild through the
weekend. Dry high pressure builds over the region so light winds
will be the rule.
Next surge of Pacific air arrives Monday ahead of the next cold
front. GFS and European model (ecmwf) continue there very warm trend with 925mb
temperatures forecast to range from +12 to +14c across the
central cwa by Monday afternoon. We will likely see similar highs
Monday afternoon as was seen Friday afternoon. Only limiting
factor will be cloud cover and that appears to be rather limited
at the moment. Downsloping winds off the Buffalo Ridge will be an
issue as well as strong south/southwest winds develop out ahead
of the next cold front.
This front exits the area Monday night and it will likely go
through dry. Some cooling behind front but still questionable to
what degree. The models diverge on development of the next trough
moving across the western conus. The GFS continues more of a
split flow regime with the southern trough passing to the south of
the area Wednesday. The following trough is more amplified than
the the European model (ecmwf) and draws in cooler air headed into the weekend. The
European model (ecmwf) lifts the southern stream trough a bit farther north,
enough to the clip the southeast cwa Wednesday/Wednesday night.
Its following trough is more progressive and doesnt draw in much
cooler air. Ridging aloft and warmer air should return into next
Aviation...(for the 18z tafs through 18z Saturday afternoon)
issued at 1154 am CST Fri Nov 24 2017
Area of light rain is moving east quickly late this morning, and
there should be a couple hours of spotty light rain from west
central Minnesota to west central WI. Not all is reaching the ground
with some virga. South central Minnesota will just see some broken mid
clouds and mostly aloft echoes, though a few showers may reach the
ground. After precip clears, expect mostly clear skies.
Other concern is wind. Direction will vary between west and
northwest, but should mostly be northwest this afternoon in Minnesota,
and become northwest by mid/late afternoon at Keau and krpd.
Gusts over 20 knots are also expected this afternoon with gradient
and some mixing.
Kmsp...winds will mostly be west-northwest this afternoon with
some gusts over 20 knots. There may be some lesser winds at times
down to 7-8 knots, but the weaker winds shouldn't last very long.
Also, few showers are possible but they would be light. Showers
will be a little more prevalent north and east of kmsp.
/Outlook for kmsp/
Sat...VFR. Winds northwest 10g20 kts.
Sun...VFR. Winds northwest 5-10 kts.
Mon...VFR. Winds S at 10g20 kts.