National Weather Service Twin Cities Area Forecast Discussion

Data Provided by the National Weather Service

FXUS63 KMPX 271118

Area Forecast Discussion
National Weather Service Twin Cities/Chanhassen MN
518 AM CST Mon Jan 27 2020

.SHORT TERM...(Today through Tuesday)
Issued at 313 AM CST Mon Jan 27 2020

If you like cloud cover, we continue to have the weather for you! A
stagnate airmass is expected to remain in place through the short
term as the southern stream jet remains active along the Gulf Coast
and the northern stream stays way up across the Canadian arctic.

Upper wave that passed over Sioux Falls overnight failed to produce
any precip over MN, so we were able to cancel the winter weather
advisory in western MN early. With no appreciable forcing through
Tuesday, this period will go off dry. As for clouds, forecast
soundings from the GFS in particular would say we could punch some
holes in the stratus on Tuesday, but given the time of year and
limited mechanical mixing we`ll have from light winds, the safest
course of action to take is assume the clouds will remain in place
and likely remain in place for a few more days to come. Beside the
clouds, given the low level moisture in place, we`ll also have to
deal with some haze/fog as well Monday night, though the HREF/NBM
are both much more optimistic on their vis forecasts for Monday
night than they were for Sunday night. Think the only way we get fog
is if a location looses the stratus and with stratus expected to
reign through the short term, the fog threat will continue to be low.

For temperatures, we have seen enough cold air get advected in to
knock about 5 degrees off our highs/lows the next couple of days,
with highs only expected to be in the 20s, while lows only drop off
4-8 degrees given the expected cloud cover.

.LONG TERM...(Tuesday night through Sunday)
Issued at 313 AM CST Mon Jan 27 2020

The split flow regime will continue next week keeping the bulk of
the active weather, associated with the southern jet, along the
southern tier of the nation. Two waves of energy move across the
Upper Midwest next week. The first remains dry, as most of the
energy moves southeast across the central plains by Wednesday. The
second wave will dive southward across southern Canada and into
the Upper Midwest by late in the week. Both the EC/GEM are
stronger with this wave compared to the GFS. However, limited
moisture should keep anything minor and uneventful. It will remain
cold enough so the precipitation type will be snow vs. freezing

A big change develops across the west coast by the end of the week,
and into the weekend. A very anomalous upper ridge begins to build
across northern California with record warmth possible in this
region. This ridge will lift the active northern jet stream well
north into Canada by the weekend. Only the southern jet will be
active, especially in the Gulf region. This upper ridge that
builds across California late in the week will also spread the
warmth eastward across the Rockies and into the plains over the
weekend. Over the past few days, the warmth of this dome of high
pressure aloft has been well advertised. Both the EC/GFS are
showing very anomalous high (1000/850MB) temperatures spreading
across the plains late in the weekend. Percentiles (>99%) and
return intervals (every 10 year or greater) both support a rare
event with the amount of warmth expected in the central plains by
Sunday/Monday. How far north this warmth spreads remains
questionable, but it looks as though the warmest temperatures will
be south of Minnesota. Either way, it will be very warm for the
first couple of days of February, with readings approaching, or
exceeding 40 degrees across southern Minnesota.

Past this warm period, the much anticipated cool-down is still
expected, with more normal readings after the 4th of February.


.AVIATION...(For the 12Z TAFS through 12Z Tuesday morning)
Issued at 518 AM CST Mon Jan 27 2020

IFR/MVFR cigs will go nowhere today, thanks in large part to the
light winds and limited mixing expected. If we were to see any
cloud openings overnight, they would likely fog in pretty quick,
but with stratus expected to remain strong, not anticipating fog

KMSP...Not really seeing any guidance popping cigs above 017 until
Tuesday morning. Until we start seeing otherwise with the clouds,
will forecast them to remain in place with nothing more than a
diurnal trend in heights.

Tue-Thu...MVFR cigs/chc IFR. Winds lgt and vrb.





NWS MPX Office Area Forecast Discussion