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Area forecast discussion 
National Weather Service Twin Cities/Chanhassen Minnesota
641 PM CDT Friday Oct 9 2015

Short term...(this evening through saturday)
issued at 343 PM CDT Friday Oct 9 2015

Light northwesterly winds will gradually become south southwesterly
tonight as the surface ridge slides east while an area of low
pressure develops across the Lee side of the northern rockies. The
forecast is dry.

Early afternoon water vapor imagery together with GFS 500mb heights
and surface analysis showed a strong 965mb middle latitude cyclone
crashing on shore the British Columbia coast. This cyclone was the
downstream result of a 160kt jet rounding the base of a longwave
trough over the Gulf of Alaska. Systems of this magnitude are
certainly a sign of fall...and the weather that will follow in the
extended period holds true to that as well. Until that time...the
upper Midwest will be in the warm sector of a developing surface low
..with anomalously high h850 temperatures of 15 to 20c
overspreading the region on Saturday. Did not make any significant
changes to the previous forecast...other than to bump up temperatures in
western Minnesota a degree or two. The warm dry weekend remains on track.

Long term...(saturday night through friday)
issued at 343 PM CDT Friday Oct 9 2015

The next seven days will be nearly precipitation-free and besides a
strong cold front that is expected to move through the area Sunday
night into Monday...the weather will be mild and tranquil.

An anomalously strong system even by October standards arrives
Sunday into Monday. The warm sector of the system on Sunday will
bring near-record warm to Minnesota...and well above normal temperatures
to Wisconsin...followed by a sharp cool down and 30-50mph winds
Sunday night into Monday with a cold frontal passage. The warmest
air at 850mb will remain in western Minnesota with values approaching
23-24 c. Using the gefs standardized anomalies...the air mass
in western Minnesota would be in the ballpark of the 99
percentile...with the remainder of the forecast area 95-99
percentile. surprise we are expecting high temperatures to
flirt with our record daily highs that are in the middle 80s on

The warm-up will be followed be a strong autumn cold front that
will drop temperatures 20-25 degrees on Monday and bring strong northwest winds
with the cold advection beginning late Sunday night. The top of
the mixed layer off the forecast NAM soundings have winds between
40-50kts in western Minnesota...and closer to 40 kts in eastern Minnesota and
WI. We will probably end up with solid Wind Advisory criteria
during this time /sustained winds of 30 miles per hour or gusts to 45 mph/.
According to the naefs and gefs...the wind is not as anomalous as
the temperatures on Sunday and the cold advection on Monday is
quite normal for October. So...the warm-up is definitely the more
unusual component to this system based on modeling/climatology.


Aviation...(for the 00z tafs through 00z Saturday evening)
issued at 641 PM CDT Friday Oct 9 2015

VFR conditions through the period. Gusty southerly winds will
increase quickly on Saturday due to a tightening pressure
gradient. Sustained speeds of 15 to 20 knots are likely along with
gusts from 25-30 knots. The top end wind speeds and gusts are most
likely west of the Twin Cities through krwf.

Kmsp...few concerns through the period. Southerly winds gusting
to around 25 knots from late morning through the afternoon on

/Outlook for kmsp/
sun...VFR. Winds SW 10-15 kts.
Monday...VFR. Winds northwest 20-25g35 kts.
Tuesday...VFR. Winds SW 5-10 kts.


Mpx watches/warnings/advisories...


Short term...jrb
long term...clf

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