Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Twin Cities/Chanhassen Minnesota
300 PM CST Tuesday Mar 3 2015
Short term...(this evening through wednesday)
issued at 300 PM CST Tuesday Mar 3 2015
Blizzard conds did not materialize as predicted but there were a
few areas in west central that had temporary whiteout
conds...especially in areas that received 3-6 inches of snow
earlier today. Winds remained strong this afternoon with 25 to 35 miles per hour
sustained winds and gusts in excess of 45 miles per hour at times...especially
along the Buffalo Ridge in west central Minnesota. There was a small band
of 5-7 inches of snow that fell near Alexandria earlier today
where the strongest forcing aloft was noted. Elsewhere...a quick
1-4 inches of snow was common...especially in central Minnesota. Far
southern Minnesota actually had some freezing rain...but this was mainly
confined to Rochester.
Although winds will remain brisk tonight...gusty winds over 45 miles per hour
will drop off after sunset. As temperatures fall into the single digits
this evening...wind chill values will fall well below zero. A Wind
Chill Advisory has been issued based on temperatures falling into the
single digits below zero and sustained winds of 10 to 15 miles per hour
across west central to central and east central Minnesota. Elsewhere wind
chill values will fall to between 15 to 25 degrees below zero.
Not much change for Wednesday forecast as the Arctic high slowly
builds overhead. Temperatures Wednesday afternoon will be 20 to 30 degrees
below normal. Some clouds will develop in eastern Minnesota and western
WI...but no precipitation is expected.
Long term...(wednesday night through tuesday)
issued at 300 PM CST Tuesday Mar 3 2015
A very cold morning remains in store for the region on Thursday with
surface high pressure overhead along with a cold pocket near -22c at
850mb. Lows from 5 below to 15 below zero remain in the forecast.
Could this be our last below zero reading for the winter season? The
reason being is that over the past several days the GFS and European model (ecmwf)
have been advertising a pattern shift across the Continental U.S. From a deep
trough over the center of the country to one that is more zonal.
Between the beginning and end of the long term forecast...Thursday
through next Tuesday...500mb heights across the forecast area rise from 528dam
to 564dam. Blended guidance indicates highs climbing into the upper
30s and lower 40s during the weekend with 40s and even some 50s by
Tuesday. The warmest readings are most likely across southwest
Minnesota where snow cover is at a minimum and the surface winds are
west southwest off the Buffalo Ridge. Certainly a big change coming
by this time next week with longer term guidance showing the pattern
persisting into the following weekend. With the height rises and warm air advection
will come a few opportunities for some precipitation this weekend.
At this point...small probability of precipitation are in the forecast for Sunday as a low
pressure system passes eastward along the international border.
Otherwise...dry weather is forecast for the remaining period of the
Aviation...(for the 18z tafs through 18z Wednesday afternoon)
issued at 1115 am CST Tuesday Mar 3 2015
Last band of moderate/heavy snowfall in far eastern Minnesota...moving toward
the east-northeast at 45 kts late this morning. Some residual light snow is
evident behind the main bands in central Minnesota...but believe this is
more flurry activity with visibilities of 3-5sm. There is some convective
type reflectivity enhancement noted in far western Minnesota/eastern South Dakota
on regional radar where some localized snow showers will be
possible during the afternoon. This should also enhance the IFR visibility
in blsn in wc/SW/SC Minnesota. Confidence remains moderate with 1sm in
blsn at kaxn/krwf with a temporary period of 1/4sm blsn at krwf
due to the strong winds and some snsh. Elsewhere...strong northwest winds
will develop with some areas of 4-6sm in blsn. Conds should
improve this evening with gusty winds diminishing. No other
aviation concerns past 3z.
By 18z...only -sn is possible for an hour with more blsn reducing
visibilities temporary to 4-6sm through 1z. Otherwise...ceilings will lift to
VFR but strong northwest winds will develop. Expect winds of 18-22 kts by
middle afternoon with gusts up to 30 kts at times. These winds will
diminish this evening...but redevelop Wednesday afternoon along with
some MVFR ceilings. High confidence of visibilities becoming MVFR/VFR this
afternoon. Lower confidence on MVFR ceilings.
/Outlook for kmsp/
Wednesday nght...VFR. Winds west-northwest 5-10 kts.
Thursday...VFR. Winds SW 5-10 kts.
Friday...VFR. Winds west-southwest 5-10 knots.
Minnesota...Wind Chill Advisory from midnight tonight to 9 am CST Wednesday
Winter Weather Advisory until 6 PM CST this evening for mnz041-