Scientific Forecaster Discussion

Return to Local Conditions & Forecast

Without Abbreviations
With Abbreviations

Area forecast discussion...updated 
National Weather Service Aberdeen South Dakota
608 am CST Sat Feb 6 2016

Update...
issued at 605 am CST Sat Feb 6 2016

12z aviation discussion updated below.

&&

Short term...(today through Monday afternoon)
issued at 421 am CST Sat Feb 6 2016

Main story for today is the abnormally warm air that will push east
into the County Warning Area throughout the day. Increased highs a few degrees
across the region based on the latest forecast 925mb temperatures by late
this afternoon. Should also see decent mixing winds...especially
over central South Dakota. There are some cirrus clouds rounding the upper
ridge axis and beginning to slide southeast into the Dakotas. If a
thick cirrus shield materializes today...highs may fall a few
degrees short of forecast. But if we see mostly sunny skies...then
widespread middle/upper 40s to low 50s will be common.

Attention then turns to the increasing winds tonight through
Sunday...and the possible blizzard conditions over the far eastern
County Warning Area. Decided to upgrade the high wind watch to a warning based on
the continued impressive low level wind fields and BUFKIT soundings.
Moved up the start time of the warning to start things this
evening/overnight over central South Dakota. Struggled with this though as it
appears there will be an initial surge of strong winds will the
frontal passage...then perhaps a lull for a good chunk of the night
before winds really pick up again Sunday morning. Day shift may want
to make further adjustments but tried to capture the initial wind
surge and possible strong winds maybe in more of the advisory levels
overnight. Strong winds will continue through the day Sunday...with
gusts around 65 miles per hour possible over central South Dakota.

Other concern is the snow possibility on Sunday over the far eastern
County Warning Area and the possible blizzard conditions when you combine this with
the strong winds. Models continue to bring some light snow accums to
the eastern County Warning Area perhaps in the 1 to 2 inch range...although there
may have been a slight eastward move with the western fringe of the
wrap around snow. Expect there to be some convective elements/snow
showers during the day Sunday with some heavier bursts of snow. Its
within these heavier snow showers where blizzard conditions can be
expected. In fact...the NAM soundings in BUFKIT are actually showing
some minimal amounts of cape over the eastern County Warning Area Sunday afternoon.
Will continue with the watch at this point as there is still
uncertainty as to the areal coverage of light snow/snow showers and
just where the western fringe of precipitation potential sets up. Any
eastward movement in the low could keep a lot of the precipitation further
east so will wait until 12z model runs come in.

Long term...(monday evening through friday)
issued at 421 am CST Sat Feb 6 2016

The models continue to have very good agreement and have been
consistent with the upper level flow pattern across the US through
the long term. The period starts out with a large upper level high
pressure area over the western US with large troughing across the
eastern US. This upper level flow weakens through the period as it
pushes slowly east through Friday. At the end of the week
..troughing moves into the West Coast. This pattern puts our region
east of upper ridge and in northwest flow through the period. At
this time...the models show two decent clipper systems moving
southeast across our region for Tuesday night and Wednesday and
again Thursday night and Friday. The first one passes across eastern
South Dakota while the second one passes farther west across southwest South Dakota.
These two clippers will bring chances of light snow. If models
remain consistent...we may have to increase probability of precipitation with these systems.
Otherwise...our region will remain in the battle zone between colder
Canadian air and milder Pacific air. Temperatures across our County Warning Area
will vary widely from west to east. For most of the period
..temperatures will vary from the upper teens to lower 20s far east
in the County Warning Area to the upper 30s to the lower 40s far west.

&&

Aviation...(for the 12z tafs through 12z Sunday morning)
issued at 605 am CST Sat Feb 6 2016

VFR conditions are expected at all locations through today and
tonight. The main issue during this taf period will be the
increasing winds as a strong surface low pressure area slides
southeast out of Canada through tonight into northern Minnesota.
This will bring a tightening surface pressure gradient along with
very strong winds off the surface mainly tonight. Therefore...expect
west to northwest winds to increase to 20 to 30 knots with gusts up
to 40 knots tonight.





&&

Abr watches/warnings/advisories...
South Dakota...High Wind Warning from midnight tonight to 9 PM CST Sunday for
sdz004-005-009-010-016-017-034>037-045-048-051.

Blizzard watch from Sunday morning through late Sunday night for
sdz007-008-011-019>023.

High Wind Warning from 5 PM this afternoon to 8 PM MST Sunday for
sdz003-015-033.

High Wind Warning from 6 am to 9 PM CST Sunday for sdz006-018.

Minnesota...blizzard watch from Sunday morning through late Sunday night for
mnz039-046.

&&

$$

Update...mohr
short term...tmt
long term...mohr
aviation...mohr

National Weather Service Glossary of Abbreviations