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Area forecast discussion 
National Weather Service northern Indiana
635 PM EST Wednesday Nov 26 2014

Synopsis...
issued at 333 PM EST Wednesday Nov 26 2014

A fast moving system will bring a reinforcing shot of cold air to
the region Friday morning. Lake effect snow showers are expected
in the wake of this system across parts of far Southern Lower
Michigan and Northwest Indiana. Lows tonight will drop into the
middle 20s. Thanksgiving day highs will reach the lower to middle
30s.

&&

Short term...(this evening through thursday)
issued at 332 PM EST Wednesday Nov 26 2014

Stratus was finally beginning to erode in SW sections and a narrow
area of drier air was winning out. Upper low over southeast Iowa will
continue to drift slowly southeast reaching portions of Kentucky by
12z Thursday. Cloud cover will fill back in again this evening persist
into the overnight hours and beyond as next wave...currently over
northern Minnesota...drops southeast and forces a frontal boundary across
the region later tonight into Thursday. Hi res models show a nice
band of focused Omega and moisture which will start over portion of NE
Illinois and then drift east into northwest parts of the area in the 9 to
12z Thursday window and then rapidly shift east through 18z Thursday. Will
continue with slight chance to chance probability of precipitation for snow showers across much of
the area along and in the wake of the Front. Lake effect snow bands
will attempt to organize and expand inland as favorable fetch
between 290 and 320 degrees sets the stage for locations as far
south as US 6 and far east as Route 13/US 131. Moisture will be
somewhat limited in the morning but favorable inversion heights above
7000 feet and a few hundred j/kg of cape should allow for decent
coverage of snow showers. Accumulations look to be limited by
combination of 1) lack of Colorado-location of dgz and best
lift...2)limited moisture...3) surface temperatures in 30 to 33 degree range. As a
result...local accums of maybe an inch or 2 have been gridded up
with focus Thursday afternoon into evening. NAM/local WRF have been
persistent on bands setting up into 1 or 2 dominant bands that could
move well inland and drop into portions of Kosciusko and Noble
counties. Inversion heights will be slowly dropping by this time which
will also help limit accums (hopefully). Have went with likely to
Cat probability of precipitation through the afternoon and then increase probability of precipitation to high chance
Thursday evening with later shifts to monitor trends of models. Local
accums of 1 to 2 inches would be possible again...mainly Thursday
evening. Idea of an advisory was tossed around between here and kgrr
but was decided to hold off given concerns about exact positioning
and intensity of bands. Regardless...motorists may encounter rapid
changes in visibilities Thursday into Thursday evening in the above mentioned
area so allow a bit of extra time and monitor speeds when
approaching snow bands. Lows tonight will drop into the middle 20s with
highs Thursday heading towards freezing.

&&

Long term...(thursday night through wednesday)
issued at 332 PM EST Wednesday Nov 26 2014

Still looks like a relatively quiet long term period with
temperature questions and fluctuations expected. Long term begins
Friday with warm air advection developing along with weak lift. Best
forcing and moisture still appears to be over north and northeast
County Warning Area so allowed middle chance probability of precipitation for light snow to continue there with
slight chance a bit further south. Surface temperatures to warm slowly but
expect readings on Saturday to reach well into 40s with 50s expected
on Sunday in warm sector.

Still some timing differences with next short wave and associated
surface front coming into the region. Temperatures should return to below
normal on Monday. Differences continue through next week with
baroclinic zone location. Models now hinting at a weak northern
stream wave that may keep colder air in place through Tuesday or
Wednesday. European model (ecmwf) was much colder than GFS and also much weaker with an
approaching middle week system. GFS indicating a strong low developing
in plains and moving into Great Lakes with warmer temperatures and
rainfall possible Wednesday into Thursday. Given model differences opted to
stay closer to superblend inits and general ensemble output for now.

&&

Aviation...(for the 00z tafs through 00z Thursday evening)
issued at 632 PM EST Wednesday Nov 26 2014

MVFR ceilings in place over the area this evening should predominate
during this taf period. Low level flow will veer northwesterly overnight
as low pressure moves east-southeast from MO and stronger low off the middle
Atlantic coast moves north-northeast. Shortwave moving east-southeast across the Great Lakes should
cause scattered -shsn across northern Indiana by Thursday with lake effect
enhancement resulting in highest impact at ksbn where some periods
of IFR conditions are possible. Steepening low level lapse rates and
incrsg pressure gradient should also result in considerably
stronger winds Thursday with some northwest gusts in the 20-25kt range.

&&

Iwx watches/warnings/advisories...
in...none.
Michigan...none.
Ohio...none.
Lm...Small Craft Advisory from 7 am Thursday to 4 am EST Friday for
lmz043-046.

&&

$$

Synopsis...Fisher
short term...Fisher
long term...Lashley
aviation...jt



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