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Area forecast discussion 
National Weather Service northern Indiana
739 PM EST Wednesday Dec 17 2014

issued at 730 PM EST Wednesday Dec 17 2014

Occasional lake effect snow flurries and light snow will continue
through Thursday...but little to no snow accumulation is expected.
Another upper level system will approach the region Thursday and
weaken as it lifts into Indiana during the afternoon bringing a
slight chance of some light snow. Low temperatures tonight will
drop into the middle 20s...with high temperatures on Thursday
reaching back into the lower 30s.


Short term...(this evening through thursday)
issued at 240 PM EST Wednesday Dec 17 2014

Current trough swinging across the Great Lakes this evening is
showing some erosion in the cloud deck behind it across western
Illinois. The question is how far east this partial clearing moves
towards our area while at the same time Southern Plains clouds
advance northeast toward that clearing patch. End result may be
some brief and partial clearing for some of the southwest

The light snow that has been occurring will be carried as a chance
throughout the night in the same areas currently affected. Still
expect no more than a light covering of snow at worst for some
areas. Mainly cloudy sky and flow turning more off the lake should
keep min temperatures to no lower than lower 20s tonight.

Thursday...the Southern Plains system is depicted by most models
to weaken as it moves into ridge behind current trough in our
area. Net result will be maintenance of cloud cover and low threat
for light...non-accumulating snow Thursday afternoon. Temperatures
will rebound little...climbing no more than lower 30s in the afternoon.


Long term...(thursday night through wednesday)
issued at 240 PM EST Wednesday Dec 17 2014

In the wake of Thursday trough exiting the area models show high
pressure building over the Great Lakes and air drying out
suggestive of diminished cloud cover. Hesitant to delve to far
into partly cloudy sky given persistence of low cloud decks
without much wind to scour them out. Minimum temperatures on track in
low to middle 20s and didn't change much.

Friday may show a few peaks at the sun with no weather to speak
of. This should allow maximum temperatures to reach middle and upper 30s under
light east wind.

Friday night into Saturday models continue the trend of next
approaching system to reach no further north than southern Indiana
with precipitation and an overcast sky for our area.

High pressure will essentially remain in control from Friday night
into Monday afternoon. Beyond that time frame fairly significant
system is expected to move into Midwest but latest trends are a
bit warmer leaning to more rain than snow. With high uncertainty
at times will keep a rain snow mix start converting to all rain by
Tuesday then back to a mix or all snow Wednesday. Again
uncertainty is high and many more model runs should sort this out.


Aviation...(for the 00z tafs through 00z Thursday evening)
issued at 730 PM EST Wednesday Dec 17 2014

Sheared upper level short wave will continue to shift east of the
area to the eastern Great Lakes tonight. This will result in some
subtle veering of low level winds to provide a favorable fetch for
some very light lake effect snow showers or perhaps pockets of
very light patchy drizzle/freezing drizzle. Any precipitation should be
quite light given strong middle level subsidence in wake of departing
wave and dry middle level profiles. While periods of flurries/lights
snow showers are possible through Thursday...timing remains quite
difficult to pin down...and with expectation of no accumulation or
notable visibility restrictions....will run with dry tafs for the 00z
cycle. Synoptic subsidence will keep inversion heights relatively
consistent and thus will maintain 2-3k feet ceilings through the period.


Iwx watches/warnings/advisories...
Lm...Small Craft Advisory until 11 am EST Thursday for lmz043-046.



short term...tucek
long term...tucek

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