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Area forecast discussion 
National Weather Service northern Indiana
327 PM EDT Wed Oct 26 2016

issued at 323 PM EDT Wed Oct 26 2016

Expect showers to move across the area this evening with a
diminishing trend overnight. Low temperatures tonight will drop
into the 40s. Clouds will linger much of the day Thursday and high
temperatures will only reach the upper 40s north and the middle
50s south. It will begin to warm up again on Friday with highs
returning back to the 60s over most of the region.


Short term...(this evening through thursday)
issued at 322 PM EDT Wed Oct 26 2016

Precipitation across northeast Illinois and Northwest Indiana ahead of
potent short wave and surface front. Strong low level jet and ample
low level moisture coupled with upscale lift near frontal boundary
producing rain and embedded tsra. Regional radar mosaic shows this
area already well into northwest County Warning Area at 19z and extending southwest.
Hires guidance has been lagging a few hours and keeps weakening pcpn
as it moves east. While radar mosaic does show a slight diminishing is not as much as models indicate. Expect most of this
rain to continue a steady eastward movement across County Warning Area into the
early evening before exiting the east by mid to late evening. Drying
to take place overnight but low stratus deck and moisture may lead
to light showers or drizzle late tonight and early Thursday. For now
kept a slight chance pop in western areas to account for this. Will
allow night shift to monitor drizzle/light shra trends for any
additional expansion after 12z/Thu. Trajectories behind surface low
to remain cyclonic Thu morning with sfc-850mb Delta T/S to around 13-
15c. Could see some very light showers or sprinkles off the lake but
moisture depth rather shallow and not worthy of a measurable pop at
this time. With this cyclonic flow and trapped moisture expect Perma-
cloud to linger during until at least late in the day.


Long term...(thursday night through wednesday)
issued at 322 PM EDT Wed Oct 26 2016

Several short waves and associated surface waves will pass by mainly
to our north through the long term period. This will keep our area
in a relatively warm pattern for late October and early November
with still no signs of any significant cold air infiltrating the
region. Models continue to fluctuate on weak trailing boundaries
south of these fast moving northern stream waves and pcpn chances
associated with each through the week. Inherited blends rather
benign and see no reason to really add any pops given the pattern
and lack of strong forcing with best dynamics and moisture to our
north. Temps to remain well above normal through the period and
already reflected in grids.


Aviation...(for the 18z tafs through 18z Thursday afternoon)
issued at 135 PM EDT Wed Oct 26 2016

A potent low pressure system will track through the southern Great
Lakes during the taf period. Rain showers currently on radar will
impact ksbn near the onset of the period and kfwa a few hours
later. Thunder chances are minimal and any lightning observed over
the past several hours has been well south of the terminals. Given
little to no instability despite strong forcing, left out thunder
in tafs. Cold front swings through with winds veering from
southeasterly early to west/northwesterly late. Low level wind shear possible for
a brief time, particularly at ksbn, with calming winds during the
frontal passage overnight. Moist boundary layer and subsidence
inversion will keep low clouds entrenched across the area behind
the front, with confidence increasing in IFR ceilings, possibly
LIFR at ksbn.


Iwx watches/warnings/advisories...
Lm...Small Craft Advisory until 11 PM EDT this evening for lmz043-046.


short term...Lashley
long term...Lashley

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