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Area forecast discussion 
National Weather Service northern Indiana
641 PM EST Friday Mar 6 2015

issued at 355 PM EST Friday Mar 6 2015

A pair of clipper systems will move through the Great Lakes
through the weekend. The second...stronger system...will bring
just a slight chance of rain or snow to the southern Great Lakes
Sunday afternoon. The much anticipated warming trend will
continue. Lows overnight will only dip back into the lower to middle
20s. Highs on Saturday will push into the upper 30s to lower 40s.


Short term...(this evening through saturday)
issued at 353 PM EST Friday Mar 6 2015

4-5mb/3hr fall/rise couplet approaching along with ample early
March insolation leading to Lower/Middle 20kt gusts this afternoon with
continued upward trend of surface temperatures with highs likely around 22 UTC.
Lack of full decouple/continued low level warm air advection should keep surface temperatures
from plunging overnight...and favored 3 hrly temperature curve modified
only partly towards latest blends including short/higher res
guidance. Negligible moisture associated with first upstream high belted
clipper system with surface low moving through northestern James Bay. This
frontal boundary/associated wave becomes stretched/diluted in deference
to stronger upstream/southern Saskatchewan clipper. Similar wind gusts tmrw
anticipated given near identical isallobaric
differential...perhaps a bit hir owing to slightly deeper mixed
layer. Held line on probability of precipitation and lowered cloud coverage over a blinded
blended approach as models appear overzealous in blyr
saturation...espcly in light of dry regional/upstream dd/precipitable water and
lack of snowpack for minor sublimation and melt
where snowpack/piles are in contact with paved sfcs.
Furthermore...southern trailing fringe of height falls associated
with Sat system becomes quite negligible across southern Great Lakes leaving
primary succinct hfc to track from Lake Superior-lake ont 12 UTC Sat-00 UTC
sun. This appears to be in line with gradual retreat of northern
longwave trough and return toward normalcy/strong insolation across
southern tier states. Given 925mb 0c isotherm northeastward penetration into
all but far northestern County Warning Area by late Sat afternoon have continued slight upward
nudge to prior forecast maximum temperatures.


Long term...(saturday night through friday)
issued at 353 PM EST Friday Mar 6 2015

Benign stretch of weather is expected to continue Sunday into
next week as troughing/lower amplitude west-northwest flow relaxes and polar
jet shifts off to the north. This will afford a rather
substantial moderating trend and gradual melt off of snow with
middle-week highs likely approaching 50f. Only threat...albeit
low...for any light precipitation looks to be Sunday afternoon/early evening across
the north as corridor of warm advection tied to a weak clipper
system progresses through. Dry otherwise with a slight cooldown
possible by later Wednesday night-Thursday behind a backdoor


Aviation...(for the 00z tafs through 00z Saturday evening)
issued at 637 PM EST Friday Mar 6 2015

Low pressure was over western Quebec with a trough southwestward into Iowa this
evening. Upstream observation suggest models are too moist in low levels along
the trough... thus... maintained VFR forecast in tafs overnight and
Saturday morning. Another low over southern Manitoba will move southeast to
southeastern Ontario Saturday with a trailing cold front moving through northern
Indiana in the afternoon. Some lower ceilings are evident in the vicinity of
this front so forecast MVFR ceilings late in the period with SW winds
shifting to west-northwest as front moves through.


Iwx watches/warnings/advisories...


short term...Murphy
long term...steinwedel

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