Area Forecast Discussion
Issued by NWS Louisville, KY

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FXUS63 KLMK 271046

646 AM EDT Fri Mar 27 2015

...Updated Aviation Discussion...

.SHORT TERM (Now through Saturday)...
Issued at 300 AM EDT Fri Mar 27 2015

A deep upper trough will cross the region today. Water vapor shows
this feature nicely. Forecast soundings still show some sharper
lapse rates as this feature crosses us, as well as a brief period of
ice crystal growth. Timing for this crossing looks to be during peak
heating, so the chance for snow mixing in with rain looks to be
limited. Precipitable water is pretty low with this system as well,
so the chance for measurable precipitation consequently is low.

As for temperatures today, we should see the 40s for most locations.
Skies should clear out quickly as the trough axis shifts to our
east. As northwest winds pour in colder air, most sites should see a
hard freeze by daybreak Saturday, with lows in the lower 20s.
Surface high pressure will become centered over the region by the
end of the day Saturday, but despite sunshine highs look to struggle
to reach 40 degrees, near record cold maxes for the day.

Record Cold Maxes for Next Couple of Days:
     Mar. 27   Forecast     Mar. 28   Forecast
     (year)                 (year)
SDF  32 (1947) 44           41 (1916) 42
LEX  29 (1947) 43           37 (1947) 39
BWG  33 (1947) 46           39 (1899) 44

.LONG TERM (Saturday Night through Thursday)...
Issued at 240 AM EDT Fri Mar 27 2015

The long term will begin with dry weather and unseasonably cold
temperatures a high pressure slides across the region. Aloft
northwesterly flow will continue into mid week then transition to
more a more zonal flow.

As mentioned above, surface high pressure will slide across the
region overnight. This high will be east of the forecast area by
daybreak Sunday with winds shifting to southerly. This should keep
temperatures from completely bottoming out. Regardless, a hard
freeze looks likely with lows in the lower to mid 20s.

A cold front will begin to approach from the northwest on Sunday and
move through the area Monday morning. Southwesterly winds will
advect in warmer air Sunday with temps rising into the 50s. A few
showers will be possible across southern IN late in the afternoon
Sunday with the best chance for rain overnight Sunday into Monday.
Moisture return doesn`t look that great with this system, so will
continue to carry scattered showers as opposed to likely coverage.

Some lingering showers in the east will move out by mid day Monday.
High pressure will once again bring dry weather through Tuesday
night. The next front looks to move through on Thursday sometime.
Ahead of this, southerly winds will once again usher in warmer and
moister air. A shortwave moving through during the day on Wednesday
could spark some showers or thunderstorms as soundings indicate we
could see weak surface based instability developing. Showers will
increase along and ahead of the front Wednesday night with a few
thunderstorms continuing to be possible. This precip will move out

Temperatures next week will be above normal Tuesday through
Thursday. Highs will range from the mid 60s to lower 70s. Lows will
range from the lower 40s Tuesday morning to the lower 50s by
Thursday morning.


.AVIATION (12Z TAF Update)...
Issued at 645 AM EDT Fri Mar 27 2015

Have some lower-end VFR vsby`s out there this hour, and may see a
couple hours below especially at BWG. Otherwise, an upper level
disturbance still looks to move into the region this afternoon,
bringing additional cumulus clouds as well as some isolated showers.
Think the best chance is down at KBWG, so have put vicinity wording
in for now this afternoon. Ceilings may briefly go into the MVFR
range as that moisture moves into the other sites as well. Expect
better conditions tonight.




Short Term........RJS
Long Term.........EER
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