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Area forecast discussion 
National Weather Service northern Indiana
329 PM EST sun Feb 14 2016

issued at 307 PM EST sun Feb 14 2016

Snow will continue to overspread the area late this afternoon and
continue into early Monday as an upper level system moves through.
Snowfall totals from this system will generally range between 1
and 3 inches. Temperatures will continue to slowly rise tonight
from the teens and lower 20s in the evening, to the middle and
upper 20s by dawn Monday. Another weak upper level trough will
move into the area on Monday, possibly causing some light snow,
mainly across eastern portions of the area, but little or no
additional accumulation is expected. Southerly winds will persist
Monday allowing for considerably warmer temperatures than today,
with highs generally in the middle 30s.


Short term...(this evening through monday)
issued at 307 PM EST sun Feb 14 2016

Vorticity maximum moving into western Illinois this afternoon will continue to shear out as it
moves east across our area overnight. Although best forcing and
moisture transport associated with the low level jet will bypass our area
to the south, there is rather strong 500-300mb q vector
convergence moving into the area ahead of the vorticity maximum and modest
warm air advection implied by kiwx/amdar veering wind profiles aiding uvm and
allowing area of snow to advance east-NE across western portion of our
County Warning Area this afternoon. With system weakening as it moves through the area, snow
chances peak early tonight, then gradually decrease overnight. No
significant change in forecast amounts with storm totals from this afternoon to
late tonight generally 1-3", highest SW County Warning Area and lowest NE. Warm air advection
overnight should result in temperatures slowly rising from the
teens/l20s in the evening to the M-u20s by dawn.

A weaker shortwave will move into the area on Monday while low level
warm air advection continues. Given weak forcing with this feature and middle level
moisture scoured out by tonight's system, just maintained
chance/schc pops, mainly across eastern portions of the County Warning Area. Some
potential for precipitation to change over to liquid Monday as middle level
moisture diminishes, however, bufr soundings suggest low levels
will remain unsaturated, allowing for some evaporational cooling
which would support snow grains as opposed to drizzle/freezing
drizzle, so no change to ptype forecast at this time. Continued low level warm air advection
should allow temperatures to rise into the m30s on Monday.


Long term...(monday night through sunday)
issued at 307 PM EST sun Feb 14 2016

Main item of note for this long term period is potential for snow
late Tuesday. Models continue to struggle immensely with exact
placement and strength of compact pv anomaly set to dive across
the Ohio Valley on Tuesday. Much of the parent jet energy is still
offshore and confidence in any one solution remains low. General
trend of the 12z guidance was for a weaker and further south
solution...although 12z GFS still paints a decent swath of light
snow across our southern counties. Did not change inherited
forecast much with middle to high range chance probability of precipitation. Given southern
and slightly weaker trend in latest deterministic well
as potential for surface temperatures in the low to middle 30s...suspect any
snow amounts will be light and impacts minimal...if at all. Will
continue to keep an eye on it though. Still expect precipitation shield
of lead wave to stay just east/southeast of our County Warning Area border Monday night but
did carry some low chance probability of precipitation for the Lima area.

Rest of the long term relatively quiet. After a brief shot of weak
cold air advection on Wednesday...still expect temperatures to shoot into the 50s by Friday
given eastward fold of Stout Central Plains ridge and strong warm air advection. A
few rain showers possible on Friday...along with windy conditions as
surface low swings through the Great Lakes. Postfrontal airmass not
particularly colder and appears mild weather will persist through
next weekend.


Aviation...(for the 18z tafs through 18z Monday afternoon)
issued at 1147 am EST sun Feb 14 2016

Area of snow over Iowa/Illinois associated with middle level vorticity maximum and
low level warm air advection will move east and impact the terminals this
aftn/eve. Some shearing out of the system expected as it moves
east over the next 24hrs and into very dry airmass, so stuck with
conditions lowering to IFR per previous tafs as opposed to LIFR
which currently is occurring upstream in IL/IA. Winds will veer
from southeast to south as a weak surface trough reflection lifts north across
Indiana tonight. This weak southerly flow will likely cause low
ceilings moving into the area with the snow this afternoon to persist
through the end of the taf period.


Iwx watches/warnings/advisories...


short term...jt
long term...agd

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