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Area forecast discussion 
National Weather Service northern Indiana
807 PM EDT Thursday Aug 27 2015

issued at 805 PM EDT Thursday Aug 27 2015

High pressure overhead will move east through the lower Great
Lakes to the middle Atlantic region over the next few days. This will
allow temperatures to warm above normal by early next week. In
the meantime...a weak upper level system will bring a chance for
showers and thunderstorms this weekend. Lows tonight will be in
the lower to middle 50s. Highs Friday will range from 75 to 80.


Short term...(this evening through friday)
issued at 330 PM EDT Thursday Aug 27 2015

Quiet short term period with clouds and fog potential the main
issues. Fog and stratus from this morning has turned into an
extensive cumulus field this afternoon. Some breaks and clearing noted on
periphery along with cellular look on satellite so expect much of
this to dissipate early evening with loss of heating. Focus then
turns to any fog development again tonight. Surface high will be moving
east but winds will be calm or light and variable through midnight.
Slight gradient to develop late but still only should see winds in
the 3-5 knot range. With boundary layer still moist and dry air
aloft could still see some patchy fog develop but not expecting as
widespread or dense.

Light southwest wind should develop Friday with increasing high
clouds through the day. Deeper mixing with filtered sunshine support
MOS and 2m temperatures into the 70s during the afternoon.


Long term...(friday night through thursday)
issued at 330 PM EDT Thursday Aug 27 2015

Shortwave over Wyoming/Colorado this afternoon expected to move east to the upper MS
valley Friday night. Building ridges over the plains and East
Coast should cause this system to weaken and move slowly southeast across
the Midwest this weekend. Rather diffuse warm front and
accompanying 850 mb Theta-E advection expected to overspread northwest
portion of County Warning Area Friday night possibly resulting in scattered showers late.
Combination of building diurnal instability... slowly approaching upper
trough and lingering west-east oriented boundary ahead of the low should
lead to scattered showers/thunderstorms Saturday afternoon... greatest coverage
northern portion of County Warning Area... with some convection likely lingering
into Saturday night. Weakening trough should be over the County Warning Area Sunday
leading to a similar diurnal increase in convection... though
coverage probably less than previous day with highest probability of precipitation shifting
to southeast County Warning Area ahead of weak trough axis. By Monday this weak upper trough/cool
pool should be southeast of the County Warning Area with deep layer ridging building east
from the plains across the Great Lakes. This should result in little or
no deep convection/rainfall in our County Warning Area Monday-Thursday next week.

Temperatures expected to warm to close to normal over the weekend with
highs in the u70s/l80s and lows in the l-m60s. Building deep layer
ridging across the Great Lakes next week should cause above normal temperatures.
Light winds and little cloudiness in this time frame should result
in large diurnal ranges with lows in the l-m60s and highs in the M-


Aviation...(for the 00z tafs through 00z Friday evening)
issued at 807 PM EDT Thursday Aug 27 2015

Surface ridge overhead will continue to push eastward into the
western New York by Friday evening. This will allow light surface
flow to gradually veer southerly by midday Friday. Drier low level
profiles and lower xover temperatures should keep both br limited to a
few hours around sunrise and any ceilings primarily in VFR category.


Iwx watches/warnings/advisories...


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

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