Area Forecast Discussion
Issued by NWS Northern Indiana

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FXUS63 KIWX 261732

Area Forecast Discussion
National Weather Service Northern Indiana
132 PM EDT THU MAY 26 2016

Issued at 121 PM EDT Thu May 26 2016

High pressure will remain nearly stationary over the southeastern
U.S. causing warm moist conditions across our area through the
Memorial Day weekend. Temperatures will remain well above normal
with highs in the lower or middle 80s and lows in the 60s. A low
chance of mainly afternoon thunderstorms will continue into early
next week.


Issued at 1024 AM EDT Thu May 26 2016

The main focus into this afternoon will be on shower/storm chances
along eastward progressing MCV/convective outflow reaching the
IN/IL border as of this writing. Weakening of this convective
system going as planned given outrun from LLJ support focused
more into the Ohio Valley. However, gradual/continued boundary
layer destabilization and just enough convergence in advance of
the slow moving outflow support a slight bump to PoPs, especially
across southwestern zones (Monticello/Logansport/Peru) late
morning and early afternoon. Low chances for isolated to scattered
convection elsewhere mid to late afternoon. Lightning, brief heavy
rains, and winds to 40 mph will be the primary threat from any
convection given lacking flow/warm profile. Only minor tweaks to
temps, sky cover, winds otherwise.


.SHORT TERM...(Today and Tonight)
Issued at 402 AM EDT Thu May 26 2016

Water vapor this morning shows substantial drying and subsidence
behind departing short wave. Area of showers and thunderstorms was
moving out of northern locations and should see clearing and dry
conditions early this morning. Focus then shifts to approaching MCV
from upstream overnight convection in the MS valley. HRRR trends
this morning have shown increasing chances for some redevelopment of
convection across IL which may then move across primarily our
Indiana counties mid morning into early afternoon.
However...latest run available prior to issuance has backed off
and washes convection out before reaching our west. As we have
seen over the last 24 hrs...convective models are not very good
with placement and development of these weakly forced complexes.
Not much focus synoptically so will continue to keep low chance
pops in forecast given increased low level moisture and increasing
instability with afternoon CAPEs above 2k j/kg. Will not take much
to set off a few storms in this environment. Models showing
another very small scale perturbation moving through tonight into
Friday so again continued low chance PoPs into Friday morning.
Severe threat remains low with lack of deep shear and weak forcing
but enough CAPE to support isolated strong to pulse severe storms
if they can manage to develop.

High temps today will once again push the lower to mid 80s. Highs a
bit tricky today given upstream convection and potential for
convective cloud debris or development of additional storms.
Maintained highs similar to Wednesday readings. It will be more
humid today as mix out of dew points expected to be less than
yesterday. Afternoon apparent temps to reach middle and possibly
upper 80s in some locations.


.LONG TERM...(Friday through Wednesday)
Issued at 402 AM EDT Thu May 26 2016

It continues to sound like a broken record but not much change in
long term forecasts. Moist but generally weak flow expected over
the region during this period with several small scale short waves
rippling through. Deeper and slightly stronger flow looks possible
this weekend with good GOMEX tap but more clouds may limit
instability. Question will also be timing and strength of short
waves. Models doing their typical bullish and widespread
development which is likely overdone given what we have seen so
far in this weakly forced environment. Chose to keep PoPs in the
low to mid chance range through the period until we see something
better to focus/initiate more widespread convection. Superblend
init generally looked good with only some minor modifications.
While PoPs are spread through the entire does not
look like a washout by any means. It will remain warm and muggy
with highs in the lower 80s and lows in the 60s with dew points in
the 60s.


.AVIATION...(For the 18Z TAFS through 18Z Friday Afternoon)
Issued at 121 PM EDT Thu May 26 2016

Wk shrtwv induced by early morning MO/IL mcs was lifting ne
across nrn IN this aftn accompanied by a line of shra/ts. Radar
suggests a wkng trend as the line moves into an area of weaker mid
level lapse rates over ne IN, so just fcst tempo -shra and vcts at
FWA from 18-19z. This line should be east of SBN by 18z. Latest
HRRR indicates pockets of moderate instability will develop behind
the line this aftn suggesting additional tsra psbl, but given lack
of forcing, threat too low to mention in tafs. generally vfr
conditions the remainder of the TAF period, except some mvfr
stratus/br expected around dawn given moist boundary layer now in


.IWX Watches/Warnings/Advisories...


SHORT TERM...Lashley
LONG TERM...Lashley

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