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fxus63 kind 252240 
afdind

Area forecast discussion
National Weather Service Indianapolis in
640 PM EDT sun Aug 25 2019

Update...
the aviation section has been updated below.

&&

Synopsis...
issued at 323 PM EDT sun Aug 25 2019

An upper level system combined with a surface cold front will bring
rain to central Indiana at times tonight into Tuesday evening.
Another front will bring rain chances early next weekend. Otherwise
dry conditions are expected. Temperatures will be near normal to
below normal into next week.

&&

Near term...(rest of this afternoon and tonight)
issued at 323 PM EDT sun Aug 25 2019

This afternoon some showers were across southern Illinois and
southwest Kentucky. These were moving north or north-northeast. Dry
air is holding across much of central Indiana, with just far
southern and western areas seeing higher dewpoints.

Believe that far western and southern areas may see a light shower
for the remainder of today, so have some slight chance pops in those
areas. Elsewhere believe the drier air will win out, but will keep
an eye on it.

Warm advection and moisture advection will continue tonight across
the area. This will allow the atmosphere to slowly moisten up and
for forcing to gradually increase. With this in mind went chance or
lower category pops this evening.

By late tonight forcing and moisture will be enough to go with
likely category to categorical pops across much of the area. At the
moment, based on expected forcing, it looks like the southeast
forecast area will see the highest chances and highest quantitative precipitation forecast.

Given only slow increases in dewpoints expected, the blend's low
temperatures look reasonable.

&&

Short term...(monday through wednesday)
issued at 323 PM EDT sun Aug 25 2019

Models are close enough that the National blend of models
initialization was accepted for most items.

Isentropic lift will continue across the area Monday, as will a good
flow of moisture from the south. Thus, likely category or higher
pops look good for the entire forecast area. Forcing shifts to the
north and east during the day, so pops will diminish south and west
during the afternoon.

The area will be in a relative lull Monday night as the first round
of forcing will have moved off to the east, and the cold front/next
upper support is to the west. Will have low pops during the evening,
with an increase in pops overnight, but most areas still staying in
the chance category.

The cold front will move in on Tuesday. Timing is faster then
previously thought, so the amount of instability will be lower.
Remnants of stronger thunderstorms to the west of the area will move
through early Tuesday, with perhaps some additional weaker
development Tuesday afternoon. Will go likely category pops for now.

Kept some low pops in the east Tuesday evening for any lingering
convection, then dry weather should rule for Wednesday as drier air
flows into the area.

&&

Long term /Wednesday night through Sunday/...
issued at 244 PM EDT sun Aug 25 2019

The last few days of August will see an amplified flow aloft
across the country with a persistent ridge centered over the
southwest U S and a broad trough over the eastern U S courtesy of
a deep early autumn-type upper low near James Bay. This will keep
central Indiana and the Ohio Valley within a dry northwest flow
regime that will gradually relax into the Holiday weekend.

A weak frontal boundary will slide south into the region Friday
and Saturday but will have limited moisture as low level winds
suggest the Gulf of Mexico will be cut off. Hard to justify much
more than low chance pops both days before dry weather resumes
Sunday. Highs will be seasonable through the period...generally
running a few degrees below normal in the upper 70s and lower 80s.
Lows will focus in the upper 50s to the mid 60s.

&&

Aviation /discussion for the 260000z tafs/...
issued at 638 PM EDT sun Aug 25 2019

Short term model data suggest scattered shower activity, ahead of
approaching upper low, may arrive in the vicinity of the southern
terminals as early as 260400z. It appears the precipitation may
become more widespread by the pre dawn hours of Monday, when a
25-30 kt 850mb jet noses towards southern Indiana. Embedded
lightning strikes are possible late tonight, but generally poor
lapse rates should prevent lightning activity from getting too
widespread.

Otherwise, sustained warm/moist advection should allow ceilings to
gradually fall tonight, with the potential for areas of IFR
ceilings to develop from the south after about 260800z. Surface
winds 100-120 degrees at 6-9 kts this evening will veer a bit
towards 110-140 degrees by sunrise Monday.

&&

Ind watches/warnings/advisories...
none.
&&

$$

Synopsis...50

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