Scientific Forecaster Discussion

Return to Local Conditions & Forecast

Without Abbreviations
With Abbreviations

fxus63 kind 240744 

Area forecast discussion
National Weather Service Indianapolis in
344 am EDT Mon Jun 24 2019

the synopsis...near term and short term sections have been updated


issued at 344 am EDT Mon Jun 24 2019

The approach and passage of an upper low through the lower Great
Lakes will bring the threat for showers and thunderstorms once
again today. The expansion of high pressure into the area tonight
and Tuesday should bring a well needed break from the rain and
storms. Other than a small threat for storms Wednesday as a weak
wave aloft passes through the region...mainly dry weather is
expected into the weekend as a warm and humid airmass settles
across the Ohio Valley.


Near term /today/...
issued at 344 am EDT Mon Jun 24 2019

Sunday evening convection has shifted well off to the northeast of
the region early this morning leaving a mix of clouds in its wake
across the region. Muggy airmass lingered early this morning with
07z temperatures in the upper 60s and lower 70s.

Upper low tracking across the Missouri Valley early this morning
will shift into the lower Great Lakes this afternoon while taking
on a negative tilt. As the better forcing aloft associated
arrives with the upper low this afternoon...moisture will increase
across the area as a low level jet noses into the Ohio Valley.
While model soundings show instability levels are likely to be
lower than Sunday...the upper low and presence of slightly deeper
bl shear than Sunday will again enable a potential for severe
convection to develop during the afternoon hours. The best threat
for severe storms will focus over the northeast half of the
forecast area where upper level diffluence should be more
pronounced and the axis of highest precip water values will

Damaging wind gusts will again be a primary concern from storms
later today although model soundings showing highly saturated
conditions through 15kft with generally poor lapse rates which may
mitigate a more substantial wind threat outside of localized wet
microbursts. Cooling aloft as the upper low approaches supports a
greater hail threat from any stronger cell with an elevated core.
While a few showers are possible this morning...primary timeframe
for most organized convection will occur during the afternoon
before storms shift east into Ohio by late day. Will carry highest
pops over eastern counties during the afternoon before dropping
them back into the early evening.

Temps...trended towards the warmer metmos for highs this afternoon
as even a little bit of sun should enable much of the area to warm
into the upper 70s. Could see lower 80s in the lower Wabash valley
where less convection is anticipated.


Short term /tonight through Wednesday night/...
issued at 344 am EDT Mon Jun 24 2019

Forecast challenges focus on wrapping up rain and storm chances this
evening and considering a low threat for storms Wednesday as a
weak upper wave passes through the area.

The overall pattern will transition through the short term from the
progressively unsettled and active regime to a warmer...drier and
more summerlike pattern as zonal flow aloft develops then gives
way to broad ridging by early Thursday.

While the bulk of the convection will be east of the area by late
day...could still see isolated showers and storms linger until
the upper wave axis passes by late evening. Will hold onto low
chance pops through about midnight then go dry thereafter. Surface
ridging expanding into the Ohio Valley on Tuesday will bring
mainly sunny skies and warmer temperatures to central Indiana. A
weak upper wave tracking along in the zonal flow regime aloft will
swing across the region on Wednesday. Moderate instability
develops by the afternoon and despite meager levels of bl shear
and helicity...potential for isolated to scattered pulse-type
convection will exist across much of the forecast area.

Any storms will diminish with the loss of heating Wednesday evening
as the upper wave departs to the east. The upper level ridge
centered over the Southern Plains will expand northeast towards
the Ohio Valley Wednesday night with dry conditions and mainly
clear skies returning.

Temps...low level thermals support a return to widespread 80s for
both Tuesday and Wednesday across the forecast area with mid to
upper 80s possible Wednesday. Could see heat indices peak in the
lower 90s Wednesday afternoon over parts of the area. Lows will
largely fall into the 60s through the period. An overall model
blend will work well.


Long term /Thursday through Monday/...
issued at 259 am EDT Mon Jun 24 2019

The long term period will generally be dry to end the week, with
low chances for storms returning over the weekend. Temperatures
will be much more Summer like than those experienced lately, with
temperatures even climbing slightly above normal at times as the
ridge strengthens.

Blended initialization handled things relatively well and required
only minor adjustment.


Aviation /discussion for 240600z taf issuance/...
issued at 1134 PM EDT sun Jun 23 2019

VFR for all sites but klaf to start. At klaf should see MVFR
ceilings through much of the taf period. At khuf may see some
bouncing around VFR to MVFR ceilings for an hour or two. Elsewhere
think VFR could last into the morning before MVFR ceilings arrive.
Should be noted that NAM is still much more pessimistic, but it
also is overdoing rain through the overnight so discounted it.

Chances for thunderstorms will move in during the afternoon and
will have a thunderstorms in the vicinity going during this time along with some rain showers.
Winds should be out of the south/south-southwest by issuance time and become
more southwesterly through the day on Monday.


Ind watches/warnings/advisories...none.



National Weather Service Glossary of Abbreviations