Area Forecast Discussion
Issued by NWS Indianapolis, IN

Home | Current Version | Previous Version | Graphics & Text | Print | Product List | Glossary Off
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50

FXUS63 KIND 281449

Area Forecast Discussion
National Weather Service Indianapolis IN
1049 AM EDT SAT MAY 28 2016

AVIATION section updated


Issued at 330 AM EDT Sat May 28 2016

A warm and humid air mass will persist across the region through the
weekend with chances for showers and thunderstorms as a series of
upper waves pass through the Ohio Valley. Rain chances will end once
a weakening cold front passes through on Sunday...with less humid
weather for Monday and Tuesday. Scattered thunderstorms will return
to central Indiana by mid week as a storm system tracks through the
region. Cooler and drier conditions are expected by next weekend.


.NEAR TERM /rest of Today/...
Issued at 940 AM EDT Sat May 28 2016

.UPDATE...Only minor tweaks made to grids mainly to raise POPS to 50
percent across the eastern half of our region where the deepest
moisture will be. High res model shows an increase in showers and
storms this afternoon as it moves north northeast across our region.
Otherwise...the remainder of the near term is on track.

Portion of previous near term discussion follows...
The Ohio Valley will remain entrenched within a moist southwest flow
aloft as a stubborn upper low over the central plains this morning
lifts northeast through the course of the day. Weak and poorly
defined perturbations aloft continue to eject out from the upper low
and lift into the area and will once again serve to offer forcing
for convective development today...especially this afternoon during
peak heating.

Deeper moisture advecting into the region courtesy of stronger low
level flow helping to generate the isolated activity early this
morning. A few lightning strikes cannot be ruled out with
mesoanalysis indicating subtle instability present...but overall
primarily anticipating showers through mid morning. Slightly
stronger wave aloft poised to lift into the Ohio Valley this
afternoon and with the airmass becoming more unstable with
heating...expect more of a convective component over the forecast
area with scattered thunderstorms developing. Primary focus for
greatest convective coverage likely to align over the eastern half
of the forecast area where axis of deeper moisture will reside...but
chance pops are warranted over all of central Indiana this
afternoon. With boundary layer shear lacking...expect convection to
remain largely disorganized later today with brief heavy downpours
as the main impact.

Temps...Expect less sunshine than Friday for most as model soundings
and RH progs showing a lot of potential for clouds through the
course of the day.  This will serve to keep max temps cooler than
Friday...with low level thermals supporting highs generally in the
lower 80s.


.SHORT TERM /Tonight through Monday Night/...
Issued at 330 AM EDT Sat May 28 2016

Forecast challenges focus on convective chances through Sunday
followed by drier weather for Memorial Day as weak high pressure

The aforementioned upper low will become slowly absorbed into the
mean flow aloft on Sunday as it tracks east across the Great Lakes.
The remnant wave aloft will enhance lift across the region and
combine with a weakening cold front to provide another round for
scattered convection during the afternoon and evening Sunday. Strong
surface heating will produce a modestly unstable airmass with
steepening lapse rates as cooler and drier air in the mid levels
arrives Despite weak low level flow and boundary layer shear...the
frontal boundary and wave aloft should support potential for more
organized and stronger convection in a multicellular mode.
Thermodynamic profiles suggestive of gusty wind and hail potential
with stronger cells. Timing differences still exist between various
models...but chance pops remain warranted and focused during the
second half of the afternoon into the evening as the front tracks
across the area.

Drier air will overspread the region Sunday night as weak surface
ridging reestablishes and the weakening wave aloft departs off to
the east. A dry and slightly less humid airmass will settle into the
Ohio Valley for Memorial Day and Monday night with the surface ridge
in control over the area and slowly rising heights aloft.

Temps...Warm weather will continue across the region through the
short term. Low level thermals remain supportive of highs rising
into the mid 80s both Sunday and Monday for most areas.


.LONG TERM /Tuesday Through Friday/...
Issued at 231 AM EDT Sat May 28 2016

Models are close enough that the SuperBlend initialization was
accepted for most items.

During the long term, an upper trough will move into the area. A
surface frontal system will also move through. The result will be
rain chances through most of the period.

The GFS appears to be well overdoing rain chances early in the
period given expected forcing at that time. Its influence on
SuperBlend requires cutting back on SuperBlend`s PoPs on Tuesday.

Above normal temperatures early in the period will give way to near
to slightly below normal values by Friday.


.AVIATION /Discussion for the 281500z taf update/...

VFR conditions will continue the next few hours. As convective
temperatures are reached...sct SHRA/TSRA are expected to develop.
Radar trends shows ongoing development across central
Indiana...but coverage remains widely scattered.

Rapid refresh continues to show development expected to increase
over the next several hours. Will insert precise prevailing precip
once that becomes evident on radar. VCSH/VCTS for now.

(Discussion for the 281200Z TAF Issuance)...
Issued at 636 AM EDT Sat May 28 2016

Outside of convection, VFR conditions expected. Winds will become
gusty this afternoon.

While an isolated shower cannot be ruled out this morning, it
appears that the sites will likely remain dry with mainly mid cloud

This afternoon winds will gust near 20kt. Instability will build and
scattered showers and thunderstorms will develop. At the moment
believe coverage will be enough to use a VCTS mention for a few
hours during peak heating.

Convection will then diminish and winds will decrease. &&

.IND Watches/Warnings/Advisories...NONE.


.IND Watches/Warnings/Advisories...


AVIATION...50/JP is the U.S. government's official web portal to all federal, state and local government web resources and services.