Area forecast discussion
National Weather Service Indianapolis in
107 am EDT Wednesday Jun 19 2013
Update...
the aviation section has been updated below
&&
Synopsis...
issued at 330 PM EDT Tuesday Jun 18 2013
A cold front will move through the area early tonight bringing
scattered thunderstorms. Overnight high pressure will build in and
then persist across the area through the end of the work week.
Another system could bring some more rain early next week. After a
brief cool down Wednesday...above normal temperatures will return
for the weekend into early next week.
&&
Near term /tonight/...
issued at 928 PM EDT Tuesday Jun 18 2013
Instability is on the wane as heating ends and only isolated weak
thunderstorms remain...forming and dying along outflow boundaries
from previous convection. The airmass over southern Indiana is
fairly well worked over...so expect the gradual dissipation of these
storms to continue with the area likely free of storms by midnight.
Have already cancelled what remained of Severe Thunderstorm Watch
324.
Minor tweaks were made to min temperatures and sky cover...but these
changes are relatively insignificant.
Previous discussion follows.
Issued at 330 PM EDT Tuesday Jun 18 2013
Scattered thunderstorms have formed across central Illinois along
the cold front...and these will spread east-southeast across the
southern half of central Indiana this evening. Meanwhile isolated
storms have formed across northern Illinois.
An upper trough and an upper jet will move across the area late this
afternoon and early this evening. These should aid in scattered
thunderstorm development...especially near the cold front. Plenty of
instability around as well. Will go high chance probability of precipitation south before
00z with chance or slight chance north.
After 00z...will keep slight chance probability of precipitation north /as storms are across
northern Illinois at the moment/ and chance probability of precipitation south. Will quickly
diminish probability of precipitation though as instability wanes after sunset. Will be dry
all areas before 06z.
There could be some strong to severe storms across southern sections
of the area ahead of the front...and Storm Prediction Center has this area in a Severe
Thunderstorm Watch until 02z.
For temperatures went closer to the warmer met MOS numbers since
drier air is taking is time coming south behind the front.
&&
Short term /Wednesday through Friday/...
issued at 330 PM EDT Tuesday Jun 18 2013
Focus is on any chances for rain...then on sky and temperatures.
Models are close enough with most features that a blend can be used.
High pressure will move in during the short term...with an upper
ridge just to the south and west.
The NAM keeps a dewpoint gradient across the forecast area...and
then generates isolated convection along it at times during the
short term. However the NAM looks too high with its
dewpoints...especially compared to the other models. Thus believe
NAM/S convection is also overdone...so will keep forecast dry
through the short term.
Skies will be clear to partly cloudy during the period with the high
in control. For temperatures generally stuck with a blend which
looks good given expected sky cover and dewpoints.
&&
Long term /Friday night through Tuesday/...
issued at 147 PM EDT Tuesday Jun 18 2013
An upper ridge will maintain control over the region through most
of the extended period...however there will be periods where it
will weaken or break down slightly as a few short waves cross
through the region and bring small chances for showers and
thunderstorms to the region starting Sunday and continuing through
early next week. Allblend handled the pattern well so did not
deviate except for quality control.
&&
Aviation /discussion for the 19/0600z taf issuance/...
issued at 107 am EDT Wednesday Jun 19 2013
Isolated light showers continue to linger just west of kbmg...but
they should dissipated in the next hour or so. VFR will be the
prevailing flight category as high pressure builds further into taf
sites early this morning. There could be some very brief periods of
MVFR fog conditions at khuf and kbmg early this morning. Winds will
be out of the northeast/east at 5 to 10 kts.
&&
Ind watches/warnings/advisories...none.
&&
$$
Synopsis...50
near term...50/nield
short term...50
long term....smf
aviation...tdud/jh
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