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Area forecast discussion 
National Weather Service northern Indiana
1254 am EDT Sat Jul 4 2015

Synopsis...
issued at 1250 am Sat Jul 4 2015

High pressure will move slowly east into the area tonight and
Saturday resulting in mainly clear skies. Lows tonight will be in
the middle 50s with highs Saturday in the lower 80s... except only in
the middle 70s close to Lake Michigan.

&&

Short term...(this evening through saturday)
issued at 339 PM EDT Friday Jul 3 2015

Quiet weather is expected for the 4th of July...with an upper
level ridge building overhead and surface high pressure below. As
a result...have mostly clear to partly cloudy skies across much of
the County Warning Area later tonight and Saturday.

Only fly in the ointment is the surface low shifting to the east across
Kentucky this afternoon. This has brought a few isolated
showers/sprinkles to the southern County Warning Area and a broken-overcast deck of high
clouds around 15kft to much of the area. NAM and host of other
models are overdoing probability of precipitation/quantitative precipitation forecast thus far...so have stuck to using the
hrrr as it has done well with the more isolated nature of showers
today. With dry air in the low levels it seems pcp has failed to
make it far northward thus far...and expect it to stay that way this
evening.

With high pressure moving overhead...skies clearing...and
winds light/variable would expect some fog development late
tonight...but with drier airmass expected was hesitant to add
anything into forecast. If anything...thinking it will be more of a br
situation with visible 3-5 miles further to the south where there is a
bit more moisture.

&&

Long term...(saturday night through friday)
issued at 339 PM EDT Friday Jul 3 2015

Disjointed upper level pattern will continue into Sunday. Another
northern stream vorticity maximum should weaken across the western Great
Lakes during the day Sunday while forcing with southern stream
trough generally remains south of the area. Moisture will be
limited and with local area likely split by forcing once again will
continue to keep this period dry. Some very low probability may
exist for an isolated shower to develop in the afternoon along lake
breeze boundary across Northwest Indiana...but not of large enough
confidence to insert mentionable probability of precipitation at this time.

Cut-off pv anomaly across the lower Ohio Valley may try to get
ingested back into northern stream late Sunday night into
Monday...but it still appears as though chances of showers and
thunderstorms will hold off until the Monday night/Tuesday
timeframe. No significant changes made to previous likely probability of precipitation for
this period. Overall severe potential looks to be on the low side
given expected unfavorable diurnal timing...meager middle level lapse
rates...and local area remaining on extreme southern fringe of
stronger forcing working across the northern Great Lakes.

Chance of showers/thunderstorms to continue Tuesday evening in
association with slowing frontal boundary...mainly southeast half.
Cooler conditions for Wednesday and Thursday with perhaps an
isolated shower/thunderstorm across the southeast as a weak middle
level trough may induce weak downstream low level thetae advection
in association with boundary in vicinity. Maintained idea of
previous forecast with better chances of showers and thunderstorms
Thursday/Friday as low level boundary makes a more aggressive
northward surge.

&&

Aviation...(for the 06z tafs through 06z Saturday night)
issued at 1246 am EDT Sat Jul 4 2015

High pressure building into northern Indiana this morning as
surface low over southern Ohio moves to the east. Patchy radiational cooling
br expected early this morning with best chance of visibility restrictions
at FWA where low level moisture appears to be a bit higher. Surface
high will move across the area today. Northwest flow aloft should mix
down to the surface but speeds will be less than 10kt. Ridging/warming
aloft along with subsidence should result in little or no cloud
cover. Surface high will move east from Indiana to Ohio tonight. Skies
should remain clear with gradient weak enough to result in
light/variable winds. Some radiational cooling fog/br possible
overnight but not included in tafs at this time.

&&

Iwx watches/warnings/advisories...
in...none.
Michigan...none.
Ohio...none.
Lm...none.
&&

$$

Synopsis...jt
short term...mesoscale discussion
long term...marsili
aviation...jt



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