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Area forecast discussion 
National Weather Service northern Indiana
853 PM EDT Monday Jul 28 2014

issued at 338 PM EDT Monday Jul 28 2014

Cooler and less humid conditions will prevail through much of the
upcoming week as low pressure remains well north of the region.T here
is a small chance for showers and possibly a rumble of thunder
Tuesday as a weak disturbance moves through the region. Lows
tonight will drop into the lower 50s...with some locations
reaching the upper 40s. Highs on Tuesday will climb back into the
lower to middle 70s.


issued at 822 PM EDT Monday Jul 28 2014

Vorticity maximum dropping across Southern Lake Huron this evening has
allowed for low clouds to persist past diurnal peak heating...but
should diminish over next few hours as this vorticity maximum slides into
southeast Ontario. Next upstream vorticity maximum across east central
Wisconsin will drop into the southern Great Lakes later this
evening...with some indications that low clouds may try to build
back into far northwest locations late evening/overnight. Have
made minor tweaks to sky cover to account for current trends. Only
other change that may be considered for evening update is slightly
cooler mins...with some localized upper 40s not out of the
question given ideal radiational cooling conditions and dry low
level air mass.


Short term...(this evening through tuesday)
issued at 336 PM EDT Monday Jul 28 2014

A pleasant but cold period will be in store as pocket of colder air
filters into the region. Skies should become mostly clear this
evening into the overnight hours allowing for a rapid drop in temperatures.
Later tonight...a disturbance will rotate through the flow and bring
an increase in middle clouds. Challenge comes with chances for
showers/isolate thunder starting middle morning Tuesday into the afternoon
hours. 500 mb temperatures get towards -16 c in the north and east...but
overall lapse rates above 850 mb rather poor. 1000-850 mb lapse
rates not bad and enough to get cumulus popping and maybe some isolated
to at best scattered showers. Models vary...but do show potential for 1km
mixed layer cape between 400 j/kg (sref) and 1000 j/kg (nam). This
would be sufficient for at least a mention of thunder. Have left at
slight chance for now. Highs will climb into the lower 70s.


Long term...(tuesday night through monday)
issued at 336 PM EDT Monday Jul 28 2014

Steady state amplified follow regime expected to continue through this
period...anchored out west by upper ridge extndg northward through southwestern Canada
and east by deep upper low centered near James Bay. As a result expect continued
dry nwrly ll follow and pleasant temperatures through the period.

In light of consensus positioning of middle level trough and dry airmass
residing over the lakes threw out allblend pop guidance as
unseasonable Cool Lake composite Theta-E sink continues.


Aviation...(for the 00z tafs through 00z Tuesday evening)
issued at 822 PM EDT Monday Jul 28 2014

VFR conditions expected to persist through this forecast period.
Winds to become light west northwest this evening with loss of
diurnal mixing...with some potential of VFR low clouds working
into ksbn overnight. Next upstream vorticity maximum to drop into Southern
Lower Michigan Tuesday afternoon...which may provide enough
forcing during peak heating for scattered afternoon showers to
develop. Higher stability with Lake Michigan shadow should limit
shower potential at ksbn. Will omit any precipitation mention from both
terminals at this time...with coverage of showers somewhat in
question at this time due to limited moisture. West winds early
Tuesday should veer northwest and increase to 10 to 15 knots
Monday afternoon as next surface trough tracks through the area.


Iwx watches/warnings/advisories...
in...beach hazards statement until 4 am CDT Tuesday for inz003.

Michigan...Beach hazards statement until 5 am EDT Tuesday for miz077.

Lm...Small Craft Advisory until 5 am EDT Tuesday for lmz043-046.



short term...Fisher
long term...T

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