Area forecast discussion
National Weather Service northern Indiana
556 am EDT Wednesday Jun 19 2013
Synopsis...
issued at 355 am EDT Wednesday Jun 19 2013
Canadian high pressure will bring cool and dry conditions to the
region for the next two days. This high will exit to the east by
Friday and southwest winds will bring increasing temperatures with
a chance of showers and thunderstorms by the weekend.
&&
Short term...(today and tonight)
issued at 355 am EDT Wednesday Jun 19 2013
Splendid weather in store for the local forecast area today. Rapidly
lifting East Coast trough and downstream amplification from Pacific
northwest closed upper low will force building midlevel heights and
Ava over our region. This combined with good confluence aloft and
lake aggregate effects will support a marvelous low level
anticyclonic gyre over the Great Lakes today. Expect nearly full
sun...except for perhaps a few diurnal cumulus...and temperatures
slightly below normal for middle June. Competing effects for high temperatures
today with lingering thermal trough...at least early in the
day...and strong insolation from very high June sun angle. 850mb
temperatures will only be around 11c by this afternoon. Mixing this to the
surface gives low/middle 70s but expect mixing depths will be a bit
higher than 850mb and strong sun should help US climb into the middle
to upper 70s. The exception will be in our far northwest where a
decent lake breeze is expected to develop given weak gradient winds.
This would be an almost 30 degree diurnal swing from cool morning
lows but seems plausible given dry airmass and good insolation.
Bumped inherited maximum temperature forecast up by a degree or two in a few
spots but no major changes necessary. Temperatures tonight will not be
quite as cool as last night given some slight airmass modification
but should still drop into the low to middle 50s under clear skies and
light east-southeast surface winds.
&&
Long term...(thursday through tuesday)
issued at 355 am EDT Wednesday Jun 19 2013
Sig downstream height rises expected this period inadv of deep layered trough
pivoting through the northern rockies. Broad multi-model/ensemble
consensus builds core of middle-upper ridge axis across the southern lakes into
sun before shifting eastward in association/west ejection of sig northern rockies SW into
southern mb. Prior to that doubt precipitation chances here until lt period in concert
west/warm middle level temperatures overtop weak ll follow and deemed inadequate boundary
layer Theta-E will result in effective middle level capping inversion
through Friday.
Later period probability of precipitation/weather generally held per eastward progression of sharp middle level
trough through southern Canada and some inherent breakdown in middle level
ridge across the southern lakes expected. However lack of height falls west/southern extent
portend isolated chances at best and befitting prior gridded stance.
&&
Aviation...(for the 12z tafs through 12z Thursday morning)
issued at 555 am EDT Wednesday Jun 19 2013
VFR conditions expected to continue for the rest of this taf
period as large Canadian high pressure system maintains dry and
stable conditions for the Great Lakes region. Broken 5kft stratus
deck currently around ksbn is expected to dissipate and shift
eastward by later this morning with only a few diurnal cumulus for the
rest of the day. Weak pressure gradient will bring light winds
with a variable wind direction at ksbn this afternoon due to
possible lake breeze influence. Dry airmass will prevent fog
formation tonight despite clear skies and calm winds.
&&
Iwx watches/warnings/advisories...
in...none.
Michigan...none.
Ohio...none.
Lm...none.
&&
$$
Synopsis...agd
short term...agd
long term...T
aviation...agd
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