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Area forecast discussion 
National Weather Service northern Indiana
655 am EST Sat Nov 28 2015

issued at 655 am EST Sat Nov 28 2015

Light rain and patchy drizzle will gradually taper from northwest
to southeast through the morning hours. Some light rain may linger
southeast of Route 24 this afternoon. Cloud cover will then begin
to decrease from north to south later this afternoon...though any
breaks may be few and far between south of Route 24. High
temperatures today will only reach around 40...and lows tonight
will dip back into the middle 20s to around 30.


Short term...(today and tonight)
issued at 421 am EST Sat Nov 28 2015

Rather benign near/short term period as frontal wave moves east-northeastward through
Ohio Valley. Final vestiges of low level isentropic upglide
/especially when accounting for uvm owing to local pressure
tendency/derivative on i285-290k surfaces ejecting from ecntl
Illinois to along and S of Route 24 corridor early this am and will
account with separate prefirst period. While some rapl mix across northestern
Illinois earlier this evening and some up AWOS across Southern Lower Michigan...have
maintained all liquid as magnitude and depth of maximum tw aloft greater
across County Warning Area per rap analysis...certainly do not anticipate snow mix per
relative warm cloud top temperatures suggesting lack of/or at least
questionable ice Crystal nucleation per amdar and rap soundings. All
but far southeastern third of County Warning Area difficult to measure especially bynd 15
UTC as feature weakens/pushes eastward while focus sags southeastward as
increasing dry air entrains with dvm associated with surface ridge
strengthening/building eastward through cntl lower Michigan through the day. Held
line on temperatures given anticipated laggard cloud cover with afternoon
partial clearing relegated primarily north of Route 24. Poor
insolation opportunity amid persistent 925mb cold air advection/low solar zenith
angle/short duration of shortwave flux. Slight lowering of min temperatures
for sun am as well...inline with guidance...accentuating north/S
gradient as northern County Warning Area most likely and more readily to decouple
per proximal southern ridge well as remove marine
layer bleed in as offshore/downslope component favors a cold


Long term...(sunday through friday)
issued at 421 am EST Sat Nov 28 2015

Sunday still looking relatively pleasant...though seasonably cool.
Shortwave midlevel ridge/Ava will slide over the region and support
general subsidence/high pressure. Some lingering clouds possible in
our southern counties with stalled front just to our south but most
areas will likely see a fair amount of sun. 925mb temperatures around 1c
support highs generally in the low to middle 40s.

Western Continental U.S. Upper low then pinwheels into the region on Monday.
Associated increase in southerly flow will push old frontal boundary
back north with a decent swath of 290-295k isentropic ascent and
moisture convergence. Some rain possible Monday afternoon but low
level flow does not really ramp up until late Monday night...along
with arrival of midlevel cva bullseye. Still some uncertainty as to
exact timing/track of ejecting low but kept just chance probability of precipitation Monday
afternoon with better chances for more widespread/moderate rain
Monday night. Quantitative precipitation forecast amounts nothing to write home about...a few tenths
at best given relatively quick shot of mediocre forcing and
moisture. Moist cyclonic flow in the wake of lifting cyclone to
bring scattered rain/snow showers with the help of Warm Lake Michigan
waters Tuesday night into Wednesday. Previously mentioned
timing/track issues lead to continued uncertainty with regard to
timing and coverage of precipitation but best chances will be across our
northern counties and should remain generally scattered. Most areas
will not see any snow accumulation given warm surface temperatures but a
few locations in our Michigan counties could see a quick dusting
Wednesday morning if better precipitation rates arrive before sunrise. Kept
Wednesday night dry but should be noted that scattered snow showers could
persist into the evening if slower European model (ecmwf) solution verifies. Dry
and seasonably cool to end the week.


Aviation...(for the 12z tafs through 12z Sunday morning)
issued at 655 am EST Sat Nov 28 2015

Primary change to maintain lowered conditions a bit longer across
northern Indiana as Ohio Valley frontal wave slow to track northeastward.
Longer duration ceilings below 2kft at ksbn. IFR ceilings into midday
followed by fueling/alternate criteria a bit longer at kfwa.


Iwx watches/warnings/advisories...
Lm...Small Craft Advisory until 7 am EST this morning for lmz043-046.



short term...Murphy
long term...agd

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