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Area forecast discussion 
National Weather Service northern Indiana
329 PM EDT Tuesday Sep 30 2014

issued at 144 PM EDT Tuesday Sep 30 2014

Cool and cloudy conditions will continue across the region through
Tuesday night. Dry conditions and more seasonable temperatures are
expected Wednesday and Wednesday night. Above normal temperatures
are expected during the day on Thursday...before shower and
thunderstorms chances return to the area Thursday afternoon into


Short term...(this evening through wednesday)
issued at 329 PM EDT Tuesday Sep 30 2014

High amplitude pattern evident this afternoon on water vapor
imagery. Closed low digging through the eastern Great
Lakes...another one moving up into the Dakotas...and well defined
middle level ridge sandwiched in between. Substantial middle level drying
trailing behind fist upper low has allowed for some mixing out of
low clouds over SW County Warning Area...but much of the area expected to remain
mostly cloudy with ample low level moisture to remain in place and
light NE flow tonight. Good vertical moisture profile for fog
development tonight but expected cloud cover will limit radiational
cooling so any fog should be patchy at most. Surface high pressure
builds into the Great Lakes region on Wednesday and middle level ridge
shifts eastward over the area. May still struggle with morning
clouds but then give way to clearing skies by mid-day. Seasonable
temperatures with overnight lows generally in the middle 40s and highs Wednesday
near 70.


Long term...(wednesday night through tuesday)
issued at 329 PM EDT Tuesday Sep 30 2014

Impressive wrapped up cyclone over western South Dakota will lift out rapidly northward
through the northern plains short term in response to sig upstream SW
kicker diving into the pacnw this afternoon. Sig deep eastward trough
amplification expected thereafter west/eventual closed low development across the
northern lakes likely by weeks end. As a result...a sig poleward surge of
moisture will take place ahead of deepening surface frontal zone west/most preferred
timing being lt Thursday night/Friday am per consensus means as made some
sig early period adjustments to prior probability of precipitation.

Otrws strong ll cold air advection to wrap eastward through southern flank of middle level cyclone lt
Friday into Sat west/sharply colder temperatures compared to Thursday. Ll wrly follow
does not Bode well for lake based rain showers development southward into northern in and
will truncate prior southward extent. However far northern areas that do see rain showers
on Sat will most likely hold in the 40s.

Slw moderation to follow as deep lakes cyclone fills and weakens eastward
into early next week. Secondary clipper wave diving through western
periphery of 500 mb height anomaly may trigger addnl rain showers lt sun into early
Monday although more northern track of this ftr and ll moisture scour ahead of
lead system warrants nothing more than slight chance mention at this range.


Aviation...(for the 18z tafs through 18z Wednesday afternoon)
issued at 145 PM EDT Tuesday Sep 30 2014

Extensive area of low clouds persisting over much of the area this
afternoon. Some clearing to the south and west of sbn and FWA as middle
level drying allowing for some mixing out. May realize a little of
this by late this afternoon at the taf sites but expect clouds to
fill back in overnight with ample low level moisture in light NE
flow. May see some patchy fog developing overnight but uncertainty
exists in getting sufficient radiational cooling with cloud cover so
will leave as MVFR for now. Surface high pressure builds into the
Great Lakes region on Wednesday resulting in VFR conditions by middle
morning with light easterly flow.


Iwx watches/warnings/advisories...
Lm...Small Craft Advisory until 8 PM EDT this evening for lmz043-046.


short term...Jal
long term...T

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