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Area forecast discussion 
National Weather Service northern Indiana
129 PM EDT Friday Oct 24 2014

issued at 1106 am EDT Friday Oct 24 2014

While conditions are expected to be dry...skies today and tonight
will remain partly to mostly cloudy. Afternoon highs will reach
into the low to middle 60s in most areas. Lows tonight will be in the
upper 40s. Otherwise...a warm and pleasant weekend is in store.
Skies will be partly to mostly clear...with highs in the 60s and
low 70s.


Short term...(today and tonight)
issued at 342 am EDT Friday Oct 24 2014

Fractured middle level trough/moisture axis with little/no reflection
in the low levels will translate east through the area this
morning/early afternoon. Associated weak support from a vorticity maximum
(showing up over Southern Lake Michigan on morning water vapor) and thinning
corridor of 850 mb moisture may be enough to generate a few spotty
light showers/sprinkles into mainly western portions of the forecast area
this morning...otherwise only impact will be slow eastward progression
of a broken/overcast low cloud deck. Modest height rises/subsidence in
wake of this weak trough should allow clouds to mix/scatter out a
bit later today...with afternoon highs expected to recover into the
upper 50s to middle 60s (dependent on cloud cover).

A rather strong shortwave and deepening surface low will emerge from a
Pacific northwest/SW Canada 150+ knots upper jet and track into Ontario and the
northern lakes by later tonight. The fold over of a more pronounced
low-middle level Theta-E ridge in advance of the system cold front will
result in a mild night for late Oct standards. Could also see isolated
showers/sprinkles and stratus develop late tonight given modest
925-850 mb warm air advection surge...although confidence/probability in any
measurable precipitation remains too low for a mentionable pop given lack of
height falls and unfavorable position in right exit region of a southern
Canada to northern lakes upper jet.


Long term...(saturday through thursday)
issued at 342 am EDT Friday Oct 24 2014

System of note for this period lies out near 140w this morning and will turn
inland along the West Coast early Sat. Downstream follow and perturbation
streaking through James Bay continues to oscillate in some degree amg
model solutions which as yet continues to yield some uncertainty in
regard to temperatures mainly Sunday. 00z suite as a whole much more
subdued west/backdoor cold front Sat night and indicate robust ll warm air advection developing
by afternoon. Thus in nod of gefs agreement and decided upward trend see
no reason to not bump sun temperatures up higher again.

West/progressive pattn aloft in place western system quickly amplifies northeastward
into central Ontario Tuesday as trailing sharp cold front bursts east. Ll
thermal ridge ahead of this ftr quite strong west/core of 16-18c 850 mb temperatures
nosing into the Southern Lake Monday. Even a conservative mix down from h9
portends addnl upward headroom likely and seems prudent to use
warmest guidance blend possible. Sig ll moisture/Theta-E surge within broad
low level jet west/western Gomex origins follows Monday night/Tuesday ahead of eastward surging
cold front. Given favorable Theta-E ridging lt Monday night and modest mass moisture
flux northwest third added a slight chance pop for rain showers west/thunderstorms and rain possible as whats
left of plains eml advts overhead. Otrws gist of prior Tuesday forecast
holds west/higher probability of precipitation warranted at least for western half in proximity to
tail end of greater glancing height falls.

Vigorous dry slot wraps eastward Tuesday night and cut probability of precipitation substantially
through evening and altogether late as frontal boundary is clearing the East
Coast at that time. Ridging and seasonably cool temperatures expected in wake
of this system Wed-Fri.


Aviation...(for the 18z tafs through 18z Saturday afternoon)
issued at 125 PM EDT Friday Oct 24 2014

Skies beginning to partially clear this afternoon with subsidence
behind departing weak short wave. Expect conditions to trend to
VFR this afternoon. Another weak short wave will approach again
tonight with similar timing as last night. This wave looks to have
a slightly deeper moisture plume but dynamics not as strong. There
does appear to be a narrow window of lift and moisture along weak
low level boundary that may allow for a few sprinkles or light
showers. Regardless...tafs will have MVFR ceilings and visible with moist
lower levels as this wave approaches. Expect Sat morning to remain
cloudy again with mixing and clearing following main front by


Iwx watches/warnings/advisories...


Synopsis...mesoscale discussion
short term...steinwedel
long term...T

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