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Area forecast discussion 
National Weather Service northern Indiana
330 PM EDT Tuesday Sep 16 2014

issued at 330 PM EDT Tuesday Sep 16 2014

Clouds will gradually decrease overnight as high pressure settles
into the region. This will also bring overnight lows around 40.
Highs on Wednesday will be in the middle to upper 60s. Dry
conditions and moderating temperatures are expected for the rest
of the week.


Short term...(this evening through wednesday)
issued at 330 PM EDT Tuesday Sep 16 2014

Little more than a cloud and temperature forecast through tomorrow as
Great Lakes and Ohio Valley remain on the subsident side of
expansive trough over eastern noam. Residual boundary layer
moisture and diurnal heating have led to a decent stratocu field
across the County Warning Area this afternoon. Dry air advecting from the
northwest will gradually erode these clouds by later this evening
though...especially with the loss of daytime heating. Expecting
mostly clear skies overnight with nearly calm winds as surface
anticyclone settles directly overhead. Surface dewpoints in most
areas will likely be too low for any impactful fog based on
NAM/GFS bufr soundings and MOS guidance but will have to keep an
eye on our southern counties where low level moisture remains a
bit higher. Otherwise...excellent radiational cooling conditions
expected. Good boundary layer decoupling and efficient longwave
radiative losses should allow temperatures to drop to around 40f tonight.
Some middle/upper 30s and patchy frost may even be possible in our
Michigan counties. Highs tomorrow will likely be a few degrees
warmer as thermal profiles slowly moderate under nearly full sun
and light westerly flow. Didn't deviate too far from inherited
forecast of middle to upper 60s...which is similar to newest MOS


Long term...(wednesday night through tuesday)
issued at 330 PM EDT Tuesday Sep 16 2014

Middle-level ridging will build into the area for the first half of
the long term period with increasing temperatures into the
weekend. This ridge is replaced by a longwave trough by the end of
the weekend as the remnants of Hurricane Odile phase with a strong
wave moving out of Canada. Have trended towards the slower...more
amplified European model (ecmwf) and GFS as the Gem seems to struggle phasing the
systems and the propensity for recurving tropical cyclones to
amplify the pattern. Thus...have kept precipitation onset after
00z Sunday with the highest probability of precipitation between 06z and 12z. Some concern
regarding heavy rain potential due to added tropical moisture and
precipitable water values over 2 Standard deviations above normal...but the
quick movement of the front will act as a limiting factor in this
regard. Once this system moves through...our area will be cool and
dry as an expansive trough envelopes the entire eastern Continental U.S.. the
coldest day will be Monday as h850 temperatures between 1 and 4 celsius
favor high temperatures struggling to reach even the low 60s in
the NE half of the County Warning Area.


Aviation...(for the 18z tafs through 18z Wednesday afternoon)
issued at 135 PM EDT Tuesday Sep 16 2014

Diurnal stratocu is currently in full swing but conditions
expected to remain predominately VFR through the afternoon as
drier air filters south. Expect clear skies by tonight with the
loss of daytime heating and persistent dry air advection. Winds
will also be light as high pressure settles directly overhead but
not expecting any fog development given low surface dewpoints. VFR
conditions will then persist through tomorrow.


Iwx watches/warnings/advisories...


short term...agd
long term...Bentley

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