Scientific Forecaster Discussion

Return to Local Conditions & Forecast

Without Abbreviations
With Abbreviations

Area forecast discussion 
National Weather Service northern Indiana
700 am EDT Thursday may 28 2015

issued at 425 am EDT Thursday may 28 2015

A weak high pressure system moving east across the Great Lakes will
provide fair weather across our area today and tonight. Scattered
showers and thunderstorms will likely return to the area in the
Friday through Saturday time frame... as a cold front drops slowly
southeast across the region. Highs today will be in the lower 80s
with lows tonight in the lower 60s. Temperatures will remain above
normal Friday... but cool down from northwest to southeast across
the area over the weekend as the front moves through.


Short term...(today and tonight)
issued at 425 am EDT Thursday may 28 2015

Cold front has moved southeast of the County Warning Area this morning... followed by a weak high
pressure system moving east along the Michigan/in border. Some radiational
cooling fog being reported by ASOS/AWOS across the area but it has
been transient thus far and generally not impacting visibilities
significantly and with lingering moisture quite shallow... didn't
mention in the morning portion of the forecast. Upper level ridge expected
to move across the area today providing mostly sunny skies. Boundary
layer mixing up to around 850mb expected this afternoon which based on
recent tamdar east of Chicago should result in highs in the l80s.

Low level winds across the area will gradually veer from east to south
tonight as an upper level trough and associated surface cold front move east into
the northern/Central Plains and upper Midwest. This will result in
increasing moisture/cloudiness/gradient mixing across our area
overnight which should limit radiational cooling with well above
normal lows in the l60s expected. Continued dry forecast as forcing/moisture appear
too limited to support showers in our area overnight.


Long term...(friday through wednesday)
issued at 425 am EDT Thursday may 28 2015

Challenges this period include the chances for severe storms Friday
and Saturday along with chances for heavy rainfall. NCEP and
other models overall have really been struggling the past few days
handling the interaction and merging of a southern stream short
wave and a northern stream upper trough associated with a cold front
Friday and Saturday. Cips analogs support over an inch of rainfall
over the entire forecast area. National Weather Service hazards outlook issued
yesterday highlighted the potential for heavy rain over the
southeast half of the forecast area. Chances for severe weather
late this week appears limited given warm middle level temperatures
and limited deep layer shear. Will mention the potential for
locally heavy rain in the hazardous outlook. Favor the GFS this
package which has had better run to run consistency than the European model (ecmwf)
and appears to be on track handling this system much better now.
Showers and some storms are likely Friday night through Saturday.
Conditions should be mainly dry Sunday through Wednesday with
temperatures returning to the 80s by Tuesday or Wednesday.


Aviation...(for the 12z tafs through 12z Friday morning)
issued at 647 am EDT Thursday may 28 2015

Radiational cooling fog has mainly impacted rural areas this
morning and should burn off by taf start time. Relatively dry
airmass over the area today should result in just scattered cumulus. Modest
east-southeast flow will veer southerly by this time tomorrow advecting increasing
moisture into the area. This suggests some potential for stratus/br
but signals modest so kept forecast VFR with this issuance.


Iwx watches/warnings/advisories...


short term...jt
long term...skipper

Visit US at www.Weather.Gov/iwx (all lower case)

Follow US on facebook...twitter...and youtube at:

National Weather Service Glossary of Abbreviations