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Area forecast discussion 
National Weather Service northern Indiana
738 PM EDT Monday Jun 1 2015

Synopsis...
issued at 457 PM EDT Monday Jun 1 2015

Tonight and Tuesday will be dry under clearing skies tonight and
mostly sunny skies Tuesday. Low temperatures tonight will range
from the lower 40s in southern Michigan to around 50 near the Ohio
River. High temperatures on Tuesday will be in the lower 70s.

&&

Short term...(this evening through tuesday)
issued at 332 PM EDT Monday Jun 1 2015

Height rises in wake of northern stream portion of broad middle level
trough axis will allow subsident/dry air associated with
strengthening surface ridge to slowly settle into the lower/eastern
Great Lakes tonight into Tuesday. This process will cut off upper
pv anomaly across the lower Ohio/Tennessee valleys...with deeper moisture
and associated cloud cover in deformation axis gradually sinking
southeast of our area overnight into Tuesday morning. Potential for full
decoupling under clear skies/light winds overnight across
northern/western zones does bring patchy fog into question given
moist soil conditions from recent heavy rainfall...with some
chance for low stratus to fill back into our southeast zones toward
daybreak. However...bulk of guidance/sref probabilities not all
that excited about fog/stratus potential with airmass advecting in
rather dry. Will hold off on adding any fog in the forecast for now
given these trends. Ample sunshine (although expect at least a
scattered cumulus field to pop) and airmass modification tomorrow
should afford a decent temperature recovery into the upper 60s-low
70s...still 4 to 8 degrees below normal for early June. Dry with
light east-northeast winds otherwise.

&&

Long term...(tuesday night through monday)
issued at 332 PM EDT Monday Jun 1 2015

Have maintained a relatively consistent picture in terms of the
extended forecast with primary forecast concerns on evolution of cut
off pv anomaly across the lower Ohio Valley...and additional chances
of showers and thunderstorms mainly Friday.

Easterly low level flow will gradually veer more southeast Tuesday
evening as anticyclone shifts across the eastern Great Lakes. This
will allow for some modest low/middle level positive thetae advection
to work northwestward across portions of the Ohio Valley through
Wednesday. A bit more impressive low level moisture is expected
across the southeast portions of the area on Wednesday which should
promote a better afternoon cumulus field...but otherwise have kept
conditions dry for given very weak nature of forcing and very
limited instability. Not completely out of the question an isolated
shower may pop up during peak heating across the far southeast if a
favorable diurnal timing to vorticity maximum rotating around cut-off pv
anomaly to the south verifies. Seasonable conditions expected
Wednesday with highs from the upper 70s to around 80. Overall trend
in medium range guidance past several cycles has been toward a
slightly more northeast positioning of the cut off pv anomaly across
southern portions of middle Atlantic for Thursday. Did maintain slight
chance probability of precipitation across the east for Thursday with at least some better
confidence in more appreciable low level moisture in place.
However...very weak forcing suggests low confidence at this point.

A stronger synoptic wave is expected to progress through north
central Continental U.S. Ridging for the Thursday/Friday period...bringing
another frontal boundary southward across the Great Lakes
region. Guidance is having a difficult time resolving the
strength/progression of this wave due to convective feedback issues
over the corn belt and also some possible phasing discrepancies with
aforementioned departing middle Atlantic pv anomaly. At this
point...opted to maintain consistency with low to Middle Range chance
probability of precipitation Friday given better forcing and weak to moderate instability
possible. Confidence is low for this upcoming weekend in terms of
precipitation potential given uncertainties with Friday wave...but will
continue to carry low chance probability of precipitation at this point with possibility of
low level boundary hanging up across the region. A stronger northern
stream short wave may drive a stronger cold front across the region
toward the end of the period...so have maintained chance probability of precipitation
through day 7. Cooler temperatures expected Saturday...with moderation once
again for Sunday-Monday period in advance of the next frontal system.

&&

Aviation...(for the 00z tafs through 00z Tuesday evening)
issued at 735 PM EDT Monday Jun 1 2015

Skies were clearing with VFR conditions expected this evening.
Still possiblity of some patchy fog forming overnight. 18z hires
guidance shows very thin layer of moisture which could aid in MVFR
br with light or calm winds. Drying from north to help offset. Did
add a tempo group at kfwa where models more in agreement with
moisture.

&&

Iwx watches/warnings/advisories...
in...none.
Michigan...none.
Ohio...none.
Lm...none.
&&

$$

Synopsis...lothamer
short term...steinwedel
long term...marsili
aviation...Lashley



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