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Area forecast discussion 
National Weather Service Cleveland Ohio
700 PM EST Friday Feb 12 2016

low pressure over southern Ontario will move east into Quebec this
evening. An Arctic cold front trailing the low will drop south
into the area this evening. Saturday...Arctic high pressure over
the upper Midwest will begin building toward the area. The high
will move through Sunday night and exit to our east on Monday as
another low moves in from the west.


Near term /through Saturday/...
only made tweaks to the hourly precipitation chances. Forecast still on
target. Intense band now east of cle...dropping visibility in
heavy snow to 1/2 mile or less at times.

Previous discussion...manual forecasts show one cold front to our
north about to move into the area however based on 925mb temperature
packing as well as surface temperatures believe there may be two. Snow
showers are developing in southeastern lower Michigan and northern Indiana along and
just behind a Canadian cold front that will move into the area
this evening. Temperatures behind this front are similar to temperatures
across Northern Ohio. Further to the north across northern lower Michigan...temperatures
drop off into the teens with single digits north of that depicting
the Arctic boundary. The first front will move into the area late
this afternoon west and early evening central and east and should
be accompanied by a period of light to moderate Snow. Lake effect
snow showers could begin as well as winds line up though the
northwest but would expect the best development to be behind the
second front. This second front will come through middle to late
evening. Put around an inch accumulate in for most places outside the
lake effect areas this evening/tonight. Believe the best chance
for lake effect remains Ashtabula Erie and Crawford counties where
Lake Huron moisture will also be favored. That said...not
completely comfortable about not having a headline in lake and
Geauga as well. While there is a short fetch and only Lake Erie
moisture to work with...orographic lift plus synoptic lift within
the favorable snow growth region and good moisture below 800mb
should support lake effect snow. Will issue an advisory there
lasting through Saturday afternoon. Will go with 3 to 5 inches
tonight and another couple inches Saturday. No other headline
changes. Will continue with up to 6 to 8 in the warning area. As
for temperatures will go a few degrees below guidance and close to the
previous forecast.


Short term /Saturday night through Sunday night/...
northwest flow across lakes Huron and Erie continue Saturday. Main
concern would be the short fetch outside any Lake Huron
band...drying depicted by the nam12 as well as the possibility of
a shrinking mixed layer in the Arctic air. BUFKIT forecast
sounding however continued to show ample low level moisture below
about 7500 feet...extreme instability to the lake and very little
shear. The short fetch however will remain. Will have the advisory
for lake and Geauga continuing into the afternoon but day shift
will be able to evaluate how efficient snow production is. As for
forecast changes...have increased probability of precipitation along the Lakeshore back
toward Cleveland. While not much accums expected given the short
fetch am concerned that snow showers do develop and spread across
the area. Dry air will move into the area Saturday night and early
Sunday with the broad Arctic high that builds in. Will taper probability of precipitation
to chance Saturday night and go dry Sunday. For Sunday afternoon.
Sunday night the high will move east and allow low pressure to
approach from the west. Models develop warm advection snow that
should overspread the area through the night from the southwest.
Brought a chance pop into the southwest before midnight and then
expanded it east to near a kcle-kyng line by 12z Monday while
increasing to SW tier to likely. Temperatures well below normal through
the period. Wind chill values as low as -15 tonight and -15 to -20
Saturday night.


Long term /Monday through Friday/...
he models remain consistent with a surge of warm advection Monday
and some light snow. Temperatures should recover to near normal.

The models are still not in agreement on the southern branch
short wave Monday night into Tuesday. The European model (ecmwf) remains the odd man
out with the deterministic model taking the surface low west of
the Appalachians...perhaps because it drops the trailing short wave
so far south into the lower Mississippi valley? The other models
take the surface low across the southern Appalachians and up the
Piedmont...the inland track up the East Coast. The East Coast
track seems more typical of this type of system and the heaviest snow
would be in the Appalachians but it is still too have much confidence
in any track. In any case...there may well be some snow develop
across northeast Ohio and northwest PA under the trough aloft. Will
continue with a chance of snow mainly from around I-71 east Monday
night into Tuesday and continue to monitor the model trends.

The models have been suggesting a reinforcing push of Arctic or
semi- Arctic air later Wednesday into Thursday. There are some
questions on timing and the GFS still develops a wave on the front
that most of the the other models do not have. Will have a chance of
snow showers mainly across northeast Ohio and northwest PA.

Things should dry out by Thursday but it will probably be colder
than earlier forecasts assuming that some Arctic air has
spilled back across the region. Highs mostly in the 20s.

Warm advection precipitation...light snow... may develop by early Friday
morning as a large ridge from the middle of the country moves east.
Warmer temperatures should spread across the area Friday afternoon and
night. Highs climbing into the 40s..perhaps heading toward the 50s?


Aviation /00z Saturday through Wednesday/...
at 00z an intense snow squall extended from near eri southwest
towards mfd...moving southeast. The snow squall is expected to
reach cak/yng between 00-01z with a 30-60 minute window of near
white out conditions with west northwest winds gusting to around 30
knots. This band has pushed south of cle although snow showers will
continue at NE Ohio sites as lake effect snow showers develop. Eri
will be most likely to see additional moderate to heavy snowfall
through Saturday with upstream moisture from Lake Huron enhancing
snow showers. Otherwise tol/fdy may see a passing snow shower but
will be brief and will tend to see clouds scatter out tonight.
Northwest winds will be breezy with gusts of 20-25 knots.

Outlook...non VFR in snow showers through Saturday night mainly
for the snowbelt of extreme NE Ohio/northwest PA. Non VFR Monday and
Monday night in light snow especially NE Ohio/northwest PA.


winds will shift from southwest to northwest on Lake Erie
tonight as Arctic high pressure builds across the lake tonight into
Saturday. With relatively warm water and very cold air aloft there
will be maximum mixing and winds around 30 knots sustained. We could
approach gale force for a few hours but sustained gale force winds
will be brief and no Gale Warning in effect. The combination of
winds and waves will make for significant freezing spray and risk of
ice accretion and the heavy freezing spray warning will be in effect
tonight into Saturday night. Ice formation will be significant this
weekend especially on Western Lake Erie and an ice advisory remains
in effect.

Winds will diminish by Sunday as the surface high pressure moves
across the lake. Winds will come around from the south on Sunday and
remain south on Monday until low pressure develop along the East
Coast. Then winds will back to the northeast and north for a while on
Tuesday. A reinforcing cold front will drop across the lake on
Wednesday and winds will become northwesterly again.


Cle watches/warnings/advisories...
Ohio...Lake effect Snow Advisory until 4 PM EST Saturday for ohz012-
Wind Chill Advisory from 10 PM this evening to 10 am EST
Sunday for ohz003-006>014-017>023-027>033-036>038-047-089.
Lake effect snow warning until 10 PM EST Saturday for ohz014-
PA...Wind Chill Advisory from 10 PM this evening to 10 am EST
Sunday for paz001>003.
Lake effect snow warning until 10 PM EST Saturday for
Marine...heavy freezing spray warning from 10 PM this evening to 3 am
EST Sunday for lez061-142>149-162>169.


long term...kosarik

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