Toledo Weather - Tue, May 20, 2014

spc ac 201244

day 1 convective outlook
nws storm prediction center norman ok
0744 am cdt tue may 20 2014

valid 201300z - 211200z

...there is a slgt risk of svr tstms from ern ia to srn wi...nrn
il...nrn ind...srn lower mi...and much of ohio...

...there is a slgt risk of svr tstms from sern wy to nern co...

...summary...
severe thunderstorms with the potential to produce damaging
winds...a couple of tornadoes...and large hail are expected to
develop late this afternoon and early evening from eastern iowa to
the wisconsin/illinois border. initially...the greatest threat from
these thunderstorms will come in the form of large hail and perhaps
a tornado or two. into the late evening and overnight the storms
should form into a squall line complex with damaging winds and hail
possible from northern illinois east across southern lake
michigan...northern indiana...southern lower michigan...and
northwest ohio.

isolated to scattered late afternoon and evening storms are possible
along and east of the front range of the rockies from southeast
wyoming to northeast colorado. some storms may produce hail and high
winds.

...synopsis...
morning water vapor satellite loop and objective analysis data
depict two vigorous mid/upper lows on either coast...one digging
sewd across coastal/central ca...the other spinning sewd away from
cape cod and the gulf of maine. the expansive midsection of the
nation is dominated by a broad belt of generally anticyclonic
mid/upper level flow with a 70-90kt 300mb jet arcing from the four
corners region to the nrn plains to the upper ms valley. a shortwave
disturbance over the nrn plains was cresting the periphery of the
broad upper ridge and will contribute to modest height falls and
strengthening deep-layer wly flow over the upper ms valley and great
lakes regions today and tonight.

at the sfc...a weak cold front associated with low pressure over srn
manitoba arcs from mn across cntrl/wrn ia to swrn ks and then
wwd/nwwd to the front range of the rockies. warm/moist air ahead of
the front was being transported enewd across the middle ms valley
and midwest...aided by 40-50 kt low level jet from the plains to
great lakes. forcing for ascent along the advancing cold front is
forecast to strengthen from ia to wi this afternoon coincident with
the approach of the nrn plains shortwave trough and maximum in
diurnal destabilization.

...ern ia/srn wi/nrn and cntrl il/nrn ind/srn lwr mi/oh...
large scale mid-level pattern is one that favors the effective ewd
transport of steep lapse rates from the high plains to the midwest.
the steeper mid-level lapse rates associated with the eml plume are
just becoming evident in morning soundings from dvn and ilx.
moisture transport into this region is also being aided on the large
scale by persistent sly low level flow on the wrn flank of ern u.s.
anticyclone. expect sfc dewpoints to continue to climb and reach the
low to mid 60s f from ia to srn wi beneath a modest capping
inversion associated with the eml. daytime heating ahead of the cold
front should support moderate to locally strong sfc-based
instability /sbcape 2000-2500 j/kg/ by late afternoon.

there are a variety of forecast scenarios across the midwest slgt
risk area today and tonight. that variety introduces uncertainty as
to timing of convective initiation...storm mode...and possible
mcs/qlcs evolution. the most likely scenario given an abundance of
guidance...the pattern and time of year...is that robust convection
will initiate ahead of the cold front from ern ia to srn wi in the
21z to 00z time frame. bulk shear in the 40-50kt range...and
aforementioned instability parameters...will be more than adequate
for supercells with the potential to produce very large hail and
strong winds. a tornado threat will also exist during this initial
phase...especially near weak frontal waves and/or storm-scale/
mesoscale boundaries. the combination of strengthening upper forcing
and linear convergence on the advancing front should contribute to
an evening transition to a forward propagating qlcs. this transition
should occur amidst moderate instability...and on the srn edge of
50-60kt mid-level wly flow. the evolving qlcs could produce numerous
damaging wind events from the chicago area south and east across
lake michigan to nrn ind/swrn lwr mi through late evening. isolated
significant wind gusts are possible if qlcs upscale growth is
realized relatively early in the evening when sfc-based instability
will be greater. however...certainty in this scenario is not
sufficient enough at this time to warrant higher significant wind
probabilities and/or the introduction of a mdt risk for some of the
area.

severe hail/wind potential with the advancing squall line should
wane with ewd extent and a decrease in sfc-based instability through
the late night/early morning hours. nonetheless...some severe
wind/hail potential may spread as far east as the oh/wv/pa border
areas before daybreak wednesday.

...front range to cntrl high plains...
in the wake of a frontal passage...modest low-level upslope flow and
sfc dewpoints in the 40s should contribute to at least isolated
storms developing through late afternoon/early evening. most
guidance suggests no more than scattered development given generally
neutral large scale ascent and height rises aloft. any storms that
can form will do so amidst steep mid-level lapse rates and a veering
low-level wind profile. thus there is a risk for organized updrafts
capable of large hail and strong winds.

..carbin/bothwell.. 05/20/2014

click to get wuus01 ptsdy1 product

note: the next day 1 outlook is scheduled by 1630z

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fxus61 kcle 201348
afdcle
area forecast discussion
national weather service cleveland oh
948 am edt tue may 20 2014

synopsis...
a warm front will move into western ohio this afternoon. it should
cross all of ohio by wednesday morning. as low pressure moves
across the central great lakes wednesday evening it will allow a
cold front to slide across the region. this front may not clear
eastern ohio until thursday morning. high pressure will build in
for the end of the week.
&&

near term /until 6 pm this evening/...
scattered showers continue to move east across the area and have
begun to push into the extreme east. so will go ahead and add a
mention of showers in that area. as the day time heating picks up
with the few breaks of sun expected...showers with a few
thunderstorms are possible in the afternoon.
warm front lies across indiana at this time and is expected to
lift northeast across the region tonight. models hinting at
potential mcs tracking east along the boundary tonight so will
have to monitor that situation as it develops.
previous discussion...
showers that moved across the central county warning area
have fallen apart as it moved into the drier air across the east.
we are now watching the next round of showers develop over indiana
and moving into nw oh. these area also rather light with maybe a
few hundredths possible. these should decrease as we begin to mix
this morning.
previous discussion...
5h piece of jet energy and some middle level moisture have been
enough to cause an area of light showers/sprinkles across the
western county warning area. as it continues to move eastward
drier air at the lower level should make it shrink in coverage and
may be little more than sprinkles across the central and eastern
county warning area.
we will then wait for a warm front to move into the western portion
of ohio this afternoon. as the boundary lifts northward with
additional low level moisture and the region reaches its highs the
stage will be set for the development of showers and
thunderstorms. the main show will likely wait until the overnight
hours. in any event we will begin to mention some isolated thunder
chances this afternoon into the early evening.
it will be warmer today but the amount of cloud cover will play a
roll. highs across the central and west should be able to get into
the 70s. a few upper 70s will be possible across nw ohio if
clouds thin a bit during the afternoon. cooler with highs
approaching 70 across the eastern third of the area since the
warm front will take longer to arrive.
&&

short term /6 pm this evening through friday night/...
the warm front interaction with the convection that develops over
illinois and indiana will be interesting to watch this evening
into the overnight hours. current thinking is that strong to severe
thunderstorms that develop west of the region will organize into
an mcs that will track near the warm front. the main concern will
be strong damaging winds but large hail will be possible.
thought about the need of a flash flood watch but not confident
enough on the track of an mcs. best way to handle this would be as
we see the mcs develop and hoist a watch at that time.
the warm front should lift north of most of the county warning
area by mid morning on wednesday. we will then see how well the
atmosphere recovers from the first round of thunderstorms. however
warmer and more unstable air will advect into the region wednesday
afternoon ahead of the front. a stronger piece of jet energy will
be moving into the county warning area wednesday evening which
will increase the lift near and ahead of the cold front. this
strong jet should help to generate a squall line that could bring
another round of strong damaging winds to the region. of concern
is the increasing low level shear as the jet energy arrives
wednesday evening. if storms remain isolated/scattered there could
be a chance that the storms will rotate which would increase the
tornado threat. more details on this over the next 24 hours.
the front should clear the county warning area by thursday
morning. however some lingering showers may persist across the ne
portion of the region as the upper level low takes up residence
over the new england states. the showers may not exit the region
until friday afternoon as high pressure builds into the central
great lakes.
it will be warm on wednesday after the region recovers from
tonights thunderstorms. highs should be in the 70s to near 80
wednesday afternoon. cooler thursday into friday with highs slightly
below seasonal averages.
&&

long term /saturday through monday/...
models remain in good agreement that high pressure will build over
the region from the west on saturday as the upper level trough
shifts out over the atlantic. the air mass dries out considerably and
expecting skies on saturday to range from mostly sunny in the west
to partly sunny for just a fraction of the day in the east before
clouds mix out. areas closer to the lake will be influenced by the
marine layer with mostly sunny skies but temperatures running a
little cooler than inland locations.
a gradual warming trend gets underway over the weekend beneath the
building upper level ridge. temperatures expected to warm 4-6
degrees between saturday and sunday into the low to mid 70s...then
be closer to 80 or possibly even lower 80s for memorial day. the
air mass will be fairly dry so expecting humidity to be low with a
dry forecast.
&&

aviation /12z tuesday through saturday/...
vfr conditions remain across the area with ceilings decreasing to
4-6 kft from west to east as moisture continues to increase. this
increase in moisture will also result in scattered showers which can
already be seen on regional radars across nw ohio. the challenge for
today will be timing thunderstorms...especially as instability
increases tonight. it looks like energy moving around the ridge will
cause an increase in thunderstorm activity starting around
03z...with the possibility of a large thunderstorm complex
developing. some of these thunderstorms will produce heavy
rainfall with ifr visibilities. strong wind gusts will also be
possible...mainly at tol/fdy. only included vcts in the tafs for
now given the uncertainty in timing. southeast winds will veer to
the south overnight as a warm front lifts north.

outlook...non vfr conditions possible in showers and thunderstorms
tuesday night and wednesday.
&&

marine...
southeast to easterly flow of 5 to 15 knots expected on the lake
today...veering to the south overnight with the passage of a warm
front. showers and thunderstorms are possible overnight into
wednesday...some of which could be strong. an area of low pressure
will move across the lake on wednesday with a cold front pushing
south across the lake early thursday. winds will shift to the
northwest behind the front and waves in the nearshore waters east of
cleveland will build to near 4 feet. a small craft advisory may be
needed for a window of time before high pressure starts to build in
from the west on friday with decreasing winds and waves. the
extended forecast is calling for generally good boating conditions
as we head into the memorial day weekend.
&&

cle watches/warnings/advisories...
oh...none.
pa...none.
marine...none.
&&
$$
synopsis...mullen
near term...lombardy/mullen
short term...mullen
long term...kec
aviation...kec
marine...kec

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Toledo 7-day forecast
Last Update: May 20, 2014 9:38 am

This Afternoon: A chance of showers, with thunderstorms also possible after 2pm. Mostly cloudy, with a high near 77. Southwest wind 13 to 15 mph. Chance of precipitation is 50%. New rainfall amounts of less than a tenth of an inch, except higher amounts possible in thunderstorms.

Tonight: Showers and thunderstorms likely, mainly after 4am. Cloudy, with a low around 61. Southwest wind 6 to 9 mph. Chance of precipitation is 60%. New rainfall amounts between a quarter and half of an inch possible.

Wednesday: Showers and thunderstorms likely, mainly before 7am. Mostly cloudy, with a high near 80. Light southwest wind becoming west 5 to 10 mph in the morning. Chance of precipitation is 60%. New rainfall amounts between a quarter and half of an inch possible.

Wednesday Night: Partly cloudy, with a low around 55. West wind around 10 mph.

Thursday: Sunny, with a high near 70. Northwest wind 9 to 16 mph.

Thursday Night: Partly cloudy, with a low around 50.

Friday: Mostly sunny, with a high near 69.

Friday Night: Partly cloudy, with a low around 49.

Saturday: Sunny, with a high near 76.

Saturday Night: Mostly clear, with a low around 52.

Sunday: Sunny, with a high near 78.

Sunday Night: Mostly clear, with a low around 58.

Memorial Day: Mostly sunny, with a high near 80.

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