Toledo Weather - Mon, Jun 6, 2016

This morning, the Marginal Risk as a little below Toledo. Late this morning, the Marginal Risk included Toledo and southeast Michigan.

Now the SPC may upgrade the risk to Slight.

md 0829 concerning outlook upgrade for portions of the lower great lakes and ohio valley region

mesoscale discussion 0829
nws storm prediction center norman ok
1041 am cdt mon jun 06 2016

areas affected...portions of the lower great lakes and ohio valley
region

concerning...outlook upgrade

valid 061541z - 061645z

summary...a categorical upgrade to slight risk is being planned for
the 1630z day 1 convective outlook...for portions of the lower great
lakes and ohio valley region. clusters of fast-moving thunderstorms
with damaging wind gusts will likely move across the area this
afternoon.

discussion...the latest observational data and short-range model
guidance offer increasing confidence that fast-moving convective
clusters will have the potential to produce dmgg wind gusts across
portions of the lower great lakes and ohio valley region this
afternoon. this activity will be in association with a vigorous
upper-level disturbance approaching the area from the wnw...ahead of
which a destabilizing air mass will exist amidst strong deep-layer
flow. additional meteorological reasoning for the upgrade will be
provided in the forthcoming day 1 convective outlook.

..cohen/weiss/bunting.. 06/06/2016

...please see www.spc.noaa.gov for graphic product...

attn...wfo...pbz...rlx...cle...iln...dtx...iwx...grr...ind...

lat...lon 41568262 41727994 41287933 40657937 39788087 39258290
39588525 40288613 41278623 42508565 42808418 42588284
41568262

---

md 0830 concerning severe potential...watch possible for portions of cntrl and srn lower michigan and lake michigan

mesoscale discussion 0830
nws storm prediction center norman ok
1118 am cdt mon jun 06 2016

areas affected...portions of cntrl and srn lower michigan and lake
michigan

concerning...severe potential...watch possible

valid 061618z - 061845z

probability of watch issuance...60 percent

summary...fast-moving tstms with dmgg-wind potential will likely
move across the area this afternoon...and the issuance of a severe
thunderstorm watch may be required early this afternoon.

discussion...organized convection has already developed across
portions of e-cntrl wi immediately in advance of a mid-level vort
max orbiting around the swrn rim of a deep cyclone centered over wrn
quebec. forward extrapolation of the vort max takes it on a path
reaching near detroit around 20z/21z and near cleveland ohio around
22z/23z. this suggests that dcva will spread across the region near
and prior to peak heating. despite only limited low-level moisture
available -- e.g. dewpoints in the lower/middle 50s -- steepening
low/mid-level lapse rates with adiabatic cooling aloft related to
the dcva will support sufficient buoyancy for tstm intensification
this afternoon.

upstream vwps at grb and mkx sample deep unidirectional flow with
wlys at 30-45 kt through the lower/middle portion of the convective
layer. this kinematic profile supporting elongated straight
hodographs...combined with ample high-level flow enhancing
convective ventilation...suggests that splitting tstms and
fast-moving convective clusters will likely spread across the region
during the afternoon hours. the relatively dry thermodynamic
profiles will encourage evaporational cooling to accelerate
downdrafts and convective momentum transport...facilitating the
potential for dmgg wind gusts. isolated svr hail may also occur
given cooling profiles aloft and anticipated splitting tstms. there
is some uncertainty regarding the timing of the more robust increase
in svr potential which extends to possible ww issuance...though the
svr risk will likely increase this afternoon.

..cohen/weiss.. 06/06/2016

...please see www.spc.noaa.gov for graphic product...

attn...wfo...dtx...apx...iwx...grr...

lat...lon 41918563 42188665 42988734 43738706 43888646 43928554
43958380 44008281 42748269 41938351 41918563

---

md 0833 concerning severe potential...watch possible for much of ohio...portions of cntrl/ern indiana...wrn pa...wrn wv panhandle

mesoscale discussion 0833
nws storm prediction center norman ok
0211 pm cdt mon jun 06 2016

areas affected...much of ohio...portions of cntrl/ern indiana...wrn
pa...wrn wv panhandle

concerning...severe potential...watch possible

valid 061911z - 062145z

probability of watch issuance...60 percent

summary...portions of the lower great lakes and the ohio valley
region are being monitored for possible severe thunderstorm watch
issuance.

discussion...convective development is ongoing across portions of
the lower great lakes and the ohio valley region. visible satellite
loops indicate relatively shallow cumulus development within a
pocket of deeply mixed boundary-layer air from nrn indiana extending
into nwrn ohio. the leading edge of the deeper mixing aligns with a
weak sfc trough/wind-shift axis that has some semblance to a
dryline...with sfc warming/drying to its w. this boundary arcs swwd
into w-cntrl indiana...and agitated cu development is becoming
concentrated in its proximity. farther e...a more widespread cu
field is evident from central ohio ewd to the upper ohio
valley...with a few showers developing from e of the columbus metro
toward pittsburgh.

the 18z special raob from wilmington ohio samples the slightly
moister air e of the dryline-like boundary...while also indicating
steep low-level lapse rates -- e.g. 9 c/km in the lowest 3 km agl.
comparison of this raob to the 12z iln raob suggests ascent having
taken place through an elevated warm layer above 650 mb...with
cooling noted at the base of this warm layer. vis imagery confirms
the overall manifestation of this warm layer via flat/laterally
expanding cu cells. however...slight modifications to the most
recent wilmington raob to account for additional diabatic sfc-layer
heating suggest that sufficiently deep mlcape layers will arise by
around 20z/21z for convective deepening to take place sufficiently
for an increasing svr risk. the approach of a strong mid-level vort
max and speed max from the wnw will further support convective
development and intensification...initially evolving from the
aforementioned incipient-convection regimes.

upstream vwps at iwx and lot suggest that deep unidirectional/wly
flow will continue to overspread the region...with 30-45 kt of flow
through the lower/middle portion of the convective-cloud layer --
supporting ample convective momentum transport. dmgg wind gusts will
be possible...especially given substantial sub-cloud evaporational
cooling in the relatively dry environment. straight hodographs will
also support splitting tstms capable of marginally svr hail given
cooling thermal profiles aloft...although tstms should tend to
congeal into small...fast-moving clusters with strong outflow winds.

uncertainty regarding ww issuance stems from uncertainty in the
timing of more robust increase in svr potential. this is especially
the case given the presence of only modest buoyancy -- i.e. mlcape
around 250-750 j/kg -- and weak low-level convergence.
however...given the favorable kinematic profiles for dmgg wind
gusts...and given the steep low-level lapse rate
environment...convective and observational trends will continue to
be monitored for possible severe thunderstorm watch issuance.

..cohen/weiss.. 06/06/2016

...please see www.spc.noaa.gov for graphic product...

attn...wfo...ctp...pbz...rlx...cle...iln...iwx...ind...

lat...lon 40708579 41248337 41538043 41317877 40317905 39438118
39258337 39318604 39968648 40708579

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