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acus01 kwns 161951
swody1
Storm Prediction Center ac 161950
Day 1 convective outlook
National Weather Service Storm Prediction Center Norman OK
0250 PM CDT Wednesday may 16 2012
Valid 162000z - 171200z
..there is a slight risk of severe thunderstorms across parts of the
northeast...
..the northeast...
Broken bands of thunderstorms have developed from northern New York/Vermont southwestward
across PA and into Ohio this afternoon...along and ahead of an
advancing surface cold front as per prior forecast expectations.
With 1000 to 1500 j/kg mixed layer cape ahead of the front and the
upper trough -- and associated belt of stronger flow aloft --
pivoting across the Great Lakes region into the northeast/New
England...threats for hail and damaging winds can be expected the
remainder of the afternoon and early evening.
..ern NC and vicinity...
A cluster of thunderstorms has developed along the sea breeze
boundary this afternoon...within a moderately unstable environment.
Shear supportive of multicell clusters suggests that local/limited
severe potential should persist through sunset.
.Goss.. 05/16/2012
Previous discussion... /issued 1044 am CDT Wednesday may 16 2012/
..northeast states...
A strong upper trough is rotating eastward across the Great Lakes
region and Ontario this morning...while a 70+ knot middle level jet
rounds the base of the trough and noses into NY/VT. At the
surface...a cold front extends from Northern Ohio into Lake Ontario
with a pre-frontal boundary across central New York. Present indications
are that both boundaries will become convectively active later today
with a threat of large hail and damaging winds across portions of
eastern PA/New York and western New England.
Visible satellite trends suggest that the first convection may form
along the pre-frontal trough over central New York into northeast PA.
Strong heating will promote steep low level lapse rates...and
dewpoints in the 50s to lower 60s will help yield MLCAPE values of
1000-2000 j/kg. Storms that form will be in an environment of
sufficient deep layer effective shear for supercell structures
capable of large hail and damaging winds. Storms will likely spread
eastward across parts of Vermont/New Hampshire and western Massachusetts/CT before weakening
this evening. Present indications are that southerly onshore flow
will limit destabilization in areas farther east...and across the
NYC area.
..eastern Carolinas...
Scattered thunderstorms are expected to form once again today along
the seabreeze of eastern SC/NC. Ample low level moisture and
sufficient southwesterly flow aloft may result in a few intense
cells capable of hail and gusty/damaging winds.
Mesoscale Discussion
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acus11 kwns 161937
sels mesoscale discussion
Storm Prediction Center mesoscale discussion 161937
vtz000-maz000-nyz000-paz000-162130-
Mesoscale discussion 0825
National Weather Service Storm Prediction Center Norman OK
0237 PM CDT Wednesday may 16 2012
Areas affected...central and eastern New York...western New England
Concerning...Severe Thunderstorm Watch 280...
Valid 161937z - 162130z
The severe weather threat for Severe Thunderstorm Watch 280
continues.
Summary...a severe threat persists across the watch area with the
greatest threat over central and northern portions.
Discussion...storms continue to develop over the region...with the
strongest activity from east central New York into Vermont with likely hail and
wind. Surface observations indicate rapid drying with dewpoints now
in the middle 40s f across northern PA and S central New York. Farther east...the 18z
alb sounding showed substantially more low level moisture near the
instability axis with upper 50s to low 60s f on average. MLCAPE was
near 1000 j/kg using this sounding...a bit less than previously
forecast.
Areas of heating will continue ahead of the ongoing storms...and
some further intensification will be possible.
.Jewell.. 05/16/2012
..please see www.Spc.NOAA.Gov for graphic product...
Attention...WFO...btv...aly...bgm...buf...ctp...
Latitude...Lon 41787725 42467691 43027599 44177481 45037402 45077239
44907202 44267222 43287253 42387333 41897365 41677450
41587499 41427608 41597687 41787725
