New York, NY...Philadelphia, PA...Baltimore, MD...Washington, DC...Newark, NJ...
Columbus, OH...Boston, MA...Oklahoma City, OK...Pittsburgh, PA...Cincinnati, OH...
SPC AC 141723
Day 2 Convective Outlook
NWS Storm Prediction Center Norman OK
1223 PM CDT Mon May 14 2018
Valid 151200Z - 161200Z
...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FROM PARTS OF
NORTHEAST PA/SOUTHEAST NY INTO WESTERN NEW ENGLAND...
Severe thunderstorms, primarily capable of damaging winds, are
forecast across parts of the Mid-Atlantic and New England Tuesday
afternoon and evening. Other strong storms will impact portions of
northeast New Mexico into the southern Plains.
...Mid-Atlantic into New England...
Zonal, slightly cyclonic mid-level flow will evolve across the
region on Tuesday. Within this flow regime, a subtle but coherent
impulse will advance east from the Midwest towards Pennsylvania/New
York through the day. This progression should be favorably timed for
boundary-layer heating to occur behind early morning precipitation
(associated with a prior shortwave trough) and ahead of a cold front
associated with the secondary impulse. Additionally, surface dew
points should rise into the mid/upper 60s to near 70 from northeast
PA / NJ into southern/central New England by the afternoon. Combined
with 700-500mb lapse rates upwards of 7-7.5 C/km, these
boundary-layer conditions should yield MLCAPE values around
2000-2500 J/kg across parts of the Mid-Atlantic, and around
1000-1500 J/kg into parts of New England.
As the secondary wave approaches, low-level confluence (albeit not
particularly strong) and mid-level ascent are expected to focus
convective development/intensification from parts of western PA
northeastward to the Hudson Valley and western New England. In
conjunction with this wave, westerly 500mb flow will be robust --
around 50-70 kt. Relatively straight hodographs suggest cells will
organize into bowing segments that accelerate east across parts of
PA, the Hudson Valley, and portions of western/southern New England.
Some potential exists for enhanced/focused eastward propagation
along a remnant outflow boundary from morning convection, and this
would locally maximize the damaging wind threat (possibly from
northeast PA/southeast NY into western CT/MA). Considering the
mid-level wind fields, reasonable confidence in destabilization, and
convective signal from several CAMs, the slight/marginal risks have
been expanded northward, and an enhanced risk has been introduced
from parts of northeast PA into far western New England.
While background near-surface winds will generally be veered and not
particularly strong, localized backing in area valleys and/or ahead
of line-embedded vortices may favor a couple of tornadoes as well.
Convective potential continues to appear uncertain/unorganized.
Complexities regarding outflow from the prior period, combined with
subtle/convectively augmented impulses within the mid-level flow
regime, will impact the focus of stronger convection across the
region. Despite this, steep mid-level lapse rates and strong surface
heating will encourage isolated pockets of strong/damaging winds and
perhaps large hail with the most intense cores during the afternoon
...MAXIMUM RISK BY HAZARD...
Tornado: 5% - Slight
Wind: 30% - Enhanced
Hail: 5% - Marginal
CLICK TO GET WUUS02 PTSDY2 PRODUCT
NOTE: THE NEXT DAY 2 OUTLOOK IS SCHEDULED BY 0600Z