SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0258 PM CDT Thu Jun 16 2022
Valid 162000Z - 171200Z
...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS
OF NEW YORK AND PENNSYLVANIA...
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS THE MIDDLE
AND LOWER MISSOURI VALLEY VICINITY...
...SUMMARY...
Scattered severe thunderstorms will continue across parts of the
Northeast and Ohio Valley this afternoon/evening. Large hail,
damaging winds, and possibly a few tornadoes can be expected.
Strong/severe thunderstorms with hail/wind will also develop across
portions of the central Plains into the lower Missouri Valley
region. Isolated strong storms will also continue across the Gulf
Coast states.
...Discussion...
Only minor line adjustments appear necessary with this outlook
update, as severe storms continue to evolve as expected from the
Lake Ontario vicinity to central Ohio on western fringes of the ENH
outlook, from central Maryland to northwestern Georgia through the
southern extension of the SLGT risk, and across portions of the
central Gulf Coast area/lower Mississippi Valley within the MRGL
risk area.
Meanwhile, storm development remains likely across the Mid Missouri
Valley area, and then spreading east-southeastward across the Lower
Missouri Valley this evening/overnight.
..Goss.. 06/16/2022
.PREV DISCUSSION... /ISSUED 1141 AM CDT Thu Jun 16 2022/
...Northeast/Mid-Atlantic States...
An active severe-weather day is expected across the region, with
essentially all convective modes/hazards possible. Steady
large-scale height falls, along with a strengthening of cyclonically
curved westerlies, will occur via the approach of the upstream
trough over Ontario. Upstream regional 12z soundings/upper-air data
sampled 50+ kt mid-level winds early this morning over Lower
Michigan into Illinois (and likely Indiana).
A very moist and potentially unstable air mass is in place across
the Northeast, where daytime highs well into the 80s F and dewpoints
near 70F will yield MLCAPE values of 2000-3000 J/kg with little
capping inversion. General thinking remains that thunderstorms will
form this afternoon along an approaching cold front, initially from
western/northern New York into northwest Pennsylvania into
eastern/central Ohio, with additional development possible within
the warm sector in vicinity of the mountains and/or lee trough.
Low-level winds are not forecast to be particularly strong, but
favorable deep-layer shear and degree of instability suggest that
discrete supercells will be possible, capable of very large hail and
possibly a few tornadoes. This activity will spread
east/southeastward during the afternoon/evening especially across
the Enhanced Risk area that includes much of New York and
Pennsylvania. Upscale growth into short bowing segments can be
expected as storms spread toward additional parts of the
Mid-Atlantic this evening, although a more stable air mass will
likely persist for coastal areas.
...Central Appalachians/Carolinas...
On the eastern periphery of the Tennessee Valley-centered upper
ridge, mid-level temperatures have cooled since yesterday, by as
much as 1-2.5C at 700 mb over the past 24 hours as per 12z observed
soundings from KRNK/KGSO. This should result in a more active day
for thunderstorms across the region including the potential for
pulse-type downbursts capable of localized wind damage. A gradual
clustering/modest organization of storms could occur, pending
sufficient storm development, aided by a modestly enhanced belt of
northwesterly mid-level winds, which are noted on the northeast
periphery of the upper ridge. Several convection-allowing models
(such as NSSL-ARW and NAM 3km) lend credence to this possibility.
...Parts of Nebraska/Kansas into Missouri/Illinois...
A cold front will sag southward across the Midwest, while the front
remains quasi-stationary from western/northern Kansas into northern
Missouri. A northward-building upper ridge (centered over the
Mid-South) will influence additional capping and likely limit deep
convective development during the day. The most likely scenario is
for storms to develop/increase this evening into the overnight
along/north of the boundary as the low-level jet strengthens. Large
hail would be the main threat initially, but damaging wind potential
may also emerge, particularly as storm mergers occur and storms tend
to grow upscale.
...Gulf Coast States...
Although probably not as widespread as across Alabama/Georgia late
yesterday afternoon into evening, west/southwest-moving afternoon
and early evening thunderstorms are again expected from the Florida
Panhandle westward into parts of Mississippi/Louisiana. Hot and
humid conditions with temperatures in the mid/upper 90s and large
CAPE values will promote damaging wind gusts in the stronger cores.
Read more CHECK UPDATE ZOOM GRAPHIC
http://dlvr.it/SSKjw5
