SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0244 PM CDT Fri May 27 2022
Valid 272000Z - 281200Z
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF
THE MID-ATLANTIC AND NORTHERN HIGH PLAINS...
...SUMMARY...
Occasional damaging wind gusts and a tornado or two remain possible
this afternoon across parts of the Mid-Atlantic region.
Thunderstorms may produce severe gusts this afternoon into early
evening over portions of the northern High Plains.
...20Z Update...
Have reconfigured the Slight Risk across NC into the Mid-Atlantic. A
small area of 15% severe wind probabilities have been maintained
ahead of a line moving quickly northeastward across far eastern PA
into NJ and vicinity. Current expectations are for this convection
to gradually weaken as it moves into southern NY and New England and
encounters a less unstable airmass. But, it may still pose a threat
for isolated strong/gusty winds in the short term. See Mesoscale
Discussion 939 for more details.
A separate Slight Risk has been maintained from portions of central
NC into southern/central VA. Recent observational and satellite
trends show attempts at destabilization in the wake of the morning
convection across this area. Deep-layer shear associated with the
upper trough to the west remains fairly strong, around 40-50 kt.
Some recent high-resolution model guidance suggests that as MLCAPE
increases into the 1000-1500 J/kg range over the next few hours,
thunderstorms may intensify ahead of a moisture gradient noted in
surface observations over western/central NC. Even with a
predominately meridional component to the deep-layer shear, enough
speed shear should be present for organized updrafts, with
multicells and perhaps a couple of supercells possible. Damaging
winds will probably be the main threat if convection can strengthen,
although a brief tornado or two and some hail also remain a
possibility.
No changes have been made to the Slight Risk across parts of WY/SD.
..Gleason.. 05/27/2022
.PREV DISCUSSION... /ISSUED 1129 AM CDT Fri May 27 2022/
...Carolinas/Mid-Atlantic this afternoon...
A broken line of storms has persisted since early this morning, with
new development east of the band in the destabilizing warm sector
where surface temperatures have warmed into the 78-82 F range with
dewpoints near 70 F. Vertical shear is sufficient for organized
line segments or rotating cells ahead of (and within) the band, with
attendant threats for occasional damaging gusts and a couple of
tornadoes.
...Southeast OH into western VA and central NC this afternoon...
Additional storm development may occur farther west this afternoon,
immediately in advance of the midlevel trough, and west of this
morning/ongoing convection. Buoyancy will be weaker compared to
areas farther east, and low-level shear will be relatively weak,
which suggests that isolated damaging winds will be the main threat
this afternoon.
...Northeast WY/western SD this afternoon/evening...
A midlevel shortwave trough will move eastward from the northern
Rockies to the northern High Plains by this afternoon/evening.
High-based supercell development is expected this afternoon in the
Slight risk area, in a deeply mixed environment with some increase
in midlevel flow. As such, the primary threat with these storms
will be severe outflow gusts later this afternoon into this evening.
Read more CHECK UPDATE ZOOM GRAPHIC
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