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Topic: SPC Apr 30, 2022 1730 UTC Day 2 Convective Outlook (Read 73 times) previous topic - next topic

SPC Apr 30, 2022 1730 UTC Day 2 Convective Outlook

SPC Apr 30, 2022 1730 UTC Day 2 Convective Outlook

[html]SPC 1730Z Day 2 Outlook
     
Day 2 Outlook Image

Day 2 Convective Outlook 
NWS Storm Prediction Center Norman OK
1230 PM CDT Sat Apr 30 2022

Valid 011200Z - 021200Z

...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS SUNDAY
AFTERNOON/EVENING ACROSS THE SOUTHERN HIGH PLAINS...

...SUMMARY...
Very large hail, damaging winds, and a few tornadoes will be
possible Sunday afternoon into early Sunday night across the
southern High Plains.

...Southern High Plains Sunday afternoon/night...
In the wake of an occluded cyclone over western IA, a surface cold
front will stall across central TX this afternoon.  This boundary
will begin to move northward as a warm front Sunday morning, in
response to High Plains lee cyclogenesis in advance of another
shortwave trough digging southeastward from the Pacific Northwest
toward areas near/north of the Four Corners.  Rich low-level
moisture is present south of the stalling front, where lowest 100 mb
mean mixing ratios are in the 14-15 g/kg range (corresponding to dew
points in the upper 60s to lower 70s).  This moisture will spread
northwestward during the day to the east of the developing lee
trough.  The ongoing extreme drought has recently supported more
rapid surface heating and vertical mixing of moisture during the
afternoon, though this effect could be offset by the initial
moisture return above the surface and downward mixing of moisture in
the warm advection regime.

The increasing low-level moisture beneath typically steep midlevel
lapse rates (7.5-8.5 C/km) will result in moderate-strong buoyancy
by afternoon (MLCAPE in excess of 2000 J/kg) to the east of a
developing dryline in NM.  Wind profiles will also beco*e more
conducive to supercells with moderately strong westerly flow aloft,
atop increasing low-level hodograph size/clockwise curvature through
the afternoon/evening in the warm advection regime.  It appears that
the cap will be relatively weak, so scattered thunderstorm
development is likely by mid-late afternoon from southwest TX
northward near the TX/NM border, with multiple clusters/supercells
possible.  Convection will likely persist into the overnight hours,
while spreading eastward near the warm front into OK.

Large hail will be a co*mon threat with the supercells during the
afternoon/evening, potentially up to 2 to 3 inches in diameter given
the strong steep lapse rates/strong buoyancy with long hodographs.
Steep low-level lapse rates and large DCAPE will favor the potential
for occasional severe outflow gusts, especially with clusters of
storms by evening.  The tornado threat is a bit more co*plicated.
Low-level shear will beco*e more favorable for low-level rotation in
supercells by evening, with the expectation of somewhat richer
moisture with eastward extent and closer to the surface warm front.
However, the more discrete storm modes are more probable farther
west in a somewhat drier environment, so the tornado threat may
ultimately co*e down to areas of locally richer moisture and
favorable storm interactions.

...Upper OH Valley into VA/NC Sunday afternoon/evening...
A weakening shortwave trough and surface cold front will move across
the upper OH Valley tomorrow afternoon/evening, and a slow-moving
warm front will extend eastward near the NC/VA border.  Modest
low-level moisture/buoyancy and some increase in midlevel flow will
support the potential for isolated damaging winds and some hail with
convective clusters along the warm front and ahead of the cold
front.

..Thompson.. 04/30/2022


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Source: SPC Apr 30, 2022 1730 UTC Day 2 Convective Outlook (http://ht**://www.spc.noaa.gov/products/outlook/day2otlk_1730.html)