Probability of damaging thunderstorm winds or wind gusts of 50 knots or higher within 25 miles of a point. Hatched Area: 10% of greater probability of wind gusts 65 knots or greater within 25 miles of a point.
SPC AC 251730
Day 2 Convective Outlook
NWS Storm Prediction Center Norman OK
1230 PM CDT Thu Mar 25 2021
Valid 261200Z - 271200Z
...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF
THE NORTHEAST...SOUTHEAST...LOWER MISSISSIPPI VALLEY...AND CENTRAL
Isolated strong to severe storms may occur Friday across parts of
the Northeast, central Plains, and from the eastern Carolinas into
southern Georgia. Late Friday night a few strong storms with hail
may develop across parts of the lower Mississippi Valley.
A shortwave trough with attendant 80-100 kt mid-level jet should
move northeastward from the Lower Great Lakes across the Northeast
and southern Ontario/Quebec through Friday evening. Southwesterly
flow in the 850-700 mb layer is also forecast to be quite strong,
generally 50-70+ kt. A surface low initially near Lake Erie should
develop east-northeastward along/near the International border. Even
though low-level moisture will likely remain limited, with surface
dewpoints generally in the mid to upper 50s, modest diurnal heating
and cooling mid-level temperatures may support MLCAPE up to 500 J/kg
across parts of the Northeast. Given the strength of low-level flow,
low-topped storms capable of producing isolated strong to damaging
winds and perhaps a brief tornado may develop along/ahead of a
surface cold front Friday afternoon.
A weak surface low should develop over western KS by Friday evening
as a low-amplitude shortwave trough ejects northeastward across the
central Plains through the day. A warm front should extend east from
the low across northern KS, with a surface trough/dryline extending
southward through west-central KS. Low-level moisture is expected to
remain quite limited, with surface dewpoints in the upper 40s to
perhaps 50F south of the warm front over KS. Despite this meager
moisture, surface heating and cool temperatures aloft may support
the development of weak instability (MLCAPE up to 500 J/kg) by
Friday afternoon/early evening. A couple strong to severe storms may
develop both along the warm front near the KS/NE border, and farther
west near the triple point. 30-40 kt of effective bulk shear and the
weak instability should support organized, low-topped storms posing
a threat for hail, strong/gusty winds, and perhaps a brief tornado
through Friday evening.
...Carolinas into Georgia...
Stronger large-scale forcing for ascent associated with the
shortwave trough over the Northeast will likely remain displaced to
the north of this region. A strong southwesterly low-level jet
initially extending from the Mid-Atlantic to eastern NC Friday
morning should move offshore by mid day. Even though a moist
low-level airmass will be in place ahead of a cold front from GA to
NC, there remains considerable uncertainty in overall storm coverage
through Friday afternoon. Any storms that can form along or ahead of
the front may pose an isolated strong/gusty wind threat given weak
to moderate instability and strong deep-layer shear. The tendency
for low-level winds to veer/weaken through the day, combined with
only shallow convergence along the cold front suggests that the
overall severe threat should remain quite isolated/marginal.
...Lower Mississippi Valley...
A front should stall along the central Gulf Coast vicinity during
the day, before lifting northward as a warm front Friday night as a
southerly low-level jet strengthens over the lower MS Valley.
Gradual destabilization and lift associated with this process may
contribute to elevated storms late Friday night into early Saturday
morning across parts of the lower MS Valley/Mid-South. Given that
MUCAPE may reach 1000-1500 J/kg and sufficient (35-40 kt) of
effective bulk shear, a few instances of marginally severe hail may
occur with this convection.
CLICK TO GET WUUS02 PTSDY2 PRODUCT
NOTE: THE NEXT DAY 2 OUTLOOK IS SCHEDULED BY 0600Z