Greatest risk for strong to severe storms still likely in time range
from mid afternoon into early this evening. Strong winds aloft tied
to the MCV results in effective shear over 40 kts which is strong
for middle of summer with low-level shear 25-30+kts also strong. The
shear combined with seasonable instability (highs in the mid 80s
with dewpoints in the mid 60s) with MLCAPES 1000-1500j/kg and DCAPES
to around 1000j/kg sets the stage for storms with damaging winds the
primary threat, but not the only threat. Within slight risk over
WNY, SPC probs have WNY in a 5 pct risk for tornado (increased from
ydy) which is pretty rare for our severe weather season. Looking at
parameters specific to forecasting tornado potential (STP, LCL,
effective helicity) we are looking to be on the high end for past
tornado days in WNY. Continue to mention this risk in the HWO. It
certainly looks justified. Best potential will be mid to late
afternoon as storms will initially be discrete with possible
supercells. Eventually though given the strong 0-1km shear and the
approaching front, storms should become linear as they move east
toward Genesee valley and perhaps western Finger Lakes/SE Lake
Ontario region with gusty to damaging winds the prime threat.
Finally, torrential downpours will be likely in any storm as PWATS
surge to over 2 inches. Storms will be moving, so would likely need
to have training storms for larger flooding risk.