SPC AC 041942
Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0242 PM CDT Thu Nov 04 2021
Valid 042000Z - 051200Z
...NO SEVERE THUNDERSTORM AREAS FORECAST...
...SUMMARY...
Organized severe thunderstorms are not expected across the U.S.
today.
...20Z Outlook Update..,
Low-level convergence still appears relatively weak, but latest
satellite imagery suggests that the initiation of at least one or
two thunderstorms is possible by 22-23Z over interior southern
Florida, within a confluent low-level regime south of Lake
Okeechobee into areas east of Fort Myers. This is where insolation
within a seasonably moist boundary layer has contributed to CAPE on
the order of 1000-1500 J/kg. Beneath moderate to strong
southwesterly flow in the 500-300 mb layer, deep-layer shear is
strong, but it is still not obvious that storms will be able to pose
more than a small to perhaps marginally severe hail, and locally
strong, but sub-severe, wind gust risk. As a result severe
probabilities are being maintained at less that 5 percent.
Otherwise, this activity seems likely to weaken after dark, with the
loss of daytime heating, and probabilities for thunderstorm activity
over inland areas of central and southern Florida appear generally
low.
..Kerr.. 11/04/2021
.PREV DISCUSSION... /ISSUED 1058 AM CDT Thu Nov 04 2021/
...FL...
A large upper trough remains in place over the eastern CONUS today,
with a southern stream jet max tracking across the Gulf of Mexico
toward FL. Increasing large-scale lift ahead of this feature will
result in expanding coverage of showers and thunderstorms over the
southern FL peninsula this afternoon and tonight. Ample low-level
moisture and MLCAPE values approaching 1000 J/kg will support a few
robust thunderstorms will heavy rain and perhaps gusty winds.
However, low and mid-level winds are rather weak today. This should
limit the risk of severe storm activity to very isolated and brief
in nature.
Elsewhere, a few lightning flashes are possible this afternoon over
the mountains of northern ID and vicinity. This threat should end
by 00z.
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