SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook
NWS Storm Prediction Center Norman OK
1221 PM CDT Sun Apr 23 2023
Valid 241200Z - 251200Z
...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS MONDAY ACROSS
PARTS OF THE FLORIDA PENINSULA...
...SUMMARY...
Strong thunderstorms may impact interior and Atlantic coastal areas
of the Florida Peninsula Monday, and pose at least some risk for
severe weather.
...Synopsis...
Within a persistent split flow across the mid-latitude eastern
Pacific into Atlantic, one blocking high, centered near Newfoundland
and Labrador, appears likely to remain prominent through this period
and beyond. This high will be flanked to its southeast by a low
over the mid-latitude Atlantic, and to its southwest by a low which
is forecast to begin redeveloping southeast of the Upper Midwest
through the lower Great Lakes region.
Upstream, within one increasingly amplified branch of westerlies,
models suggest that mid-level ridging will build across southern
portions of the eastern mid-latitude Pacific, toward U.S. Pacific
coastal areas, while a downstream short wave perturbation digs into
the Great Basin with a developing embedded mid-level low. In
advance of the latter feature, a moistening southerly return flow
likely will commence across the lower Rio Grande Valley into the
southern Great Plains. However, relatively cool surface-based air,
associated surface high pressure encompassing most areas east of the
high plains, likely will be maintained, while inhibition increases
aloft, associated with the northward and eastward advection of
elevated mixed-layer air.
Across the Gulf Coast/Gulf of Mexico vicinity, models indicate
considerable strengthening of westerly mid/upper flow through the
period. As this occurs, it appears that a perturbation emerging
from the lower Rio Grande Valley today will overspread the Florida
Peninsula during the day Monday.
...Florida...
To the south of a reinforcing, but stalling and weakening surface
front, models indicate that low-level moisture will be maintained or
begin to increase across much of the southern and central peninsula
during the day Monday. It appears that this will include mid/upper
60s surface dew points on easterly near-surface flow, particularly
across central and southern Atlantic coastal into interior areas,
beneath relatively cool mid-level temperatures. With insolation,
this may contribute to moderate mixed-layer CAPE on the order of
1000-2000+ J/kg, prior to the approach of the mid-level short wave
trough Monday afternoon.
Aided by the strengthening large-scale forcing for ascent, it
appears that this destabilization may yield increasingly widespread
thunderstorm development across interior into Atlantic coastal areas
through late afternoon. Beneath the moderate to strong mid/upper
flow, deep-layer shear may become conducive for some of this
convection to organize, with supercell structures also possible,
which may pose a risk for severe wind and hail before convection
weakens by Monday evening.
..Kerr.. 04/23/2023
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