LIVE MAP (ABOVE) ... SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0106 AM CDT Thu Jun 08 2023
Valid 081200Z - 091200Z
...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS
OF TEXAS...THE SOUTHEAST...THE NORTHERN PLAINS...AND THE MONTANA
VICINITY...
...SUMMARY...
Isolated strong to severe thunderstorms are expected today across
parts of Texas, the Southeast, Dakotas, and northern Rockies/High
Plains. Isolated damaging winds and hail should be the main threats.
...Synopsis...
A large area of cyclonic flow is progged over the eastern U.S.
today, surrounding a low over New England. Meanwhile, a weaker low
will shift northward across the Great Basin. In between, ridging
will prevail across the central U.S. through Friday morning.
At the surface, a baroclinic zone will extend from southern New
England across the Gulf Stream and then back onshore across the
Southeast this afternoon. From there, the front will arc
northwestward across the Plains, to eastern Montana. Elsewhere,
high pressure will prevail.
...Texas...
Questions with respect to ongoing, early-period convection and
associated cloud cover remain evident, which complicates the
forecast across Texas. From a larger-scale perspective, afternoon
heating in areas uncontaminated by ongoing clouds/convection will
result in moderate destabilization, leading to
reintensification/redevelopment of storms. With enhanced
northwesterly flow aloft prevailing across central and southern
Texas, atop low-level southerlies, shear will be sufficient to
support organized storms. However, the aforementioned uncertainties
result in questions regarding both location -- and number -- of
stronger storms, and this is borne out by the latest solutions from
the various CAM runs. The HRRR in particular would support a
potential upgrade to slight risk, depicting an MCS developing across
central Texas and then propagating/expanding southeastward across
the Texas Coastal Plain with time. However, other CAMs are much
less bullish with respect to convective coverage/organization. As
such, will hold off on any upgrade at this time, and maintain
broad/low probability risk area for hail/wind.
...The Southeast...
Isolated thunderstorm development is forecast to begin early this
afternoon, from southern South Carolina into southern Georgia, as a
moist boundary layer ahead of a weak cold front advancing very
slowly southeastward across the region destabilizes. While the
stronger westerlies aloft will remain to the cool side of the
boundary, ample shear is expected along and just ahead of the
boundary, which will likely support a few sustained/organized
updrafts. While much of the stronger convection may remain just
offshore, a few storms capable of producing gusty winds and/or hail
near severe levels are expected. Risk may linger through sunset,
until storms diminish diurnally and/or shift offshore.
...Northern Plains...
A series of very weak mid-level cyclonic disturbances will continue
shifting southward across the north-central U.S., within cyclonic
flow on the back side of the New England upper low. As a moist
airmass just to the eastern/cool side of a quasi-stationary surface
front extending northwest to southeast from eastern Montana to
Nebraska heats/destabilizes, widely scattered thunderstorm
development is expected. While flow aloft is forecast to remain
rather weak, some upscale growth of convection into one or two
southeastward-moving clusters may occur. A few of the strongest
convective elements may prove capable of producing hail/wind gusts
in excess of severe levels, before storms diminish diurnally.
...Montana vicinity...
As a series of weak cyclonic disturbances aloft shift northward
across the northern Rockies/northern High Plains, scattered
afternoon thunderstorms are forecast to develop, as daytime
heating/destabilization maximize. While flow aloft will remain
relatively weak/easterly, ample CAPE atop a moderately deep mixed
layer during peak heating suggest potential for a few stronger
storms -- capable of gusty/potentially damaging winds, and
severe-caliber hail. Risk may continue locally through the evening
hours, as large-scale ascent persists across the region.
..Goss/Squitieri.. 06/08/2023
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