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Topic: SPC Jul 12, 2022 1300 UTC Day 1 Convective Outlook (Read 42 times) previous topic - next topic

SPC Jul 12, 2022 1300 UTC Day 1 Convective Outlook

SPC Jul 12, 2022 1300 UTC Day 1 Convective Outlook

[html]SPC 1300Z Day 1 Outlook
     
Day 1 Outlook Image

Day 1 Convective Outlook 
NWS Storm Prediction Center Norman OK
0759 AM CDT Tue Jul 12 2022

Valid 121300Z - 131200Z

...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF
THE MID-ATLANTIC/DELMARVA...

...SUMMARY...
Thunderstorms, acco*panied by a risk for damaging winds, are
expected from New England through the Mid-Atlantic States into the
central Appalachian region and Tennessee Valley, especially this
afternoon and early evening. A few strong storms may also be noted
across the Upper Midwest and over the central High Plains.

...New England/Mid-Atlantic/Central Appalachians...
A relatively favorable setup for severe weather is in place across
the region, and portions of the Mid-Atlantic/Delmarva have been
upgraded to an Enhanced Risk with a somewhat higher/semi-focused
corridor of likely severe storms mainly capable of wind damage.

Early this morning, a notable shortwave trough/speed max are
crossing the Lower Great Lakes/southern Ontario vicinity and will
reach northern New England later today. 12z regional observed
soundings already sample strong westerlies aloft at locations such
as IAD/BUF/PIT, with the Pittsburgh (PIT) sounding also sampling a
plume of relatively steep mid-level lapse rates that will advect
eastward today.

Surface heating will lead to steep low-level lapse rates ahead of
the eastward-advancing front and near a pre-frontal surface trough.
This will likely lead to scattered convective development ahead of
the front by midday, which will spread into New England later in the
afternoon. Scattered convection may be delayed a few hours across
the middle Atlantic into the central Appalachians as large-scale
forcing will be negligible at lower latitudes. Even so, ample
buoyancy will be noted across the warm sector and forecast shear
should support the possibility for organized updrafts, potentially
including a few initial supercells. Damaging winds will be the
primary severe threat with convection this afternoon/evening across
this region, but a few instances of hail and/or a brief tornado
could also occur

...Upper Midwest/western Great Lakes...
A secondary clipper-type shortwave trough will dig southeastward
over the region later this afternoon into tonight. Low-level
moisture will be limited, but cooling temperatures aloft and strong
surface heating could support some stronger semi-low-topped storms
this afternoon through early evening. Locally damaging winds and
possibly hail could occur particularly across northern/eastern
Minnesota into northern Wisconsin.

...Central High Plains...
Moderate northwesterly flow aloft will exist on the northern/eastern
periphery of an upper ridge centered near the Four Corners area.
Scattered thunderstorms are expected to develop by mid/late
afternoon and spread southeastward across southeast Wyoming and
northeast Colorado into the Nebraska Panhandle. While PW values are
not particularly high across this region, SBCAPE values could
approach 1500 J/kg, which should be enough to warrant at least some
threat for several hail and gusty winds.

..Guyer/Leitman.. 07/12/2022


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Source: SPC Jul 12, 2022 1300 UTC Day 1 Convective Outlook (http://ht**://www.spc.noaa.gov/products/outlook/day1otlk_1300.html)