SPC Jan 19, 2025 0600 UTC Day 1 Convective Outlook

SPC 1200Z Day 1 Outlook

Day 1 Convective Outlook  
NWS Storm Prediction Center Norman OK
1100 PM CST Sat Jan 18 2025

Valid 191200Z - 201200Z

...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS THIS MORNING
INTO THIS AFTERNOON ACROSS CENTRAL FLORIDA...

...SUMMARY...
Strong thunderstorms may impact parts of central Florida this
morning into this afternoon, and pose at least some risk for a
tornado and locally damaging wind gusts.

...Synopsis...
Seasonably cold, stable conditions will generally prevail across the
U.S. through this period and beyond.  A blocking mid-level ridge,
centered over the northeastern Pacific, may undergo some suppression
and shift inland across British Columbia and the Pacific Northwest
coast.  However, positively tilted, large-scale downstream troughing
likely will be maintained across much of the remainder of North
America, reinforced across much of the Southwest by another digging
short wave trough. 

A more notable downstream short wave perturbation is forecast to
accelerate across the northern Mid Atlantic into the Canadian
Maritimes, after bottoming out across the lower
Mississippi/Tennessee Valleys, as a prominent ridge builds across
the subtropical western Atlantic and Caribbean.  Models indicate
that associated forcing for ascent will support more substantive
deepening of an initially modest surface frontal wave, as it
migrates offshore of the Mid Atlantic coast through the Canadian
Maritimes mid day through late tonight.  In the wake of the cyclone,
cold surface ridging will continue to build to the lee of the
Rockies, with the frontal zone demarcating the leading edge of the
cold intrusion advancing through the southeastern Gulf of Mexico,
Florida Peninsula and away from the remainder of the Atlantic
Seaboard.

...Florida...
In advance of the cold front, low-level moistening and daytime
heating may contribute to a narrow corridor of modest boundary-layer
destabilization across the central Florida Peninsula.  It appears
that this will peak during the early afternoon, aided by weak
mid-level cooling.  However, guidance also suggests that warm sector
clockwise curved low-level hodographs may maximize over inland areas
prior to mid morning, before tending to shrink and trend more linear
as the deepening surface low progresses northeastward into and
offshore of the Mid Atlantic coast.  If at least weak boundary-layer
destabilization can take place prior to weakening of the low-level
shear and forcing for ascent, the environment might become conducive
to supercell structures posing a risk for a tornado or locally
damaging wind gusts.  Otherwise, potential for scattered pre-frontal
thunderstorm development may linger over portions of the central
Florida Peninsula into this afternoon, accompanied by at least some
risk for locally damaging wind gusts, in the presence of strong
deep-layer shear.

..Kerr/Halbert.. 01/19/2025

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