From Dumas Walker@21:1/175 to All on Sunday, March 16, 2025 09:14:00
ACUS01 KWNS 161241
SWODY1
SPC AC 161240
Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0740 AM CDT Sun Mar 16 2025
Valid 161300Z - 171200Z
...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FOR WESTERN
INTO CENTRAL PENNSYLVANIA...
...SUMMARY...
Sporadic damaging wind swaths and a few tornadoes will be the
primary threats this morning through dusk across a broad portion of
the East.
...OH Valley/northern Middle Atlantic...
Water-vapor imagery this morning shows an upper trough over the MS
Valley with an embedded mid-level vorticity maximum rotating
northeastward over the lower OH Valley. This mid-level feature will
be accompanied by an intense belt of flow (110+ kt at 500 mb)
shifting eastward across the upper OH Valley/central Appalachians
through the day. In the low levels, a surface low over southeast
Lower MI will develop northward reaching the Quebec/Ontario border
by late afternoon. A moist/weakly unstable warm sector to the
southeast of the low will only slightly destabilize through peak
heating. Yet, short-term model guidance indicates 200-500 J/kg
MLCAPE will develop later this morning across the central
Appalachians into the eastern OH/western PA border region. A
strongly forced band of convection is forecast to gradually evolve
over the upper OH Valley. Largely unidirectional southerly flow and
elongated hodographs will support a risk for scattered damaging
gusts (55-70 mph) and perhaps a couple of brief tornadoes with this
activity. The area of greatest model agreement for a convective
line posing a risk for severe appears most likely/concentrated
across western into central parts of PA. Farther south, gradual intensification of convection within a weakly unstable airmass will
support a risk for damaging gusts and perhaps a tornado or two
through early evening.
...Southeast...
The southern portion of a mid-level trough will continue east
through the lower MS Valley into the Southeast today, as a low-level
jet steadily shifts east across north FL through much of SC by
mid-late afternoon while gradually weakening south of North
Carolina. An ongoing broken band of pre-frontal strong to severe
thunderstorms will move east into a weakly unstable airmass
(reference the 12 UTC Charleston, SC raob). Prior to a gradual
weakening of 850-mb flow by early to mid afternoon, adequately
enlarged hodographs within a destabilizing airmass (1000-1500 J/kg
MLCAPE across north-central FL with considerably weaker instability
over the coastal Carolinas) will support organized storms, including
line segments (mainly north) and some supercells (south). Scattered
damaging gusts (55-70 mph) and a couple of tornadoes are possible as
the severe threat shifts east through the period.