Day 1 Convective Outlook  
NWS Storm Prediction Center Norman OK
0719 PM CST Tue Dec 31 2024

Valid 010100Z - 011200Z

...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PART OF
THE MID-ATLANTIC...

...SUMMARY...
Isolated damaging gusts, hail and a brief tornado will be possible
in parts of the Mid-Atlantic including New Jersey and southern Long
Island early this evening.

...Mid-Atlantic/New Jersey/Southern Long Island...
The latest water vapor imagery shows a negatively-tilted shortwave
trough moving northeastward across the Mid-Atlantic and central
Appalachian Mountains. At the surface, a trough is located from
Maryland extending southwestward into the western Carolinas, with a
warm front analyzed from the Delmarva eastward into the western
Atlantic. Near the warm front, the latest RAP has an axis of
instability, with MLCAPE over land estimated to be in the 500 to
1000 J/kg range. The latest radar imagery shows the remnants of a
bowing line segment near the coast of southern New Jersey. The HRRR
suggests additional thunderstorms may develop northward along the
coast of New Jersey to near southern Long Island over the next
couple of hours, where instability is forecast to increase. For this
reason, the threat for marginally severe gusts and hail is expected
to continue. A brief tornado will also be possible if a bowing
segment can become organized...reference MCD 2324.

Further south across north-central North Carolina, isolated
thunderstorms are ongoing near the surface trough ahead of an axis
of weak instability. These storms are forecast to gradually weaken
as they move eastward into northeastern North Carolina this evening.

..Broyles.. 01/01/2025

Day 1 Convective Outlook  
NWS Storm Prediction Center Norman OK
0138 PM CST Tue Dec 31 2024

Valid 312000Z - 011200Z

...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM THE CENTRAL
APPALACHIANS TO THE MID ATLANTIC...

...SUMMARY...
Damaging gusts, isolated hail, and a brief tornado remain possible
this afternoon from the central Appalachians into parts of the
Mid-Atlantic.

...20z Update...
The previous forecast remains valid with minimal changes. The
western edge of the Marginal Risk area has been removed from
portions of eastern KY and western WV, as the aforementioned upper
trough has moved eastward. Weak buoyancy (200-400 J/kg MUCAPE) is
present across parts of WV and VA where clear skies have allowed
surface temperatures to warm to near 60 F beneath the mid-level cold
core. Despite very minimal surface moisture (dewpoints in the 30 to
40s F) steep mid and low-level lapse rates (7-7.5 C/km) will
continue to allow for 35-50 kt of 0-3 km flow to mix down to the
surface. Several gusts of 45+ kt have been observed with low topped
convective bands ahead of and along the cold front. As these storms
move eastward, they will continue to pose a risk for damaging winds
through the afternoon. Isolated small hail and perhaps a brief
tornado also remain possible with any stronger rotating cells, given
relatively strong low-level speed shear. See the prior discussion
and MCD 2322 for more info.

..Lyons.. 12/31/2024

.PREV DISCUSSION... /ISSUED 1025 AM CST Tue Dec 31 2024/

...KY to the Mid Atlantic Region...
A potent, negatively-tilted shortwave trough will move from the
upper OH Valley into NY/PA today, with an associated 80-100 knot
mid-level speed max nosing across the Carolinas.  Strong large-scale
forcing and low-level warm advection is resulting in sufficient lift
for the development of multiple lines/clusters of low-topped
convection (some with lightning) across parts of OH/KY/TN/WV.  This
activity will move quickly eastward through the day across the
central Appalachians and into the Mid Atlantic region this
afternoon/evening.  

Forecast soundings show cold mid-level temperatures, resulting in
steep lapse rates aloft.  This will continue to support a threat of
thunderstorms through tonight.  Low-level moisture is quite limited,
and forecast CAPE values are below 500 J/kg.  Nevertheless,  low and
mid-level wind fields are very strong, which could easily mix down
within any more-organized convection.  Low-level shear is also
strong enough to support updraft rotation (as already noted in a few
cells this morning in KY) which could pose a risk of a brief tornado
or occasional hail through the period.

Day 3 Convective Outlook  
NWS Storm Prediction Center Norman OK
0124 PM CST Tue Dec 31 2024

Valid 021200Z - 031200Z

...NO THUNDERSTORM AREAS FORECAST...

...SUMMARY...
Thunderstorms are not expected Thursday.

...Synopsis...
A stable pattern will persist through Thursday, with an upper ridge
along the West Coast and a broad region of cyclonic flow aloft to
the east. That ridge will push eastward across the Great Basin
through Friday morning, as a shortwave trough approaches the coastal
Pacific Northwest. Meanwhile, an embedded wave is forecast to
amplify toward the lower MS Valley/Southeast, with developing
precipitation from LA into southern MS and AL.

At the surface, high pressure will be in place over the Southeast,
with east to northeast winds across the Gulf of Mexico. A secondary
surge of polar air will spread south across the MO/MS Valleys late,
pushing the moist air mass just off the TX Coast even farther south.

While a few thunderstorms may occur over the western Gulf waters,
activity over land is unlikely. Minimal elevated instability may
develop into the lower Sabine Valley and into southern LA, but the
overall probability of rogue flashes appears to be less than 10%
within the larger-scale precipitation shield atop the surface stable
layer.

..Jewell.. 12/31/2024

Day 2 Convective Outlook  
NWS Storm Prediction Center Norman OK
1043 AM CST Tue Dec 31 2024

Valid 011200Z - 021200Z

...NO THUNDERSTORM AREAS FORECAST...

...SUMMARY...
Thunderstorms are not expected Wednesday.

...Synopsis...
An upper low will be situated over northern Ontario with a broad
area of lower heights across the Canadian Prairies. South of this
low, a broad fetch of moderate to strong high-level flow will extend
from the western US into the Southeast, with a leading wave ejecting
in negative-tilt fashion across the Northeast. With time, upper
ridging will occur along the West Coast.

At the surface, high pressure will be centered over the central to
southern Plains, with a deepening low over Maine, in association
with the upper wave. As a result, northerly winds will exist along
the Gulf Coast, with offshore flow along the East Coast as well. The
end result will be stable conditions across the bulk of the CONUS,
with little if any thunderstorm or lightning potential. While a
flash or two cannot be ruled out ahead of the New England surface
low, any weak elevated instability should remain largely offshore.

..Jewell.. 12/31/2024

Day 1 Convective Outlook  
NWS Storm Prediction Center Norman OK
1025 AM CST Tue Dec 31 2024

Valid 311630Z - 011200Z

...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON
AND EVENING FROM EASTERN KENTUCKY INTO THE MID ATLANTIC REGION....

...SUMMARY...
Damaging to isolated marginally severe gusts, isolated large hail,
and a brief tornado are possible today from the central Appalachians
to parts of the Mid-Atlantic.

...KY to the Mid Atlantic Region...
A potent, negatively-tilted shortwave trough will move from the
upper OH Valley into NY/PA today, with an associated 80-100 knot
mid-level speed max nosing across the Carolinas.  Strong large-scale
forcing and low-level warm advection is resulting in sufficient lift
for the development of multiple lines/clusters of low-topped
convection (some with lightning) across parts of OH/KY/TN/WV.  This
activity will move quickly eastward through the day across the
central Appalachians and into the Mid Atlantic region this
afternoon/evening.  

Forecast soundings show cold mid-level temperatures, resulting in
steep lapse rates aloft.  This will continue to support a threat of
thunderstorms through tonight.  Low-level moisture is quite limited,
and forecast CAPE values are below 500 J/kg.  Nevertheless,  low and
mid-level wind fields are very strong, which could easily mix down
within any more-organized convection.  Low-level shear is also
strong enough to support updraft rotation (as already noted in a few
cells this morning in KY) which could pose a risk of a brief tornado
or occasional hail through the period.

..Hart.. 12/31/2024

Day 1 Convective Outlook  
NWS Storm Prediction Center Norman OK
0657 AM CST Tue Dec 31 2024

Valid 311300Z - 011200Z

...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM THE CENTRAL
APPALACHIANS TO PARTS OF THE MID-ATLANTIC...

...SUMMARY...
Damaging to isolated marginally severe gusts, isolated large hail,
and possibly a brief tornado, are possible today from the central
Appalachians to parts of the Mid-Atlantic.

...Synopsis...
In mid/upper levels, a progressive shortwave pattern will persist
within a broadly cyclonic flow field covering much of the CONUS from
the Rockies eastward.  The most important of these features for
convective potential will be a well-developed shortwave trough --
evident in moisture-channel imagery from a low over IL south-
southeastward to western portions of KY and the lower Tennessee
Valley region.  Though the 500-mb low may not remain closed, the
trough will remain strong and shift east-northeastward up the Ohio
Valley today, reaching OH, WV and the western Appalachians of VA/NC
by 00Z.  The trough should pivot over the northern Mid-Atlantic and
offshore from the Delmarva Peninsula by 12Z.

At the surface, 11Z analysis showed a low between CMI-MTO, related
to the shortwave trough aloft, a cold front arching southwestward
across western parts of TN/KY, and a warm front east-southeastward
across northeastern KY that will shift northeastward over portions
of WV and southern OH through the early afternoon, as the low
occludes and moves northeastward.  By 00Z, the low should reach the
CLE area, with cold front moving eastward across western parts of VA
and NC, and warm front moving north up the Atlantic Coast and across
the Delmarva Peninsula. An older frontal zone, now well offshore,
should continue to weaken, with considerable theta-e advection
occurring to its west near the coast.

...Central Appalachians to Mid-Atlantic...
Episodic lines and clusters of thunderstorms are expected to move
eastward across the outlook area today, from the northern
Cumberland/southern Allegheny Plateau region eastward toward coastal
Delmarva and vicinity, with occasional strong/isolated severe gusts
and hail the main severe modes, but with marginal tornado threat as
well. 

Large-scale ascent will spread over this region in the form of
strong midlevel DCVA/cooling immediately preceding the trough, as
well as the peripheral/ageostrophic influences of the left exit
region of a strong 250-300-mb jet, centered from the Ozarks to the
western Carolinas.  Associated destabilization aloft will offset
modest (but diurnally steepening) low-level lapse rates and marginal
moisture behind the offshore front.  This yields an area of 100-300
J/kg MLCAPE already apparent in objective analyses between RAOBs,
over southern IN, despite cool surface conditions.  This weakly
buoyant regime is forecast to expand and strengthen somewhat
(300-600 J/kg) as it moves eastward over eastern KY late this
morning into midday.  Long, somewhat curved low-level hodographs and
strong low-level shear are expected, supporting potential for
embedded/low-topped supercells, as well as LEWP/bow features with
any linear modes. 

The area of large-scale lift and accompanying strong-severe
convective potential then will shift across WV to VA/MD/DC and the
Delmarva region, encountering theta-e advection from a modified
post-frontal airmass over the Atlantic.  This regime then should
move offshore, where even more-extensive convective development is
likely overnight.  The wind and tornado areas have been shifted
south out of most of PA, where the low-level stable/inversion layer
should hold, and expanded westward into portions of eastern KY,
where surface-based buoyancy will exist as the cold-core region
moves overhead.  Severe potential probably will be discontinuous
across this corridor, and a lack of more-robust buoyancy precludes
more than a marginal unconditional severe threat for this outlook
cycle. 
------------------

...Epilogue (RE)...
This is my final SPC outlook, forecast and shift.  With a
cyclonically swirling storm of memories, I retire mourning the end
of a rewarding era, yet ever grateful, blessed with a career of
public service devoted to excellence.  For a poor kid from
inner-city east Dallas, carrying a passion for tornadoes from
earliest awareness, and a relentless drive to research and forecast
them, it has been everything the dream promised, and more.  I hope
the American taxpayers have found my time worth their money.

Even through this autumnal transition of life's seasons, I'll stay
as inspired as ever by the tempestuous sky above -- to observe,
photograph and study it, and keep giving back to the science in some
way, as long as physically and mentally able.  It just won't be on
rotating shifts.  The forecasting baton passes to another generation
of sharp minds, just as the lead crew in the 1990s did for us "young
pups of SELS" in Kansas City.  The SPC is in great hands.

There isn't enough room here to thank everyone from early childhood
through OU, NSSL, NHC, NSSFC/SELS, and SPC -- family, friends,
instructors, mentors, students, and colleagues -- but be assured I
do.  Nothing has granted greater career fulfillment than to deliver
severe-weather forecasts with detailed, science-based insights,
customized for each situation, shift after shift for over three
decades, and to write related research papers.  Thanks for reading
and using them, any or all.  Stay weather-aware!

..Edwards/Grams.. 12/31/2024

Day 4-8 Convective Outlook  
NWS Storm Prediction Center Norman OK
0322 AM CST Tue Dec 31 2024

Valid 031200Z - 081200Z

...DISCUSSION...
Expansive ridging is forecast to gradually shift from the Plains
into the MS Valley and Southeast on D4/Friday, with stable
conditions prevailing. 

A shortwave trough is expected to progress from the western Great
Basin through the Four Corners and into central/southern High Plains
on D5/Saturday, continuing eastward across central/southern Plains
and Mid/Lower MS Valley on D6/Sunday. Surface cyclogenesis appears
probable over the southern High Plains on D5/Saturday ahead of the
approaching shortwave, with a warm sector characterized by mid 60s
dewpoints likely to precede the resulting surface low and attendant
cold front. Thunderstorms are possible from central TX/OK eastward
through the Lower MS Valley on D6/Sunday, as the cold front
interacts with the moderately moist and buoyant air within the warm
sector. Deep-layer vertical shear is expected to be strong enough to
support organized storms (i.e. greater than 40 kt from 0-6 km). 

Mid/upper level pattern is similar between the EPS and GEFS, but the
surface pattern has notable differences, with most GEFS members
favoring a slower and more southerly track to the surface low. This
is matched by the deterministic runs of the ECMWF and GFS, while the
Canadian splits the difference. Even though some severe appears
probable, these differences limit the forecast confidence, making it
difficult to ascertain the most likely corridor for severe
thunderstorms. Additionally, all of the deterministic guidance
continues to show notable run-to-run variability. All of these
factors combined with the extended range of the possible severe
(i.e. Day 6) result in too much uncertainty to delineate any risk
areas with this outlook.

The risk for thunderstorms will likely continue along the Gulf Coast
on D7/Monday as this system continues eastward. By D8/Tuesday, cold
and dry conditions are anticipated across the entire CONUS.

Day 3 Convective Outlook  
NWS Storm Prediction Center Norman OK
0149 AM CST Tue Dec 31 2024

Valid 021200Z - 031200Z

...NO THUNDERSTORM AREAS FORECAST...

...SUMMARY...
Thunderstorms are not expected Thursday.

...Synopsis...
A shortwave trough is forecast to rotate through the central/eastern
CONUS upper troughing on Thursday, progressing cyclonically from the
central Plains through the Mid MS Valley into the Southeast States
and southern Appalachians. Another, more northerly shortwave trough
is expected to move across the Upper Midwest and Upper Great Lakes.
Progression of these waves will help maintain upper troughing across
the eastern CONUS into early Friday. Farther west, upper ridging
will gradually shift across the western CONUS, ahead of a strong
shortwave trough expected to approach the Pacific Northwest coast
early Friday morning.  

At the surface, ridging associated with a dry continental airmass is
expected to gradually shift eastward from the TN Valley/Southeast
towards the Mid-Atlantic. Another surge of cold air is anticipated
across the Plains, helping to reinforce the dry conditions from a
preceding cold front. A weak low may develop along the TX coast,
along a weak inverted trough, helping to preclude any inland
moisture return. Dry and stable conditions across the CONUS will
prevent thunderstorm development.

..Mosier.. 12/31/2024

Day 2 Convective Outlook  
NWS Storm Prediction Center Norman OK
1235 AM CST Tue Dec 31 2024

Valid 011200Z - 021200Z

...NO THUNDERSTORM AREAS FORECAST...

...SUMMARY...
Thunderstorms are not expected Wednesday.

...Synopsis...
Broad cyclonic flow is expected to persist across the CONUS on
Wednesday as one shortwave trough exits the Northeast and a series
of low-amplitude shortwave troughs follow in its wake across the
Plains. The strongest of these latter shortwaves is expected to move
southeastward from the northern Rockies into the central Plains.  

At the surface, a low is forecast to begin the period over southern
New England before then quickly moving northeastward. Surface
ridging associated with a dry continental airmass will settle in
across the central and eastern CONUS, precluding any thunderstorm
potential. Dry and stable conditions are anticipated across the
western CONUS as well.

..Mosier.. 12/31/2024

Day 1 Convective Outlook  
NWS Storm Prediction Center Norman OK
1154 PM CST Mon Dec 30 2024

Valid 311200Z - 011200Z

...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PART OF
THE CENTRAL APPALACHIANS AND MID-ATLANTIC...

...SUMMARY...
Isolated severe thunderstorms, associated with marginally severe
gusts, hail and possibly a brief tornado, are expected to develop
today from the central Appalachians into the Mid-Atlantic.

...Central Appalachians/Mid-Atlantic...
A negative-tilted mid-level trough will move eastward into the
central Appalachian Mountains today, as a 90 to 100 knot mid-level
jet moves through the northern Gulf Coast states. At the surface, a
low will move through the Ohio Valley, as a warm front advances
northward into the Mid-Atlantic. This afternoon, scattered
thunderstorms are expected to develop near a cold pocket aloft
associated with the mid-level low. In addition, a line of
thunderstorms is forecast to develop in the central Appalachians,
where lift will be enhanced by the left exit region of the mid-level
jet. RAP forecast soundings across the central Appalachians by early
afternoon have MUCAPE in the 300 to 500 J/kg range, and steepen
low-level lapse rates to around 7 C/km. This should be enough for
isolated severe gusts along the leading edge of the strongly-forced
the line. In addition, afternoon forecast soundings in the
Mid-Atlantic have 0-3 km storm-relative helicity in the 250 to 350
m2/s2 range suggesting that a marginal tornado threat will also be
possible. Hail could also occur with cells embedded in the more
organized parts of the line. The severe threat is expected to
continue into the late afternoon, as the line of storms moves
through the Mid-Atlantic region.

..Broyles/Thornton.. 12/31/2024