• Hello, please take a minute to check out our awesome content, contributed by the wonderful members of our community. We hope you'll add your own thoughts and opinions by making a free account!

Severe New Years Severe Weather Event

Another spin up might be forming on the Alabama/Georgia state line. May need to extend warning into Georgia.34D7EC57-E86D-4275-8DF7-ADF3148CA4FA.png
 
widespread thunderstorm warning throughout the CHA metro area, but literally zero lightning/thunder. nothing at all showing on lighningmap.org
radar looks rather threatening though. just weird
 
Why are the storms out front failing to strengthen?

We are missing a key ingredient, lift maybe? Just a porchcaster but the air and dew just seem primed
 
Last edited:
Jan 2, 2022 1300 UTC Day 1 Convective Outlook​
Updated: Sun Jan 2 12:34:24 UTC 2022 (Print Version | 20220102 1300Z Day 1 shapefile | 20220102 1300Z Day 1 KML)​
CategoricalTornadoWindHail
Pop. Cities CWAs RFCs Interstates Counties ARTCC FEMA Tribal
map_background.gif
day1otlk_1300.gif
Categorical Day1 1300Z Outlook
Day 1 Risk​
Area (sq. mi.)​
Area Pop.​
Some Larger Population Centers in Risk Area​
SLIGHT​
93,927​
8,336,729​
Tallahassee, FL...Savannah, GA...Columbia, SC...Charleston, SC...Macon, GA...​
MARGINAL​
41,968​
5,247,227​
Jacksonville, FL...Mobile, AL...Columbus, GA...Gainesville, FL...Fayetteville, NC...​
Forecast Discussion
SPC AC 021234

Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0634 AM CST Sun Jan 02 2022

Valid 021300Z - 031200Z

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS TODAY THROUGH
TONIGHT ACROSS PARTS OF THE SOUTHEAST/CAROLINAS...

...SUMMARY...
Thunderstorms with damaging wind gusts, a few tornadoes, and
isolated large hail are possible across parts of the Southeast and
Carolinas today through tonight.

...Southeast AL area today to the eastern Carolinas overnight...
A pre-frontal band of convection has sagged southeastward overnight
across southeast MS, central/southern AL, north GA, and the Piedmont
of the Carolinas. This convection is well ahead of the stronger
synoptic cold front/Arctic air mass now surging across the lower MS
Valley and northwest Gulf of Mexico. This pre-frontal band may
continue to focus convection during the day from southeast AL into
GA, where gradual cooling aloft (2-3 C cooling in the 700-400 mb
layer compared to current profiles) and a little low-level
warming/moistening will contribute to MLCAPE increasing to 1500-2000
J/kg by late afternoon. Given the continued strong deep-layer
vertical shear, the stronger storms from southeast AL into southwest
GA will be capable of producing damaging winds, isolated large hail,
and perhaps a tornado or two.

The primary cyclogenesis will occur tonight from west
central/southwest GA into the Carolinas (likely moving along the
residual pre-frontal convective boundary), in response increasing
height falls aloft with the amplifying midlevel trough. Related
increases in forcing for ascent, low-level warm/moist advection, and
strengthening vertical shear (both deep-layer shear and low-level
hodograph curvature) should be sufficient to support convection
persisting overnight night in a broken band along or just ahead of
the synoptic cold front and near the deepening surface cyclone.
Buoyancy will be somewhat limited overnight (MLCAPE near 500 J/kg)
from southeast GA into the coastal plains of the Carolinas, but
effective bulk shear of 60-70 kt and effective SRH near 300 m2/s2
will favor embedded supercells and/or line segments capable of
producing damaging gusts and a couple of tornadoes.

..Thompson/Kerr.. 01/02/2022
 
SPC has raised the "threat" with the current Day 1. N. FL, S/SE GA, and Coastal SC/NC
Threat has expanded back to the NW about 50-75 miles and they mention a tornado driven upgrade to enhanced is possible from central GA into western and central SC.
 
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
Forecast is on track in the immediate term, with isentropic ascent
beginning to force widespread rainfall across the area. There is
concern, especially with 12z HREF suite, that 1-3" (with locally
higher amounts) of rain could fall over saturated grounds this
afternoon and tonight. As a result, we have issued a Flash Flood
Watch along I-20 and east, and the Pee Dee Region. This runs from 4p
to 4a, and should cover the majority of the event. Be wary of flood
prone roadway and locations as the rain falls this evening, as flash
flooding is a possibility. Temperatures through the evening hours
will generally stay in the low and mid 60s as the system to our west
begins to materialize.

...Potential for Noctural Severe Thunderstorms, Including
Tornadoes...

SYNOPTIC SET UP
===============

Impressive and synoptically evident cold season severe weather event
looks like it could be on tap for the Carolinas. Positively tilted
and deep shortwave trough currently over Oklahoma and TX will begin
to shift phases as an additional subtropical jet streak pushes into
the base of the trough and phase into the phased jet structure
across the eastern US. This will quickly sharpen this shortwave, and
force a close, negatively tilted trough across the TN Valley by 1a
Monday. Ahead of this, a duel jet streak structure will set up
across the Carolinas ahead of this, with the region placed in the
entrance region of a 185kt+ 250 hPa jet streak across the northeast
and the exit region 120kt+ 250 hPa jet streak. It is quite
impressive, and will lead to a rapid response in the low-levels of
the atmosphere. The wind field is expected to strengthen very
quickly as we get into the overnight hours tonight, with an 80kt 500
hPa jet streak overspreading a 50kt 850 hPa low-level jet.
Additionally, a strong surface low is expected to rapidly develop
and strengthen from central GA through central NC tonight.
Guidance varies on strength, but its expected to strengthen from
nothing this morning to a deep, closed surface cyclone between
998mb and 1000mb in strength.

MESOSCALE DETAILS
=================

This is quite the complicated set up for severe weather, and is
conditional (largely on realization of instability). The
aforementioned surface low is expected to develop across
southwestern GA and move into northern SC. This will lift a warm
front north of the area, placing us in a narrow warm sector over
much of our area as we get into the overnight hours. Surface
pressure falls will be on the order of 7-10mb/6hr, and this is
expected to result in backed and strengthening surface flow through
the night. This will combine with the aforementioned strong low and
mid level wind field to yield long and curved hodographs across the
region, with 0-1km SRH on the order of 400+ m2/s2 across the region.
The primary question mark is that of instability. There is a wide
range of thought on this, with some guidance pointing to 250-500
j/kg MLCAPE developing ahead of the front, and others suggesting 0
j/kg MLCAPE will develop. The event hinges on whether or not we get
any appreciable CAPE from this. And while synoptic forcing will be
very impressive, and likely will augment any MLCAPE we can get, if
we don`t actually get CAPE then storms will have a hard time
surviving in that kind of shear environment.

CONFIDENCE AND EXPECTATIONS
===========================

This is quite the challenging forecast, and forecaster confidence is
medium at best. The SPC has placed the region in a Slight Risk for
severe storms, owing to the high end shear environment in place
across the region. However, the higher end instability outcomes in
this set up would yield a high end severe weather threat. This
system is beginning to take shape currently with a surface low noted
across southern Alabama and southwestern Georgia. Within a moisture
rich environment and increasingly strong large scale ascent,
widespread showers and thunderstorms are expected to develop and
overspread the region over the next several hours.

The severe weather threat is not expected to begin materializing
until 10p or 11p this evening to our southwest. The surface low is
expected to be centered across northern Georgia by this point, and
widespread convection will be developing ahead of the front. Hi-res
guidance is consistently indicating a narrow band of 61-64F
dewpoints ahead of the front, which should be enough to yield 250-
500 j/kg of MLCAPE. Given synoptic scale forcing, this would be
enough to yield severe storms. I want to note - this is a thin
margin between instability and no instability. If the instability
materializes, this could be a high end severe weather event, with
tornadoes (some strong) and damaging winds possible across the
forecast area. The entire area is under the gun, with areas along
and east of I-20 most likely to see severe weather.


Something for the Carolinas to watch tonight. This looks like an all or nothing deal though depending on instability. This discussion is from CAE, but much of both states have this threat.
 
Back
Top