Pretty remarkablly anomolous severe event Jan. 8/9 over panhandle

[beanskip]

Rare 70-knot lower level jet with sub 990-low and warm front pushing ashore.

Even shy of severe threat, looks like non-storm related straight line winds that could gust over 50 mph.

Storm warnings for 13-15 foot swells.

Basically, a rare, major event for western Florida, among other places. 

[strongwxnc]

Rare 70-knot lower level jet with sub 990-low and warm front pushing ashore.
Even shy of severe threat, looks like non-storm related straight line winds that could gust over 50 mph.
Storm warnings for 13-15 foot swells.
Basically, a rare, major event for western Florida, among other places. 

Going to be very interesting for sure over the next two-ish days!


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[NavarreDon]

Rare 70-knot lower level jet with sub 990-low and warm front pushing ashore.
Even shy of severe threat, looks like non-storm related straight line winds that could gust over 50 mph.
Storm warnings for 13-15 foot swells.
Basically, a rare, major event for western Florida, among other places. 

I don’t post much anymore except for tropical weather, and Mnt snow but this caught my eye and brought me over here. The Mets at MOB are great with severe weather and I don’t think I’ve seen an AFD like this from them ever! Very rare conditions for these part. Sorry for the long post but here is the disco…

NEAR TERM...
(Now through Tuesday Night)
Issued at 413 PM CST Sun Jan 7 2024

Where to begin. Probably with the fact that with the current
trends, we have leaned towards higher confidence in an extremely
high impact event for our area. Very strong winds, potentially
moderate coastal flooding, high marine impacts and the potential
for a significant severe thunderstorm event including damaging
winds and potentially a couple significant (EF-2+) tornadoes.
Honestly when you put all the potential impacts together this
could be one of the more impactful non- tropical systems we ever
had. Take this system seriously!

Synoptic Overview...A rather potent upper low will eject into the
Ohio River valley Monday into Tuesday night. The impressive nature
of this system continues to be represented within ensemble
guidance with 500 Mb heights at a climatological min within the
ECMWF, meaning this is an anomalously deep low. With anomalously
deep lows usually come very strong jet dynamics and right now
looking at a 110 to 120 knot jet streak developing around the base
of the upper low late Monday night into early Tuesday morning.
Little further down a powerful 70 to 80 knot 850 mb jet will
develop over our area during the same time and unfortunately
trends within the higher resolution guidance have even hinted at
increasing to 85+ knots. This is relatively rare territory even in
some of our more impactful events. At the surface, these intense
dynamics will allow for a powerful surface low to deepen into the
upper 980s as it lifts across northeastern Arkansas. Expect rain
to likely begin Monday afternoon as the synoptic warm front lifts
northward and persisting throughout the overnight hours. Rain may
become intermittent for a brief period before the final line of
storms pushes through early Tuesday morning likely clearing out as
we approach the noon Tuesday timeframe. Given how dynamic this
system is we expect a plethora of hazards to come.

Severe...Unfortunately, things trended the wrong way for us
amongst the high resolution guidance and the makings of a
significant severe thunderstorm threat appears on our doorstep. As
mentioned in yesterdays afd, extreme environments tend to end in
extreme results and the expected environment is quickly trending
towards extreme. Going into yesterday the limiting factor was the
instability. As worried, the proximity to rich Gulf Moisture
coupled with the intense low level wind field should have no
issued working instability inland across our area as the marine
boundary lifts northward. All the high resolution guidance has
around 1000 J/KG of MLCape making its way to the highway 84
corridor with some guidance hinting at near 2000 J/KG near the
I-10 corridor and has trended upward with time. Not great Bob,
when that was suppose to be the limiting factor. On top of the
instability the shear will be ludicrous with that 80 knot LLJ. 0-1
KM SRH values in the warm sector are hovering around the 500 to
600 m2/s2 with insane low level curvature and high streamwise
component. It would be immature to not at least mention that
sometimes these shear environments can be too much especially with
lower amounts of instability much like last years; however,
intense jet dynamics in the right entrance region of the upper jet
will likely overcome all of those issues. Expect two rounds of
severe weather to be possible with both capable of significant
severe. The first round is a little more conditional as
instability and synoptic ascent will be more limited compared to
round two. However, this round will be along the lifting marine
boundary around midnight. This will likely involve embedded
supercells lifting with the boundary leading to the potential for
damaging winds and tornadoes. Given the shear environment and the
boundary, a strong tornado cannot be ruled out. Then the real show
arrives shortly after and persists through the overnight in the
form of a rather strong QLCS. This heavily forced squall line will
only intensify as the upper jet overspreads and the LLJ
increases. The combination of strong kinematics and low level
instability with 0-3km cape values likely approaching 100k/kg or
more will support strong vertical stretching in a incredibly rich
vorticity environment. QLCS tornadoes will likely be common with
this line including the potential for a few strong QLCS tornadoes
(EF-2+). Along with the tornadoes, strong damaging winds will also
be likely with wind gusts in excess of 70 mph given 850 and 925
mb winds will already be high. This has the potential to be a
rather intense severe event occurring overnight. Be sure to
continue to stay updated and have multiple ways to receive
warnings that are battery operated and charged as power may go out
well before severe thunderstorms arrive.

Beach/Coastal Hazards....Given the anomalously low pressures and
tight gradient winds it will be outright howling across the marine
waters. Winds have only trended upward since yesterday. Given the
incredibly long fetch of strong winds, seas will quickly climb to
high surf warning criteria. Surf heights along the coast Monday
night through Tuesday will likely approach 10 feet plus leading to
likely beach erosion, life threatening surf and rip currents and
likely coastal overwash along flood prone barrier islands. On top
of the intense wave action, strong low level winds will also push
water leading to coastal flooding. Current PETSS guidance supports
at least solid coastal flooding and with current trends we are
quickly approaching coastal flood warning criteria Monday evening
for Mobile Bay. For now the plan will be for a coastal flood
advisory in the coming packages as confidence increases and we
will have to monitor closely for a possible coastal flood warning.
Nonetheless, the usual flood prone areas should expect at least
minor to possibly moderate coastal flooding and overwashing.

Wind Impacts...As if the rest of the discussion didn`t spell it
out, it is going to be windy. Winds have trended upward with most
of the area likely seeing gusts up to 50 mph even as far inland as
highway 84. Along the coast winds will be peaked with gusts up to
60 mph possible as the strong low level jet and instability move
inland. A rather rare high wind warning has been issued for the
coastal areas with a high end wind advisory for the remainder of
the area. The compounding impacts of increased winds, weekend
trees from the last few months of drought and rainfall saturating
the soil will likely lead to trees coming down across the area.
Power outages will be possible well before any severe
thunderstorms arrive which could lead to a nasty combination.
Charge battery powered methods of receiving warnings before going
to bed and be sure to secure loose items outside.

Heavy Rainfall Impacts...Confidence in rainfall happening is high
but the heavy rainfall and flooding does It seem as likely outside
of maybe a few urban areas. PWATS will steadily climb in advance
of the system and elevated instability north of the lifting warm
front Monday evening will allow for a shot for some heavier rain.
The issues are 1. we are still dry from the last few months. 2.
the rather quick moving nature, especially with the second line
could force things to be fully rate driven and not sure we get the
rates long enough to overcome our relatively high flash flood
guidance. If that first round of rain Monday evening is stronger
and or the warm front gets hung up along the coast, then we might
see some minor flash flood concerns develop. Right now the best
area for heaviest rain is across southeastern Mississippi before
the eventual squall line gets moving east. This is honestly a
rather low confidence flooding situation and will likely be driven
heavily on the progression of the warm front and rain rates.

All and all Monday night into Tuesday looks to be impactful for
our area with or without strong thunderstorms. The environment has
continued to come together the full gambit of impacts are
becoming likely. Keep up to date with this system as potential
impacts may change as we get more details. BB/03


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[beanskip]

"Not great Bob."

 

[NavarreDon]

"Not great Bob."
 
:lol:

Reminds me of the GSP crew back in the day!


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[eyewall]

Yep it is going to be a wild ride all the way up to NC tomorrow.

[NavarreDon]

YIKES!!!

National Weather Service Mobile AL
345 PM CST Mon Jan 8 2024

...New NEAR TERM, SHORT TERM, LONG TERM, MARINE...

.NEAR TERM...
(Now through Tuesday)
Issued at 345 PM CST Mon Jan 8 2024

No mincing words here, our concerns for the overnight period
tonight is serious. A incredibly impactful system has begun across
our area and conditions will rapidly deteriorate throughout the
night. The potential for significant severe appears likely across
most of the area including the potential for several significant
tornadoes (EF-2+) and damaging winds in excess of 70 mph. While
the current severe risk is at an enhanced, the ceiling of this
environment could easily support a more significant severe threat
and only minor confidence questions are holding back from higher
severe probs. Nonetheless, these confidences may not improve until
we see the white of its eyes and this event needs to be treated
seriously. On top of significant severe, intense wind gusts of 50
to 60 mph, minor to moderate coastal flooding and extremely high
surf will all be possible overnight tonight. Coastal and wind
impacts will likely be on the higher end for non-tropical systems
for the Mobile area.

I`ll keep the synoptics short here as by this point its about
small scale things and impacts. I think we all understand by this
point there`s a rather strong system moving through.

Severe Threat...The makings of a significant severe thunderstorm
threat looks likely tonight and into Tuesday morning. An intense
low level jet will usher plenty of warm air and rich Gulf moisture
into the area with temperatures/dew points rising nearly 20
degrees over the next 18 hours. These factors will likely have no
issue working instability inland across our area as the marine
boundary lifts northward. All the high resolution guidance
continues to have around 1000 J/KG of MLCape making its way to
the highway 84 corridor with some guidance hinting at near 2000
J/KG near the I-10 corridor. On top of the instability the shear
will be absolutely insane with 0-1 KM SRH values in the warm
sector hovering around the 500 to 700 m2/s2 and with no surprise,
forecast soundings continue to indicate very significant low
level curvature. Intense jet dynamics in the right entrance
region of the upper jet will likely lead to widespread convective
coverage beginning around midnight, likely overcoming the intense
shear allowing for storms to rapidly organize. This event will go
from 0 to 100 very quickly as the upper jet moves in and the
intense low level jet increases. Rain will likely begin well
before the severe weather arrives and things will likely go from
showers and a few elevated thunderstorms to numerous severe storms
in a couple hours. DO NOT LET YOUR GUARD DOWN BEFORE MIDNIGHT.

Expect two possibly three rounds of severe weather to be possible
with rounds two and three capable of significant severe. The
first of three rounds is a little more conditional as the marine
boundary moves inland. Given the shear environment, relatively
low freezing level heights and deep EL`s, elevated storms would be
possible with some hail probably around 1 inch in diameter. This
will likely occur prior to midnight and in the grand scheme of
things this threat is a mole hill compared to the mountain ahead.

The second round is when things will begin to rapidly go downhill
as the clock strikes midnight (or around that time). Recent high
res-guidance continues to uptrend in the possibility of a few
discrete to semi-discrete supercells developing along a
confluence band ahead of the main line as the marine boundary
lifts north shortly around midnight or just after. Given the shear
environment and the boundary, this environment would be more than
supportive of strong tornadoes and if these cells truly are able
to take full advantage of the environment then the ceiling may be
higher. The big question for higher end potential is can these
storms sustain themselves with a lot of cell interactions,
intense shear, modest but quickly increasing instability and stay
within the optimal boundary spot to remain tornado producers.
Unfortunately, some of our strongest tornadoes locally have
occurred in environments along these marine boundaries and warm
fronts when they are able to sustain themselves within the
optimal boundary mode. While we are still unsure about this
potential, the high impact nature of this period warrants great
concern and if confidence continues to increase this would likely
be the driving force into any potential severe upgrades heading
into the evening.

Then final punch will arrives shortly after round two in the 2 am
to 8am timeframe in the form of a rather strong QLCS. This
heavily forced squall line will only intensify as the upper jet
overspreads and the LLJ increases. The combination of strong
kinematics and low level instability with 0- 3km cape values
likely approaching 100k/kg or more will support strong vertical
stretching in a incredibly rich vorticity environment. This
environment will truly peak east of I-65 across the western
Florida Panhandle and into south central Alabama. Based off recent
research this environment will be primed for QLCS tornadoes and
given the upper echelon shear environment, strong QLCS tornadoes
(EF-2+) could be possible. Along with the tornadoes, strong
damaging winds will also be likely with wind gusts in excess of 70
mph given 850 and 925 mb winds will already be high. This has the
potential to be a rather intense severe event occurring
overnight. Be sure to continue to stay updated and have multiple
ways to receive warnings that are battery operated and charged as
power may go out well before severe thunderstorms arrive.

Wind Impacts...An extremely tight pressure gradient will develop
over the area through tonight as the surface low pressure drops into
the upper 980s. This will result in very windy conditions. Winds
have already been gusting to 30 mph across the area this afternoon
and are expected to increase into the evening. Winds well offshore
have continued to climb with gusts to near 55 mph already. These
winds will steadily move towards the coast this evening. A high
end Wind Advisory has been issued for much of the area for wind
gusts of 40-50 mph. Winds will be even higher along the coast with
gusts up to 60 mph possible late tonight and early Tuesday
morning as a powerful low level jet pushes into the area. A rather
rare High Wind Warning has been issued for these coastal areas.
The compounding impacts of increased winds and ongoing rainfall to
saturate the soil will make trees and power lines more
susceptible to being blown over outside of any thunderstorms.
Because of this, power outages will be possible well before any
severe thunderstorms arrive so it is very important to have
multiple ways to receive warnings overnight. Be sure to charge
battery powered methods of receiving warnings before going to bed
and be sure to secure loose items outside.

Beach/Coastal Hazards....Very strong onshore flow will result in
dangerous rip currents and extremely high surf conditions at all
area beaches. Surf heights of 10 to 15 feet are expected and will
likely lead to beach erosion and coastal overwash along flood
prone barrier islands. A High risk of Rip Currents is in effect
through early this week and a High Surf Warning remains in effect
through Wednesday morning. On top of the intense wave action,
strong and persistent low level winds will push water inland
leading to coastal flooding. The current forecast supports solid
coastal flooding with coastal flood warning conditions potentially
occurring within Mobile Bay. Given that these strong low level
jet scenarios tend to over perform with coastal flooding, we went
ahead and upgraded Mobile Bay to a Coastal Flood Warning. Expect
potentially moderate coastal flooding across most of the barrier
islands and Mobile Bay.

Heavy Rainfall... PWATS will steadily climb in advance of the system
with values approaching the climatological maximum for this time of
year. This moisture combined with better instability will result in
some heavier rain rates this afternoon and overnight. Storms will be
capable of producing heavy rainfall in a short period of time, but
given the progressive nature and the fact that we are still in a
drought, there is still low confidence in significant flooding
impacts. Most areas will likely see 2-4 inches of rainfall now
through Tuesday with some areas potentially picking up 6 inches in
this time frame. A localized advisory or warning cannot be ruled
out.

This is about as serious as it gets across our area with respects
to impacts. Please remain weather aware tonight and have an
emergency plan in place. Be sure to have a way to receive
warnings that will wake you up and quickly go to your safe place.
Prep your safe place now as power outages might make things
difficult tonight. Trust us we do not want to be issuing tornado
warnings at 4 am either and hopefully things find a way to pan out
to the better. We will be right here with you through the night!
BB/03


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[beanskip]

I've seen hurricane AFDs not written that ominously!

 

[Tyler Penland]

Would not want to be under this line. All kinds of imbedded rotation.

[Tyler Penland]

This beast just came ashore a tick west of PCB.

[eyewall]

The Mariana supercell is a dangerous one for sure moving into SW GA.

[NavarreDon]

Some sporty weather here in Navarre but overall an under performer for us in the west. Things cranking up as the line moves east of Okaloosa County. Stay safe Skip!!!


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[NavarreDon]

Possible tornado in Panama City Beach this morning.








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https://x.com/jimmypatronis/status/1744738611122389464?s=46&t=0ZvB_AF2VfA6c0SDxf53yA

[NavarreDon]

The Mariana supercell is a dangerous one for sure moving into SW GA.

Indeed!







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[Tyler Penland]

Continuous line of severe storms from VA line to the gulf.

Incredible.

[DanLarsen34]

We are fortunate that this system wasn’t a few hours slower. There are several discrete tornadic supercells just off the coast of NC at the moment with intense couplets.

That being said, a few of these may continue to make landfall and impact the coast before the evening is over.

[hazwoper]

How rare is it to have super cells with large imbedded tornadoes forming off the cost of the Carolinas and making landfall in mid January.  Serious question.

[SENC]

1 hour ago, DanLarsen34 said:

We are fortunate that this system wasn’t a few hours slower. There are several discrete tornadic supercells just off the coast of NC at the moment with intense couplets.

That being said, a few of these may continue to make landfall and impact the coast before the evening is over.

Brother had a "intense" couplet come ashore here in Surf city,, taking out alot of trees.. 

[NavarreDon]

PCB confirmed at EF-3….ouch!

https://x.com/nwstallahassee/status/1745252730929877365?s=46&t=0ZvB_AF2VfA6c0SDxf53yA


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