Spring/Summer Weather Thread

downeastnc

Old Mossy Horns
Pushing 80 today and some models suggest some shots at some of the first organized severe threats next week possibly.....

Leaf out is running behind schedule for most of NC but the next few days should really get that going, along with the mosquitos and ticks.....
 

downeastnc

Old Mossy Horns
Next Wed/Thur looks like there is potential for some severe type storms over the south.....getting to be that time of the year.....we look for strong LLJ's at around 850 MB this means strong winds under 5k ft this time of year....

Both the Euro and GFS show a strong LP area over the Ohio Valley and a strong LLJ over the SE....we will see how it trends....

Euro.png

GFS png.png
 

downeastnc

Old Mossy Horns
This Wed sure looks like the first chance this spring at a fairly decent tornado outbreak over the deep south AKA Dixie Alley....how much of the threat transfer up to NC Thur is still back and forth in the models as far as how far north the warm front gets etc....Folks in AL/MS/TN and maybe GA are looking primed though to get some big nasty long lived tornados Wed.....

SPC has us under a 15% chance though for Thur this far out and thats typically a bad sign.....

For deep south Wed

day4prob.gif

NC Thur

day5prob.gif
 

shaggy

Old Mossy Horns
Couple monster tornados yesterday in Texas but luckily over sparsley populated areas. One was a mile wide wedge with a gtg of up to 185mph. These people got lucky and just missed it and were in the outer edge of the winds and missed the core of the tornado.

 

downeastnc

Old Mossy Horns
Tues shaping up to be miserable......drizzly, rainy day with temps struggling to get into the low to mid 40's for most.....then still watching Thur for possible severe weather......Wed looks bad for Dixie Alley but not sure how far north the warm front gets in NC Thurs and the exact timing etc.....gonna be a wet week regardless though.
 

downeastnc

Old Mossy Horns
This temp map shows the CAD wedge Tues well.....pushes it all the way to Alabama.....you can see how the cold dense air has filtered down the east side of the Apps.....it will actually be much warmer in Boone than Winston......

aaaa.JPG
 

downeastnc

Old Mossy Horns
Dew points are in single digits and low teens over a lot of NC today, the RH is also very low around 20-25%.....these are pretty low values for mid March....
 

downeastnc

Old Mossy Horns
Thur is unfortunately trending in the wrong way, still several mitigating factors to work out that would lessen or intensify the risk......but Wed/Thur is going to see at least a small to medium tornado outbreak across the SE it appears....


Would not be surprised to see the SPC go with a high risk area in parts of AL/MS tomorrow.....the latest soundings suggest prime environment for very strong long track wedge type tornados....
 
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downeastnc

Old Mossy Horns
Going to shift the storm threat to this new thread.....as Shaggy showed they SPC bumped us to a mod risk for tomorrow a rare day 2 upgrade.....though looking at the soundings for Thur I am not surprised and frankly it looks like a bad bad day.....the top analog to this setup is April 15-16 2011......which many of you will remember.

This does not mean its gonna be that bad only that the potential is there for that kind of day....there are a lot of mitigating factors that could make tomorrow a total bust, such as a lot of showers and other what is known a "pre" convection that basically bleeds instability off preventing things from reaching full potential, or the timing being slower by 4-5 hrs etc.....so we will know better in the morning just how bad it will be but it dont look good, there will probably be 3-4 big supercell thunderstorms that produce several longer track type strong tornados in the state.....lets hope that is wrong.....

The day 2 15% Tor threat hatched is rare in these parts......


1615978763692.png

Also today is going to be very bad in AL/MS with a rare high risk issued.....people will likely die today from tornados.....
 
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downeastnc

Old Mossy Horns
You sound almost happy about it, what gives?

Not sure what in that makes you think it sounded happy....the statement about people dying today from tornados is more to highlight the seriousness of the situation that is unfolding in Dixie alley today and tomorrow for the rest of the SE.....hopefully people take this seriously and heed the warnings and most importantly have a plan to protect themselves and their families if they find themselves in harms way.
 

45/70 hunter

Twelve Pointer
We were landing at RDU from Las Vegas when that Raleigh tornado hit. It was the bumpiest flight I've ever been on. We had to take several alternate routes to get home because of roads blocked. It was a sick feeling the closer we got to home the worse it was. Our house was was safe but we were only a mile as the crow flies from torn up homes and businesses. Too close for me!!
 

shaggy

Old Mossy Horns
So this is the SPC......storm prediction center.......kind of like the NHC for severe weather. These are the guys that all the NWS offices follow for their severe weather forecast. This is their discussion for our areas tomorrow. Ominous wording.

SPC

North Carolina/South Carolina/Georgia/Virginia/Florida...
A positively-tilted upper-level low will move into the Tennessee
Valley on Thursday as a 75 to 90 kt mid-level jet moves across the
Southeast and Carolinas. At the surface, a low will move eastward
into the central Appalachians. At 12Z, a warm front will be located
from northern Georgia eastward across northern South Carolina. This
boundary will move northward across central and eastern North
Carolina during the morning. To the south of this front, surface
dewpoints across the warm sector will be in the mid to upper 60s F.
As surface temperatures warm, a pocket of moderate instability is
expected to develop to the south of the warm front across eastern
North Carolina by late morning. Convective development will be aided
by the low-level jet. Severe thunderstorms associated with large
hail, wind damage and a tornado threat, is expected during the mid
morning hours.

Further to the west, a band of large-scale ascent associated with
the approaching upper-level system will overspread the central
Appalachians around midday. Thunderstorms are expected to initiate
just ahead of this band of ascent around midday and move eastward
into the Appalachian foothills during the early afternoon. Ahead of
the storms, the environment will consist of MLCAPE in the 2000 to
2500 J/kg range, 0-6 km shear of 50 to 60 kt and storm relative
helicities of 300 to 350 m2/s2. This will support intense supercell
development. Tornadoes, wind damage and large hail will be likely
with the stronger storms. A long-track tornado will be possible
along or in the vicinity of the warm front. The time of maximum
threat is forecast to be in the 18Z to 22Z time window. A regional
outbreak of severe storms, along with several significant tornadoes
are expected from discrete cells that develop across the warm sector
from central North Carolina southward across much of South Carolina.
 

downeastnc

Old Mossy Horns
So this is the SPC......storm prediction center.......kind of like the NHC for severe weather. These are the guys that all the NWS offices follow for their severe weather forecast. This is their discussion for our areas tomorrow. Ominous wording.

SPC

North Carolina/South Carolina/Georgia/Virginia/Florida...
A positively-tilted upper-level low will move into the Tennessee
Valley on Thursday as a 75 to 90 kt mid-level jet moves across the
Southeast and Carolinas. At the surface, a low will move eastward
into the central Appalachians. At 12Z, a warm front will be located
from northern Georgia eastward across northern South Carolina. This
boundary will move northward across central and eastern North
Carolina during the morning. To the south of this front, surface
dewpoints across the warm sector will be in the mid to upper 60s F.
As surface temperatures warm, a pocket of moderate instability is
expected to develop to the south of the warm front across eastern
North Carolina by late morning. Convective development will be aided
by the low-level jet. Severe thunderstorms associated with large
hail, wind damage and a tornado threat, is expected during the mid
morning hours.

Further to the west, a band of large-scale ascent associated with
the approaching upper-level system will overspread the central
Appalachians around midday. Thunderstorms are expected to initiate
just ahead of this band of ascent around midday and move eastward
into the Appalachian foothills during the early afternoon. Ahead of
the storms, the environment will consist of MLCAPE in the 2000 to
2500 J/kg range, 0-6 km shear of 50 to 60 kt and storm relative
helicities of 300 to 350 m2/s2. This will support intense supercell
development. Tornadoes, wind damage and large hail will be likely
with the stronger storms. A long-track tornado will be possible
along or in the vicinity of the warm front. The time of maximum
threat is forecast to be in the 18Z to 22Z time window. A regional
outbreak of severe storms, along with several significant tornadoes
are expected from discrete cells that develop across the warm sector
from central North Carolina southward across much of South Carolina.

The meat of it...the warm front placement will be critical to how much of NC gets into the warm sector.....the eastern side of that boundry is the area where the strongest longest lived tornados will probably occur....


This will support intense supercell
development. Tornadoes, wind damage and large hail will be likely
with the stronger storms. A long-track tornado will be possible
along or in the vicinity of the warm front. The time of maximum
threat is forecast to be in the 18Z to 22Z time window. A regional
outbreak of severe storms, along with several significant tornadoes
are expected from discrete cells that develop across the warm sector
from central North Carolina southward across much of South Carolina.
 

Ceehawk37

Six Pointer
Word from folks I know in Bama is it’s getting rough. Already some damage to smaller rural areas and the bulk of the storm hasn’t gotten to the more populated areas yet. Going to be a rough ride for them tonight. This system should be bearing down on us here in SC sometime tomorrow. Not liking the projected highs for us with this kind of system moving in. Keep your heads on a swivel fellas.
 

Homebrewale

Old Mossy Horns
An incoming storm system will bring one or more rounds of showers and thunderstorms, and may also bring the potential for severe weather -- some potentially significant -- to the state on Thursday. This has the potential to be an all-hazards event and encompassing most of the state.

OVERVIEW/TIMING: A potent storm system centered over the mid-Mississippi Valley will translate eastward into the Ohio Valley today into the tonight. Ongoing severe weather is expected to worsen considerably over the Deep South and Tennessee Valley this afternoon, with widespread severe weather and tornadoes expected. These storms are expected to coalesce into a line and move eastward towards the Mountains tonight into tomorrow morning. Areas of rain will be possible over interior North Carolina late Wednesday night, with a brief pause expected before scattered showers and thunderstorms associated with this cold front begin moving across the Mountains Thursday morning into Thursday midday. This front will then move across the Foothills and Piedmont Thursday afternoon into Thursday evening, and over the Coastal Plain and Outer Banks Thursday night. Ahead of this front, scattered thunderstorms are expected to develop during the day Thursday and continue through the afternoon and evening hours Thursday across much of central and eastern North Carolina. It is these storms that hold the greatest risk for severe weather tomorrow – in particular the risk for tornadoes, of which some could be strong -- though there will also be a risk for severe weather associated with storms along the passing cold front as well.

SEVERE WEATHER CONCERNS: The mechanics of this system and how exactly the ingredients available (and how much of each) will interact, and when, all remain somewhat fluid in the forecast guidance, and at this point the threat may be somewhat localized in nature, though the scope of the threat itself covers a very large part of North Carolina and has the potential to produce dangerous weather. Overall, the most likely time for strong tornadoes -- of which there may be some – within North Carolina will be between noon and 7PM. Here are the issues we currently see by region:

Mountains/Immediate Foothills (Asheville, Bryson City, Boone, Wilkesboro): The severe threat here is expected to be relatively low over the Mountains and immediate foothills, as colder air is expected to be wedged in and slow to disperse as the cold front and associated storms approach tomorrow morning into midday. Localized damaging winds and hail with an isolated tornado will be the main concerns here.

Eastern Foothills/Western Piedmont (Hickory and then the I-77/I-85/US-29 corridor from Charlotte through High Point and Triad metro and back through Statesville): warmer air is expected to build in during the midday and early afternoon; isolated to scattered thunderstorms capable of producing tornadoes, a few of which could be particularly strong, may be possible ahead of the front Thursday midday through Thursday afternoon with the main front moving through by Thursday evening with the threat for isolated tornadoes, damaging winds and large hail.

Eastern Piedmont/Sandhills (Raleigh/Durham/Burlington/Uwharrie/Fayetteville): Isolated to scattered thunderstorms are expected ahead of the front tomorrow midday through late-afternoon; these storms will be capable of producing tornadoes, a few of which could be particularly strong, as well as damaging straight-line winds and large hail. Additional thunderstorms capable of producing tornadoes, damaging winds and large hail will be possible along the cold front itself Thursday evening into Thursday night.

Coastal Plain/Outer Banks (Wilmington/Washington/Morehead City/New Bern/Kinston/Rocky Mount/Clinton): Isolated to scattered thunderstorms are expected ahead of the front Thursday midday into Thursday evening; these storms will be capable of producing tornadoes, a few of which could be particularly strong, as well as damaging straight-line winds and large hail. Additional thunderstorms capable of producing tornadoes, damaging winds and large hail will be possible along the cold front itself Thursday night.

IMPACTS: If all the available ingredients coalesce in these storms tomorrow as they could, then the results could be uncommonly bad, and tomorrow's Storms Prediction Center outlook certainly suggests this (link: https://www.spc.noaa.gov/products/outlook/day2otlk.html), as much of the state in in a Level 4 (Moderate) risk for severe weather with level 3 (Enhanced) and 2 (Slight) further west towards the Foothills and Mountains. Localized, significant, damage to trees, property and infrastructure is possible tomorrow and tomorrow night, with an attendant threat to life. It's very important to prepare and plan ahead of time and execute that plan promptly if severe weather is imminent. Pay close attention to the latest alerts coming from the National Weather Service tomorrow. Consider moving outdoor business Thursday to another day; any outdoor business that must be conducted should be done with strict attention to the weather. Further updates will be issued as needed tomorrow.
 
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