SimeonNC
Member
@Myfrotho704_ What is your opinion about a potential ice threat from this?
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Wintry January 14-16th storm potential.
- Thread starter TheBatman
- Start date
iGRXY
Member
Need a blend of the GFS and the EURO. EURO has the NE confluence we want and need to get the cold out ahead of the storm. The GFS has the Western Ridge and lack of the Pacific Northwest S/W helping our vort to dig more but also is pumping the SER out ahead of it. We need to see more stream separation as all the models have trended with today with the wave coming out of Canada, need the GFS to be right with the lack of the S/W that dives down in the PNW that screws up the ridging in the west that allows our vort to dig across Texas, and we need the Euro to be correct on a more pressing NE confluence out ahead of the main S/W
Euro looks like it would be better. The S/W that screws up the strength of the western ridge is weaker this run
Couldn’t really say right now. If we dig the feature in the NE more and amp something back out west up, then it’s definitely possible
griteater
Member
It's a big blocking ridge over Greenland, yes, but regardless, it still comes down to what is going on up under the block...i.e. what is the size / location / configuration of the 50/50 low and how that relates to the height pattern and incoming waves over the CONUS
In this case of the UKMet, the weakness in the height field over the Ohio Valley and into the Northeast (compared to the Euro), in concert with the wave being less positive tilt, opens the door for the surface low and warmth to be located farther NW
iGRXY
Member
griteater
Member
Just documenting what the Atlanta/Greenville/Charlotte/Raleigh corridor needs to see in order for this to work (Jan 11 06z Euro Control run)
tractor girl
Member
For who? NC/VA/TN or board wide (including central/eastern Georgia and midstate SC)?
Not the poster you responded to but it would just be a matter of how far S did it get and when could it potentially flip negative. It could potentially include any of the locations you mentioned above
weather bubba
Member
LONG TERM /SATURDAY THROUGH THURSDAY/...
As of 355 PM Thursday...
Much drier air will advect into central NC on Saturday with strong
westerly flow behind the cold front, so skies will become sunny.
With a strong pressure gradient between the departing low over the
Great Lakes and high pressure over the Gulf Coast, winds may gust to
25-35 mph. Winds will relax on Sunday as the low exits into Canada
and the gradient relaxes, but they still may gust to 15-25 mph. Dry
weather and mostly sunny skies will continue, as high pressure moves
across the Deep South and we get zonal flow aloft. Temperatures will
drop to near or slightly above normal over the weekend with highs in
the upper-40s to upper-50s and lows in the upper-20s to lower-30s.
Forecast confidence greatly decreases early next week. It looks
unsettled with a broad trough over the eastern two-thirds of the
country, but models are still struggling on the details. One weak
sheared-out wave looks to pass to our NW on Sunday night - Monday,
which just looks to mainly result in some mid and high clouds here
as low levels look dry. So only have slight chance POPs on Monday
and cut down POPs a bit from NBM. It also appears there will be a
surface low that moves NE from the Gulf of Mexico off the Southeast
coast sometime Monday-Tuesday, but at least as of now, models keep
it too offshore for significant precipitation to make it this far
inland. However, a more vigorous shortwave aloft diving down from
the Northern Plains looks increasingly likely to affect us on Monday
night into Tuesday evening with a decent chance of precipitation.
The 12z ECMWF trended toward a flatter and drier wave with only
light precipitation across the area, though its ensembles are
wetter. The 12z GFS and CMC have a sharper trough with stronger
height falls so are also wetter. Given the deterministic ECMWF
appears to be an outlier, went with high chance POPs on Tuesday.
Given precipitation type, it is still too early to determine
details, but GFS forecast soundings show potential for at least a
period of snow, mainly in the north and west. 12z ECMWF and GFS
ensembles have trended more wintry, with a majority now depicting
measurable snow in the Piedmont. So kept a chance of rain or snow
across much of the Piedmont, and over a larger area as the
precipitation is exiting on Tuesday evening and the colder air is
rushing in. Temperatures on Monday-Tuesday are still uncertain and
will depend on how the pattern ultimately shakes out, but expect
below-normal highs with the clouds and precipitation. Conditions
will dry out on Wednesday, and it should turn sharply colder with
high pressure building in. Forecast highs are in the mid-30s to
lower-40s with lows in the teens and 20s, and these may need to be
adjusted down further with time. Temperatures look to moderate
somewhat on Thursday.
&&
RDU seems to be hinting at a possible threat next week. We'll have to keep watching those models and keep hoping the trends keep getting better until then.
As of 355 PM Thursday...
Much drier air will advect into central NC on Saturday with strong
westerly flow behind the cold front, so skies will become sunny.
With a strong pressure gradient between the departing low over the
Great Lakes and high pressure over the Gulf Coast, winds may gust to
25-35 mph. Winds will relax on Sunday as the low exits into Canada
and the gradient relaxes, but they still may gust to 15-25 mph. Dry
weather and mostly sunny skies will continue, as high pressure moves
across the Deep South and we get zonal flow aloft. Temperatures will
drop to near or slightly above normal over the weekend with highs in
the upper-40s to upper-50s and lows in the upper-20s to lower-30s.
Forecast confidence greatly decreases early next week. It looks
unsettled with a broad trough over the eastern two-thirds of the
country, but models are still struggling on the details. One weak
sheared-out wave looks to pass to our NW on Sunday night - Monday,
which just looks to mainly result in some mid and high clouds here
as low levels look dry. So only have slight chance POPs on Monday
and cut down POPs a bit from NBM. It also appears there will be a
surface low that moves NE from the Gulf of Mexico off the Southeast
coast sometime Monday-Tuesday, but at least as of now, models keep
it too offshore for significant precipitation to make it this far
inland. However, a more vigorous shortwave aloft diving down from
the Northern Plains looks increasingly likely to affect us on Monday
night into Tuesday evening with a decent chance of precipitation.
The 12z ECMWF trended toward a flatter and drier wave with only
light precipitation across the area, though its ensembles are
wetter. The 12z GFS and CMC have a sharper trough with stronger
height falls so are also wetter. Given the deterministic ECMWF
appears to be an outlier, went with high chance POPs on Tuesday.
Given precipitation type, it is still too early to determine
details, but GFS forecast soundings show potential for at least a
period of snow, mainly in the north and west. 12z ECMWF and GFS
ensembles have trended more wintry, with a majority now depicting
measurable snow in the Piedmont. So kept a chance of rain or snow
across much of the Piedmont, and over a larger area as the
precipitation is exiting on Tuesday evening and the colder air is
rushing in. Temperatures on Monday-Tuesday are still uncertain and
will depend on how the pattern ultimately shakes out, but expect
below-normal highs with the clouds and precipitation. Conditions
will dry out on Wednesday, and it should turn sharply colder with
high pressure building in. Forecast highs are in the mid-30s to
lower-40s with lows in the teens and 20s, and these may need to be
adjusted down further with time. Temperatures look to moderate
somewhat on Thursday.
&&
RDU seems to be hinting at a possible threat next week. We'll have to keep watching those models and keep hoping the trends keep getting better until then.
Last edited:
packfan98
Moderator
18z eps backed off from 12z. Looks a little more suppressive.
Flotown
Member
seems more reasonable but hey who knows...ill take it18z eps backed off from 12z. Looks a little more suppressive.
Flotown
Member
any word on 18z euro...earlier on than previous post?
So I think there are several thoughts floating around about what we need. Here is my take, using the 6z Euro Control as the ideal solution for the Carolinas folks.
In my opinion, in order to get more stream separation, which results in height suppression and the cold press over the Carolinas, we need something to tug on the base of the northern stream trough. That something appears to be this rather innocent piece of vorticity that enters the CONUS around hour 96 (on the 6z Euro Control from last night):
Moving ahead in time, by 120 this area of vorticity has strengthened as it digs southeastward, and the energy in the main northern stream trough is beginning to drive into it. Simultaneously, this is helping to pull apart the northern stream trough and allow the eastward component to suppress the height fields / increase the cold press into the Carolinas. Without this action, the trough stays more congealed and almost counterintuitively it is a warmer AND drier solution.
You can see the impacts of this in the 6z run compared to other recent runs by the end of the control run - the base of the trough digs less, and you have less precipitation AND less of a cold press. IMO, to get a significant winter storm, we just need to consolidate some energy that this upper trough can be pulled to and allow some northern stream separation. At this stage of the game, a piece of yet-modeled energy could easily appear, we should all know this has happened many times in the past and ruined a beautifully modeled winter storm at this range. Maybe for once, it will go the other way and work in our favor.
The past few runs have trended the wrong direction with this piece of energy, but hopefully a new piece (or the same one) will reappear/restrengthen in future runs. I think that is what we need to head to glory.
In my opinion, in order to get more stream separation, which results in height suppression and the cold press over the Carolinas, we need something to tug on the base of the northern stream trough. That something appears to be this rather innocent piece of vorticity that enters the CONUS around hour 96 (on the 6z Euro Control from last night):
Moving ahead in time, by 120 this area of vorticity has strengthened as it digs southeastward, and the energy in the main northern stream trough is beginning to drive into it. Simultaneously, this is helping to pull apart the northern stream trough and allow the eastward component to suppress the height fields / increase the cold press into the Carolinas. Without this action, the trough stays more congealed and almost counterintuitively it is a warmer AND drier solution.
You can see the impacts of this in the 6z run compared to other recent runs by the end of the control run - the base of the trough digs less, and you have less precipitation AND less of a cold press. IMO, to get a significant winter storm, we just need to consolidate some energy that this upper trough can be pulled to and allow some northern stream separation. At this stage of the game, a piece of yet-modeled energy could easily appear, we should all know this has happened many times in the past and ruined a beautifully modeled winter storm at this range. Maybe for once, it will go the other way and work in our favor.
The past few runs have trended the wrong direction with this piece of energy, but hopefully a new piece (or the same one) will reappear/restrengthen in future runs. I think that is what we need to head to glory.
Chattownsnow
Member
SimeonNC
Member
If it means anything the 0z NAM has more of a cold press than the 18z NAM for the weekend.
SimeonNC
Member
The end of the NAM. I don't think other models had the IP/ZR over Texas. Also it's a lot colder for Monday morning, at least for NC.
Guys this is what we need to have a nice almost board wide hit. When it is snowing all the way down to the Gulf of Mexico in Texas. That’s how you make it happen.
Note: yes I know it’s the 84 hour nam. ?
Note: yes I know it’s the 84 hour nam. ?