Southeast February Mid/Long Range Discussion II

[GaWx]

To confirm, the 12Z Euro ensemble mean is much colder than the 0Z Euro ensemble mean just as the 12z Euro op. is much colder than the 0Z Euro op. However, as one might expect with such a major change/very cold run, the 12Z Euro ens. mean isn't as cold as the 12Z Euro op. (mainly because it is an ensemble mean of several dozen members...they tend to smooth out each other to some extent) just in case Cheeznado wonders about my post.

Edit: yes, the Euro has a bit of a warm bias.

[ATL_Militarypolice]

Rocking! Let's keep it going to 00z. Anyone have info on the CMC or UKMet?

Here's the Ukie at 144. Tall elongated Western Ridge trying to establish cross-polar flow. PV in eastern Canada, with an east based -NAO trying to develop. Don't have any temps maps...

[NCSNOW]

Rocking! Let's keep it going to 00z. Anyone have info on the CMC or UKMet?

I just might stay up tonight for the sake of having a half hearted excuse to do so for the first time this winter season. I've gotten 2 times the amount of work and regular sleep this winter compared to past years.

FYI: Greensboro (PTI) topped the 60 degree mark 12 times in January 2012. So far this winter season (D,J.F) we have only had 2 days where the max temp didn't reach 40 degrees. I'd say we've paid our debt off to mother nature for the past 2 winters, espeacilly considering last February/March winter was over with.

[burgertime]

I just might stay up tonight for the sake of having a half hearted excuse to do so for the first time this winter season. I've gotten 2 times the amount of work and regular sleep this winter compared to past years.

FYI: Greensboro (PTI) topped the 60 degree mark 12 times in January 2012. So far this winter season (D,J.F) we have only had 2 days where the max temp didn't reach 40 degrees. I'd say we've paid our debt off to mother nature for the past 2 winters, espeacilly considering last February/March winter was over with.

I'll def. be up tonight for the GFS runs...might not be able to make it for the Euro though.

[appstate00]

.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...

-- Changed Discussion --

AS OF 225 PM EST FRIDAY...LOW CONFIDENCE FORECAST CONTINUES FOR THE

MEDIUM RANGE AS THE MDLS CHANGE FROM RUN TO RUN. SHORT WAVES OPEN UP

AND MOVE NEAR OR OVER THE AREA THRU WED NITE. THEN A DEEP UPPER LOW

DIVES TO BAJA THU. THE GFS IS MUCH MORE PROGRESSIVE WITH THIS SYSTEM

SPINNING SHORT WAVE ENERGY AROUND THE LOW AND OVER THE SE US WHILE

THE ECMWF RETROGRADES THE LOW AND DEVELOPS A TROF OVER THE ERN

CONUS. AS EXPECTED...THIS LEADS TO SIGNIFICANT DIFFERENCES AT THE

SFC. THERE IS AGREEMENT THAT HIGH PRESSURE BUILDS INTO THE AREA LATE

TUE AND DEVELOPS A COLD AIR DAMMING PATTERN WED. THE GFS AND THE

PREVIOUS ECMWF SHOWED A CLIPPER-LIKE SYSTEM MOVING THRU WED AND WED

NITE. THE NEW ECMWF DEVELOPS A STRONG MILLER-A GULF LOW WED TAKING

IT UP THE SERN COAST WED NITE AND THU. SINCE THERE WAS AGREEMENT ON

LOW END PRECIP CHANCE...WENT WITH SLIGHT CHC POP WED AFTERNOON AND

NITE. WILL NOT INCREASE ATTM GIVEN THE UNCERTAINTY. THE NEW ECMWF

CONTINUES ITS GENERALLY DRY FCST FOR THU IN THE WAKE OF THE

DEPARTING SYSTEM AND FRI AS A WEAK CLIPPER-TYPE COLD FRONT MOVES

THRU. THE GFS HOWEVER...DEVELOPS A STRONG GULF LOW FOR THU AND

MOVES IT ACROSS THE SERN US ON FRI. GIVEN THE WIDE RANGE IN THE

GUIDANCE...HAVE KEPT THE FCST DRY FOR NOW. WILL HAVE TO WATCH THE

FCST OVER TIME AS H85 TEMPS AND PARTIAL THICKNESSES WOULD INDICATE

POTENTIAL FOR WINTRY PRECIP WITH EITHER OF THE GULF LOWS. FOR NOW...

HAVE ABOVE NORMAL LOWS SUN NITE DROPPING TO NEAR NORMAL MON NITE

THEN BOUNCING AROUND ABOVE NORMAL FOR THE REST OF THE PERIOD. HIGHS

A LITTLE ABOVE NORMAL MONDAY RISE TUE THEN BOUNCE AROUND A LITTLE

ABOVE NORMAL THRU THE WEEK.

-- End Changed Discussion --

[Cheeznado]

To confirm, the 12Z Euro ensemble mean is much colder than the 0Z Euro ensemble mean just as the 12z Euro op. is much colder than the 0Z Euro op. However, as one might expect with such a major change/very cold run, the 12Z Euro ens. mean isn't as cold as the 12Z Euro op. (mainly because it is an ensemble mean of several dozen members...they tend to smooth out each other to some extent) just in case Cheeznado wonders about my post.

Edit: yes, the Euro has a bit of a warm bias.

The Euro ensemble spaghetti shows the Op to be the extreme cold outlier of the entire series. Yes, it is cold, but the mean does not even brong the 540 thickness line to ATL. while the op has us below 522DM.

[tnweathernut]

The Euro ensemble spaghetti shows the Op to be the extreme cold outlier of the entire series. Yes, it is cold, but the mean does not even brong the 540 thickness line to ATL. while the op has us below 522DM.

How many individual members do bring the 540 line to ATL?

[Poimen]

The EURO ensemble mean at 240, no where near as robust with the cold/block as the op.

[Cold Rain]

The EURO ensemble mean at 240, no where near as robust with the cold/block as the op.

Still not a terrible look, though. It'll be important to see how things are trending.

[tnweathernut]

So which model blinks first on the gulf low idea next week? Euro finally showing one or the GFS taking it away?

[jmundie]

To confirm, the 12Z Euro ensemble mean is much colder than the 0Z Euro ensemble mean just as the 12z Euro op. is much colder than the 0Z Euro op. However, as one might expect with such a major change/very cold run, the 12Z Euro ens. mean isn't as cold as the 12Z Euro op. (mainly because it is an ensemble mean of several dozen members...they tend to smooth out each other to some extent) just in case Cheeznado wonders about my post.

Edit: yes, the Euro has a bit of a warm bias.

Thanks for that. Pretty sure Mariettawx was making fun of me earlier. I may not have a lot of posts, but am no fool.

/offtopic

[bhamwx205]

So which model blinks first on the gulf low idea next week? Euro finally showing one or the GFS taking it away?

Gfs

[BIG FROSTY]

So which model blinks first on the gulf low idea next week? Euro finally showing one or the GFS taking it away?

Euro, it's going to be rocking around here!!!

[POWERSTROKE]

be careful how excited you get we are still more than 72hrs out! Heck who cares anymore I'm in too what do we have to lose!!

[LithiaWx]

Thanks for that. Pretty sure Mariettawx was making fun of me earlier. I may not have a lot of posts, but am no fool.

/offtopic

Nope, I wasn't making fun of you. I've never heard of the Euro having a warm bias before, it was a legitimate question. Still not sure I buy it though, but Larry saying it makes me think it's correct. I wish there was a way to show solid data on that but I fear it's more opinion than provable fact. That doesn't mean that the opinion isn't pretty universally accepted either.

[dsaur]

Ok, Burgerman, I'm liking the idea of the two lows still, but one might not be so necessary for two, though it certainly won't hurt for the cold factor..... so I guess it's fair we bet on each others solution, lol. It will be very interesting watching how this all pans out, seeing how the 18z still has the gulf popping, and the cold even closer....though we seem a long way from a scenairo that makes sense. T

[jmundie]

Nope, I wasn't making fun of you. I've never heard of the Euro having a warm bias before, it was a legitimate question. Still not sure I buy it though, but Larry saying it makes me think it's correct. I wish there was a way to show solid data on that but I fear it's more opinion than provable fact. That doesn't mean that the opinion isn't pretty universally accepted either.

If you do a google search for it, I definitely found some stuff talking about the ECMWF tropical model having a warm bias. But I've been a lurker since 2006 on eastern, and I know I didn't just make it up. In fact, I've seen several snow storms in my day that the euro had as rain, even 24 hours out.

[Cold Rain]

I haven't researched it, but I believe the warm bias of the euro is not that the whole model is warm in the longer ranges but moreso that certain situations, like cadding, in the longer range tends to be underdone.

I don't believe you can look at a 5 day+ 500 mb or surface temp prog and categorically describe the model as warm-biased.

If I'm wrong here, somebody please correct me.

[Met1985]

Good stuff today guys. Still we no it will change but in the right or wrong direction? Also weathernut i agree a lot about your middle of the month storm. Things will progress i think in a better direction for us. We just have to be patient.

[burgertime]

Ok, Burgerman, I'm liking the idea of the two lows still, but one might not be so necessary for two, though it certainly won't hurt for the cold factor..... so I guess it's fair we bet on each others solution, lol. It will be very interesting watching how this all pans out, seeing how the 18z still has the gulf popping, and the cold even closer....though we seem a long way from a scenairo that makes sense. T

18z is a tad colder. Looks like I might getting two pair now.

[dsaur]

Yeah, you might need two pair to stand up to all the coming prevarication, as the models say, "yeah", or maybe "no", or, "what I really meant was"...., lol. I like that the Doc. has maybe hinted at something other that the usual poker faced "you think I care" attitude. It's something. I still like the trailing low idea, but no reason we can't score on both The big story is the low that won't go away...and now wants to bring a friend to bat cleanup. T

[buckeyefan1]

West-based -NAO at 240

This is a thing of beauty I miss images like these being shown, now it's wait and see if it continues to be shown in future runs

[tnweathernut]

Per HM in the med range thread. I thought it was interesting and worth a re-post in our thread since not everyone goes there.

"You can analyze every cluster of thunderstorms all you like in the Tropics and talk about what happened in January, but the simple truth is that the regime has shifted. Now I am not suggesting an epic cold pattern is coming or that blizzard after blizzard is on the way, but this is NOT the same setup. This is the furthest east the forcing has gotten all winter, the NH AAM anomalies have reversed and the solar parameters continue to decline toward a probable min later this month during the next IMF dip. Our issue is not going to be the PV retreating to Alaska as much as it will be the tight / fast nature to the vortex (since the center of the stratospheric vortex will be essentially over the PV)."

[Met1985]

Per HM in the med range thread. I thought it was interesting and worth a re-post in our thread since not everyone goes there.

"You can analyze every cluster of thunderstorms all you like in the Tropics and talk about what happened in January, but the simple truth is that the regime has shifted. Now I am not suggesting an epic cold pattern is coming or that blizzard after blizzard is on the way, but this is NOT the same setup. This is the furthest east the forcing has gotten all winter, the NH AAM anomalies have reversed and the solar parameters continue to decline toward a probable min later this month during the next IMF dip. Our issue is not going to be the PV retreating to Alaska as much as it will be the tight / fast nature to the vortex (since the center of the stratospheric vortex will be essentially over the PV)."

Ya i just got through reading that. Great stuff on that read and wow learning a lot!

[Carvers Gap]

After a day straight from the gates of Hades, I pull up the Euro expecting samo, samo...but no. Nice surprise. Though the op is a cold outlier, still looks good. Cautiously optimistic.

[jmundie]

Not sure if it lends credibility to, or away from the euro, but the 12z no gaps has a colder, wetter version of the storm midweek. Assuming the whole column is good below 850, would be a solid 3-6 inch event for middle and eastern tn, with the exception of maybe eastern valley.

[BrierCreekWx]

I haven't researched it, but I believe the warm bias of the euro is not that the whole model is warm in the longer ranges but moreso that certain situations, like cadding, in the longer range tends to be underdone.

I don't believe you can look at a 5 day+ 500 mb or surface temp prog and categorically describe the model as warm-biased.

If I'm wrong here, somebody please correct me.

I would imagine any warm bias mainly would exist in surface temps. I'd be surprised if the whole model was just warm, otherwise that would be a pretty easy fix: Temp=Temp-warmbias. In all seriousness, I think the ECMWF does have a warm bias in it's surface temperatures, but that doesn't really determine rain vs. snow (it's more about the entire sounding).

[Cold Rain]

I would imagine any warm bias mainly would exist in surface temps. I'd be surprised if the whole model was just warm, otherwise that would be a pretty easy fix: Temp=Temp-warmbias. In all seriousness, I think the ECMWF does have a warm bias in it's surface temperatures, but that doesn't really determine rain vs. snow (it's more about the entire sounding).

Gotcha. Makes sense. As a general rule, I try to avoid looking at surface temps on any model outside of a couple/few days. I focus more on the H500 look and see where the players are first and then look at H850 temps. If the H5 looks good, I worry about the surface temps later.

[griteater]

I would imagine any warm bias mainly would exist in surface temps. I'd be surprised if the whole model was just warm, otherwise that would be a pretty easy fix: Temp=Temp-warmbias. In all seriousness, I think the ECMWF does have a warm bias in it's surface temperatures, but that doesn't really determine rain vs. snow (it's more about the entire sounding).

That's the way I've always seen it mentioned...a slight warm bias with suface temps only.

[BrierCreekWx]

That's the way I've always seen it mentioned...a slight warm bias with suface temps only.

Yeah I've taken graduate level NWP courses and I've never heard it mentioned in there, but I think I've seen it mentioned some where and in my limited experience looking at surface temps (I normally focus on thicknesses), I've only ever really noticed raw surface temps that have appeared to be too warm.