February/March 2021 - Frigid or Flop? Pattern/Longterm Forecast Thread.

[John1122]

That 1951 event was just a monster winter storm in the mid state. It hit from the Plateau west. My grandfather recorded 1.6 inches of ice and 3 inches of snow from it. And that was less than half what Nashville received. He recorded a temperature of 27 degrees the morning of February 1st and 12 by 6pm. Nashville was 10-15 degrees colder.  The most amazing thing was the far east side was warm, Knoxville was mid 40s into the day on February 1st and crashed as soon as the precip stopped.  Tri was in the 60s.  Must have been downsloping. Tri fell from 62 degrees to 13 by 11:59 February 1st.  49 degrees in a day has to be one of the biggest drops there ever. 

[Wurbus]

Euro more suppressed and colder toward next weekends 1st storm. Not as amped. 2nd storm appears to have more energy and hass one hell of an ice storm in south Georgia. Starts at 204 and is still going at 222. Some moisture is starting to reach TN by 216. I don't have any ice maps, but I'm sure it would be devastating in that area.

East TN does get some snow toward the end of the run from the 2nd system. Probably 3-6 inches for all of East TN.

[jaxjagman]

Shows as the LP starts up the east coast it bring up a warm nose in Eastern Parts,on to the next run,sure it will be different

 

ECMWF Deterministic FORECAST FOR: TYS    LAT=  35.82 LON=  -83.98 ELE=   981

                                            00Z FEB05
                 2 M     850    1000    FZING    SFC     SFC    6 HR    SNCVR
                 TMP     TMP     850     HGT     WIND    PCP     QPF     LIQ 
                 (C)     (C)     THK    (FT)    (KTS)   TYPES   (IN)    (IN) 
FRI 00Z 05-FEB   6.1     3.6     133    7614    18010                           
FRI 06Z 05-FEB   6.2     3.9     133    6502    22008                           
FRI 12Z 05-FEB   2.0    -1.1     130     950    29006           0.14            
FRI 18Z 05-FEB   4.7    -4.8     130    1070    26004           0.00            
SAT 00Z 06-FEB   2.4    -3.2     131    2171    23004           0.00            
SAT 06Z 06-FEB  -0.6    -2.7     131    2319    21004           0.00            
SAT 12Z 06-FEB  -2.3    -1.8     131    2712    22003           0.00            
SAT 18Z 06-FEB   7.3    -1.6     132    2859    11001           0.00            
SUN 00Z 07-FEB   2.7    -3.0     130    1612    16004           0.07            
SUN 06Z 07-FEB   1.0    -0.7     130    2032    01003           0.11            
SUN 12Z 07-FEB   0.5    -3.6     130     586    34003           0.22            
SUN 18Z 07-FEB   4.7    -2.4     131    1323    04004           0.01            
MON 00Z 08-FEB   1.7    -2.2     131    1966    09003           0.00            
MON 06Z 08-FEB  -2.1     0.8     131    5375    08003           0.00            
MON 12Z 08-FEB  -2.8    -0.4     131    4579    12004           0.00            
MON 18Z 08-FEB  10.1     2.4     133    6786    23002           0.00            
TUE 00Z 09-FEB   4.6     3.8     134    7801    11005           0.00            
TUE 06Z 09-FEB   4.8     5.8     133    8410    17005           0.00            
TUE 12Z 09-FEB   5.2     6.7     134    8161    11003           0.01            
TUE 18Z 09-FEB  14.2     7.3     135    7646    23009           0.05            
WED 00Z 10-FEB   7.0     1.8     132    5695    30007           0.08            
WED 06Z 10-FEB   0.2    -3.1     129     214    33005           0.01            
WED 12Z 10-FEB  -4.2    -4.9     127       0    01004           0.00            
WED 18Z 10-FEB   1.7    -3.7     129     175    35003           0.00            
THU 00Z 11-FEB  -1.1    -2.6     129     207    05004           0.00            
THU 06Z 11-FEB  -4.4    -1.8     129      10    03003           0.00            
THU 12Z 11-FEB  -5.6    -3.9     128       0    04003           0.00            
THU 18Z 11-FEB   2.0    -6.5     128     291    36004           0.00            
FRI 00Z 12-FEB  -1.5    -8.7     128       7    01005           0.00            
FRI 06Z 12-FEB  -5.7   -10.0     126       0    02007           0.00            
FRI 12Z 12-FEB -10.4   -10.6     124       0    02007           0.00            
FRI 18Z 12-FEB  -3.2   -11.0     125       0    01007           0.00            
SAT 00Z 13-FEB  -6.4   -11.6     125       0    02006           0.00            
SAT 06Z 13-FEB  -9.3    -9.9     125       0    03007           0.00            
SAT 12Z 13-FEB  -9.9    -7.3     125       0    03007           0.00            
SAT 18Z 13-FEB  -1.4    -5.2     127       6    04005           0.00            
SUN 00Z 14-FEB  -1.5    -5.2     128       0    02004           0.00            
SUN 06Z 14-FEB  -2.6    -1.9     128    1177    03003           0.08            
SUN 12Z 14-FEB  -2.9    -0.3     129    3836    04004           0.25            
SUN 18Z 14-FEB   0.1     0.5     130    4812    02004           0.12            
MON 00Z 15-FEB   0.2     0.6     130    5111    00003           0.17 

 

 

[John1122]

The Euro is odd to me in that you're very very rarely going to see frozen along the gulf coast with temperatures that warm here.  At 210 its 29 in Knoxville and 29 in Columbus Georgia 400+ miles south. At 216 it's 31 in Knoxville to Trj and thats some of the warmest temperatures in the entire south on either side of the Apps. Anything is possible but I just don't see it playing out that way.  To get cold down to the GOM and have frozen precip there you usually have to be in the 10s and single digits here.  

[Uncle Nasty]

If the temps are going to be as cold as advertised late next week AND there is moisture my gut tells me Chattanooga will be looking south to see the white stuff. I've seen way too many good snows get suppressed just to our south when we finally get cold air in our area and moisture from the gulf.

Plenty of time to feel this one in. Let's hope for temps in the upper 20's to low 30's if we all get the moisture. After that bring in the motherload of cold so it can have staying power.

Sent from my moto z4 using Tapatalk

[Carvers Gap]

The 12z GFS has a light wintery mix over middle and western forum areas just after hour 100.  There are at least two waves of this.  Very icy look.

[Carvers Gap]

That is a major overrunning event in middle and west TN which is being portrayed on the 12z GFS.  Wave three of ice now inbound.

[1234snow]

The 12z GFS has a light wintery mix over middle and western forum areas just after hour 100.  There are at least two waves of this.  Very icy look.

It almost doesn’t break apart the waves this run. Almost continuous moisture of some intensity for the forum.

[Carvers Gap]

1 minute ago, 1234snow said:

It almost doesn’t break apart the waves this run. Almost continuous moisture of some intensity for the forum.

1054 hp rolling in around 168.  That is a nasty, nasty setup. 

[Matthew70]

Sheesh.  So tornadoes and Damaging winds and now ice.  Seriously I think we’ve had enough damage

[Carvers Gap]

Big 1057 high in WY at 186.

[jaxjagman]

8 minutes ago, Carvers Gap said:

That is a major overrunning event in middle and west TN which is being portrayed on the 12z GFS.  Wave three of ice now inbound.

Definite icey'

 

GFS 0.5 Degree FORECAST FOR: BNA    LAT=  36.12 LON=  -86.68 ELE=   591

                                            12Z FEB05   * - APPROXIMATED
                 2 M     850     SFC     SFC     700    6 HR     500    1000 
                 TMP     TMP     PRS     RHU     RHU     QPF     HGT     500 
                 (C)     (C)    (MB)    (PCT)   (PCT)   (IN)    (DM)     THK 
FRI 12Z 05-FEB  -1.5    -3.0    1015      88       7             547     535    
FRI 18Z 05-FEB   6.1    -3.9    1016      48      41    0.00     544     531    
SAT 00Z 06-FEB   3.6    -3.6    1015      63      54    0.00     544     532    
SAT 06Z 06-FEB   1.8    -2.8    1018      72      31    0.00     547     533    
SAT 12Z 06-FEB   0.8    -2.3    1019      75      24    0.00     549     534    
SAT 18Z 06-FEB   8.0    -1.5    1018      54      81    0.00     551     536    
SUN 00Z 07-FEB   5.0    -4.0    1013      76      97    0.01     549     539    
SUN 06Z 07-FEB   2.2    -3.2    1013      96      97    0.34     544     533    
SUN 12Z 07-FEB  -3.6    -4.6    1019      86      38    0.06     547     531    
SUN 18Z 07-FEB   0.7    -3.8    1023      69      21    0.00     550     532    
MON 00Z 08-FEB  -1.1    -1.7    1023      79      34    0.00     553     535    
MON 06Z 08-FEB  -2.5    -1.1    1025      85      40    0.00     558     539    
MON 12Z 08-FEB  -2.7     1.8    1024      87      29    0.00     560     542    
MON 18Z 08-FEB   8.3     1.9    1022      59      29    0.00     562     544    
TUE 00Z 09-FEB   6.0     4.3    1018      84      46    0.00     562     548    
TUE 06Z 09-FEB   5.2     2.0    1019      93      59    0.00     563     547    
TUE 12Z 09-FEB   5.1     1.6    1019      96      27    0.00     563     547    
TUE 18Z 09-FEB   7.2     2.1    1020      87      82    0.01     565     548    
WED 00Z 10-FEB   1.7     3.8    1021      92      94    0.05     564     547    
WED 06Z 10-FEB  -0.6     4.2    1021      92      99    0.06     564     547    
WED 12Z 10-FEB  -2.8     3.4    1022      90      93    0.08     562     545    
WED 18Z 10-FEB  -1.4     3.5    1022      87      51    0.00     563     545    
THU 00Z 11-FEB  -1.2     2.8    1021      92      85    0.00     563     546    
THU 06Z 11-FEB  -1.6     5.1    1021      92      83    0.02     564     547    
THU 12Z 11-FEB  -2.3     5.4    1019      93      99    0.07     564     548    
THU 18Z 11-FEB  -0.8     5.3    1019      93      99    0.09     564     548    
FRI 00Z 12-FEB  -1.4     4.1    1017      94     100    0.03     561     547    
FRI 06Z 12-FEB  -3.2     2.0    1017      94      99    0.26     558     545    
FRI 12Z 12-FEB  -6.4    -0.9    1018      93     100    0.06     553     539    
FRI 18Z 12-FEB  -4.3    -6.8    1020      90      95    0.03     549     534    
SAT 00Z 13-FEB  -9.2   -12.5    1024      93      93    0.06     544     525    
SAT 06Z 13-FEB -16.1   -16.2    1031      92      83    0.02     537     514   

[BNAwx]

With that flow, it might not be done with the mischief yet...

[Carvers Gap]

I think what is happening is the SER is going to fight east of the Apps.  To me, this looks like cold moving across the entire forum area and banking up against the Apps in reality.  As BNA noted(think that is right) having a front draped SW to NE is a recipe for winter weather.  

[Carvers Gap]

The trend with the 12z GFS is to push further south with the cold post 100.  

[Carvers Gap]

So here is why this is so difficult to predict.  Think about how a hurricane when it is approaching the coast at a 90 degree angle, the cone is easy to set for the most part.  Now, if the hurricane is running parallel to the coast...much tougher.  Any degree of change to a storm running parallel to the coast could result in hundreds of miles of changes in landfall forecasts.  Pretty much the same deal with this overrunning event next week.  The slightest change in angle of that boundary is moving that frozen boundary all over the place.  

[Carvers Gap]

Man, going to get ridiculously cold if we get frozen before that cold shot.  The scenario is there where we could have wide spread power outages prior to  a really severe cold outbreak.

[Wurbus]

Yeah, looks like it could possibly be single digit highs and lows in the negatives for much of the region!

[Carvers Gap]

Give it a day or so, but may be time for a separate thread for that cold shot and potential overrunning event.    If modeling is even halfway correct, that event could be significant for many in the forum area - if not ice, then severe cold.  Really tracking two events right now...the system this weekend and the cold/potential overruning event later next week.  

[BNAwx]

6 minutes ago, Carvers Gap said:

Man, going to get ridiculously cold if we get frozen before that cold shot.  The scenario is there where we could have wide spread power outages prior to  a really severe cold outbreak.

Yeah.  Not a good look.  Might need to gas up the generator we got after the tornadoes last March...

[Bigbald]

Just wow at the gfs cold, 

[Wurbus]

3 minutes ago, Bigbald said:

Just wow at the gfs cold, 

It is no joke. Just looking at Knoxville, we are in the single digits and negatives for 30+ hours. Nashville was pushing 40 hours.

[Wurbus]

Y

 

You don't see a 1040 HP sitting over Memphis everyday.....

[Bigbald]

I cant see beyond 240, but, for example, wise va was low single digits and deeply negative for like 4 days straight.  This is ice age type stuff lol

[Carvers Gap]

Just now, Wurbus said:

Y

 

You don't see a 1040 HP sitting over Memphis everyday.....

@AMZ8990, that right over your house?

[Carvers Gap]

12z CMC also has the overrunning event for later next week.  It is a bit further east and less cold.  I think we are looking at the potential for the front stalling at the spine of the Apps and/or the Plateau.  

Edit:  Well some of it must get past the Apps as there is also a decent CAD signature for NC during part of that event.

[Carvers Gap]

The CMC has 4-5 waves of frozen precip which slowly press the boundary eastward.  

[Matthew70]

To say this would not be catastrophic and dangerous with that much ice and cold temps to me is an understatement.

[Carvers Gap]

12z CMC is very icy for the eastern valley areas.

[Bigbald]

By hr 305, when the damn finally breaks and low 50s return to large swath of tn, I predict mankini Monday cause 50s will feel about like 80