February 8-9 Cold Rain Event

[pasnownut]

Glad to see the good trends continue.  Pulling for you all as I also needed some help.  Now just hope the King seals the deal for many.

Good luck.

Nut

 

[MN Transplant]

4 minutes ago, Deck Pic said:

 

Problem is most of that falls between 9z and 11z...and the flip for me probably happens around 10z/11z....the implication hasn't really changed here in DC...A burst of heavy wet snow at the end...whether it is cosmetic or dumps 1-2" is yet to be seen. GFS would suggest 1-2" given it is such a dynamic moisture bomb.  I think for me that is pretty much the upside.  

This

[Scraff]

Not sure when it will settle in with everyone, but we should all know if Euro plays rock steady, GFS seems to always play catch up. Not always, but a majority of the time. Anyway, once the Euro runs and goes boom, then it's bread and tp time!  

[mappy]

4 minutes ago, WxWatcher007 said:

Indeed. But compared to past runs down here, this is great. Always fun being on the razors edge.

Oh I know. It is a big improvement for places south, for sure. 

4 minutes ago, psuhoffman said:

I like when the lowball is. Tends to work out that way. 

 fair

3 minutes ago, supernovasky said:

Regular ratios

Still won't happen. This will not be a 10:1 snowstorm, for anyone. 

[SomeguyfromTakomaPark]

1 minute ago, feloniousq said:

The WAMU announcer guy was just talking about Winter Storm Watches for the area overnight.  For whom, exactly, within range of that station?

They always say WSW for the area even if it's just for the far north counties.  Also, they sometimes don't check for the latest NWS updates. 

[AmericanWxFreak]

not sure what it is......BUT I LIKE IT

[yoda]

Just now, WxWatcher007 said:

No doubt. I just want all the big ones on board. 

Next up is the Canadian... lets see how that goes

[MN Transplant]

14 minutes ago, AmericanWxFreak said:

Hi

 

If I am reading the label and context correctly, these are very deceptive maps.  That is prior 6 hr precip but current time temps.  

[yoda]

 

06z NAVGEM at hr 30

[ohwxguy]

9 minutes ago, NorthArlington101 said:

Ripping and below 32 in the metro at 24h!

It's a bit deceptive.  The GFS shows basically nothing for DC on the 6 hour 18z chart, which means the precip shield is moving out of DC by around 12z (7 am).  So while 2 meter temps drop to freezing at 24 hours out, DC is already drying out if the GFS is correct.

At 09z, under the heaviest precipitation, the GFS has temperatures above freezing from the surface up to higher than 800 mb.  So the window is only about 2-3 hours, between about 4 am - 7 am.  Before that it's still likely too mild for much more than a rain/snow mix and after that it's basically dry.

[BTRWx]

3 minutes ago, MN Transplant said:

 

If I am reading the label and context correctly, these are very deceptive maps.  That is prior 6 hr precip but current time temps.  

You're missing "average" and "rate" from your context.

[clskinsfan]

Cobb data from 12Z NAM is anyone cares:

KMRB:

170209/0600Z  18  08010KT  40.7F  RAIN    0:1| 0.0|| 0.00|| 0.00|| 0.029    0:1|  0.0|| 0.00|| 0.00|| 0.03    0|  0|100
----------------------------------------------+----++-----+-------------++--------------++-------------++-----------+---+---
170209/0700Z  19  02007KT  39.1F  RAIN    0:1| 0.0|| 0.00|| 0.00|| 0.147    0:1|  0.0|| 0.00|| 0.00|| 0.18    0|  0|100
170209/0800Z  20  35014KT  36.0F  RASN    0:1| 0.0|| 0.00|| 0.00|| 0.190    0:1|  0.0|| 0.00|| 0.00|| 0.37   28|  0| 72
170209/0900Z  21  36018KT  32.4F  RASN    0:1| 0.0|| 0.00|| 0.00|| 0.189    0:1|  0.0|| 0.00|| 0.00|| 0.55   88|  0| 12
170209/1000Z  22  36017KT  31.0F  SNOW    5:1| 0.7|| 0.00|| 0.00|| 0.121    5:1|  0.7|| 0.00|| 0.00|| 0.68  100|  0|  0
170209/1100Z  23  35014KT  30.1F  SNOW    8:1| 0.4|| 0.00|| 0.00|| 0.059    6:1|  1.1|| 0.00|| 0.00|| 0.73  100|  0|  0
170209/1200Z  24  35014KT  29.7F  SNOW    8:1| 0.1|| 0.00|| 0.00|| 0.009    6:1|  1.2|| 0.00|| 0.00|| 0.74  100|  0|  0

 

DCA:

170209/0600Z  18  08008KT  46.7F  RAIN    0:1| 0.0|| 0.00|| 0.00|| 0.022    0:1|  0.0|| 0.00|| 0.00|| 0.04    0|  0|100
----------------------------------------------+----++-----+-------------++--------------++-------------++-----------+---+---
170209/0700Z  19  10010KT  46.7F  RAIN    0:1| 0.0|| 0.00|| 0.00|| 0.019    0:1|  0.0|| 0.00|| 0.00|| 0.06    0|  0|100
170209/0800Z  20  11010KT  46.1F  RAIN    0:1| 0.0|| 0.00|| 0.00|| 0.049    0:1|  0.0|| 0.00|| 0.00|| 0.11    0|  0|100
170209/0900Z  21  06007KT  44.3F  RAIN    0:1| 0.0|| 0.00|| 0.00|| 0.130    0:1|  0.0|| 0.00|| 0.00|| 0.24    0|  0|100
170209/1000Z  22  36014KT  42.9F  RAIN    0:1| 0.0|| 0.00|| 0.00|| 0.170    0:1|  0.0|| 0.00|| 0.00|| 0.41    0|  0|100
170209/1100Z  23  35018KT  36.6F SNRAPL   0:1| 0.0|| 0.00|| 0.00|| 0.152    0:1|  0.0|| 0.00|| 0.00|| 0.56   26| 22| 52
170209/1200Z  24  35017KT  33.5F    DZ    0:1| 0.0|| 0.00|| 0.00|| 0.022    0:1|  0.0|| 0.00|| 0.00|| 0.58    0|  0|100

 

Iad:

170209/0300Z  15  05008KT  48.8F  RAIN    0:1| 0.0|| 0.00|| 0.00|| 0.004    0:1|  0.0|| 0.00|| 0.00|| 0.00    0|  0|100
170209/0400Z  16  05007KT  47.2F  RAIN    0:1| 0.0|| 0.00|| 0.00|| 0.005    0:1|  0.0|| 0.00|| 0.00|| 0.01    0|  0|100
170209/0500Z  17  07007KT  46.7F  RAIN    0:1| 0.0|| 0.00|| 0.00|| 0.004    0:1|  0.0|| 0.00|| 0.00|| 0.01    0|  0|100
170209/0600Z  18  08008KT  45.4F  RAIN    0:1| 0.0|| 0.00|| 0.00|| 0.017    0:1|  0.0|| 0.00|| 0.00|| 0.03    0|  0|100
----------------------------------------------+----++-----+-------------++--------------++-------------++-----------+---+---
170209/0700Z  19  09007KT  44.5F  RAIN    0:1| 0.0|| 0.00|| 0.00|| 0.076    0:1|  0.0|| 0.00|| 0.00|| 0.11    0|  0|100
170209/0800Z  20  07004KT  44.7F  RAIN    0:1| 0.0|| 0.00|| 0.00|| 0.074    0:1|  0.0|| 0.00|| 0.00|| 0.18    0|  0|100
170209/0900Z  21  35011KT  43.6F  RAIN    0:1| 0.0|| 0.00|| 0.00|| 0.105    0:1|  0.0|| 0.00|| 0.00|| 0.28    0|  0|100
170209/1000Z  22  34019KT  37.5F  RAIN    0:1| 0.0|| 0.00|| 0.00|| 0.250    0:1|  0.0|| 0.00|| 0.00|| 0.53   16|  0| 84
170209/1100Z  23  34018KT  32.8F  RASN    0:1| 0.0|| 0.00|| 0.00|| 0.111    0:1|  0.0|| 0.00|| 0.00|| 0.64   86|  0| 14
170209/1200Z  24  35017KT  32.1F  FZDZ    0:1| 0.0|| 0.00|| 0.00|| 0.006    0:1|  0.0|| 0.00|| 0.00|| 0.65    0|  0|100

Bwi:

170209/0300Z  15  04009KT  48.1F  RAIN    0:1| 0.0|| 0.00|| 0.00|| 0.007    0:1|  0.0|| 0.00|| 0.00|| 0.01    0|  0|100
170209/0400Z  16  05008KT  47.2F  RAIN    0:1| 0.0|| 0.00|| 0.00|| 0.011    0:1|  0.0|| 0.00|| 0.00|| 0.02    0|  0|100
170209/0500Z  17  07008KT  46.7F  RAIN    0:1| 0.0|| 0.00|| 0.00|| 0.003    0:1|  0.0|| 0.00|| 0.00|| 0.02    0|  0|100
170209/0600Z  18  08007KT  46.3F  RAIN    0:1| 0.0|| 0.00|| 0.00|| 0.014    0:1|  0.0|| 0.00|| 0.00|| 0.04    0|  0|100
----------------------------------------------+----++-----+-------------++--------------++-------------++-----------+---+---
170209/0700Z  19  09008KT  45.6F  RAIN    0:1| 0.0|| 0.00|| 0.00|| 0.048    0:1|  0.0|| 0.00|| 0.00|| 0.08    0|  0|100
170209/0800Z  20  10010KT  45.2F  RAIN    0:1| 0.0|| 0.00|| 0.00|| 0.050    0:1|  0.0|| 0.00|| 0.00|| 0.13    0|  0|100
170209/0900Z  21  05007KT  43.6F  RAIN    0:1| 0.0|| 0.00|| 0.00|| 0.147    0:1|  0.0|| 0.00|| 0.00|| 0.28    0|  0|100
170209/1000Z  22  36014KT  41.1F  RAIN    0:1| 0.0|| 0.00|| 0.00|| 0.218    0:1|  0.0|| 0.00|| 0.00|| 0.50    0|  0|100
170209/1100Z  23  35017KT  34.4F SNRAPL   0:1| 0.0|| 0.00|| 0.00|| 0.189    0:1|  0.0|| 0.00|| 0.00|| 0.69   48| 28| 24
170209/1200Z  24  35016KT  31.9F  SNOW   10:1| 1.0|| 0.00|| 0.00|| 0.095   10:1|  1.0|| 0.00|| 0.00|| 0.78  100|  0|  0
----------------------------------------------+----++-----+-------------++--------------++-------------++-----------+---+---
170209/1300Z  25  34015KT  31.4F  SNOW    7:1| 0.1|| 0.00|| 0.00|| 0.010   10:1|  1.0|| 0.00|| 0.00|| 0.79  100|  0|  0

[BTRWx]

4 minutes ago, ohwxguy said:

It's a bit deceptive.  The GFS shows basically nothing for DC on the 6 hour 18z chart, which means the precip shield is moving out of DC by around 12z (7 am).  So while 2 meter temps drop to freezing at 24 hours out, DC is already drying out if the GFS is correct.

At 09z, under the heaviest precipitation, the GFS has temperatures above freezing from the surface up to higher than 800 mb.  So the window is only about 2-3 hours, between about 4 am - 7 am.  Before that it's still likely too mild for much more than a rain/snow mix and after that it's basically dry.

um...

[Deck Pic]

GFS - Temps 9z/10z/11z/12z/13z

DCA - 47/38/35/32/31

BWI - 37/34/31/28/27

IAD - 40/34/32/31/30

[ohwxguy]

Just now, BTRWx said:

um...

That chart isn't a depiction of conditions at 12z.  It's showing the precip over the previous 6 hours, which means between 6z and 12z. 

[das]

19 minutes ago, Paleocene said:

GFS now has the freezing line roughly at the south side of the beltway by 12z tomorrow. It's been dropping every run - yesterday this time it was along I-70ish.

A special thank you to this guy:

[yoda]

Lol 12z GGEM at 24 bullseyes us

[SomeguyfromTakomaPark]

2 minutes ago, Deck Pic said:

GFS - Temps 9z/10z/11z/12z/13z

DCA - 47/38/35/32/31

BWI - 37/34/31/28/27

IAD - 40/34/32/31/30

Awesome, thanks for posting that.  Like you were saying, almost nothing falls after 12z, so a brief period of heavy snow is probably our best case scenario from like 11z-13z or something like that.  

[ohwxguy]

Just now, BTRWx said:

Well it's not much different 6 hours after that frame.

It's *very* different for the following 6 hour window, starting at 12z and ending at 18z.

 

[stormtracker]

1 minute ago, das said:

A special thank you to this guy:

Mitch was going on about this guy yesterday...it was a good ob.   Now i'm wishing that thing was a little stronger.

[BTRWx]

3 minutes ago, ohwxguy said:

That chart isn't a depiction of conditions at 12z.  It's showing the precip over the previous 6 hours, which means between 6z and 12z. 

I see what you mean.  The 1 hr precip charts show nothing close to the 850mb precip map.  Why is this just coming up though?  Until today, the timing didn't seem off that much from the 850mb charts.  Wth?

[BTRWx]

1 minute ago, ohwxguy said:

It's *very* different for the following 6 hour window, starting at 12z and ending at 18z.

 

I deleted that other comment.  I added +2 instead of +3 * 2

[SomeguyfromTakomaPark]

1 minute ago, ohwxguy said:

It's *very* different for the following 6 hour window, starting at 12z and ending at 18z.

 

Yeah and you can check the 3-hr totals using IWM.  There is less than 0.1 for the entire subforum after 12z.

[usedtobe]

My temp is 70+ which makes me wonder about the GFS temp forecast.  The last time we got that warm, the models backed off on the cold on the 18Z and 00Z runs. 

[CAPE]

[feloniousq]

Temps are anywhere from 2-8 degrees above forecast in Virginia and S. MD right now.  We are getting really hyped about a 37 degree rainstorm a-comin'.

[BTRWx]

7 minutes ago, DCTeacherman said:

Yeah and you can check the 3-hr totals using IWM.  There is less than 0.1 for the entire subforum after 12z.

Have we all been misinterpreting that from the beginning of time???  I know I'm not the only one.

[Paleocene]

3 minutes ago, usedtobe said:

My temp is 70+ which makes me wonder about the GFS temp forecast.  The last time we got that warm, the models backed off on the cold on the 18Z and 00Z runs. 

I had a similar thought. It's 69 at work in College Park. A few hours ago, temp forecasts said we weren't gonna get over 65 today.

[RichmondTarHeel]

It is a good bit warmer than was forecasted.  Already up to 66 here in Tysons. 

[CAPE]

CMC starting to look more GFS like with snowfall location/amounts.