February 5-6 Sir Mix A Lot/OBS

[WEATHER53]

2 hours ago, high risk said:

      A couple of important points, from a model perspective:

   - The only modeling system that actually tracks and accumulates freezing rain every model time step is RAP/HRRR

   - For all other models, the various sites are making assumptions that the forecasted precip type on the hour applies to the entire hour.    This is ok if they have hourly output from the model, but if it's 3-hourly (or even less frequent), it's pretty inaccurate

   - For most of the U.S. models, the precip type output shows freezing rain if the falling hydrometeors are rain, and the skin temp is at or below 32.    So, the plots of "accumulated freezing rain" are tallying ice the same whether it's 31.9 or 26

   - The FRAM stuff is better, but it's very much tied to rates and wind, and in my mind, it accumulates too generously when temps are marginal.

   - ZR at 31 degrees is very different if it's been in the 20s and temps are rising  as opposed to being in the mid 30's with falling temps.   None of these ZR products really account for that.

 

   So, even if you see big amounts of freezing rain on maps for the areas around DC, it's critical to assess the temperature trends.    With temps in the mid 30s during the day falling to 31 or 32, I'm really skeptical about icing potential.   The precip falling at night probably helps a bit, and maybe an initial burst of sleet cools surfaces enough, but the overall setup argues for the real icing potential to be well north and northwest of the city.

 

 

Let’s get the sleet laid down and that way the freezing rain has some granular and is not slick ice 

[WEATHER53]

16 minutes ago, Imgoinhungry said:

Yea id say that seems to be just a tad overdone.


.

Would the rain  runoff freeze into like mini drifts?

[Weather Will]

WB OZ EURO: may have to extend ice storm warning a tick eastward. Temps below freezing NW until at least sunrise.

[Interstate]

We should turn this thread to OBS

 

30.9/20.9 here in 21057

[aldie 22]

Anything falling out there...radar seemed to blossom this morning 

[mappy]

13 minutes ago, aldie 22 said:

Anything falling out there...radar seemed to blossom this morning 

Nope. Been virga all morning 

[clskinsfan]

31/19 Luckily the roads have been treated well throughout my area. And the temps have been above freezing the past couple of days. Hope to keep power though. 

[NorthArlington101]

Some kind of light mix in Arlington. Didn't believe the ob from my family member but got a pic to prove it. 
 

edir: mPING report corroborates 

[Terpeast]

Nothing falling here. Just was out for half an hour. But cold. 34/19

[Paleocene]

[clskinsfan]

3k busted high on temps at initialization. 

[hstorm]

34.9 here.  No precip this morning

[scope1]

Seeing some very light flurries just now. 

[clskinsfan]

FV3

[stormtracker]

17 minutes ago, clskinsfan said:

FV3

Seems like a more reasonable solution.

[H2O]

36/22  Crows are noisy this morning and when that happens things happen.  We just can't tell yet.

[Paleocene]

1 minute ago, stormtracker said:

Seems like a more reasonable solution.

3k NAM looks similar. Shows more on the ridges which tracks with experience with ice storms

 

[mappy]

6 minutes ago, Paleocene said:

3k NAM looks similar. Shows more on the ridges which tracks with experience with ice storms

 

You know there is a local view that shows the DMV area much better? 

[Interstate]

2 minutes ago, mappy said:

You know there is a local view that shows the DMV area much better? 

Yeah if you pay for it

[mappy]

6 minutes ago, Interstate said:

Yeah if you pay for it

Ohhh. Shoot, sorry. I didn’t realize that was pay only 

[hstorm]

RGEM is not budging.  I am skeptical.

[WhiteoutMD]

7 minutes ago, hstorm said:

RGEM is not budging.  I am skeptical.

does this include sleet?

[mappy]

1 minute ago, WhiteoutMD said:

does this include sleet?

No. Just liquid in the form of freezing rain. It doesn’t necessarily represent accretion on surfaces. 

[mappy]

Just now, hstorm said:

I believe that it does.  But someone who knows more can correct me if I'm wrong!

Even with sleet, the Northern VA numbers seem very high east of the Blue Ridge.

It doesn’t include sleet. Freezing rain only. The FRAM includes sleet, as well as all ice accretion. You should look at FRAM instead of the freezing rain

[hstorm]

5 minutes ago, mappy said:

It doesn’t include sleet. Freezing rain only. The FRAM includes sleet, as well as all ice accretion. You should look at FRAM instead of the freezing rain

Thank you.  I deleted my (inaccurate) post once I saw yours!

[mappy]

Just now, hstorm said:

Thank you.  I deleted my (inaccurate) post once I saw yours!

All good! Each of those output options have little question marks next to it that explain what they represent  

[mappy]

For what it’s worth, GFS is pretty icy for areas north of 70

[TSSN+]

Just now, mappy said:

For what it’s worth, GFS is pretty icy for areas north of 70

Buckle up. I took off tomorrow. 

[mappy]

Just now, mappy said:

For what it’s worth, GFS is pretty icy for areas north of 70

 

[HighStakes]

2 minutes ago, mappy said:

For what it’s worth, GFS is pretty icy for areas north of 70

And temps never really get that warm after precip moves out. Maybe mid 30's by late day.