January Discobs 2026

[pazzo83]

52 minutes ago, WEATHER53 said:

Low if 12 here and I’m noticing humidity is not bone dry overnight and wondering if the snow pack interaction is keeping dew points higher and squashing the radiational?

seems plausible

[wxmeddler]

1 hour ago, WEATHER53 said:

Low if 12 here and I’m noticing humidity is not bone dry overnight and wondering if the snow pack interaction is keeping dew points higher and squashing the radiational?

The thing to realize about dew points in this range is that the difference in water vapor between 10F and 0F is between bupkis, and slightly less than bupkis. Once you get down to negatives you're in "absolute bupkis" territory. 

That is to say that radiational cooling (~200 W/M^2) will absolutely overwhelm whatever tiny vapor pressure is being released by sublimination. Long-Wave radiational cooling will tank the temperatures (and therefore dew points) if given the chance to do so. The only thing that will stop radiational cooling is a blockage of the long wave infrared energy to space (ie. Clouds or Fog).

[rjvanals]

NAM 3k still likes a dusting through the metro this evening 

[MN Transplant]

3 hours ago, pazzo83 said:

is there a good explanation for the big misses from the various model outputs?  Was there a model that was better on our actual realized temps?

The NAM 3km is doing pretty well IMBY, but isn't cold enough in the low-lying areas.  The HRRR is the inverse.  The globals are having all sorts of problems.  The fundamental answer is that the models just have so much trouble handling the very stable winter boundary layer and how much mixing there is.  

[WEATHER53]

23.5 for my high so it was very cold mostly low 20’s around DC 

[pazzo83]

high of 28F here, 26/27F at DCA.

[BTRWx's Thanks Giving]

Even tonight's flurries faded away. 

[WxUSAF]

When will the radar start showing my dusting?

[katabatic]

Hi temp here was 11.8 (currently 7.9) with very light snow this afternoon. Maybe 1/2" but seems to have tapered off now. For the first time in many days, the wind has subsided and is rather pleasant to take a walk outside and get out of the house.

[Paleocene]

Street finally got plowed today here in Moco. The County contractor who did it was driving an older RWD salt truck with completely bald tires. He was slipping all over the place. It literally took him two hours to do a single, flat block that is no more than 600 feet long. I felt bad for the guy, he did not have the proper equipment to fight this battle. But he got the job done eventually, even though he had to dig himself out a couple times.

On a neighboring street, the County literally sent a front-end loader to clear a solid concrete icy mess. Props to them for showing up. Never seen snow removal like this in this area in my 16 years here.

[snowfan]

Cleanup in aa co continues

 

[LongRanger]

21 for the day's max, wind has gone calm, so maybe we set a new min temp for this winter tonight

[snowfan]

Down 6 degrees to 18. Come on single digits!

[ThePhotoGuy]

24.8 for the high. Bright sunshine today made it feel warmer. 

[MN Transplant]

mPING report of snow and weak radar returns around Chesapeake Beach

[LordBaltimore]

Everybody saddle up. Set your alarms. Make sure your outdoor temp sensors are in working order and properly sited. Tonights the night

We're going sub-zero

[kgottwald]

Three days of sunshine and not even the roofs of the houses across the street have lost their snowcover. Normally those are the first places to melt off, almost always the day after the snow.

[WEATHER53]

Tonight IS a cold one.  We all saw last two nights pretty early on temps being forecasted  too cold.   Right now it’s 17.6 so 0-5 not off based  12 last night and 9 night before gets eclipsed. 

[WEATHER53]

2 hours ago, WxUSAF said:

When will the radar start showing my dusting?

Not since 2:30 pm

[pazzo83]

18 minutes ago, WEATHER53 said:

Tonight IS a cold one.  We all saw last two nights pretty early on temps being forecasted  too cold.   Right now it’s 17.6 so 0-5 not off based  12 last night and 9 night before gets eclipsed. 

temps have leveled off here - 20F.  They rose slightly at DCA, up to 24F.  Single digits aren't happening tonight for the urban areas.

[SomeguyfromTakomaPark]

3 minutes ago, pazzo83 said:

temps have leveled off here - 20F.  They rose slightly at DCA, up to 24F.  Single digits aren't happening tonight for the urban areas.

That’s good, low single digits is pipe bursting weather. 
 

man this snowpack is bulletproof.  Have we ever had a colder stretch after a storm than this?

[LordBaltimore]

3 minutes ago, pazzo83 said:

temps have leveled off here - 20F.  They rose slightly at DCA, up to 24F.  Single digits aren't happening tonight for the urban areas.

it's a radiational cooling night now that the winds are dying off. There's probably a 5+ degree difference between different sides of your house depending on sky exposure and distance to heat sources. Many parts of the city will reach single digits

[LordBaltimore]

Corrected reflectivity showing extent of Chesapeake bay ice as of this morning. Should start to explode tonight with calm winds

[wxdude64]

3 hours ago, katabatic said:

Hi temp here was 11.8 (currently 7.9) with very light snow this afternoon. Maybe 1/2" but seems to have tapered off now. For the first time in many days, the wind has subsided and is rather pleasant to take a walk outside and get out of the house.

Yep, FINALLY a few hours early this afternoon where it was decent to be outside without having a -30 WC. A mostly cloudy to partly cloudy day, hit 24.8 for a high, but as I said felt like 70 without the wind. Now here we are back to fighting WC's. Currently 17.7/4.5 with NNW at 10 gusting to 22 mph and seems to be increasing every few minutes. WC 6 to 1. 

[pazzo83]

1 hour ago, SomeguyfromTakomaPark said:

That’s good, low single digits is pipe bursting weather. 
 

man this snowpack is bulletproof.  Have we ever had a colder stretch after a storm than this?

not that I can remember - maybe since the 90s.

[pazzo83]

1 hour ago, LordBaltimore said:

it's a radiational cooling night now that the winds are dying off. There's probably a 5+ degree difference between different sides of your house depending on sky exposure and distance to heat sources. Many parts of the city will reach single digits

we'll see in DC - temps across the District right now are 18-22F.

[wxmeddler]

1 hour ago, SomeguyfromTakomaPark said:

That’s good, low single digits is pipe bursting weather. 
 

man this snowpack is bulletproof.  Have we ever had a colder stretch after a storm than this?

The snow pack is actually saving the underground water infrastructure right now. Our sub-surface temperature probes have hardly moved post storm. Still safely above freezing below about 4" depth.

[MillvilleWx]

8 minutes ago, pazzo83 said:

not that I can remember - maybe since the 90s.

Surprisingly, it was pretty damn cold in that run in 2010. 1/29/10 through 2/17/10 was very much below normal with both monster snowstorms in there, and the pre-cursor storm end of January. DCA has a better than -10 departure average for the temps in that time beyond the first storm end of January. For extreme cold, you do have to go back to the 90s for that run. 1994 still takes the cake around here. 

[pazzo83]

35 minutes ago, MillvilleWx said:

Surprisingly, it was pretty damn cold in that run in 2010. 1/29/10 through 2/17/10 was very much below normal with both monster snowstorms in there, and the pre-cursor storm end of January. DCA has a better than -10 departure average for the temps in that time beyond the first storm end of January. For extreme cold, you do have to go back to the 90s for that run. 1994 still takes the cake around here. 

yeah I recall 94 - we were about -10 to -15F in Staunton.  We were driving to Baltimore - the entire drive the temp never got above 0.  The Inner Harbor was frozen over completely