March 5th Snow Threat

[Bob Chill]

Widespread 3-6" from what I can tell.

[stormtracker]

It's probably drier than 18z but more noise than anything. Soundings needed.

Hmm, i didn't even look at 18z, lol.   I'm thinking this run was all special.  Still, it's great

[mitchnick]

My favorite icon

I thought I was your favorite weather icon! 

[yoda]

Widespread 3-6" from what I can tell.

 

Would be more if we can get the 750 to 800 mb warm layer to shave off a degree at hours 54 and 57

[hosj III]

Looks a little warmer than 18z. DCA looks like sleet around 2-3 AM and snow 6-7 AM

[Bob Chill]

Would be more if we can get the 700mb warm layer to shave off a degree at 54

In general, it's basically the same as 18z. Little different with totals around the region but not really much of a change.

[Scarlet Pimpernel]

Widespread 3-6" from what I can tell.

 

So, ~3-6", presumably on top of whatever sleet falls I take it.  Good that it's coming in somewhat colder, too.

 

Sounds like the GFS doubled-down.  Glad it's showing a generally consistent solution, and one that is pretty good.

 

(ETA:  That is in line with what WPC has for their 50th percentile, and what LWX put up recently on their snow map, interestingly enough.)

[Ian]

DCA sounding is kinda sketch at 9z seems more warm layer than earlier.

[WinterWxLuvr]

It's probably drier than 18z but more noise than anything. Soundings needed.

It's actually wetter out here

[Bob Chill]

DCA sounding is kinda sketch at 9z seems more warm layer than earlier.

We won't have to set alarms to get up for the flip. Should be heavy sleet for a time.

[olafminesaw]

The warm nose seems a little more persistent this run, still sleet at 9z. 

[Deck Pic]

DCA sounding is kinda sketch at 9z seems more warm layer than earlier.

 

It probably doesn't flip until like 11z.  Verbatim, maybe 2-3".  It is cold though, and we are probably sleet by 6-7z.  I guess what happens in that transition period will tell the story.  

[Amped]

Has that downsloping dryslot in western MD, I still get 4 though.

[Scarlet Pimpernel]

We won't have to set alarms to get up for the flip. Should be heavy sleet for a time.

 

Flip from sleet to snow by 6-7AM Thursday?

[Ji]

So run went from cold and shocked face look to drier and warmer....?

[Bob Chill]

Flip from sleet to snow by 6-7AM Thursday?

Looks like a lot of sleet too. Prob pinging heavily @ 1am. Maybe earlier

[mitchnick]

BWI 54 hrs.

LEV PRES  HGHT  TEMP  DEWP  RH  DD   WETB DIR SPD THETA THE-V THE-W THE-E   W     mb     m     C     C    %   C     C  deg knt   K     K     K     K    g/kg-------------------------------------------------------------------------------SFC 1008    79   0.1  -0.7  95  0.7  -0.2   5  11 272.6 273.2 272.5 282.4  3.61  1 1000   143  -0.3  -0.9  96  0.6  -0.6   5  15 272.8 273.4 272.6 282.5  3.57  2  950   551  -3.2  -3.4  99  0.2  -3.3 355  25 273.9 274.4 272.6 282.5  3.13  3  900   979  -3.1  -3.4  98  0.3  -3.3 321  26 278.3 278.8 275.3 287.4  3.29  4  850  1434  -0.7  -0.9  98  0.2  -0.8 267  23 285.4 286.1 280.1 297.3  4.20  5  800  1920   0.8  -0.1  94  0.8   0.4 243  32 292.0 292.8 283.7 305.8  4.76  6  750  2439   0.5  -0.6  92  1.1  -0.0 245  40 297.1 298.0 285.9 311.5  4.87  7  700  2991  -1.5  -1.8  98  0.3  -1.7 245  49 300.8 301.7 287.1 315.2  4.79  8  650  3579  -4.1  -4.4  98  0.3  -4.3 240  56 304.3 305.1 287.9 317.3  4.25  9  600  4208  -7.0  -7.1  99  0.1  -7.1 236  63 308.0 308.7 288.6 319.7  3.73 10  550  4883 -10.2 -10.3  99  0.1 -10.3 235  70 311.9 312.5 289.4 322.0  3.16 11  500  5612 -14.1 -14.2  99  0.1 -14.2 239  77 315.8 316.3 290.0 324.2  2.55

BWI 57 hrs.

LEV PRES  HGHT  TEMP  DEWP  RH  DD   WETB DIR SPD THETA THE-V THE-W THE-E   W     mb     m     C     C    %   C     C  deg knt   K     K     K     K    g/kg-------------------------------------------------------------------------------SFC 1008    79  -2.6  -3.2  95  0.6  -2.8  19  14 270.0 270.4 269.9 278.0  2.99  1 1000   145  -3.1  -3.7  96  0.6  -3.3  20  18 270.0 270.5 269.8 277.9  2.91  2  950   549  -6.3  -6.3 100  0.0  -6.3  16  23 270.8 271.2 269.7 277.6  2.50  3  900   970  -7.1  -7.4  98  0.3  -7.2 344  20 274.2 274.6 271.7 280.9  2.43  4  850  1421  -1.8  -2.2  97  0.4  -2.0 265  18 284.2 284.9 279.1 295.1  3.83  5  800  1906   0.3  -0.3  96  0.6  -0.0 232  31 291.4 292.2 283.4 304.9  4.66  6  750  2424   0.1  -0.8  94  0.8  -0.3 233  42 296.6 297.5 285.7 310.9  4.82  7  700  2976  -1.6  -2.0  97  0.4  -1.8 238  53 300.7 301.6 287.1 314.9  4.71  8  650  3564  -3.7  -3.9  99  0.2  -3.8 241  66 304.7 305.6 288.2 318.2  4.40  9  600  4194  -6.3  -6.4  99  0.1  -6.4 243  75 308.8 309.5 289.1 321.1  3.94 10  550  4870  -9.9 -10.0  99  0.1  -9.9 244  82 312.3 313.0 289.6 322.8  3.26 11  500  5600 -14.5 -14.5 100  0.1 -14.5 246  88 315.4 315.9 289.8 323.5  2.48

60 hours

LEV PRES  HGHT  TEMP  DEWP  RH  DD   WETB DIR SPD THETA THE-V THE-W THE-E   W     mb     m     C     C    %   C     C  deg knt   K     K     K     K    g/kg-------------------------------------------------------------------------------SFC 1011    79  -5.6  -6.3  95  0.7  -5.8   4  13 266.7 267.0 266.7 273.0  2.35  1 1000   167  -6.4  -7.1  95  0.7  -6.6   5  18 266.8 267.1 266.5 272.8  2.24  2  950   566  -9.5  -9.6  99  0.1  -9.5   7  24 267.5 267.8 266.5 272.8  1.94  3  900   982  -9.6 -10.0  97  0.4  -9.8 355  25 271.6 271.9 269.3 277.0  1.98  4  850  1427  -5.8  -6.1  98  0.2  -5.9 298  18 280.0 280.5 275.6 288.1  2.85  5  800  1906  -2.0  -2.1  99  0.1  -2.0 242  30 289.0 289.8 281.7 300.9  4.10  6  750  2421  -1.3  -1.5  99  0.1  -1.4 243  46 295.1 295.9 284.8 308.6  4.58  7  700  2969  -2.9  -3.0  99  0.1  -2.9 248  58 299.3 300.1 286.2 312.5  4.38  8  650  3557  -4.0  -4.5  96  0.5  -4.2 254  74 304.5 305.3 287.9 317.5  4.22  9  600  4185  -7.0  -7.4  97  0.4  -7.2 251  80 308.0 308.6 288.5 319.4  3.65 10  550  4860 -10.2 -10.3  99  0.1 -10.2 242  83 312.0 312.6 289.4 322.2  3.18 11  500  5590 -13.8 -13.9  99  0.1 -13.9 237  92 316.2 316.7 290.2 324.7  2.61

I can do DCA if anyone wants me to

[nj2va]

At 9z, DCA is 1.2 at 800 and 0.7 at 750. By 12z, we're -.4 and -.8, respectively so we're all snow by 12z.  We probably flip to snow around 11z?

[Scarlet Pimpernel]

Looks like a lot of sleet too. Prob pinging heavily @ 1am. Maybe earlier

 

Heh, we could wake up to a couple or so inches of sleet right as it changes to snow!

[WinterWxLuvr]

Soundings can be off too.

[Ian]

We won't have to set alarms to get up for the flip. Should be heavy sleet for a time.

Yeah just don't want to keep seeing it drag. A layer of sleet then 2-4 would be passable. It'll fight sun angle season better.

[Deck Pic]

Flip from sleet to snow by 6-7AM Thursday?

 

that seems right.  unfortunately it is only 1-2" after 12z....the "fun" is what happens overnight.  GFS says a ~4 hour period of torrential sleet.

[WinterWxLuvr]

BWI 54 hrs.

LEV PRES  HGHT  TEMP  DEWP  RH  DD   WETB DIR SPD THETA THE-V THE-W THE-E   W
     mb     m     C     C    %   C     C  deg knt   K     K     K     K    g/kg
-------------------------------------------------------------------------------
SFC 1008    79   0.1  -0.7  95  0.7  -0.2   5  11 272.6 273.2 272.5 282.4  3.61
  1 1000   143  -0.3  -0.9  96  0.6  -0.6   5  15 272.8 273.4 272.6 282.5  3.57
  2  950   551  -3.2  -3.4  99  0.2  -3.3 355  25 273.9 274.4 272.6 282.5  3.13
  3  900   979  -3.1  -3.4  98  0.3  -3.3 321  26 278.3 278.8 275.3 287.4  3.29
  4  850  1434  -0.7  -0.9  98  0.2  -0.8 267  23 285.4 286.1 280.1 297.3  4.20
  5  800  1920   0.8  -0.1  94  0.8   0.4 243  32 292.0 292.8 283.7 305.8  4.76
  6  750  2439   0.5  -0.6  92  1.1  -0.0 245  40 297.1 298.0 285.9 311.5  4.87
  7  700  2991  -1.5  -1.8  98  0.3  -1.7 245  49 300.8 301.7 287.1 315.2  4.79
  8  650  3579  -4.1  -4.4  98  0.3  -4.3 240  56 304.3 305.1 287.9 317.3  4.25
  9  600  4208  -7.0  -7.1  99  0.1  -7.1 236  63 308.0 308.7 288.6 319.7  3.73
 10  550  4883 -10.2 -10.3  99  0.1 -10.3 235  70 311.9 312.5 289.4 322.0  3.16
 11  500  5612 -14.1 -14.2  99  0.1 -14.2 239  77 315.8 316.3 290.0 324.2  2.55

BWI 57 hrs.

LEV PRES  HGHT  TEMP  DEWP  RH  DD   WETB DIR SPD THETA THE-V THE-W THE-E   W
     mb     m     C     C    %   C     C  deg knt   K     K     K     K    g/kg
-------------------------------------------------------------------------------
SFC 1008    79  -2.6  -3.2  95  0.6  -2.8  19  14 270.0 270.4 269.9 278.0  2.99
  1 1000   145  -3.1  -3.7  96  0.6  -3.3  20  18 270.0 270.5 269.8 277.9  2.91
  2  950   549  -6.3  -6.3 100  0.0  -6.3  16  23 270.8 271.2 269.7 277.6  2.50
  3  900   970  -7.1  -7.4  98  0.3  -7.2 344  20 274.2 274.6 271.7 280.9  2.43
  4  850  1421  -1.8  -2.2  97  0.4  -2.0 265  18 284.2 284.9 279.1 295.1  3.83
  5  800  1906   0.3  -0.3  96  0.6  -0.0 232  31 291.4 292.2 283.4 304.9  4.66
  6  750  2424   0.1  -0.8  94  0.8  -0.3 233  42 296.6 297.5 285.7 310.9  4.82
  7  700  2976  -1.6  -2.0  97  0.4  -1.8 238  53 300.7 301.6 287.1 314.9  4.71
  8  650  3564  -3.7  -3.9  99  0.2  -3.8 241  66 304.7 305.6 288.2 318.2  4.40
  9  600  4194  -6.3  -6.4  99  0.1  -6.4 243  75 308.8 309.5 289.1 321.1  3.94
 10  550  4870  -9.9 -10.0  99  0.1  -9.9 244  82 312.3 313.0 289.6 322.8  3.26
 11  500  5600 -14.5 -14.5 100  0.1 -14.5 246  88 315.4 315.9 289.8 323.5  2.48

60 hours

LEV PRES  HGHT  TEMP  DEWP  RH  DD   WETB DIR SPD THETA THE-V THE-W THE-E   W
     mb     m     C     C    %   C     C  deg knt   K     K     K     K    g/kg
-------------------------------------------------------------------------------
SFC 1011    79  -5.6  -6.3  95  0.7  -5.8   4  13 266.7 267.0 266.7 273.0  2.35
  1 1000   167  -6.4  -7.1  95  0.7  -6.6   5  18 266.8 267.1 266.5 272.8  2.24
  2  950   566  -9.5  -9.6  99  0.1  -9.5   7  24 267.5 267.8 266.5 272.8  1.94
  3  900   982  -9.6 -10.0  97  0.4  -9.8 355  25 271.6 271.9 269.3 277.0  1.98
  4  850  1427  -5.8  -6.1  98  0.2  -5.9 298  18 280.0 280.5 275.6 288.1  2.85
  5  800  1906  -2.0  -2.1  99  0.1  -2.0 242  30 289.0 289.8 281.7 300.9  4.10
  6  750  2421  -1.3  -1.5  99  0.1  -1.4 243  46 295.1 295.9 284.8 308.6  4.58
  7  700  2969  -2.9  -3.0  99  0.1  -2.9 248  58 299.3 300.1 286.2 312.5  4.38
  8  650  3557  -4.0  -4.5  96  0.5  -4.2 254  74 304.5 305.3 287.9 317.5  4.22
  9  600  4185  -7.0  -7.4  97  0.4  -7.2 251  80 308.0 308.6 288.5 319.4  3.65
 10  550  4860 -10.2 -10.3  99  0.1 -10.2 242  83 312.0 312.6 289.4 322.2  3.18
 11  500  5590 -13.8 -13.9  99  0.1 -13.9 237  92 316.2 316.7 290.2 324.7  2.61

I can do DCA if anyone wants me to

Do OKV and MRB Mitch

[DDweatherman]

I'm not going to be an amateur like some here and criticize the pbp. The surface temps on the gfs are nice, and the depiction of big rates on the flip is nice, but the run could easily have been better, and is in N MD than DC. That is expected but the warm layer is a known issue. In some areas, if not more than less, rates will be very heavy and could help overcome it. However, it is a bit elevated in nature with regards to the column to be negated by rates. 

[Bob Chill]

Heh, we could wake up to a couple or so inches of sleet right as it changes to snow!

Best guess for our area is .25 of sleet before the flip and .35 as snow. Won't have high res regionals for a few

[snowfan]

The warm nose seems a little more persistent this run, still sleet at 9z.

About the same at bwi. Both are snow at h60.

[Ian]

It probably doesn't flip until like 11z. Verbatim, maybe 2-3". It is cold though, and we are probably sleet by 6-7z. I guess what happens in that transition period will tell the story.

My bar for DCA is like 1.5 to 2 so still good for now. this run did seem to hang back a bit with precip maybe euro is more right there.

[Yeoman]

At 9z, DCA is 1.2 at 800 and 0.7 at 750. By 12z, we're -.4 and -.8, respectively so we're all snow by 12z.  We probably flip to snow around 11z?

eh.. I'd say 11:23z

[WinterWxLuvr]

Best guess for our area is .25 of sleet before the flip and .35 as snow. Won't have high res regionals for a few

That's a good storm

[mitchnick]

DCA 54 hrs.

LEV PRES  HGHT  TEMP  DEWP  RH  DD   WETB DIR SPD THETA THE-V THE-W THE-E   W     mb     m     C     C    %   C     C  deg knt   K     K     K     K    g/kg-------------------------------------------------------------------------------SFC 1010    58   0.9   0.2  96  0.6   0.6  17   9 273.2 273.9 273.2 283.6  3.85  1 1000   141   0.3  -0.3  95  0.6   0.1  16  14 273.5 274.1 273.2 283.6  3.73  2  950   550  -2.7  -2.8  99  0.1  -2.7   3  23 274.5 275.0 273.1 283.4  3.28  3  900   979  -2.2  -2.4  99  0.2  -2.3 323  23 279.2 279.8 276.2 289.1  3.55  4  850  1435   0.4   0.1  98  0.3   0.3 253  16 286.5 287.3 281.1 299.4  4.52  5  800  1923   1.6   0.8  95  0.7   1.2 238  29 292.8 293.7 284.4 307.6  5.08  6  750  2444   1.4  -0.3  88  1.7   0.5 242  38 298.1 299.0 286.4 312.9  4.99  7  700  2998  -1.5  -1.9  97  0.4  -1.7 239  45 300.8 301.7 287.1 315.1  4.74  8  650  3586  -4.0  -4.2  99  0.2  -4.1 231  54 304.4 305.2 288.0 317.6  4.31  9  600  4215  -6.7  -6.9  99  0.2  -6.8 231  64 308.4 309.1 288.8 320.3  3.81 10  550  4891  -9.8  -9.9  99  0.1  -9.9 235  73 312.4 313.0 289.6 322.9  3.27 11  500  5621 -13.6 -13.9  98  0.3 -13.7 241  81 316.5 317.0 290.3 325.1  2.62

DCA 57 hrs.

LEV PRES  HGHT  TEMP  DEWP  RH  DD   WETB DIR SPD THETA THE-V THE-W THE-E   W     mb     m     C     C    %   C     C  deg knt   K     K     K     K    g/kg-------------------------------------------------------------------------------SFC 1010    58  -0.9  -1.4  97  0.5  -1.1  30  12 271.4 272.0 271.5 280.6  3.41  1 1000   140  -1.5  -1.9  97  0.5  -1.7  30  17 271.7 272.2 271.5 280.6  3.31  2  950   546  -4.6  -4.7 100  0.0  -4.7  28  23 272.5 272.9 271.3 280.2  2.84  3  900   970  -6.2  -6.4  98  0.2  -6.3   2  18 275.1 275.5 272.5 282.4  2.62  4  850  1422  -0.8  -1.1  98  0.3  -0.9 254  14 285.3 286.1 280.1 297.1  4.15  5  800  1909   1.2   0.4  95  0.8   0.8 228  29 292.4 293.3 284.1 306.7  4.92  6  750  2429   0.7  -0.5  92  1.2   0.1 234  40 297.3 298.2 286.0 312.0  4.93  7  700  2982  -1.1  -1.5  97  0.4  -1.3 238  55 301.3 302.2 287.5 316.1  4.91  8  650  3571  -3.0  -3.2  99  0.1  -3.1 240  69 305.5 306.4 288.7 319.8  4.66  9  600  4203  -5.7  -5.8 100  0.1  -5.8 241  78 309.5 310.3 289.5 322.5  4.14 10  550  4881  -9.5  -9.5 100  0.0  -9.5 242  85 312.9 313.5 289.9 323.7  3.38 11  500  5611 -14.0 -14.1  99  0.1 -14.0 246  92 316.0 316.5 290.1 324.4  2.57

DCA 60 hrs.

LEV PRES  HGHT  TEMP  DEWP  RH  DD   WETB DIR SPD THETA THE-V THE-W THE-E   W     mb     m     C     C    %   C     C  deg knt   K     K     K     K    g/kg-------------------------------------------------------------------------------SFC 1014    58  -5.0  -5.5  96  0.5  -5.1  12  12 267.1 267.5 267.3 273.8  2.50  1 1000   168  -5.9  -6.4  96  0.5  -6.1  12  18 267.3 267.7 267.1 273.6  2.36  2  950   567  -9.1  -9.1 100  0.0  -9.1  11  23 268.0 268.3 267.0 273.4  2.01  3  900   985  -9.1  -9.3  98  0.2  -9.1 352  23 272.2 272.5 269.9 277.9  2.09  4  850  1430  -4.9  -5.0  99  0.1  -5.0 287  15 281.0 281.5 276.5 289.7  3.09  5  800  1912  -0.5  -0.7  99  0.1  -0.6 239  31 290.6 291.4 282.9 303.7  4.54  6  750  2428  -0.9  -1.0  99  0.2  -1.0 246  45 295.6 296.5 285.1 309.5  4.73  7  700  2978  -2.3  -2.5  99  0.2  -2.4 250  57 299.9 300.7 286.6 313.5  4.54  8  650  3566  -3.6  -3.9  98  0.3  -3.8 252  71 304.9 305.7 288.2 318.4  4.40  9  600  4196  -6.4  -6.6  99  0.1  -6.5 246  76 308.7 309.4 289.0 320.9  3.90 10  550  4873  -9.5  -9.6  99  0.1  -9.5 239  83 312.8 313.4 289.8 323.5  3.35 11  500  5604 -13.6 -13.6  99  0.1 -13.6 238  93 316.5 317.0 290.3 325.2  2.67