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Dec 9-10 storm threat

ORH_wxman

By ORH_wxman,
in New England

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Ginx snewx

Ginx snewx

Posted
Posted

/O.NEW.KBOX.WW.Y.0023.141209T0000Z-141209T1000Z/

EASTERN ESSEX MA-WESTERN NORFOLK MA-SOUTHEAST MIDDLESEX MA-

SUFFOLK MA-EASTERN NORFOLK MA-NORTHERN BRISTOL MA-

WESTERN PLYMOUTH MA-NORTHWEST PROVIDENCE RI-

SOUTHEAST PROVIDENCE RI-WESTERN KENT RI-EASTERN KENT RI-

INCLUDING THE CITIES OF...GLOUCESTER...FOXBORO...NORWOOD...

CAMBRIDGE...BOSTON...QUINCY...TAUNTON...BROCKTON...FOSTER...

SMITHFIELD...PROVIDENCE...WEST GREENWICH...WARWICK

321 PM EST MON DEC 8 2014

...WINTER WEATHER ADVISORY IN EFFECT FROM 7 PM THIS EVENING TO

5 AM EST TUESDAY...

THE NATIONAL WEATHER SERVICE IN TAUNTON HAS ISSUED A WINTER

WEATHER ADVISORY FOR LIGHT ICING...WHICH IS IN EFFECT FROM 7 PM

THIS EVENING TO 5 AM EST TUESDAY.

* LOCATIONS...MUCH OF RHODE ISLAND AND EASTERN MASSACHUSETTS.

* HAZARD TYPES...FREEZING DRIZZLE OR LIGHT FREEZING RAIN.

* ACCUMULATIONS...LITTLE IF ANY SNOW BUT A LIGHT COATING OF ICE.

* TIMING...FREEZING DRIZZLE POSSIBLE TONIGHT. A BRIEF PERIOD OF

LIGHT FREEZING RAIN AWAY FROM THE COAST OVERNIGHT. CONDITIONS

SHOULD IMPROVE IN TIME FOR THE TUESDAY MORNING COMMUTE.

* IMPACTS...SLOW TRAVEL DUE TO SLIPPERY ROADS.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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ORH_wxman

ORH_wxman

Posted
  • Author
Posted

Yeah exactly. So in my mind, if I sort of hedge cooler near 900...it may be a matter of timing the 900-850mb push. Does the NAM look warm to you at 950? That seems awfully mild at that level. Which again sucks, because you'd think mesos would be better at that. It makes me wonder if the cold wedge becomes very shallow.

 

 

Yeah it does look warm...that's part of the difficulty of the forecast. How much does the cold wedge hold? They really try and warm it up not too far above the ground....in my experience, it is usually done too quickly by model guidance.

 

This is a pretty good fetch though out of the east...we'll just have to see how stuff is verifying later tonight. The NAM warms 950mb at ORH from roughly -8C to 0C in 12 hours...by 06z tonight. So we'll know how well it is verifying this evening. By 10pm it should already be up to like -2 or -3C at 950mb.

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Professional Lurker

Professional Lurker

Posted
Posted

WWA posted for E Hampshire, E Franklin and W Hampden Counties... 2-5" of snow & sleet... not bad actually I'd sign

Yeah, advisory here too.

I get it, but i also feel that this cold air could be more stubborn than modeled.

... And earlier here there was talk of models showing isothermal blue paste/lots of lift/dynamic cooling. ...basically, I'm reading between the lines and thinking that a small shift could cause forecasts to bust low.

Because of that, I think that I'd have issued a warning, but of course I'm not sitting in the desk at BOX, and of course I have limited data/education compared to those fine folks.

... or I may just be plain wrong and am wishcasting an overperformer.

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TalcottWx

TalcottWx

Posted
Posted

I'm not sure I've ever seen that before. Exciting!

 

I wouldn't get too excited close to the shoreline or just at the coast. BOX hints at that and highlights that the icing will be brief and clear before AM commute in the Boston area. However, further inland in any direction, the advisories have been posted and duration is longer, without wording about the AM commute.

 

Let's compare wording. It's a good way to get in BOX's heads.

 

This is for the interior away from the coast :

 

HARTFORD...WINDSOR LOCKS...UNION...

VERNON...PUTNAM...WILLIMANTIC...FRAMINGHAM...LOWELL...LAWRENCE...

SPRINGFIELD...MILFORD...WORCESTER...AYER

 

* ACCUMULATIONS...SNOW ACCUMULATION OF UP TO 1 INCH...ALONG WITH

  LIGHT ICING.

* TIMING...FREEZING DRIZZLE POSSIBLE TONIGHT...THEN A WINTRY MIX

  EARLY TUESDAY MORNING.

* IMPACTS...SLOW TRAVEL DUE TO SLIPPERY ROADS.

 

Here is the advisories for coastal communities : EASTERN ESSEX MA-WESTERN NORFOLK MA-SOUTHEAST MIDDLESEX MA-

SUFFOLK MA-EASTERN NORFOLK MA-NORTHERN BRISTOL MA-

WESTERN PLYMOUTH MA-NORTHWEST PROVIDENCE RI-

SOUTHEAST PROVIDENCE RI-WESTERN KENT RI-EASTERN KENT RI-

INCLUDING THE CITIES OF...GLOUCESTER...FOXBORO...NORWOOD...

CAMBRIDGE...BOSTON...QUINCY...TAUNTON...BROCKTON...FOSTER...

SMITHFIELD...PROVIDENCE...WEST GREENWICH...WARWICK

 

 HAZARD TYPES...FREEZING DRIZZLE OR LIGHT FREEZING RAIN.

* ACCUMULATIONS...LITTLE IF ANY SNOW BUT A LIGHT COATING OF ICE.

* TIMING...FREEZING DRIZZLE POSSIBLE TONIGHT. A BRIEF PERIOD OF

  LIGHT FREEZING RAIN AWAY FROM THE COAST OVERNIGHT. CONDITIONS

  SHOULD IMPROVE IN TIME FOR THE TUESDAY MORNING COMMUTE.

* IMPACTS...SLOW TRAVEL DUE TO SLIPPERY ROADS.

 

 

BOX seems to be putting up advisories to give people a heads up that commute within the Boston area. I suspect any mentions or advisories for icing is more a precaution than something to be excited about. However, the interior just north and west of town may have lingering effects well into the AM commute.

 

 

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TalcottWx

TalcottWx

Posted
Posted

.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM TUESDAY/...
UPDATED AT 310 PM...

BASED UPON 12Z MODELS AND COLLABORATION WITH WPC/NEIGHBORING
OFFICES....WE ARE MAKING THE FOLLOWING CHANGES TO HEADLINES. MORE
DETAILS WILL FOLLOW IN A BIT...

WINTER STORM WATCH...
LEAVING WATCH IN PLACE FOR WESTERN FRANKLIN AND WESTERN HAMPSHIRE
COUNTIES IN MA DUE TO CONTINUED UNCERTAINTY IN SNOWFALL TOTALS.
THERE IS LIKELY TO BE A SHARP GRADIENT FROM HEAVY SNOW TO LITTLE
ACCUMULATION...AND IT IS QUITE POSSIBLE THAT GRADIENT ENDS UP
ACROSS NW MA. FORECAST SOUNDINGS SHOW NEARLY ISOTHERMAL PROFILE
WHICH COULD EITHER SUGGEST COLD RAIN OR HEAVY WET SNOW DEPENDING
ON INTENSITY. HOW QUICKLY COLD AIR RETREATS IS STILL IN QUESTION
SO WE PREFER TO LEAVE WATCH IN PLACE FOR THESE TWO ZONES AND ALLOW
LATER SHIFTS TO GET A BETTER LOOK.

WINTER WEATHER ADVISORY...
WE ARE MORE CONFIDENT THAT AREAS ADJACENT TO ZONES ABOVE WILL SEE
SOME ACCUMULATION AND LIGHT ICING BEFORE EVENTUAL CHANGE TO RAIN
LATER TUE. SO WE CONVERTED THE OTHER ZONES PREVIOUSLY IN WATCH TO
AN ADVISORY WHERE OUR CONFIDENCE IS HIGHER.

WE ALSO ISSUED ADVISORIES AS FAR S AND E AS I-95 CORRIDOR FROM
PROVIDENCE TO BOSTON DUE TO POSSIBILITY OF LIGHT ICING FROM
FREEZING DRIZZLE THIS EVENING...AS WELL AS POTENTIAL FOR LIGHT
FREEZING RAIN AT ONSET OF PRECIPITATION EARLY TUE MORNING.
CERTAINLY BETTER CHANCES FOR LATTER ARE ACROSS INTERIOR IN N
CT AND CENTRAL/NE MA.
 

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dendrite

dendrite

Posted
Posted

Here's my NAM sounding text for 18z tomorrow and 00z Wed.

Date: 24 hour Eta valid 18Z TUE  9 DEC 14
Station: 43.43,-71.62
Latitude:   43.43
Longitude: -71.62
-------------------------------------------------------------------------------
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
-------------------------------------------------------------------------------
  0 1000   174                                                                 
SFC  993   226   0.4  -0.4  94  0.8   0.0  37   9 274.0 274.6 273.5 284.1  3.73
  2  950   585   1.7   1.2  96  0.6   1.5  69  34 279.0 279.7 277.2 291.0  4.38
  3  900  1019  -0.0  -0.3  98  0.2  -0.2  90  32 281.5 282.2 278.2 293.1  4.16
  4  850  1476  -1.7  -2.1  97  0.4  -1.9  93  23 284.4 285.1 279.3 295.4  3.87
  5  800  1956  -4.7  -5.4  95  0.7  -5.0  95  19 286.1 286.7 279.2 295.3  3.19
  6  750  2463  -5.8  -6.5  95  0.7  -6.1 116  23 290.3 290.9 281.1 299.5  3.14
  7  700  3002  -8.4  -9.4  93  1.0  -8.7 128  35 293.2 293.7 281.8 301.2  2.68
  8  650  3574  -9.8 -10.8  92  1.1 -10.1 142  44 297.9 298.4 283.7 305.8  2.57
  9  600  4191 -11.0 -12.2  91  1.2 -11.4 171  31 303.4 303.9 285.8 311.2  2.50
 10  550  4857 -14.0 -15.3  90  1.3 -14.4 179  45 307.5 307.9 286.8 314.2  2.11
 11  500  5574 -18.4 -19.6  90  1.3 -18.7 180  59 310.7 311.0 287.4 316.0  1.61
Date: 30 hour Eta valid 0Z WED 10 DEC 14
Station: 43.43,-71.62
Latitude:   43.43
Longitude: -71.62
-------------------------------------------------------------------------------
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
-------------------------------------------------------------------------------
  0 1000    98                                                                 
SFC  984   226   1.2   0.4  94  0.8   0.8  17  15 275.6 276.3 274.8 286.5  3.99
  2  950   510  -0.4  -0.7  98  0.3  -0.5  25  32 276.8 277.4 275.3 287.3  3.83
  3  900   943   0.0  -0.1  99  0.2  -0.0  49  53 281.5 282.2 278.3 293.2  4.20
  4  850  1401  -0.2  -0.3  99  0.1  -0.2  74  57 286.0 286.7 280.7 298.5  4.40
  5  800  1886  -0.5  -0.6 100  0.0  -0.5  98  56 290.6 291.4 283.0 303.9  4.59
  6  750  2401  -1.6  -1.6 100  0.0  -1.6 122  59 294.9 295.7 284.7 308.2  4.54
  7  700  2951  -2.3  -2.3 100  0.0  -2.3 150  54 299.9 300.8 286.6 313.8  4.61
  8  650  3537  -5.6  -5.7  99  0.1  -5.7 175  46 302.6 303.3 286.9 314.4  3.84
  9  600  4159  -9.6 -12.2  81  2.6 -10.5 180  43 305.0 305.5 286.4 312.9  2.49
 10  550  4827 -13.9 -18.7  67  4.8 -15.2 174  41 307.6 307.9 286.3 312.8  1.59
 11  500  5541 -19.8 -27.4  51  7.6 -21.3 167  39 308.9 309.0 285.9 311.6  0.81
H95 is the only warm layer at 24hr (+1.7C) with an ENE wind. 6hrs later it is 0C at that layer with a NNE wind. In fact the wind backs to ENE all the way up to H85. I can't help but think the strong UVVs and underestimated CAD help this become an isothermal pasting.
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TalcottWx

TalcottWx

Posted
Posted

HRRR 19z. This model only goes out 15 hours.

 

BOS is over 32 by ~1am

BED is 26F, LWM is 25F @ 1am

 

15 hours out, with the model at it's last hour, BED and LWM are still both 30F at 5am. 40F @ Beverly, and 42F @ Logan @ 5am.

ORH stays below 30F for the run's entirety.

 

0c @ 850 pretty much hugs the Mass Pike or close to it @ 5am.

 

So as the morning commute begins, 19z hrrr says the commute is a messy one for the interior tomorrow AM.

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powderfreak

powderfreak

Posted
Posted

Here's my NAM sounding text for 18z tomorrow and 00z Wed.

 

H95 is the only warm layer at 24hr (+1.7C) with an ENE wind. 6hrs later it is 0C at that layer with a NNE wind. In fact the wind backs to ENE all the way up to H85. I can't help but think the strong UVVs and underestimated CAD help this become an isothermal pasting.

 

 

I think you are certainly good for like 5-10" of mashed potatoes before mixed or rain.  Your area holds that cold like no ones business. 

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snowgeek

snowgeek

Posted
Posted

The 18 NAM went east just enough to really hit ALB hard and of course the hills out here and the Catskills.

It still gets that pesky 900-925mb level slightly above freezing on and off all day.  Dynamic cooling and the melting effect FTW!  Your neck of the woods is looking in pretty good shape.  I can always drive up to Thacher :)

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powderfreak

powderfreak

Posted
Posted

It still gets that pesky 900-925mb level slightly above freezing on and off all day.  Dynamic cooling and the melting effect FTW!  Your neck of the woods is looking in pretty good shape.  I can always drive up to Thacher :)

 

Thatcher Park was always my go-to spot in these events, haha.  Eastern ridge there at 1,200ft always seems to do well in these east-flow events. 

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