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Winter Re-Awakening - February 12-14th Redeveloper


Baroclinic Zone
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20 minutes ago, ORH_wxman said:

It was notable for the positive bust....most were under a WWA for 2-4/3-5....and 8-10 fell north of the pike.

I had 9 south of the pike also link to all area totals lol Tolland https://www.wpc.ncep.noaa.gov/winter_storm_summaries/2007/storm25/stormsum_8.html

RHODE ISLAND...
NORTH SMITHFIELD                      10.5
CUMBERLAND                             9.5
NORTH FOSTER                           9.2
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9 hours ago, BrianW said:

Who does the observations at the airports? The FAA? Are they actually paid to do it like it's in their job description? Or are they just sort of doing a favor for the NWS?

I'm pretty sure we cannot require the FAA to take observations for us. They do hire companies or observers themselves to take manual obs at the larger airports though. The NWS hires observers to take our snow obs for LCD sites (as long as we can find someone that lives near enough the airport). We pay someone to do CON and PWM, GYX obviously we take care of, MHT we use the FAA contract observer so the quality is a little lower than our standards (since the FAA does not require 6 hourly snowfall), and AUG we can't find anyone willing.

7 hours ago, dendrite said:

I mean, I guess you could make an argument of changing the criteria to liquid equivalent of frozen precip. 6” of 10:1 with 2” of sleet is more impactful than 12” of 20:1. That’s a difference of like 1.20” QPF versus 0.60”.

We tried this once and Eastern Region was not a fan. ALY actually had a local policy that was exactly this, combo of snow, sleet, freezing rain equaling warning criteria (e.g. 3" of snow is 50% and 0.25" ice is 50%, therefore you had 100% warning). Even though it was still written in the regional directive supplement they told us no and removed it from the directive with the next update. 

Ekster and I tried. It was a storm we knew had no hope of hitting 6", but it was written as an option in the directive so we went with warnings. So we were pissed that our policy document led us astray in the end.

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18 minutes ago, OceanStWx said:

 

We tried this once and Eastern Region was not a fan. ALY actually had a local policy that was exactly this, combo of snow, sleet, freezing rain equaling warning criteria (e.g. 3" of snow is 50% and 0.25" ice is 50%, therefore you had 100% warning). Even though it was still written in the regional directive supplement they told us no and removed it from the directive with the next update. 

Ekster and I tried. It was a storm we knew had no hope of hitting 6", but it was written as an option in the directive so we went with warnings. So we were pissed that our policy document led us astray in the end.

Interesting.  And you can't issue an impact based warning...sort of like the first snowfall of the season when some offices bend the rules a bit?  

It just seems that impact wise, over 1" of frozen precipitation shouldn't be considered the same Advisory as say 0.2" QPF with good snow growth, or 30 minutes of freezing drizzle ahead of a cutter...even if that 1-1.5" QPF may not exceed 6-7" of accumulation because of IP/ZR mixing.  

Snowbanks in parking lots a day after 3-4" of sleet look the same as 8-10" of snow, does that count? :lol:

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4 minutes ago, powderfreak said:

Interesting.  And you can't issue an impact based warning...sort of like the first snowfall of the season when some offices bend the rules a bit?  

It just seems that impact wise, over 1" of frozen precipitation shouldn't be considered the same Advisory as say 0.2" QPF with good snow growth, or 30 minutes of freezing drizzle ahead of a cutter...even if that 1-1.5" QPF may not exceed 6-7" of accumulation because of IP/ZR mixing.  

Snowbanks in parking lots a day after 3-4" of sleet look the same as 8-10" of snow, does that count? :lol:

It's hard to argue impact based sub-warning criteria events in February up here. :lol:

The real question here is for places like CON on south. The GFS has the 6-7" of snow and sleet, that's a fine warning. But the NAM has 3.1" snow and sleet, that's technically not even advisory level. So our thinking was give it one more model cycle. Honestly the ME zones were probably more likely slam dunk 6" before a changeover, but the timing is later for those zones too.

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7 minutes ago, OceanStWx said:

It's hard to argue impact based sub-warning criteria events in February up here. :lol:

The real question here is for places like CON on south. The GFS has the 6-7" of snow and sleet, that's a fine warning. But the NAM has 3.1" snow and sleet, that's technically not even advisory level. So our thinking was give it one more model cycle. Honestly the ME zones were probably more likely slam dunk 6" before a changeover, but the timing is later for those zones too.

Ha true on time of year and I guess sleet doesn't cause that many issues no matter how much QPF is in it.  I don't know why I was thinking Advisory was 3", not 4". Is your warning 6" or 7"?  I might have been picturing 3"/6" for the headlines.

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I'm an off-duty met from NWS LOT (Chicago). Haven't been following closely enough to know how the models have been depicting things over there, but just wanted to note that the NAM did by far the best with the warm nose here in northern IL and into eastern IA. The other models, including RAP/HRRR, were too cold aloft and not aggressive enough in pushing the warm nose steadily northward. We're now in a full on ice storm out here (I had close to 0.2" as of an hour ago where I live) and 2m temps flatlining around 31-32 with several more hours of steady precip to go.

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16 minutes ago, sbos_wx said:

2-4" final I'm riding with Harvey 

BOS is an interesting spot for this one. Most TV mets going for with a marina influence effecting the Logan measurements maybe? Then seeing on here that some people don’t think the marina influence will not apply with this one. 

I’ll play conservative and say 3” here. Who knows what will be measured for Logan though

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30 minutes ago, RCNYILWX said:

I'm an off-duty met from NWS LOT (Chicago). Haven't been following closely enough to know how the models have been depicting things over there, but just wanted to note that the NAM did by far the best with the warm nose here in northern IL and into eastern IA. The other models, including RAP/HRRR, were too cold aloft and not aggressive enough in pushing the warm nose steadily northward. We're now in a full on ice storm out here (I had close to 0.2" as of an hour ago where I live) and 2m temps flatlining around 31-32 with several more hours of steady precip to go.

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Funny you mention that. I just looked at ORD since we have interests there, and noted the same.  

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33 minutes ago, RCNYILWX said:

I'm an off-duty met from NWS LOT (Chicago). Haven't been following closely enough to know how the models have been depicting things over there, but just wanted to note that the NAM did by far the best with the warm nose here in northern IL and into eastern IA. The other models, including RAP/HRRR, were too cold aloft and not aggressive enough in pushing the warm nose steadily northward. We're now in a full on ice storm out here (I had close to 0.2" as of an hour ago where I live) and 2m temps flatlining around 31-32 with several more hours of steady precip to go.

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That warmth aloft is always hard to stop.

00z HRRR, NAM, and GFS all have sub-warning amounts for the southern half of NH. Scooter caution flags everywhere right now.

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That warmth aloft is always hard to stop.
00z HRRR, NAM, and GFS all have sub-warning amounts for the southern half of NH. Scooter caution flags everywhere right now.
Was a red flag when we started off where I live in western Chicago metro as ZR/IP and not snow with SPC mesoanalysis off because of using RAP background which was too cold. Places well west and north in DVN CWA that were supposed to stay snow like CID and DBQ went over to ZR. Could see the mix line surging north on CC and knew it was all over. Good lesson today to err on the side of the warmth aloft being at least as aggressive as the most aggressive model.

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Funny you mention that. I just looked at ORD since we have interests there, and noted the same.  
I put together some select total ice accums as of 06z from regional ASOS sites (by adding up I6 groups in metars). Most impressive widespread ice storm in years in this area.

MLI: 0.47
DVN: 0.41
ARR: 0.32
VPZ: 0.30
DPA: 0.27
ORD: 0.22
RFD: 0.19
CID: 0.18
MDW: 0.15
PIA: 0.14
PWK: 0.09

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2 minutes ago, RCNYILWX said:

Was a red flag when we started off where I live in western Chicago metro as ZR/IP and not snow with SPC mesoanalysis off because of using RAP background which was too cold. Places well west and north in DVN CWA that were supposed to stay snow like CID and DBQ went over to ZR. Could see the mix line surging north on CC and knew it was all over. Good lesson today to err on the side of the warmth aloft being at least as aggressive as the most aggressive model.

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Yeah I was keeping an eye on my old DVN stomping grounds and saw the forecasts getting upgraded for FZRA. 

I've also noticed that here in the Northeast anyway, all the offices are forecasting snow ratio grids and deriving snow from that. And well modeling is not great with that (usually too high), and snowfall trends that way as a result.

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Yeah I was keeping an eye on my old DVN stomping grounds and saw the forecasts getting upgraded for FZRA. 

I've also noticed that here in the Northeast anyway, all the offices are forecasting snow ratio grids and deriving snow from that. And well modeling is not great with that (usually too high), and snowfall trends that way as a result.

My office started with just metro counties and west in an advisory, then expanded 1 tier south earlier today, then eventually CWA wide with 2 updates this evening. Finally we upgraded to warnings in part of the CWA then just a little while ago expanded the ice storm warnings we had issued late evening to now include most of Chicago metro except far north/northwest.

 

We have the same issue out here with the snow ratio grids used to derive the snow output. It's been less of an issue in this area this winter from what I've seen but last year we had several events with low snow ratios despite cold temps due to the lift being above the DGZ and over forecast snow amounts as a result of ratios being too high. We try to account for the ptypes in the snow amount forecast with the prob of weather type (powt) methodology (using modified bourgoin energy technique), so that when there's low hourly snow probs and/or 2m temps AOA 35, we don't accumulate snow that hour and it subtracts it out of the 6 hour snow grid.

 

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11 minutes ago, RCNYILWX said:

My office started with just metro counties and west in an advisory, then expanded 1 tier south earlier today, then eventually CWA wide with 2 updates this evening. Finally we upgraded to warnings in part of the CWA then just a little while ago expanded the ice storm warnings we had issued late evening to now include most of Chicago metro except far north/northwest.

 

We have the same issue out here with the snow ratio grids used to derive the snow output. It's been less of an issue in this area this winter from what I've seen but last year we had several events with low snow ratios despite cold temps due to the lift being above the DGZ and over forecast snow amounts as a result of ratios being too high. We try to account for the ptypes in the snow amount forecast with the prob of weather type (powt) methodology (using modified bourgoin energy technique), so that when there's low hourly snow probs and/or 2m temps AOA 35, we don't accumulate snow that hour and it subtracts it out of the 6 hour snow grid.

Oh we stole PoWT a long time ago. ;)

It's tough when modeling always has us in 15-20:1 ratios, but at least it knocks things back when we go over to predominately something other than snow.

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16 minutes ago, moneypitmike said:

BOX is pretty aggressive on totals for out here.  My zone is for 6-10", and my P/C goes with a 4-8/1-3.

We're going to need some pretty heavy rates  during the day and a slow taint if we want to get much over 5-7".

Yeah, based on mid-level warm push we might need to knock a 1/3 off.  Interestingly our "expected snowfall" and "max potential snowfall" maps from BOX are the same up here.  

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Just now, HIPPYVALLEY said:

Yeah, based on mid-level warm push we might need to knock a 1/3 off.  Interestingly our "expected snowfall" and "max potential snowfall" maps from BOX are the same up here.  

It doesn't make sense to me to have wording in the WSW product that contradicts what you're saying in the ZFP and PnC.    The WSW is less aggressive than either of those.

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9 minutes ago, moneypitmike said:

It doesn't make sense to me to have wording in the WSW product that contradicts what you're saying in the ZFP and PnC.    The WSW is less aggressive than either of those.

The major difference between those products is averaging.

The P&C is the accumulation for the grid you click on. The ZFP is the average for the zone (larger area, larger differences in totals). And the WSW is an average for multiple zones (ever larger differences in totals).

Whether they end up average higher or lower is relative to where your P&C is. 

I'm in the coastal Cumberland zone, but the far western part of it. So in a typical coastal gradient event, my P&C will be highest, the ZFP lower, and if the WSW was just coastal zones that may be even lower.

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