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HimoorWx

Napril Fools? Pattern and Model Discussion . . .

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2 minutes ago, OceanStWx said:

That's the problem with most NWS ptype tools. Now it's easy for me to say, because I don't code them up.

There are some that do the old thickness rules, but the majority use a top down approach that focuses solely on the warm layer. Many of those are designed with the middle of the country in mind, where cold air is often very shallow and doesn't dictate ptype as much as temps aloft. But we had legit 1000-1500 m deep cold layers on our last few soundings. 

Yeah, our CAD on a regional level is probably the strongest of anywhere in the country due to the geography/topography...so it builds up into the lower mid-levels pretty frequently. That can make those ptype rules based on the Midwest and plains misleading. I have given presentations on icing in New England and I often tell everyone that you have to throw out the old "valleys are the last to see ZR change to rain" rules that others areas of the country are so used to. That New England has the elevation icing events because our soundings so frequently will have normal cooling lapse rates up to about 2000 feet in many of our events. Not all of them of course, but I'd say in an overwhelming majority of them the icing is actually more intense at elevations between 1000-2000 feet than lower down. Then you can apply this observation to sleet events too...we can get sleet events with warm layers much warmer than the popular +3C cutoff due to our deeper cold inversions. It really is not an easy place to forecast mixed, transition, or icing events if you are not already quite familiar with the local climo and how the topography affects it...as you said, the models fail so often in diagnosing the ptypes in our region because they can't resolve the CAD in both magnitude and depth...almost always underestimating both.

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Coastal front evident on TDWR velocity near GHG. Winds have backed at BOS, so a nice enhancement of cold +RA for for runners. Thunder on s shore too.

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Just now, CoastalWx said:

Coastal front evident on TDWR velocity near GHG. Winds have backed at BOS, so a nice enhancement of cold +RA for for runners. Thunder on s shore too.

Upper 30s (more like mid 30s when they started in Hopkinton) and torrential downpours....good running wx.

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10 minutes ago, ORH_wxman said:

Upper 30s (more like mid 30s when they started in Hopkinton) and torrential downpours....good running wx.

Disaster. 

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22 minutes ago, CoastalWx said:

Coastal front evident on TDWR velocity near GHG. Winds have backed at BOS, so a nice enhancement of cold +RA for for runners. Thunder on s shore too.

Spring misery for those people running today.  Awful. 

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24 minutes ago, ORH_wxman said:

Yeah, our CAD on a regional level is probably the strongest of anywhere in the country due to the geography/topography...so it builds up into the lower mid-levels pretty frequently. That can make those ptype rules based on the Midwest and plains misleading. I have given presentations on icing in New England and I often tell everyone that you have to throw out the old "valleys are the last to see ZR change to rain" rules that others areas of the country are so used to. That New England has the elevation icing events because our soundings so frequently will have normal cooling lapse rates up to about 2000 feet in many of our events. Not all of them of course, but I'd say in an overwhelming majority of them the icing is actually more intense at elevations between 1000-2000 feet than lower down. Then you can apply this observation to sleet events too...we can get sleet events with warm layers much warmer than the popular +3C cutoff due to our deeper cold inversions. It really is not an easy place to forecast mixed, transition, or icing events if you are not already quite familiar with the local climo and how the topography affects it...as you said, the models fail so often in diagnosing the ptypes in our region because they can't resolve the CAD in both magnitude and depth...almost always underestimating both.

Yeah and if you want to take it a step further, over this way it's about 3,000-3,500ft elevation that always seems to be ground zero in low level cold.  Maybe it's just a micro-climate of the east slope, but 3,000ft will be the last to warm up....often extending up to 4,000ft too.

Like it's still 22-25F in the 3-4kft column on Mansfield's east side right now.  That's also why I think that area preserves snow so well and it's very hard to get that to melt and why the COOP can build ridiculous snow depths.  

Throw in a strong SE flow and upslope cooling and around these parts, that's always the last elevation to go above freezing.  

I wonder if it's the same further SE into Dendrites area? Where's the max cold layer?  Part of me thinks it's lower down that way while up this way it always seems to be mid-Slope to summits that are impossible to dislodge and warm up.

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4 minutes ago, Damage In Tolland said:

Thursday snow threat looks legit 

 

3 minutes ago, WinterWolf said:

Really?   

Looks more for CNE/NNE at the moment. Need to see a decisive trend south in redevelopment of secondary.

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Just now, ORH_wxman said:

 

Looks more for CNE/NNE at the moment. Need to see a decisive trend south in redevelopment of secondary.

Thank you for chiming in...was thinking this same thing.    Not too legit for SNE. 

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12z sounding was -8.5 C at GYX, and sure enough we're getting a lot of snow grains right now. Starting to really whiten the landscape up, holding steady at 31.

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Hope y'all got to watch the marathon. Gotta give mad props to all those runners. USA and Japan, women and men's winners!

I wonder who selected the clothing for the Kenyans and Ethiopians. They basically were put in parachute type rain jackets which created so much wind resistance. 

 

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7 minutes ago, OceanStWx said:

Lyndon launched a balloon this morning and got about -5C in the cold layer and +8 (at 803 mb) in the warm layer.

I swear we used to have a page at Plym where we saved all of our raw RAOB data. I can't seem to find it now though. Chances are there was no launch today anyway.

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16 minutes ago, #NoPoles said:

Hope y'all got to watch the marathon. Gotta give mad props to all those runners. USA and Japan, women and men's winners!

I wonder who selected the clothing for the Kenyans and Ethiopians. They basically were put in parachute type rain jackets which created so much wind resistance. 

 

Cold and parachutes...Maybe it was a suggestion by the USA contingent.  Whatever it takes to beat them.  

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