Connecticut Hail and Dual Pol

Since dual polarization capability was installed on the 3 WSR-88ds that cover Connecticut we really haven’t had much large hail to play with. There was one notable exception on July 1, 2012 that I blogged about here.

The supercell that produced the hail dropped significant hail (2″+ in diameter) in a few locations including Cheshire, Clinton and Westbrook. There were many reports of golf ball size hail in Bethlehem, Watertown, Oakville,  Wolcott, Wallingford, and Essex.

The first reports of golf ball size hail came in around 3 p.m. around Watertown. Dual pol products from OKX certainly show the presence of hail with an area of depressed correlation coefficient (generally from 0.8 to 0.95) over Watertown. One thing that’s interesting is that the largest hail was likely falling on the western flank of the highest reflectivity. Notice that ZDR is quite high to the east (in some cases over 4 or 5 dB which would indicate melting hail stones). On the Watertown/Bethlehem border ZDR is much lower – near and even sub zero in some places – this is where the largest hail was falling. As hail falls it tends to tumble so the hail appears to be spherical to the radar – hence a ZDR value near 0 dB.


Note throughout the hail core KDP values are quite high indicating there’s a large amount of liquid water mixed with the hail. The highest values of KDP are where you’d expect them – to the east where the hail is melting. The depressed area of CC becomes more impressive as the storm enters Wolcott with CC falling around 0.85 in area.



ZDR remains noisy but there is an area around 1 to 1.5 dB coincident with the depressed CC.

As the storm moves southeast toward the shoreline it actually pulsed up over Madison and Killingworth as it merged with another storm that had formed on its outflow boundary. One thing here that’s pretty cool is the BWER over North Madison that you can see on a cross section.



On dual pol you can see a noisy, but still present, hail signature on CC and ZDR over Killingworth. Note, much like before over Watertown, the lowest ZDR values are to the west (also notice lower KDP here) while the higher ZDR values can be found in an area with high KDP showing melting hail on the eastern flank.



As I mentioned in the original post last year one of the more impressive things about this supercell was the monstrous storm top divergence. Nearly 130 knots over Killingworth and Watertown shows a super impressive updraft.  Any time I see storm top divergence over 100 knots in Connecticut I pay close attention to it – 130 knots is extremely impressive.


More recently, last week’s supercell that dropped hail in Salisbury and Canaan dropped 2″ diameter hail in Columbia County New York around Ghent, Kinderhook, and Valatie.



There was a classic dual pol signature here with ZDR near 0 coincident with a large area of depressed CC. This example is a bit more “classic” than last year’s hail in Connecticut. This stuff is just so neat!


2 thoughts on “Connecticut Hail and Dual Pol

  1. Ryan, I’m interested in your blog here, but I do not understand any of it. I mentioned when I first replied here that my niece’s husband has a weather journal at It’s connected with the Roanoke Times. He has many bloggers, surprisingly many of whom know an awful lot about meteorology. Some of us just listen in. Is there any way you could begin to try to “explain your explanations?” [smile]
    Thanks for your interest in sharing, even if most of it is beyond my ken!

  2. the industrial fastpaced city of Italy and for being a fashion capitol, and therefore shopping is very important and in fact the Galleria Vittorio Emanuele II, according to the Provincia of Milano website, was initially designed in 1861, and finished in 1877 and given the name of the first King of Italy as a united country, right in the middle of the belle poque. One barista who has been working at Starbucks for five years told me, I feel taken care of by management. The sport of BMX racing attained a great honor in 2003, if the International Olympic Committee (IOC) voted to add BMX racing on the 2008 Summer months Olympic Video games in Beijing. Also though they are not the authentic deal, you might consider them as knockoff that are inexpensive and look great.There are four wine regions which consist of (North Coast, South Coast, Central Coast, and Central Valley).C’tait exceptionnel au vrai sens du terme.Through the years the purpose and designs of lanyards have evolved and have become widely used in several industries.The mini type of a chromatic cloth handbag hangs from a heartshaped key fob here.

Leave a Reply

Please log in using one of these methods to post your comment: Logo

You are commenting using your account. Log Out /  Change )

Google+ photo

You are commenting using your Google+ account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )


Connecting to %s