EWP Blog

After I blogged earlier myself, along with others earlier about the more stable airmass near the southern Lake Ontario shoreline, I went ahead and issued a severe for NORTHERN CAYUGA COUNTY IN CENTRAL NEW YORK…SOUTHWESTERN OSWEGO COUNTY IN CENTRAL NEW YORK… NORTHEASTERN WAYNE COUNTY IN WESTERN NEW YORK…despite the fact I knew earlier this activity wasn’t severe (and also per real-time reports).  A no-no on my part, but just to prove my point, this is the MESH product at the time I issued that severe thunderstorm warning. Lesson learned (Eric).

Simulated satellite imagery from 00Z WRF runs showed strong convection near the lake in the early afternoon with clearing in western New York during the late afternoon hours.  Convection only sporadically tries to develops until well after 00Z in western New York.

Hail has been below severe limits in the Monroe and Wayne counties in upstate NY.  As noted on an earlier blog, less stable air has slowly advected south across parts of these counties from Lake Ontario.  Below will is the 2102 UTC reflectivity image and corresponding MESH image from KBUF radar.  This is when storms were at their most intense with only half inch hail being reported out of the southwest Wayne Co storm. Another strong storms was developing across central Monroe Co at the time.

Here’s the 2120 UTC radar reflectivity from KBUF and corresponding MESH. The Wayne Co storm has maintained or slightly weakend as it moves towards the more stable airmass off Lake Ontario.  Meanwhile, the Monroe storm has weakened considerably and was closer to the lakeshore. This is basically 18 minutes later from the first capture.

Okay, here’s another golf ball size hail report, this time from a little bit later in far northern  Cayuga County, NY.  First, before I go further, I have to say I like the name of this county…as it sounds like an old car horn.  Anyway, from 2000-2010 a member of the public reported golf ball size hail near the town of Cato.  Here’s an image from the middle of that period (2004 UTC), using the MRMS and KTYX HSDA data.

Notice again the absence of large or giant hail in the HSDA data from KTYX (the closest radar).  I’m thinking I may have to look at higher slices from the KTYX dual-pol and start analyzing those slices of the HC data.  Of interest, notice also the TBSS appearing in the MRMS reflectivity and the KTYX HSDA data.

Kris and Eric

We had two rotating thunderstorms. One rotating storm across the southeast portion of our CWA (Image 1) and a second storm near our northern CWA border (Image 2).

Storm number 1 as seen in image 1 had a nice long rotating track that had modest rotation at times. This was a good distance from the radar so even at the lowest slice was rather elevated. Felt the rotation was weak enough and elevated enough to just keep it a svr thunderstorm warning. Reflectivity also did not look overly impressive. We did get several severe hail reports.

Storm number 2 as seen below also had a persistent rotating updraft, but rotation was not as strong as in storm number 1 above. This storm did produce golf ball size hail, but the rotation was not significant enough to warrant a tornado warning. Thus we went with severe thunderstorm warnings. WeselyWesely

Convection has developed to the east-northeast of Buffalo along the moisture gradient to the north of dryer air shown on various LAPS products.  The convection has struggled somewhat to maintain itself and a previous hail signature has diminished, perhaps feeling the influence of the dryer air to the south.

– McCormick

The image below shows the following:  Height of 50 dBZ above -20C upper left, height of 50 dBZ above 0C lower left, height of 60 dBZ above -20C upper right, and height of 60 dBZ above 0C lower right.  This image was taken at 2028 UTC 8min prior to the report (note the height of these cores lowered by the time of the report).  At this time the height of the -50 dBZ above -20C was ~13k ft.

Okay, we just got a delayed hail report from Wayne County…golf ball size hail at 1936 UTC!  So, what did some of the same data show at this time?  Here’s a look…

This first image is a four panel of the MRMS data, containing the KBUF HSDA (lower left).  At this time, the MRMS reflectivity values at -20 C were 65 dBZ.  MESH values were as high as 1.65 inches (2 minutes previous it showed 1.73 inces).  However, the HSDA still indicates sub-severe hail.

The next image contains the MRMS and KYTX radar data at about the same time.  Notice here again, the sub-severe classification of the hydrometeors.

Also worth mentioning is the 2-minute temporal resolution of the MRMS data, which can be advantageous in warning situations and could potentially keep forecasters from switching back-and-forth from radar to radar and saving time from looking at all-tilts so much…as is my primary current warning strategy.

Kris and Eric

Southwesterly winds are noted to be advecting dryer air into the southern portions of western New York.  Minimums of SB and ML CAPE are noted with this air mass as it moves into the area.  The only healthy storm so far in western New York was located on the northern side of this air mass, and every echo closer to this air mass has struggled to develop.  Convection is likely only to thrive if it develops on the moisture gradients noted in the previous mesoscale discussion and moves away from the dry air,  at least until better upper level forcing arrives.

– McCormick