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Had no chance to see any weather data at all through the day on Friday , so when I returned home I was situationally unaware. I don’t like that, and especially in May, and especially when I hear thunder as soon as I walk in the door! A quick dash to the window revealed a developing cell just to the west – the first for the new place and the WX-Perch (TM).
Had a quasi-conical, but scuddy non-rotating lowering just below a linear updraft base, so it was time to grab the camera! By the time I got back the lowering was gone and I was treated to a nice sculpted vault behind the leading shelf cloud – so at least I did get a nice structure shot out of what was going to be a very fleeting ‘low-end’ (but pretty!) event.
I like the WX-Perch! Now if this turns out to be an active season up here it will be tempting to stay put for any London events (certainly for anything outflow dominant) – or get back to the WX-Perch if I’m out chasing and it becomes apparent that it will be a “London” event – which would have the benefit of not trying to chase in an urban environment. Obviously, this isn’t a dilemma for events further from home.
Because we have had so little photogenic weather here recently (and we are entering the convective season), I thought this event might be an opportunity to improve the blog workflow and add in thumbnails for radar/other charts. These will link to to full size images and will enhance the ability to discuss and review events. This was also an opportunity to get more familiar with the archiving of Mesoanalysis data at the Storm Prediction Center’s website (thanks SPC, its nice to know these are available if I don’t archive data during an event).
That led to the discovery of how to process .gif files in Photoshop CS3. Turns out that .gif files are rather tricky to process in Photoshop, so I will note the steps at the end of this post for anyone else interested in doing the same. So, going forward, this blog will include thumbnails of radar and charts of various parameters where they add to the discussion of an event. To navigate these simply click on the thumbnail and it will open the full size image. Click ‘Back’ in your browser to return to the blog. I think that is a better approach than opening in a new tab – feel free to let me know your thoughts! Here is a .05 degree Reflectivity image from the Detroit NEXRAD of the cell at about the time I took the above picture:
The black dot on the full-size image denotes my location. The precip core is off to the WNW while the updraft feature I photographed (to my SW) is out ahead to the SE of the reflectivity. It is so nice to be able to see a cell first hand and at the same time correlate with a quasi-real-time radar image!
This weak cell developed in an environment very weak upper level flow (not shown), and out ahead of both surface and mid-level short-wave troughs over Michigan, as shown on the 21z 500mb
mesoanalysis:
,,,and on the SPC surface mesoanalysis – note the Sudbury, ON – Lansing MI short wave trough, and a SW sfc flow over SW ON:
Surface obs showing presence of fairly low dewpoints (45F at London):
along with zero Surface Based CAPE (not shown), and about 500 Jkg of Most Unstable CAPE:
…suggests we have a case of Elevated Convection (not really a surprise):
The lack of any significant 0-6 km shear also accounts for the short duration of the event (and rapid evolution to outflow dominance):
When the core arrived at my location (again the black dot on the full size version of the reflectivity image) we were treated to a nice fall of pea-sized hail!
I can enjoy a low-end convective event that offs up some photogenic moments and it is nice do get a routine down to do some improved post-mortem discussion – now bring on some REAL storms!!
******************************* Here is the process to handle GIF files in PS: 1. Open .gif in Firefox 2. Copy 3. Open New Photoshop Document in CS3 (default 1000 X 750 pixels works fine) 4. Paste gif into document 5. Right click Layer 1 > Blending Options… 6. Move “This Layer” slider from 0 to 1. 7. CTRL-SFT-E to flatten 8. Image Resize to taste and Save As .gif (GIF Options Normal).
***************** EDIT – 5-12-2011 AN even better approach is to create an PS Action that captures: 1 Image > Mode > RGB 2. Flatten Image (right click over Layer > Flatten) 3. Image Size to taste 4. Save As: GIF To do all the GIFs in a given folder go: File > Automate > Batch where the Action is the one created for this task; in/out folders are chosen (I used same for both); check “Override Save As Commands”, and “document name +” _small” + extension” Click OK and it will do all the GIFs in the folder with re-sized versions also saved a GIFs and with the suffix ‘small’.
