I'll be heading West Monday to spend the next few days chasing storms so I'll post another, more detailed blog update then with a full chase forecast this weekend when we've had more time to see exactly how things evolve to set the stage but we'll still take a brief look tonight at how I see the general synoptic-scale features coming together.
Since this is the first big, multi-day, central plains chase setup this season I thought it would also be cool to break down some of the gear I use when I'm chasing. I've had several people ask me about this so this seems like a perfect time to do so. I'm also going to post links to some of my preferred online sources for analysis data that I often use when I'm out. I typically use a suite of operational or "professional" software programs designed specifically for the most detailed forecasting and analysis work when I'm at home or in the office but obviously I don't have quite the same computing power when out on the road so I have several resources I use regularly for various things.
My Chase Gear
Believe it or not, despite the "flashy" stuff I use for weather forecasting when I'm not out chasing, I'm not a particularly high-tech storm chaser. I'm not a Luddite or anything, I just prefer a good balance between having access to the amount of data I like and being able to focus on what's actually going on around me as well.
Cameras:
- Sony FDRAX53 4K Ultra-HD Video Camera W/26.8mm Zeiss Vario Sonnar Zoom Lens, 40x Image Zoom, Optical "SteadyShot" Technology, 120fps Recording, 3" LCD, and a High-Sensitivity Image Sensor, Video/Still Photos/Time Lapses
This is my "go-to" camera for all the higher quality video I shoot and it's the one that captures most of what ends up in my YouTube videos. For one thing, it just captures unbelievably crisp video and *gasp* that's the main thing I look for in a video camera. I switch up how I utilize it based on what I'm chasing and how I'm chasing it. Sometimes I'll mount it and use it as my dash cam because it absolutely will not give you any "jello" unless you're driving Dukes of Hazard style, and even then I think it will hold a steady shot. There are several times, if I'm feeling froggy, that I'll switch out the dash cam pre-chase, and keep this one next to me for throwing on a tripod and letting it catch whatever is going on in front of us. It's also amazing for time lapses. One of the best things about this camera and one of the reasons I ALWAYS have it by my side is its ability to film at night. No need for that goofy green nightvision with this thing because it can see better than a cat at night, I swear it. There have been at least a half-dozen tornadoes I've been able to confirm (and scud I was able to confirm wasn't a tornado) that were invisible to the naked eye but a peek on the LCD screen showed exactly what was there.
Honestly, you can get the job done just fine without spending $1,000 on a video camera but if you were trying to spend that much this is the camera I'd recommend because I've gotten my money's worth for sure.
- Canon SX120IS
This is not the fanciest camera you'll ever see but this 9 year old Canon is still always in the bag. First of all, shooting photos in/near tornadoes, supercell thunderstorms, hurricanes, and any other severe weather you can think of isn't necessarily the same "user friendly" environment you might find if you're say, photographing a sunset or a wedding. This camera has always held up perfectly when photographing in dangerous, difficult conditions with rain, hail, tornadoes, and most recently milk crates and housing insulation blowing at me. I'm not sure how much it costs these days but 9 years ago it was like $90 so I'm way more comfortable having this in the field. It's still a good camera too though. A little knowledge and practice with tweaking your exposure/aperture settings/angles/etc and you can take great photos that won't look like they came from an old PowerShot camera.
- Samsung Galaxy 3
Yes, that is my phone. Yes, I still use a Galaxy 3. Listen, I've had this phone forever and it does every single thing I need it to. Plus I can export all of my apps and such to external storage which basically means my stack of Micro SD cards at home equates to unlimited storage because some new model phones scratched the ability to export apps to external storage in exchange for larger internal memory (but not unlimited internal memory). I really do consider this as another camera however. Most of the time I'll have other cameras set up with one set up on a wide-angle shot, one set up on a tight shot, and I can use my phone for miscellaneous other shots. Specs aren't too much to talk about, it takes HD photos up to 1920x1080 resolution and has the ability to manually set exposure etc so you can outdo many cheap cameras on the market these days.
Data Acquisition:
-Custom HP ProBook 450G3 Notebook
It's probably self-explanatory what I use this for and the links to sites I visit most often will be most helpful so I'll just list a few specs. (Surprisingly, I don't often have this with me because I use RadarScope and a few apps on my phone while I'm chasing solo as opposed to this. Honestly, RadarScope completely changed my life because now I can just jump in the car and go instead of hooking my laptop up)
- Intel Core i5 Processors
- Discrete Radeon Graphics
- 500GB (8GB Internal)
Miscellaneous:
There's no reason to go through every single thing I pack but I do have a few things I like to make sure I have in my bags. I vary what I take depending on whether I'm hunting for supercell tornadoes or riding out a hurricane somewhere along the coast.
- This might not seem like I should mention it but it's my blog so I am. I always pack 3 extra outfits (plus the expected number of outfits for the planned duration of the trip). I'll pack one warm-weather outfit, one cool-weather outfit (sounds crazy chasing storms when it's 80 degrees but you'd be surprised just how cold post-frontal air masses can be, and can't forget cold RFD etc). The third outfit is packed for the unfortunate scenario of a damaging storm impacting people. When storms damage/destroy people's property they can easily end up dirty and wet and having seen this happen more times than I'd like to I like to have a warm, dry set of clothes to offer them.
- Obviously the camera accessories are always in my bags.
- Extra chargers. I have learned that you can't have too many chargers for phones and whatnot but you can certainly have too few.
- Card Reader. I bought a cheap card reader that reads SD/Micro SD cards, larger memory cards from a laptop, as well as direct file transfer via USB. This comes in handy when you have mutiple devices for capturing footage because you can just take a card out, pop it in the reader, and upload that precious lightning shot to social media meaning you can start getting those "Likes" that so many need to survive a little bit quicker.
- Backup MiFi hotspots. I pack two mobile WiFi devices. One AT&T, and one Verizon. Different providers work better in different areas so I like to cover my bases.
- PAPER MAPS! These are NOT obsolete. I've found that an updated trucker's atlas will work wonders when you drop to 1 bar of 3G and you can't get Google Maps Offline to work or that GPS that loves to give orders and doesn't care how much we cuss it says State Road 37 is supposed to cross the interstate but it's actually just some guy named Atticus' driveway.
- Colored Pencils. Makes sense right? Storm chasing often consists of hours of sitting roadside waiting for the cap to break so you've got to have something to do right. I actually make sure I have these because I print off surface obs charts every chance I get and it's frustrating to not have my pencils when I want them.
- Reference Books. Oddly enough I take lots of notes when I'm chasing (things to remember for case studies, observations, etc) and I like to have paper and reference books to use.
- I always have safety/search and rescue gear like flashlights and first aid kits. I'm not going to list everything but the most useful things I've had with me are flashlights and chainsaws.
- Lastly, various random things I decide to throw in my bags for no real rhyme or reason.
29 April-3 May Severe Weather Setup
As I said earlier, I'm going to be posting a detailed chase forecast later so we're just going to look at some current observations and how they should evolve to assemble the general background environment for our multi-day severe weather outbreak this coming week.
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| Looking at the 250mb level to assess the jet stream winds we can see a split-flow regime in place with a longwave trough over the East CONUS and a ridge over the West. A strong upper-low is entering the PacNW and this is actually energy that will be associated with our storms. The polar-front jet is evident diving in from central Canada around the Great Lakes and rounding through the trough before phasing with energy from the subtropical jet over New England. This pattern has been pretty stagnant for awhile now and that's resulted in quiet weather over the Plains as it has inhibited meaningful moisture/theta-e return flow. The pattern has become more progressive now however, and as the PacNW upper-low digs into the Rockies, associated cyclogenesis will promote a strong increase of sustained theta-e return and this will fuel an extended severe weather episode. The subtropical jet is evident entering West Mexico before travelling through extreme southern Texas and rounding the base of the eastern trough over Florida. That feature resulted in a few severe storms, including a couple tornado warnings in Florida today. |
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| 500mb 0z obs show similar features as the 250mb chart but the location and amplitude of shortwaves embedded within split flow is noticeable at this level. A 50kt speed max is visible over the Iowa region and it's associated with a surface baroclinic zone that is resulting in some weak convection in the East but we're focusing on the upcoming chase. In my everyday forecasts I've assessed this feature much more but for our purpose we are more concerned with the high-pressure in the wake of this trough as it is suppressing moisture return now but by Sunday-Monday it will be positioned near the Gulf Coast and will be promoting strong moisture surges northward. |
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| The main thing I want to point out here is the beginning indications of our elevated mixed layer over the SW CONUS. 700mb is a good proxy for the location of the EML and you can see strong heating over the SW already with temps approaching 10C. As southwesterly flow becomes more prevalent in response to the digging trough early next week we should see this EML advect relatively easily over the Central Plains forming a strong cap but with very steep lapse rates atop the inversion above the moist sector (perhaps 9C/km). |
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| Tonight's surface analysis doesn't look particularly impressive but the beginning of our setup is hiding in there. A frontal system associated with the speed max we identified aloft is located near the Great Lakes with a "dry front" passing through the Ohio Valley. A cold front is crossing Florida as well and this is keeping moisture confined to the South for now but a surface-high is noted over the southern plains. Once this high slides eastward in the next 24-36 hours we will see moisture return through the central plains. Also note the frontal system in the PacNW, this is the surface reflection of our initial energy that will dig in and should help assemble our storm environment early/mid-week. |
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| I just wanted to share this to demonstrate the deep, rich moisture that isn't necessarily evident on CONUS soundings yet but is primed just upstream in Mexico to surge northward. This shows rich moisture extending up through the 850mb layer. Once the aforementioned high moves eastward and our surface-low develops over the Kansas area the southerly flow will advect this moisture well through the central CONUS resulting in a very moist warm sector ahead of our dryline. |
So now we have a solid conceptual model of how things should come together, at least in a general sense as smaller-scale details will become evident in the coming days. We can infer that the eastern trough will progress eastward as ridging aloft builds in its place and a Pacific trough will build in the West. As a shortwave pivots around the base of the western trough and digs into the central plains by Sunday-Monday we should see cyclogenesis occur with a surface-low developing somewhere in the KS/OK vicinity. This will result in strong moisture advection northward along the front range region of the Rockies. Based on upstream observations in Mexico and the Gulf we should be able to generate 60F dew points into OK by Monday. This deep moisture will continue to spread northward through Tues-Wed as a warm front moves all the way into the Great Lakes area. Steep mid-level lapse rates already becoming evident over the SW will advect over the central plains within southwesterly flow and will overlap a sufficiently deep moist sector ahead of our dryline and cold front. Surface heating beneath a strong cap will aid destabilization each day and moderate to strong instability should develop with classic "loaded gun" soundings the anticipated thermodynamic profiles. Although forcing for ascent will be weaker on Monday and Tuesday compared to Wednesday, convergence along the dryline should be enough to eventually break the cap and initiate scattered storms. (I will admit that I've already looked at forecast model cross-sections to assess the depth of mixing behind the dryline relative to the depth of moisture ahead of it and I think it's sufficient to get parcels to their LFC) We can narrow down the burst point and dryline/frontal position as we get closer to "go time". Wednesday looks like the most significant day as confidence in convective initiation is a little higher since upper-air support is more favorable as our upper-level energy arrives providing stronger forcing for ascent. Given boundary-relative flow I think storms should have a favorable "parcel residence time" to maintain intensity but also have storm motions to help maintain discrete structures. This coupled with elongated, looping hodographs suggests that supercells capable of large hail and tornadoes will be possible each day with the threat increasing daily.
The main concerns will be the strength of the cap and the effect of previous day/morning convection on destabilization and boundary positions. I don't think the early convection will inhibit this threat entirely but it could certainly affect the areal extent of the threat. The cap of course is, well, it's the cap so there's always the chance that it does what caps do.
Now that we've made a basic forecast we'll look at one or two model products to see how the models compare to our forecast. (Note: I am only posting a few graphics that blend well with the model consensus. These are not all the models I analyze while forecasting and the graphics posted do not constitute the exact forecast as, like I said, the specifics will work out in the coming days and will be covered in the chase forecast post this weekend. These are only to show a general, large-scale synoptic setup and demonstrate the relationships between various features and how we predicted them in our observation analysis)
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| Multi-Model "Spaghetti Plot" Showing Simulation of 500mb Heights. There is clearly still some divergence between models regarding small-scale details. This is a typical degree of divergence with some struggling with an embedded shortwave across the SE CONUS and differences regarding the precise amplitude of the western trough but the general idea is consistent with this run of these models. (Model Valid 12z Monday 30 April 2018) |
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| Same multi-model comparison, this time with MSLP. Quite a bit of model disagreement as expected regarding exact timing of cyclogenesis and placement of surface boundaries. |
The above graphics show GFS modeled surface dew points for Monday, Tuesday, and Wednesday (Top to Bottom) along with mid-level lapse rates for Sunday. Notice a plume of very unstable lapse rates over the SW CONUS. You can see the general organization of our moist sector and when southwesterly flow arrives, this plume of steep lapse rates will advect over the top of the warm sector, likely resulting in strong, capped instability. This should limit cells from initiating everywhere and allow the updrafts that do break the cap to be relatively explosive.
Monday 30 April 2018
GFS and ECMWF comparison of CAPE for Monday. A corridor of moderate to strong instability should exist across the central plains, although the GFS is more aggressive. Even though dynamics and upper-air support is weaker on Monday, this would certainly support severe storms and the shear profiles would support supercellular storms, although boundary-relative winds may force updrafts to shoot off the boundary fairly quickly resulting in loss of ascent. Storm-relative mid-level flow is a bit weaker too so there may be some negative interference between close-proximity cells.
Tuesday 1 May 2018
As the northern surface-low moves eastward toward the Great Lakes the severe threta shifts slightly eastward for Tuesday. Again, a corridor of moderate instability is suggested to develop ahead of a KS/OK/TX dryline. 0-6km shear overlapping the moist sector is a little on the weak side, on the order of 30kts initially. This will strengthen throughout the day so the timing of initiation could be important as it relates to the evolution of convective mode. Regardless, severe storms capable of all hazards are possible.
Wednesday 2 May 2018
Current thinking is that Wednesday could be the most significant day of this event, although anyone in the threat area may be impacted any of the days. Once again, a corridor of moderate instability is progged across the central plains. The big difference this day should be the arrival of a substantial shortwave. This shortwave will increase both deep-layer shear and forcing for ascent. The low-level cyclogenetic response will lead to the development of a dryline triple point somewhere in the Kansas vicinity. This will act to increase storm-scale ascent due to convergence and increasing baroclinicity and the potential for streamwise vorticity, which is a factor in tornadogenesis as hodographs become enhanced with a marked increase in curvature. Storm-relative winds throughout the mid-level should promote sufficient updraft/downdraft separation and parcel residence time should be favorable for storms to maintain. These factors are some of the reasons why I believe the most likely convective mode will be supercells on Wednesday with the potential for a few tornadoes, particularly in the KS/OK area. Tornado potential may increase through the evening as well coincident with the arrival of a 40-50kt low-level jet.
I'll post regular updates over the next week as I will be out each day chasing storms across the plains, starting with the initial chase target forecast this weekend.
Weather Analysis Resources
Now that we have a broad idea of what the next several days may look like regarding the potential for a widespread severe weather event, and we took a look at some of the gear I take with me to chase these storms, lets look at where in the world you can track this event as it plays out. These are just a few of the websites I've used from time to time while chasing severe storms, in no particular order. (Note: I did not create any of these sites)
- SPC Mesoanalysis Page
- Atmospheric Atlas With Chase Resource (Hotels, Gas Stations Etc.)
- Surface Observation Maps (Personal Favorite, Especially for Hand Analysis)
- GOES East Viewer (With Geographic and Mesoanalysis Overlays)
- SPC Upper-Air Obs
- WPC
- SPC
- Oklahoma Mesonet
- West Texas Mesonet
- Kentucky Mesonet
- GOES East Experimental Convective Initiation Probability
- Auto Nowcaster Convective Likelihood
- College of Dupage (Old Go-To Page Since Day 1)
- GOES East Viewer (RAMMB-Colorado State University)
- GOES East Viewer (University of Wisconsin)
- List of Common Bookmarks Provided by Western Kentucky University (Go Tops)
- SPC Composite Map
- Similar to SPC Mesoanalysis Page but for Dallas Area Using Obs Instead of RAP
- HRRR Viewer from SPC
- HRRR/HRRRX/Rapid Refresh
- Pivotal Weather
- Short-Range Ensemble Forecast Model
- NAM3/NSSL-WRF/WRF-ARW/WRF-NMMB
- Special WRF Model (3km, 12km Ensemble Runs) from Texas Tech University
- Model Site Includes Model Cross-Sections (X-Sections are Hard to Find)
- WxCaster (Awesome Site, Tons of Data, Takes Some Getting Used To but Worth It)
- MeteoCentre
- Experimental FIM Global Model
- Model Site for Lots of QG (Quasi-Geostrophic) Theory Diagnostics
- WPC Model Consistency Diagnostics
- "Chiclet" SPC CFS Dashboard (Long-Range Severe Weather Data)
- GEFS Plumes
- CIMMS Experimental Model
- NOAA Glossary (Just Thought This Would Be Cool To look At)
- List of Environmental Parameters for Severe Weather Forecasting (Put Together By My Local Office NWS LMK)
- Red Team Wx (Awesome Source for GRLevelX Placefiles. I use AH but this site has State by State shapefiles for overlaying all known roads on GRLevelX)
- StormViewLIVE (Come On, Best Place To Watch Live Storm Chasers Do Our Thing)
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