#vawx A six year anniversary storm as a precursor to a chase today?


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Sometimes the Virginia chase season really does last until Veterans’ Day. This funnel – just to the right of the rain shaft in the center – spun out from a wall cloud and storm east of Fredericksburg six years ago today. A new wall cloud is forming just to the left of the rain shaft:27oct10_edited

With that in mind I peeked at the short range models for today and found some encouraging news for a possible chase. The HRRR, the RAP, and a couple of WRF models all show varying degrees of instability to go along with significant shear this afternoon. Most of them break out a line of showers/storms crossing the I-81 corridor around 3 pm.

Will I head out this afternoon and where do I target  or would it be a waste of time and gasoline? The process will involve watching radar and surface observations and I’ll have to decide by 1 pm. Let the (guessing) games begin…

#vawx A rogue NAM sounding for Thursday 10/27

Ha! Here’s the 06Z Tuesday NAM sounding for the Piedmont area between LYH and DAN for 21Z (5 pm) this Thursday:21z-thurs-nam-sounding

The NAM buys into significant moisture advection into Southside Virginia, thus the CAPE values are well over 1000. Meanwhile the GFS pooh-poohs the moisture advection and holds CAPE to near zero Thursday afternoon.

Do I believe Thursday will involve Virginia chasing? Nope. But I will be watching the evolution of the setup as a wedge front retreats north while a cold front approaches from the west. If instability does develop then – coupled with the shear values – Thursday could turn interesting.

I’m not holding my breath…

#vawx No chasing this week but plenty of downsloping this afternoon


Nothing chaseworthy materialized this past week and there is no potential for any chasing on the horizon. Although in past years I have chased up until Veterans’ Day – Nov. 11th – that may not occur this year. (Of course I didn’t expect to chase on February 24th either but that’s another story…) This could be it for the 2016 season.

Meanwhile this afternoon’s visible satellite image is a classic example of downsloping drying out the lower atmosphere. Here’s the graphic I occasionally use to illustrate the idea:classic-downsloping-graphic

Now here’s the visible satellite image:ganimjkwbrb4

Pretty obvious.

#vawx A Friday chase doesn’t look likely


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Haven’t totally ruled out a chase on Friday 10/21 but the setup isn’t looking good. The GFS and Euro have a strong surface front plowing across Virginia early Friday, too early and with too much cloud cover for decent instability. The 12Z NAM is holding out for a weak surface low to form along the boundary and slow it down by 3 or so hours compared to the other models. Per a late Friday morning forecast sounding along the U.S. 29 corridor that may allow CAPE to boost to nearly 1000 j/kg.

Even if the NAM is correct – it was the better model during the Feb 24th deep trough setup (which created a tornado outbreak) – this would be another high shear / low CAPE situation. Those are always dicey prospects for chasing around here especially with low LCL’s making visibility difficult. On top of that this looks and feels like a squall line event vs. discrete cells.

I’ll keep an eye on it but I’m not particularly hopeful at this point.

#vawx No dice early next week, but later?



Both the GFS and Euro are now looking down their collective noses at the chances for severe weather early next week. The strong upper level winds will stay well north of the Old Dominion and no instability is showing up either.

However…having said that the GFS – but not the Euro – is bullish on the setup late next week. It develops an upper level low over the Tennessee valley such that Saturday now looks interesting with LOTS of shear and a modicum of instability.gfsus_500_spd_174

The Euro shows this low developing much further south so there’s little model agreement at this point.

So, we’ll see. Meanwhile I can hear the end of the 2016 chase season steaming down the track toward me.



#vawx Pacific Northwest systems will affect next week’s potentially severe weather here



While we East Coasters fixate on Atlantic and Caribbean tropical systems folks in the Pacific Northwest are staring at two potentially devastating storms bearing down on them. The second of these is the powerful remnant of a super-typhoon from the western Pacific.

Besides being concerned for our fellow citizens on the Left Coast we should keep in mind these systems are moving east in our direction and will affect our weather next week. Their impacts on the potential severe weather threat next week are still TBD and I expect the long range models to reflect that uncertainty by jumping around a bit over the next 48-72 hours.

So will there be chasing next week or not? Stay tuned!

#vawx So you’re saying there’s a chance?


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Yes, it’s still a week away but last night’s (0Z) GFS run is showing a strong cold front passage next Tuesday (10/18) accompanied by a decently vigorous upper level trough. I’ve been watching next week’s trends for a while now and the idea of a potential chase has been floating around for several days.

Per the GFS surface dew points increase to the mid-60s on Tuesday across Virginia. CAPE (instability) doesn’t look all that great but shear is robust. Thus this would be a typical HSLC (high shear/low CAPE) setup likely featuring low-topped storms with the potential for rotation. Whether or not the cells would be discrete or along a squall line depends on the shear orientation wrt the front.

Here’s the 0-3 km energy helicity index (left) and supercell composite parameter (right) maps at 21Z next Tuesday:

I’m not totally sold on this setup yet but it is encouraging. I could deal with another chase this fall before the convective season shuts down completely.

#vawx So did a tornado occur in Franklin county VA on Thursday Sept 29th?


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The second supercell I chased on Thursday Sept 29th cycled a number of times while I observed it. Each cycle included a hook echo on radar reflectivity plus indicated rotation on velocity scans. Here’s the earliest velocity image I saved just before the associated wall cloud passed over Martinsville:img_5792

Exactly an hour later I had moved north and then west to a position ~ 3 miles west of Museville where I was at the entrance to the inflow notch while saving this image:img_5804

Less than a mile south of me I watched a funnel spin up briefly before it and its wall cloud dissipated.

Continuing north to Penhook along Snow Creek Rd I turned west to Union Hall along Rte 40 just behind the storm. I didn’t save velocity images from this location but this video frame grab (pulled from my live streaming camera files and enhanced) was from roughly 7:13 pm:multivortex-funnel-n-of-union-hall_edited

What can be seen on the video is a multi-vortex funnel spinning around behind the building in the foreground. At this juncture the feature was perhaps a mile north of me. This feature repeated several times over the next few minutes as the wall cloud moved right to left in the frame. After carefully reviewing my live stream files I’m 90% convinced the circulation was on the ground at least once…i.e. a tornado occurred.

I’ve already sent the above info and the video files to NWS Blacksburg for their purview. I’m not completely positive this cell was still severe-warned at the time. I know for sure it wasn’t tornado warned.

I’m not quite ready to claim a tornado happened but if it didn’t it came mighty close to doing so this past Thursday. Either way it was an eventful chase!


#vawx Supercells? Hook echoes? In Virginia? On September 29th?


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With basically the same synoptic setup on Thursday Sept 29th as the prior day’s I knew I needed to get my body out chasing. I wasn’t at all disappointed.

I motored down the driveway shortly after 1 pm and headed south on U.S. Route 220 toward Martinsville. The shear and instability both looked robust in North Carolina and edging into southern Virginia so I targeted the U.S. Route 58 corridor. Heading west out of Martinsville on Rte 58 I pushed all the way to Stuart in a vain attempt to see over trees and ridge lines.

Finally falling back to a known vantage point southeast of Patrick Springs I turned off Rte 58 and pulled onto the edge of a west-facing field. This radar representation had me panting for a closer view:

Yes, folks, that is the radar hook echo that teased me to no end since I had no closer view that this:first-wall-cloud

I sat at this location live streaming for quite a while, maintaining a – distant – visual on the storm. The closest point of approach was roughly 6 miles.another-look-at-wall-cloud-1

Following an extended 4 pm news break on the local TV station I hurriedly departed in an attempt to regain position on this cell. Alas, it was steaming northward into mountainous terrain with few roads and even fewer vantage points. That was okay tho’ as I had my eye on another discrete supercell barging northward on a track somewhat east of the first one.

I spent some time roaming about the region southwest of Martinsville trying to find another decent viewing spot and failed. Thus I retreated to another known point by driving east on Rte 58 and then north on a rural road at Axton. Abundant farm and pasture lands there afforded a couple of spots from which to observe storm #2 pass directly over Martinsville.

This backlit photo shows a large wall cloud southwest of me:storm-2-from-axton

Amazingly this second supercell also exhibited a hook echo:

The storm continued to cycle and headed almost due north so I jumped back into the chasemobile to keep up with it. Traveling along VA Route 57 to Callands and then via Sago Road I wound up positioned in the inflow notch rather close to the hook:

In fact this was a bit TOO close for comfort when I watched this funnel spin up under the wall cloud about a half mile south of me:funnel-w-of-museville

I was pretty sure at the time it was a funnel and I’ve verified it via dashcam video. I was prepared to swap directions and skedaddle out of there but the funnel and wall cloud weakened. Still, I didn’t stick around this location long!

Noting the cell’s steady northward trajectory I rolled in that direction along Snow Creek Rd to Penhook along VA Route 40. The hook echo was tracking a couple of miles west of town so I stopped and tried to photo/video but didn’t have a clear sightline. Also I noted that a THIRD supercell was steaming northward to the west of storm #2 so to avoid getting cut off I barely skirted the southern edge of storm #2 and pushed west to Union Hall.

Here I pulled off into a commercial parking lot and began videoing/filming again. Unfortunately it was now past sunset and daylight was fading quickly. Even so the action roughly a mile to my north underneath the rear of storm #2 riveted my attention:funnel-n-of-union-hall

This was a definite funnel (again per video examination) and as I continued watching it spun up at least 3 separate times. The circulation may have reached the ground (i.e. a tornado may have occurred) but I couldn’t verify that given the tree line and the failing light. Doing my civic duty I called in a report to NWS Blacksburg.

When this activity moved away and out of sight I moseyed across the parking lot and snapped a grainy nocturnal photo of the wall cloud underneath storm #3 that was approaching Rocky Mount:


And that was the end of a very fruitful day. I’ll have to say that Sept 28th and 29th of this year will go down as my best non-tropically induced autumn chases in Virginia.

#vawx A long but satisfying September 28th chase


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I didn’t really expect a late September chase especially since typically those involve tropical remnants and none were to be had. I had just gotten back from a week-long vacation in the western U.S. and was fairly worn out from that. But with a stationary front hanging around plus an upper level low perched west of the Appalachians the shear and instability proved too much for me to resist.

I initially headed east on U.S. Route 460 to the Appomattox area where it looked like storms would fire early before more convection bubbled up in the late afternoon. I wound up chasing weak cells north to the U.S. Route 60 corridor before realizing that I had pushed north of the stationary front. (Northerly low level winds and smooth cloud features gave it away.)

By this time a severe-warned storm had bubbled up near Danville VA (earlier than expected). This cell was moving northeast so I doubled back south to 460, jogging east to Pamplin City where I dropped further south. At Charlotte CH it appeared that I couldn’t make a good intercept by pushing west to U.S. Route 501. Thus I continued south and then east along rural routes. Winding up on U.S. Route 360 I jogged east to Wylliesburg and then south on U.S. Route 15.

Via Rte 15 I finally made it south to the U.S. Route 58 corridor at Clarksville where I turned west to find a good vantage point. A line of several discrete cells – most of them severe warned – was steaming northeastward and I finally found a spot a few miles west of Clarksville from which to observe the northernmost cell.

Here I switched on the live stream feed and happily snapped photos, all the while keeping an eye on storm motions and hail cores to make sure I wouldn’t get pounded:

Meanwhile this was the wall cloud I observed:clarksville-wallcloud_1

A bit later:clarksville-wallcoud_2_cg

As this storm moved (barely) north of me across the Kerr Reservoir a clear RFD slot formed behind it.Wallcloud with RFD clear slot.jpg

I somewhat nervously watched a small rapidly rotating section of cloud as it passed by nearly overhead but saw nothing that caused me to move. (I did, however, release the emergency brake in preparation for a quick getaway.)

After this feature cleared to the north I pointed my attention – and the chasemobile – south to storm #2 on the line.storm-2

The hail core on this next cell was rolling directly toward me so after a few minutes I pulled up stakes and motored a couple miles southeast to another vantage point. Here I watched as the wall cloud and another RFD slot approached.wallcloud-rfd-slot-on-storm-2

Realizing that this feature was passing by to the south I checked radar and noticed a crease between storms #1 and #2 that promised rain with only possible small hail. So instead of continuing further east ahead of the line I doggedly headed into the crease, encountering heavy rain and “only” half-inch hail which I tweeted out to NWS Blacksburg.

Emerging into drier conditions west of the action I decided to drop south behind storm #2 to check out storm #3. A bit north of the metropolis of Virgilina I paused to snap this photo between the two updrafts:between-the-updrafts

I never did find a decent vantage point even after pushing across the state line into North Carolina. I thus reversed course back north and then rolled west to U.S. Route 501 where I turned north again toward South Boston. I refueled there and continued west along Route 58 to and thru Danville.

By now it was after sunset but there were more storms erupting across the Piedmont of North Carolina. I stopped west of Danville to watch some nocturnal lightning before pushing on toward home. (Haven’t had time to review any videos yet.)

By virtue of my southern trajectory I missed the solitary tornado-warned supercell that crossed thru the Lynchburg and Appomattox area (where I had been several hours earlier). That storm went up west of the Blue Ridge and wrapped up tight when it encountered the shear zone along the stationary front. Can’t catch every storm!

So after a chase of better than 300 miles and 9 hours on the road was it worth it? Yep! But I was one tired puppy when I got home.