After a chase in southern Kansas yesterday that included being on the storm that produced the Wichita tornado (we had pulled off that very cell prior to that because it was getting too close to the congested metropolitan area) the Hokie Stormchasers targeted southern Oklahoma today.  We pushed to the Paul’s Valley area south of Oklahoma City (OKC) where conditions looked ripe for strong and severe storms and were rewarded when convection began early.  We were on our first storm of the day by 2 p.m. (CDT) southwest of the OKC metroplex and noted that a cell north of “our” storm that didn’t look too promising.  That particular cell rapidly intensified and produced the tornado that created the frightening devastation and tragic deaths in the OKC area.

We didn’t pay much attention to the news at the time since we were busily engaged in maneuvering into position on our second storm of the day further south (our initial cell had fizzled).  We caught a great looking wall cloud just outside Purcell OK that was misidentified by a spotter as a tornado:

After we ran out of decent roads that would allow us to keep up with this cell we pulled off and headed south to meet the next storm south of this one while the students caught up with the news on the OKC metroplex tornado and the damage it had caused.

In the small crossroads town of Dickson, Okla., we had to turn east and run for it as a large hail core with indicated hail over 2 inches in diameter was bearing down on us.  As we pushed east through the town of Kingston we suddenly spotted through a break in the treeline a full-fledged funnel under a section of the storm several miles north of us.  Quickly pulling off the road we attempted to get a better look but failed so we pushed farther eastward past Madill, OKla.  As we rolled down the road a circulation developed literally almost overhead and dropped a funnel about 200 yards to our left.  As far as we know it never touched down to officially form a tornado but it was a bit nerve-wracking to have it be that close.  Another funnel spun down a couple of minutes later but that was a bit farther from the road…perhaps a quarter mile or so.

We finally pulled over in Boswell to duck under a gas station overhang as the hail core gained on us.  Along with several other vehicles including law enforcement cruisers we sat and waited for the wildness to pass.  With the worst of the storm now east of us we continued east and then south into Texas to wind up here in Paris.

Now out of the vehicles and in the hotel room it is proving difficult to wind down from the intensity and duration of today’s chase.  With the added emotional burden of hearing even more tragic news from the Oklahoma City storm it will be quite a while before I can relax enough to catch up on some desperately needed sleep prior to hitting the road tomorrow for another chase day.  Yes, the tornadoes in Wichita yesterday and OKC today would have happened regardless of whether we were there or not, but it is proving hard to rejoice about seeing some “good” storms today with the headlines being what they are.  Mixed feelings pretty much sums things up right now.

The remainder of the coming week will feel like summer with highs in the upper 80′s and another round of thunderstorms possible Thursday.

Meanwhile out here in the Plains the Hokie Stormchasers intercepted a tornadic supercell at close range yesterday (Saturday) near Hays Kansas.  We were on an east/west road near an intersection with two other roads so we had plenty of escape options had we needed them but we didn’t.   The storm unfolded its business end right in front of us with a developing wall cloud and obvious rear flank downdraft.

After the rain got too close we moved eastward and northward to continue chasing it but the storm accelerated and we couldn’t keep up with it.  As we traveled northward behind the storm observing the structure I noticed a funnel forming and captured it via my dashboard video.  Here’s a frame grab from that video with the funnel circled in white:

Enjoy your Sunday!

We are currently in North Platte Nebraska in position for an even bigger outbreak of severe storms tomorrow.  The Storm Prediction Center has issued a Moderate Risk for severe weather tomorrow with a significant chance of tornadoes. 

Being the weekend we expect to see chasers galore but hope that enough storms will fire to spread out the inevitable convergence.  There is another probable center of activity in southern Kansas that may help with that spreading out process.  We’ll know more about that tomorrow…

More later!!

Now we need to go jump in the vans and scoot west along I-40 to get there in time.  Follow us at the Hokie Storm Chasers blog site.

More tomorrow!

Today’s high temperature will only climb into the low 60s, which is 10-15 degrees below normal for mid-May.  After another subnormal high in the upper 60s Tuesday a warmup will commence, bringing the 80s back for the remainder of the week.  There might be some afternoon thunderstorm activity mixed in beginning Thursday so make sure you add that into your plans for this week.

This blog will shift emphasis for the next few weeks as I will be heading out to the Great Plains tomorrow morning with the Hokie Storm Chase team as a driver and co-leader.  We’ll be traveling in three six-passenger vans on two separate trips with a total of over two dozen meteorology students (it is an undergraduate field course for credit).  My head will be into weather – and storm chasing potential – out that way and I’ll have little time to pay attention to weather in the ‘Burg.  I will attempt occasional broad overviews of the weather here but most of my blog posts over the next few weeks will involve my summary of our journey and storm encounters as we travel around the Plains states.

If you’d like to follow the Hokie Storm Chasers you can via their blog or via the Twitter feed (@hokiestorm).  The blog provides a “Current Location” tab which you should be able to click on and follow our location along with a continuously updated dashboard camera photo (sorry, it won’t be live streaming video).  So along those lines here is a photo from last year in central Oklahoma with one of our three vehicles carrying a mobile mesonet on top for gathering weather data around storms:

Oh, yeah…later that evening we photographed a tornado south of this location.  I would have posted that photo but it was after dark and the image quality was not very good.

Stay tuned for updates on the road!

The dryness of the air will play a part in just how cool it gets overnight into Monday morning, since the dryer the air is the more it allows temperatures to plummet.  The current NWS Sterling thinking is that there will be enough breeze around tonight to mix the air and prevent a widespread May frost.  Their official forecast low temperature for the next two mornings is in the upper 30′s for the Fredericksburg area which would be too warm for frost.  HOWEVER…if you live in an area that is sheltered from the wind and is typically susceptible to frost I would suggest protecting any sensitive plants the next couple of nights just in case.

After a cool start to the week with highs Monday only climbing into the low 60′s (10-12 degrees below normal) the latter part of the week will feel more like May.  In fact the Climate Prediction Center’s six to ten day forecast map shows most of the nation with good chances of being warmer than normal as shown here:

I should also note that this blog will be sporadic in its coverage of the Fredericksburg area weather over the next few weeks.  More on that in Monday’s blogpost.

Happy Mother’s Day!!

With a cold front approaching the East Coast the southerly winds coupled with – finally!! – sunshine will push temperatures into the upper 80s this afternoon.  The only fly in today’s ointment is the potential for some thunderstorms later this afternoon – likely after 5 p.m. – due to a “lee trough” that will form as shown in this forecast graphic:

A lee trough, indicated by the blue line I added, is  a pressure drop that occurs east of a mountain range that can act as a trigger for showers and thunderstorms.  More extreme examples of this happen east of the Rocky Mountains but we have our own smaller version here over the Piedmont east of the Appalachians.

As a result of this feature plus the approaching cold front that will cross our region Saturday afternoon the Storm Prediction Center has placed Fredericksburg and vicinity under a 5% risk of severe thunderstorms both days.  That could translate to a few stronger storms that may bring strong winds and perhaps some hail to the region.

Saturday will feature more clouds and showers than today with the National Weather Service office in Sterling bumping the precipitation probabilities up to 70%.  The clouds and rain tomorrow will keep

Fredericksburg’s high temperature in the upper 70s, about ten degrees cooler than today.  It may be wise to keep an umbrella and rain gear handy for any of tomorrow’s outside activities, including the UMW graduation festivities.  Then, following the cold frontal passage, Sunday’s weather should provide a nice comfortable Mother’s Day with bright sunshine and highs near 70, another ten degree drop.

A quick peek at early next week reveals another couple of days with unusually cool weather under the influence of another Canadian air mass.   The NWS Sterling low temperature forecast for Monday morning is 48 degrees but I wouldn’t be surprised if a few spots around the Fredericksburg area bottomed out in the upper 30s given the dry air mass with little or no wind.  Highs both Monday and Tuesday will likely be in the upper 60s, which is several degrees cooler than normal for this point in May.

Have a great weekend!

The overall result of this snail-paced movement plus the approach of another cold front over the weekend means that each day from now through Monday has at least a chance of showers in the forecast.  The silver lining is that several of those days – including today – will feature some sunshine as well but I wouldn’t put the umbrellas and ponchos back in the closet just yet.

There has been a lot of rain over a wide swath of the Piedmont recently.  There are numerous reports of more than 4 inches of rain between Fredericksburg and the Blue Ridge mountains, including a 4.97-inch report from Spotsylvania county.  All that water has to drain off somewhere, which is why the region continues under a flood watch through this evening.  Although the Rappahannock is forecast to crest below flood stage the creeks and streams upriver could easily overflow their banks given a heavy shower or thunderstorm that dumps a lot of rain in a short period of time.  Keep an ear to the weather radio for any flood warnings that could be issued, even if it isn’t raining in your immediate vicinity.

While today’s high temperatures will top out in the upper 60s, they will climb into the 70s tomorrow through Sunday, even breaching the 80 degree mark – briefly – on Friday.  Following a cold frontal passage over the weekend temperatures will drop once again due to a cold Canadian air invasion with highs topping out in the mid to upper 60s early next week before a warmup commences.  The Spring of 2013 continues to look more like a real spring instead of a quick jump from winter to summer!

The high pressure center parked off the New England coast for the past week or so is still there but is finally showing signs of oozing farther eastward into the Atlantic.  It is being replaced by an equally snail-paced upper-level low pressure center cut off from the jet stream flow, which normally pushes such features along. (I was going to post a surface map showing today’s features but this next system looks so messy and complicated I decided not to.)

The low center has already pushed clouds northward over Fredericksburg and will follow that up with scattered showers during the day today and a steadier rainfall tonight.  This rain event will last through at least Wednesday, dumping a fair amount of liquid on Fredericksburg and vicinity.  

Here’s the potential three-day total rainfall map from the Weather Prediction Center:The medium purple shade that bisects Fredericksburg represents a three-day total of at least 1.75 inches of rain.  Given recent dry conditions plus the extended period over which this rainfall will occur the NWS Sterling office has elected not to post any flood watches in our area.  

Southwestern Virginia, however, is mostly covered in flood watches as that area is closer to the low-pressure center crossing the Carolinas and will receive appreciably more rainfall (as shown above).

As a result of the clouds and rain our high temperatures will be held down below normal levels again, which for the first week in May should reach the low 70s (F). 

Today and tomorrow the ‘Burg will struggle to reach the mid-60s with a noticeable easterly breeze helping to make those windbreakers and rain jackets feel good.  For those wanting to see more normal May temperatures the end of this week should provide some relief when temperatures climb back into the upper 70s by Thursday.