All things considered, the chance of documenting anything severe was near 0% due to the lack of overall shear, but having been 'proper' storm starved for months, the risk of widespread convection was too good to pass up. For days before, the GFS had been consistent in hinting at a chance of widespread deep convection with upper troughing behind a cold front, along with good spring diurnal heating leading to CAPE values in the region of 800 J/Kg, and LIs of -3 by late afternoon. Moisture would be marginal but sufficient for at least elevated convection.
I met with storm chase partner and designated driver for the chase, Jack, at about 1330BST. Before heading out to chase, we stopped at the local computer store in order to purchase the mobile broadband modem for this season.
Broadband in the bag, we headed toward our target area just to the southwest of the town of Wisbech, in the Fenlands of East Anglia. I chose this area in the hope instability would be maximised by giving the sun a chance to heat the land by the time the moisture arrived at our location. Also, with GFS forecasting some convergence in the region, we hoped (for a very small chance!) that a late afternoon sea-breeze would allow for the development of some misocyclones in the region and hence the small possibility of seeing a convergence zone funnel. For one reason or another, our mobile broadband failed to work, which would mean conducting this chase visually with no reference to radar/satellite and latest GFS data - makes life more difficult!
We stopped briefly to fuel up the car and ourselves, and by the time we reached our target area convection was beginning to initiate as expected. Parked on a narrow, quiet Fen lane, we could see for miles due to the flat nature of the Fens. After seeing some cumulus building quickly to our west-south-west, we decided that the most promising looking cell in the area would pass a few miles to our north, and so we went to reposition. Unfortunately, our road was closed due to a serious car accident - we stumbled across a scene of chaos with Police, Fire and Air Ambulance on scene - our thoughts go out to those involved in the accident, and wish all a speedy recovery.
The accident had delayed us somewhat, and with nothing visually vigorous to our southwest we decided to call it a day. We could see maturing cells both to our north and south, but time restraints meant we could not travel so far to intercept these cells. We did however get close enough to some of the cells to appreciate the structure.
With this chase being based on a marginal set-up, all things considered it was a semi-success. We did get to see some storm structure, and though not documenting anything of note, it was a good practice run for the set-ups we hope to see throughout this year! The broadband will be working for the next one!
Some pictures from this chase can be seen here: http://picasaweb.google.com/107852667503069707766/April25th2010StormChase#
No real hints at any chasable days for the forseeable future, so, until next time!
Sean
