Today the participant phase of the ESSL Testbed 2017 comes to an end. The upcoming months will be dominated by the reporting phase. And soon we will start to prepare the 2018 edition. Dates are already fixed: 11 June to 13 July 2018.

We thank all partners and participants of the ESSL Testbed 2017. Weather was quite interesting this year. And we are very much looking forward to continued and new collaborations for the coming years.

Here two product examples of this year:

Image: EUMETSAT NWCSAF RDT product overlay of yesterday 18 UTC with highlighted cell near Paris (mouse-over cell properties).

Image: DWD COSMO-DE EPS updraft helicity tracks for today 16 UTC: some regions show high signals.

A rare mid-summer cut-off low over the Iberian Peninsula makes it interesting to forecast for Spain (Southwest Domain at the ESSL Testbed) with participants discussing NWC SAF products …

… and NWP outputs in the other room for the day 2 forecast:

Also over the eastern Alps substantial shear can lead to some well-organized storms near the Testbed site. A mobile nowcast team would form during the afternoon, if storms would initiate close enough.

Today’s forecasting teams at the ESSL Testbed discussed several areas with a marginal risk for severe weather for today (France, Italy and Poland/Belarus) and tomorrow (Spain), mainly for the risk of marginally large hail:

This week’s US participant is Darrel Kingfield from NOAA. See what his impressions of the ESSL Testbed were during his previous stay in the year 2014 in an NSSL news article.

NOAA Hazardous Weather Testbed Forecast Program Operations Coordinator Adam Clark presented their state of affairs at the ESSL Testbed on Thursday:

ICON EPS shows elevated probabilities for excessive rainfall over parts of eastern/northeastern Germany in a 12 hour timeframe from 06 to 18 UTC today (see image). Already yesterday’s ICON EPS highlighted this area for a heavy rain threat. The maximum of the ENS members today even show 12 h accumulations of more than 120 mm in two small areas, which is extreme:

Partly based on this the day 1 forecasting team highlighted the area for a risk of heavy rainfall, while the large level 2 area over eastern Europe is mainly for severe thunderstorms with large to very large hail, severe gusts and maybe a few tornadoes:

The NWCSAF product “Rapid Developing Thunderstorms – RDT” demonstrates that it indeed is good in highlighting properties of relatively young but rapidly intensifying storms (see red bordered areas in northern half of screenshot).

Based on their nature it is much more difficult to tackle large mesoscale convective complexes, as can be seen in the southern half of the screenshot. There the detection of the most active area of MCSs or MCCs is challenging.

Today’s day 1 group even went for a small level 3 for southern France:

NWC SAF TPW (total precipitable water) product showing around 40 mm in some places of southern France and northern Italy, to be compared with 12 UTC soundings …

The NWC SAF total precipitable water products showed around 40 mm just east of forming storms over NW Italy this afternoon:

Participants from Spain, Portugal, Latvia, Germany, the Netherlands, Slovakia, Italy, Croatia and Austria started their forecast and testing discussions today:

Matt Parker from North Carolina State University in Raleigh today presented the outlook for day 2 and the following days at today’s 9 UTC severe weather briefing:

There is an elevated risk for severe weather outbrakes in Central Europe next week. See ECMWF IFS forecast for Wednesday as an example with high CAPE high shear present in many places: