Mesoscale Discussion
Valid: Fri 19 Jun 2026 10:00 to Fri 19 Jun 2026 13:00 UTC
Issued: Fri 19 Jun 2026 10:27
Forecaster: TUSCHY

This Mesoscale Dicussion was issued to update the expected severe risk for NE France into Belgium/the Netherlands.

This MD was issued to expand the level 2 area a bit more to the SW.

Latest surface data indicates a broad swath with 2m dewpoints up to 20 C and with near unimpeted diabatic heating ongoing beneath steep mid-level lapse rates. This pushes MUCAPE during the late afternoon into the 2500 J/kg range with CAMs now pointing to regional peaks in the 3500-4000 J/kg range. These anomalous peaks are well covered in strong EFI MUCAPE anomalies of IFS-ENS.

CI is still forecast within a corridor, where a northward surging dryline intersects an inland moving sea breeze circulation. CI however shifted a bit more to the SW. Thereafter, the approaching wave from the S adds more synoptic-scale lift to that event.

Shear over far NE France and especially along the fronts is adequate for a mix of multicells and supercells with very large hail, damaging gusts and excessive rain.
An impressive setup exists for an upscale growth into a progressive and cold pool driven MCS event with DCAPE exceeding 1000 J/kg admits a deep/well mixed BL. Some models point to a temperature spread of more than 20K between the cold pool and the airmass downstream, which indicates an augmented risk for one or more damaging rear inflow jet events unfolding. Swaths of severe to extreme gusts spread rapidly into W/CNTRL Belgium (including f.ex. Brussels) and a combined large hail/gust threat could increase the potential damage risk. Heavy rain will be another issue, especially for colliding cells.

This growing MCS then pushes rapidly NE along the main CAPE axis into the Netherlands, before a slow weakening trend begins due to increasing CIN. Nevertheless, this probably turns into an high-impact event also for most of the Netherlands mainly due to swaths of damging gusts in addition to large hail and heavy rain.

It remains a bit unclear, how far E the MCS will track but LPI signals in ID2-EPS data still support the idea of scattered CI over North Rhine-Westphalia (Germany), which sends an outflow W. If this outflow approaches the MD area faster than currently forecast, this could even induce a temporal weakening trend of the severe MCS. However this probability is not yet seen in latest NWP guidance. On the other hand, failing CI in W-CNTRL Germany could push strong to severe outflow gusts of the severe MCS deeper into W-CNTRL/NW Germany.