Extended Forecast
Valid: Sun 02 Jun 2019 06:00 to Mon 03 Jun 2019 06:00 UTC
Issued: Fri 31 May 2019 15:52
Forecaster: TUSCHY

A level 1 was issued across parts of Bulgaria and Romania mainly for isolated large hail and locally excessive rain.

A level 1 was issued for parts of N-Turkey mainly for large hail and severe wind gusts.


SYNOPSIS

Blocking pattern persists over S-Europe. One subtle change is the gradual filling process of the cyclonic vortex atop the S-Adriatic/N-Ionian Sea. Another change is the approach of a mobile upper trough over NW Europe with rising heights over the North Sea and S-Norway/Sweden.

A vigorous depression enters the European forecast sector from the NW with a strong vortex being placed over N-Irleand and W-Scotland. This vortex stretches an extensive warm sector over W-CNTRL Europe, which features only modest BL moisture with no real connection to any substantial moisture source.

DISCUSSION

... SE Europe ...

Along the periphery of the upper low, an extensive area with 400-800 J/kg MLCAPE (regionally up to 1000 J/kg) is forecast. DLS in the 10-15 m/s range will support only transitional stronger updrafts with isolated hail, probably approaching the severe criterion on a sporadic/temporal scale. Slow-moving thunderstorms grow upscale and produce locally heavy rain.

A level 1 was added for parts of Bulgaria and Romania, where robust BL moisture resides along the NE fringe of the vortex with some curvature in forecast hodogaphs (also seen in enhanced SRH-3 forecasts). A few multicells with large hail and locally excessive rain are possible.

Further west, rapid clustering brings heavy rain on a broader scale to S-Romania into far N-Bulgaria, but QPF amounts remain below any level threshold.

... N-France and Benelux ...

Confluent low/mid-level flow regime in the broad warm sector beneath lowering geopotential heights result in capped elevated CAPE (several hundreds J/kg). CI of GFS seems not plausible with unrealistic BL moisture anomaly forecast. Hence prefrontal convergence zone ahead of the cold front in the warm sector/embedded in a surface trough should stay inactive throughout the day. We monitor this area in case of better LL moisture input than currently forecast and hence for spotty CI.

Isolated to scattered elevated thunderstorms erupt along the eastward propagating cold front during the night but nothing severe is forecast with this activity. An extensive low probability lightning area was issued due to ongoing timing discrepancies of the cold front within the model suite.

... N-Turkey ...

Mountainous convection erupts during the day in an environment with 15 m/s DLS and 1000-2000 J/kg MLCAPE. A few thunderstorms develop in a diffluent upper flow regime and bring isolated large hail. Deeply mixed sub-cloud layer and inverted-V profiles with lots of DCAPE indicate a chance for a few severe downburst events.