Storm Forecast
Valid: Sat 01 Jun 2024 06:00 to Sun 02 Jun 2024 06:00 UTC
Issued: Fri 31 May 2024 22:39
Forecaster: PUCIK
A level 2 was issued across NE Germany and W Poland mainly for heavy rainfall.
A level 1 was issued across Germany and N Poland mainly for heavy rainfall and to the lesser degree for large hail.
A level 2 was issued across NE Hungary, SE Slovakia, NW Romania and SW Ukraine mainly for large hail, severe wind gusts and heavy rainfall.
A level 1 was issued across Estonia, Latvia, Lithuania, W Russia and Belarus mainly for large hail, severe wind gusts and heavy rainfall.
A level 1 was issued across N Finland and NW Russia mainly for severe wind gusts and large hail.
A level 1 was issued across S Sweden mainly for heavy rainfall.
A level 1 was issued across Algeria mainly for severe wind gusts.
A level 1 was issued across Bulgaria mainly for severe wind gusts and large hail.
A level 1 was issued across Georgia, S Russia mainly for heavy rainfall and large hail.
A level 2 was issued across E Georgia, parts of Armenia and Azerbaijan mainly for (very) large hail and severe wind gusts.
DISCUSSION
... E Spain ...
Compared to the previous day, refrained from Lvl 1. Already on Friday, storms struggled to fully initiate and models forecast drier air in the low to mid troposphere on Saturday. Still, a few storms that possibly form need to be monitored as strong shear will be present.
... Algeria ...
Isolated high-based storms are forecast to develop in the afternoon hours. With 0-6 km bulk shear up to 15 m/s, storms can be quite long-lived and organised. Primary threat will be severe wind gusts with pronounced Inverted-V profiles as boundary layer will be 2.5 - 3.5 km deep.
... NE Germany to W Poland ...
Models simulate a convergence zone across the Lvl 2 area with rapid and widespread storm development along it in the late morning to early afternoon hours. Forecast profiles reveal low LCLs, almost saturated low to mid-troposphere and abundant CAPE in the warm part of the cloud. Thus, storms will be efficient heavy rain producers. Furthermore, storm motion will be parallel to the convergence zone, yielding high likelihood of cell training situation. Lvl 2 is issued for widespread excessive rainfall events (of convective origin) in the area.
... Germany, central and N Poland ...
Slow moving storms will be capable of locally very heavy rainfall. Across S-Central Germany, even rather shallow convection can greatly enhance the rainrates in the stratiform rain shield. The areas of embedded convection need to be monitored to nowcast the bands with the heaviest rainfall. CAPE will increase towards the north. More isolated storms forming in higher CAPE environment across N Germany may also be capable of large hail.
... Hungary, Slovakia, Romania, W/NW Ukraine, SE Poland ...
Stronger mid-tropospheric flow is forecast over this area, yielding 0-6 km bulk shear values around 20 m/s and increasing potential for well-organised storms, including supercells. Storms will be initiated by orography or ill defined frontal boundary. Limiting factor will be dry intrusion spreading at mid-troposphere across the area. There is disagreement in the models concerning how quickly this happens. For example, ECMWF shows the dry intrusion overspreading the area fast and combined with rather skinny CAPE values, this can seriously limit the updraft strength of the storms. Decided to highlight the corridor of highest severe weather risk (NE Hungary, SE Slovakia, NW Romania, SW Ukraine) with a rather low-end Lvl 2. Here, the 0-3 km shear will approach 20 m/s. Combination of supercells and linear segments can be expected, bearing risks of large hail and severe wind gusts.
... Baltics, Belarus, W Russia...
The same situation as in the previous days remains. Multicells capable of localised heavy rainfall, large hail or isolated downbursts are forecast in the environment of 0-6 km bulk shear of up to 15 m/s and MLCAPE values up to 1.5 kJ/kg.
... S Sweden ...
Slow moving storms capable of heavy rainfall are expected in the environment of low LCLs and high RH in the low to mid troposphere.
... N Finland to NW Russia ...
Stronger flow is forecast in this area compared to further south. With 0-6 km bulk shear around 15 m/s, well organised storms are possible, capable of large hail and severe wind gusts.
... Bulgaria ...
A couple of storms may form during the afternoon hours owing to the orographic lift. While models produce only weak CI signals, it's not completely ruled out that a storm forms that survives the relatively dry environment and will use 15 -20 m/s of 0-6 km bulk shear. In case that happens, expect well organised storm capable of large hail and severe wind gusts (high LCLs, Inverted-V profile).
... Caucasus ...
Severe weather situation will continue over the area. Over the western part, heavy rainfall will be the primary threat with moist environment and skinny CAPE profiles. Further E/SE, likelihood of (very) large hail and severe wind gusts will increase with increasing CAPE and increasing shear. Here, Lvl 2 is issued for the combined threat of both.
