Skywarn Austria Forum

As the frontal boundary stalls over the range, diurnal heating of moist airmass will yield 1000 to 2000 J/kg of MLCAPE along the southern slopes of the Alps by the afternoon hours. Storms will be initiated by an upslope flow forced by the heating of the slopes. Well organised storms, including supercells are forecast given the combination of weak southeasterly surface flow with 15 to 20 m/s of westerly flow near 500 hPa. Large to very large hail, as well as isolated severe wind gusts and excessive rainfall may accompany these storms. A level 2 is introduced in the corridor, where convection allowing models simulate the highest likelihood of supercell tracks.

cobra39 hat geschrieben: ↑

Mittwoch 29. Juli 2020, 12:08

Schwergewitterstufe 1 für Wien heute?, Wr. Neustadt sogar 3, Steir. Bergland wiederum 2, stimmt das?
Denke in Wien gibt's heute gar keine Gewitter mehr.

*** Severe weather threat is expected to increase over the course of next few hours over southern Austria, Slovenia and northeastern Italy ***

In the past hour, convective initiation has been ongoing over the main Alpine range. To the south, surface observations reveal presence of very moist airmass with dewpoints ranging from 17 to 20 deg C and southeasterly to easterly flow. 12 UTC Rivolto sounding shows 2000 J/kg of MLCAPE with 15 m/s of 500 hPa flow aloft. Combined with around 5 m/s easterly to southeasterly flow, 0-6 km bulk shear values are likely around 20 m/s over the highlighted area. Recent development increases confidence in a scenario with southward propagating supercells spreading from southern Austria towards Slovenia and perhaps northeastern Italy. This scenario is also still simulated by the convection allowing models. Large to very large hail, severe wind gusts and excessive precipitation will all be possible with these storms.