Storm Forecast
Valid: Sun 09 Jun 2024 06:00 to Mon 10 Jun 2024 06:00 UTC
Issued: Sat 08 Jun 2024 23:14
Forecaster: PUCIK
A level 3 was issued was issued across N Italy mainly for very large hail, severe wind gusts and to the lesser degree for tornadoes.
A level 3 was issued across E Austria and W Hungary mainly for (very) large hail, damaging wind gusts and tornadoes.
A level 2 was issued in a belt from N Italy to Hungary mainly for (very) large hail, severe wind gusts and heavy rainfall.
A level 2 was issued for extreme SE Turkey and NW Iran mainly for (very) large hail and damaging wind gusts.
A level 1 was issued for Spain and France mainly for heavy rainfall.
A level 1 was issued in a belt from Switzerland and N Italy to Romania and Ukraine mainly for large hail, severe wind gusts and heavy rainfall.
A level 1 was issued across S Sweden, S Finland, Estonia mainly for marginally severe wind gusts and tornadoes.
A level 1 was issued across Turkey and Caucasus region mainly for heavy rainfall and large hail.
DISCUSSION
... Spain ...
Moist profiles with substantial warm cloud depths are forecast, yielding an uncharacteristic situation over the interior Spain with a predominant heavy rainfall risk. The highest risk of heavy rainfall (and also of marginally large hail) is anticipated over Catalonia, where numerous waves of storms will be possible and strongest shear is forecast.
... SE France ...
Widespread storms are forecast to develop by the afternoon hours. In the early morning hours, stronger shear will still be present over the domain, with a potential for some well-organised storms, especially close to the Alps. With time, as a core of the trough passes over the area, shear will substantially decrease, yielding slowly moving storms with heavy rainfall threat.
... Austria through extreme SW Slovakia, N/NE Slovenia to Hungary...
An outbreak of severe thunderstorms is forecast. High-resolution models are in agreement concerning a wave of supercells with high updraft helicity that will initiate in the early afternoon hours across the Alps and move towards Hungary. An upscale growth into short linear segments (bow-echoes) will also be possible. MLCAPE ranging from 1k to 2k J/kg is simulated, combined with curved hodographs, 0-6 km bulk shear around 25 and 0-3 km bulk shear around 20 m/s. Any stronger storm will be capable of (very) large hail and damaging wind gusts in such environment. Furthermore, across E and SE Austria, low-level shear will increase as well with 0-1 km bulk shear up to 15 m/s and 0-500m SRH up to 100 m2/s2. In case a supercell tracks through such environment, strong tornado will be possible. Storms will spread through Hungary during the evening hours, maintaining high intensity in strongly sheared environment.
... N Italy to W Slovenia and SW Austria ...
Another area with a potential for severe weather outbreak. Compared to the Austrian Lvl 3, a bit less shear, but more CAPE is forecast. Towards the afternoon hours, models predict 2 to 3.5 kJ/kg of MLCAPE in the wake of the Appenines along with a number of low-level convergence zones. As a synoptic-scale lift overspreads the area on the forward flank of the trough, profiles will get sufficiently moist to make for an easy initiation. High CAPE will combine with about 20 m/s of 0-6 km shear, much of it in the 1-3 km zone. Destructive hail will be likely with any sustained supercell that develops given fat and deep CAPE profile above the altitude of freezing level. Severe wind gusts are also likely due to high precipitation loading within the storms.
Some uncertainties are present in the forecast. Degree of cloudiness and the influence of the Saharan dust is one. The second one is how many storms will form once the best CAPE-shear overlap is present. Some models show the development of storms only once the shear decreases towards the core of the trough. There is a disagreement concerning this among the high-resolution models. Despite this, a Lvl 3 is introduced for an area, where the highest likelihood of damaging hailstorms will be present.
Storms will spread NE during the evening with an increase in heavy rainfall threat with upscale growth and perhaps repetitive initiation along the S flank of the Alps.
... Switzerland through Germany, Slovakia, Ukraine and Romania ...
A large belt of Lvl 1 surrounds Lvl 2 along a frontal zone where moderate CAPE will be present combined with 15 - 25 m/s of 0-6 km bulk shear. Well-organised multi or supercells capable of large hail, severe wind gusts and also heavy rainfall are forecast.
... S Sweden ...
A low-end Lvl 1 is introduced as scattered showers/low-topped thunderstorms will develop within a fast-moving short-wave trough. Moderate low-level shear is forecast with 0-1 km bulk shear locally exceeding 10 m/s and 0-1 km SRH 100 m2/s2. While CAPE will remain marginal, stronger updrafts may develop low-level rotation and produce an isolated severe wind gusts or a tornado. Both threats will be limited though. Tornadoes by the lack of hodograph curvature and severe wind gusts by somewhat modest low-level wind flow , only up to 20 m/s.
... Estonia to S Finland ...
A low-end Lvl 1 is introduced for a strongly-forced situation with fast-moving short-wave trough and a pronounced cold front. Models disagree on whether marginal CAPE will be present or not (ICON being the most aggresive), but there will be a possibility that one or more linear segments form along the front and result in isolated severe wind gusts and/or a tornado in strong low-level shear. Low-level moisture should be monitored before the front to infer the degree of threat.
... Turkey, Caucasus, Middle-East ...
Severe weather is forecast ahead of the short-wave trough moving across Turkey. Risk of heavy rainfall will be present especially in the western part of the Lvl 1 area, where slow storm motion is forecast. Risk of large hail and severe wind gusts will increase towards SE, where stronger shear, higher CAPE and higher LCLs are forecast. An area with the highest potential for well-organised, intense storms, is marked by Lvl 2.
