Hello, thank you for the report, we will investigate.

Hi @idefix37, please could you confirm that you are discussing Rain, thunder layer? Because it works well for me.... And what device/app or browser makes trouble? Thank you!

Hi @ejain, thank you for the report! We will investigate and let you know.

@Larra-Gurra, https://community.windy.com/topic/7740/is-there-a-favorites-limit-maximum-maybe-a-bug

Hello @jwmr, were the Metars for YORG available on Windy in the past?

@FlyingRockDoctor, we couldn't confirm the reported bug. Could you send us a few IDs of the stations which don't work properly on your side?

Great article! Thank you for summing up all these thoughts.

Valid: Tue 02 Jul 2019 06:00 to Wed 03 Jul 2019 06:00 UTC
Issued: Mon 01 Jul 2019 21:32
Forecaster: DAFIS

• A level 2 was issued for parts of Slovakia, Hungary, Romania, Ukraine, Moldova and Russia for severe wind gusts, large hail and excessive precipitation.

• A level 1 was issued for S France, Switzerland, S Germany, Liechtenstein, N Italy, Austria, Slovenia, Croatia, W Hungary, and Bosnia and Herzegovina for large hail, severe wind gusts and excessive precipitation.

Synopsis

The intrusion of a polar maritime air mass in Europe results in an elongated frontal boundary extending from France to Russia. The warm and moist air mass in central and eastern parts of the continent is pushed quite violently south-southeast. At the warm sector ahead of the front, we expect numerous thunderstorms which will locally become severe. In the cold sector of the front, some lower-topped thunderstorms are expected in NE Europe and Scandinavia. Local storms are also forecast in the Iberian Peninsula and Algeria, and some of them will be capable of producing large hail and severe wind gusts but their spatial coverage does not justify issuing a threat-level area.

Discussion

Slovakia, Hungary, Romania, Ukraine, Moldova and Russia

On the aforementioned boundary in eastern Europe, the weakly capped, rich in moisture and warm air mass will provide the necessary ingredients for deep moist convection. Steep mid-level lapse rates aloft create fat CAPE profiles in the NWP outputs (1000-1800 J/kg), overlapping locally with more than 15 m/s DLS. Comparable bulk-shear-0-3km speeds suggest that some of the storms will be able to evolve into supercells producing large hail and severe wind gusts. Straight forecast hodographs show the potential of convective line developments with an elevated risk of severe wind gusts, especially in Ukraine. PWAT values in an excess of 30 mm show the potential of slow-moving storms and clusters to produce excessive precipitation.
Finally, rather high LCLs and straight forecast hodographs limit tornadogenesis threat, apart from W Russia, where late in the afternoon low-level shear increases with veering winds and LCLs drop.

S France, Switzerland, S Germany, Liechtenstein, N Italy, Austria, Slovenia, Croatia, W Hungary, and Bosnia and Herzegovina

The remnants of the last week's extreme heat wave can still be found in France and Central Europe. Warm air masses with a high content of moisture will be lifted by a low-level convergence zone and diurnal heating. Very steep mid-level lapse rates create locally more than 2000 J/kg MLCAPE in the GFS solution, with the IFS and ICON-EU providing comparable values of CAPE. The CAPE-shear overlap is not very strong, compared to eastern Europe, but storms will take advantage of about 10 m/s DLS (locally reaching 15 m/s) to organize in small clusters able to produce large hail and severe wind gusts. High values of PWAT suggest that slow-moving clusters may produce excessive precipitation inside the level-1 area.

Valid: Mon 01 Jul 2019 06:00 to Tue 02 Jul 2019 06:00 UTC
Issued: Sun 30 Jun 2019 23:54
Forecaster: TASZAREK

• A level 2 was issued for a corridor from parts of E France to SW Belarus and NW Ukraine mainly for severe wind gusts, large to very large hail and excessive precipitation.

• A level 1 was issued for a corridor from S France to S Belarus and N Ukraine mainly for large hail, excessive precipitation and severe wind gusts.

• A level 1 was issued for W Russia mainly for large hail, severe wind gusts, excessive precipitation and tornadoes.

Synopsis

Thick geopotential with a warm and highly unstable tropical airmass persists over majority of S and E parts of Europe Broad low is placed over Scandinavia and induces passage of a shallow long-wave through parts of CNTRL and E Europe during a forecast period. At 1200 UTC a boundary with a cold front and very high theta-e horizontal gradient will be stretching from CNTRL France through CNTRL Germany, CNTRL Poland up to N Belarus. Thunderstorms are expected to fire-up in the warm sector ahead of that boundary. An outbreak of severe to extremely severe thunderstorms is possible in the corridor from E France to S Belarus where an overlap with a mid-tropospheric jet will be the most prominent.

Discussion

Ahead of the approaching cold front, low-level convergence zone provide rich BL moisture with MIXR up to 13-15 g/kg. Along with steepening mid-level lapse rates to more than 7 K/km, a solid corridor of 2000-3000 J/kg ML CAPE develops in the warm sector.

Selected NWP model outputs like GFS indicate values exceeding even 4000 J/kg in parts of S Germany, Czech Republic, Belarus, NW Ukraine and W Russia around 1500 UTC. Eastwardly traveling shallow long-wave provide a narrow (~100km) overlap of mid-tropospheric jet with aforementioned unstable airmass. The most prominent overlap concerns S Germany, Czech Republic, S Poland, S Belarus and W Russia with 15-20 m/s (locally >20 m/s) 0-6km shear. Low-level jet resulting in 15-20 m/s 0-3km shear will also support severe thunderstorms in Czech Republic, S Poland, S Belarus and W Russia.

Storms developing in aforementioned areas may be evolving into supercells and be capable of producing large to very large hail and heavy rain. However, a rather straight hodographs should provide rapid clustering and increase potential for damaging winds within bowing segments of convective lines. Less prominent overlap of shear and instability will be available over surrounding areas (parts of France, Alps, N Italy) where a threat for a local severe thunderstorms will still exist within slowly moving multicell clusters / pulse thunderstorms with a potential for producing severe wind gusts, large hail and excessive precipitation (PW > 35mm)

Storms developing in W Russia in the environment of clockwise-curved hodographs (SRH > 300-400 m2/s2) will have a good potential for evolving into supercells. Enhanced LLS (> 10 m/s) and LCLs below 750m will create a chances for tornadoes. Based on the most recent NWP output, current understanding is that first elevated storms may fire-up in the early morning hours over parts of W and CNTRL Poland and move eastward. Due to enhanced environmental wind shear these storms may be capable of producing severe wind gusts, large hail and heavy rainfall.

In the afternoon hours cap should start breaking and surface-based CI is expected to take place over S Germany, S France, Switzerland and Czech Republic. In the environment of 10-15 m/s (locally up to 20 m/s) these storms may be capable of producing large hail, damaging winds (especially S Germany and W Czech Republic) and heavy rain. Large hail is also possible within Alpine area where a local enhancement in vertical wind shear may take place and result in some isolated supercell event.

In the late evening hours a large MCS developing on the border of Czech Republic and Poland should move into SE Poland and later during nighttime to S Belarus and N Ukraine. The main threat with this system should be severe wind and heavy rainfall. Although environment will be supportive for well-organized storms over W Russia, a lack of prominent synoptic-scale lift induces CI to be uncertain for surface-based storms (which is also confirmed in a disagreement of different NWP model scenarios). Therefore, level 2 is not issued for this area.