Actuele ESTOFEX-verwachting
Estofex is een collectief van meteorologen en meteorologiestudenten, dat iedere dag een verwachting uitgeeft voor convectief weer in Europa. Hoewel de organisatie niet als oogmerk heeft om te waarschuwen, wordt de verwachting wel beschouwd als zeer uitgebreid en waardevol voor menig onweerverwachting. Hieronder kun je de meest recente verwachting zien die door Estofex is uitgeschreven. De verwachting is in het Engels opgesteld.
2
Storm Forecast
Geschreven door: Pistotnik
Geldig vanaf: 18 aug. 08:00 (Lokale tijd)
Geldig tot: 19 aug. 08:00 (Lokale tijd)
Bron: www.estofex.org
Veranderingen:
Geen veranderingen aangebracht behalve het leesbaar maken van datums en het opmaken van de tekst
Geldig vanaf: 18 aug. 08:00 (Lokale tijd)
Geldig tot: 19 aug. 08:00 (Lokale tijd)
Bron: www.estofex.org
Veranderingen:
Geen veranderingen aangebracht behalve het leesbaar maken van datums en het opmaken van de tekst
A level 2 and level 1 are issued for Corsica, parts of Italy and the Balkans for excessive convective precipitation, large hail and severe convective wind gusts.
A level 2 is issued for E Spain for large hail, excessive convective precipitation and severe convective wind gusts.
A level 1 is issued for central Spain mainly for severe convective wind gusts.
SYNOPSIS
Weak pressure and temperature gradients prevail across Europe under a quite fragmented circulation pattern. Mid-level lows are placed over W Russia, N Scandinavia and - weaker ones - over Romania and the Celtic Sea, all of them slowly moving eastward. Slightly lower 500 hPa geopotential also extends into the central Mediterranean region. In contrast, a subtropic ridge stretches from Morocco to the North Sea. Very warm to hot conditions continue in the range of this ridge, whereas slightly cooler, dry continental air has spread over large parts of the continent.
DISCUSSION
Corsica, Italy to Greece, the S Balkans and Romania
Though slowly receding, hot air with steep lapse rates still resides across the southern third of Europe. Low-level moisture is limited in inland areas, owing to little evaporation from the dry surfaces and deep vertical mixing, and keeps CAPE mostly confined to values below 800 J/kg. Much richer low-level moisture and CAPE well in excess of 1000 J/kg are in place in coastal and offshore areas (e.g., almost 2000 J/kg were sampled by the Sun 12 UTC Ajaccio and Trapani soundings, and even almost 4000 J/kg by the Pratica di Mare sounding), though a strong capping inversion remains in place.
In the absence of noteworthy synoptic lift and under weak deep-layer shear around or below 10 m/s, scattered thunderstorms are mostly tied to orographic features and the afternoon to evening hours. The strongest pulse storms can produce excessive rain, large hail and severe downbursts. These events are expected to be rather widely scattered from Greece to central Romania, covered by a level 1. However, Sunday's widespread and explosive storms over e.g. central Italy and Corsica suggested that it was easier than anticipated for air parcels with rich coastal moisture to break the capping inversion when picked up by upvalley and upslope circulations. Since a similar scenario is foreseen again for Monday, Corsica and the southern half of Italy are upgraded to a level 2, even more as the weak northerly background flow over thermal onshore and upslope circulations could bring deep-layer shear into the 10-15 m/s range and allow multicellular or even transient supercellular storm organization in these areas. The dominant hazards are flash floods and large hail (isolated very large hail not ruled out in case of a supercell), but severe downbursts may occur as well.
Spain
A similar setup is also present in Spain: very hot and dry, deeply mixed air with little CAPE well inland, but sea breezes with abundant low-level moisture nibbling at the east coast. Sunday's soundings from Barcelona and Murcia showed only little and no CAPE yet, respectively, but with the gradually approaching Atlantic mid-level low and more backed surface flows, the moisture is expected to penetrate farther inland on Monday, also including the lower Ebro valley. The degree to which this happens is still somewhat unclear, though, as some models still show only a few hundred J/kg CAPE over land, whereas e.g. ICON-EU and WRF even bring a plume of 2000-4000 J/kg CAPE a little distance inland.
Current thinking is that the areas well inland will see another round of scattered afternoon to evening storms that are very high-based and pose a main hazard of a few strong to severe, perhaps even dry downbursts. These winds could at least temporarily aggravate the wildfire situation, and new wildfires could be sparked by lightning strikes.
More plentiful and more vigorous storms are expected to form over the Sistema Iberico and the Pyrenees, depending on how much coastal moisture can indeed be fed into their updrafts as described above. Vertical wind shear increases to widespread 15 m/s by evening, perhaps even 20 m/s in the Ebro valley and other zones of well-pronounced onshore, upvalley and upslope circulations. Storms can organize into multi- or supercells, perhaps later also into one or two large clusters that could propagate towards the coast before the capping inversion becomes too strong. Large to very large hail and excessive rain with a possibility of dangerous flash floods are the main hazards, next to severe wind gusts as a secondary threat.
Convection can continue into the first half of the night before it finally dissipates. Elevated and non-severe storms can also travel into France then, and scattered lightning is possible in the entire band of steep lapse rates and elevated CAPE that fans out as far as SW England and Ireland.
A level 2 is issued for E Spain for large hail, excessive convective precipitation and severe convective wind gusts.
A level 1 is issued for central Spain mainly for severe convective wind gusts.
SYNOPSIS
Weak pressure and temperature gradients prevail across Europe under a quite fragmented circulation pattern. Mid-level lows are placed over W Russia, N Scandinavia and - weaker ones - over Romania and the Celtic Sea, all of them slowly moving eastward. Slightly lower 500 hPa geopotential also extends into the central Mediterranean region. In contrast, a subtropic ridge stretches from Morocco to the North Sea. Very warm to hot conditions continue in the range of this ridge, whereas slightly cooler, dry continental air has spread over large parts of the continent.
DISCUSSION
Corsica, Italy to Greece, the S Balkans and Romania
Though slowly receding, hot air with steep lapse rates still resides across the southern third of Europe. Low-level moisture is limited in inland areas, owing to little evaporation from the dry surfaces and deep vertical mixing, and keeps CAPE mostly confined to values below 800 J/kg. Much richer low-level moisture and CAPE well in excess of 1000 J/kg are in place in coastal and offshore areas (e.g., almost 2000 J/kg were sampled by the Sun 12 UTC Ajaccio and Trapani soundings, and even almost 4000 J/kg by the Pratica di Mare sounding), though a strong capping inversion remains in place.
In the absence of noteworthy synoptic lift and under weak deep-layer shear around or below 10 m/s, scattered thunderstorms are mostly tied to orographic features and the afternoon to evening hours. The strongest pulse storms can produce excessive rain, large hail and severe downbursts. These events are expected to be rather widely scattered from Greece to central Romania, covered by a level 1. However, Sunday's widespread and explosive storms over e.g. central Italy and Corsica suggested that it was easier than anticipated for air parcels with rich coastal moisture to break the capping inversion when picked up by upvalley and upslope circulations. Since a similar scenario is foreseen again for Monday, Corsica and the southern half of Italy are upgraded to a level 2, even more as the weak northerly background flow over thermal onshore and upslope circulations could bring deep-layer shear into the 10-15 m/s range and allow multicellular or even transient supercellular storm organization in these areas. The dominant hazards are flash floods and large hail (isolated very large hail not ruled out in case of a supercell), but severe downbursts may occur as well.
Spain
A similar setup is also present in Spain: very hot and dry, deeply mixed air with little CAPE well inland, but sea breezes with abundant low-level moisture nibbling at the east coast. Sunday's soundings from Barcelona and Murcia showed only little and no CAPE yet, respectively, but with the gradually approaching Atlantic mid-level low and more backed surface flows, the moisture is expected to penetrate farther inland on Monday, also including the lower Ebro valley. The degree to which this happens is still somewhat unclear, though, as some models still show only a few hundred J/kg CAPE over land, whereas e.g. ICON-EU and WRF even bring a plume of 2000-4000 J/kg CAPE a little distance inland.
Current thinking is that the areas well inland will see another round of scattered afternoon to evening storms that are very high-based and pose a main hazard of a few strong to severe, perhaps even dry downbursts. These winds could at least temporarily aggravate the wildfire situation, and new wildfires could be sparked by lightning strikes.
More plentiful and more vigorous storms are expected to form over the Sistema Iberico and the Pyrenees, depending on how much coastal moisture can indeed be fed into their updrafts as described above. Vertical wind shear increases to widespread 15 m/s by evening, perhaps even 20 m/s in the Ebro valley and other zones of well-pronounced onshore, upvalley and upslope circulations. Storms can organize into multi- or supercells, perhaps later also into one or two large clusters that could propagate towards the coast before the capping inversion becomes too strong. Large to very large hail and excessive rain with a possibility of dangerous flash floods are the main hazards, next to severe wind gusts as a secondary threat.
Convection can continue into the first half of the night before it finally dissipates. Elevated and non-severe storms can also travel into France then, and scattered lightning is possible in the entire band of steep lapse rates and elevated CAPE that fans out as far as SW England and Ireland.
De onderstaande tekst is automatisch vertaald en aangepast om het beter leesbaar te maken voor onze lezers. De inhoud kan daarom verschillen van de originele tekst. Er kunnen geen rechten worden ontleend aan onze teksten, zie disclaimer.
- Level 2 en level 1 waarschuwingen voor Corsica, delen van Italië en de Balkan voor zware convectieve neerslag, grote hagel en zware windstoten door convecties.
- Level 2 waarschuwing voor Oost-Spanje voor grote hagel, zware convectieve neerslag en zware convectieve windstoten.
- Level 1 waarschuwing voor centraal Spanje, voornamelijk voor zware convectieve windstoten.
SYNOPSIS
- Zwakke druk- en temperatuurgradiënten domineren Europa.
- Middelhoog lagedrukgebieden over W-Rusland, N-Scandinavië, Roemenië en de Keltische Zee bewegen langzaam oostwaarts.
- Subtropische rug vanuit Marokko naar de Noordzee met warm tot heet weer.
- Wat koelere en droge continentale lucht verspreidt zich over grote delen van het vasteland.
DISCUSSIE
Corsica, Italië tot Griekenland, Zuid-Balkan en Roemenië
- Heet weer met steile temperatuurgradiënten blijft in het zuidelijke derde van Europa, met beperkte lage vochtigheid.
- Rijkere lage vochtigheid en CAPE boven 1000 J/kg in kust- en offshore-gebieden.
- Scattered onweersbuien, vooral in de middag tot avond, kunnen zware regen, grote hagel en zware windstoten veroorzaken.
- Corsica en zuidelijk Italië hebben level 2 waarschuwingen door mogelijke multicellulaire of supercell-stormstructuren met grote hagel en overstromingsrisico's.
Spanje
- Hete en droge lucht landinwaarts met matige CAPE, maar meer vocht aan de oostkust.
- Stormen zijn verwacht over Sistema Iberico en Pyreneeën met mogelijke multi- of supercells.
- Grote tot zeer grote hagel en zware regen met kans op gevaarlijke overstromingen zijn de belangrijkste risico's.
- Convectie kan doorgaan in de eerste helft van de nacht voordat het afneemt, met bliksem mogelijk tot in ZW-Engeland en Ierland.