Extended Forecast
Valid: Thu 01 May 2025 06:00 to Fri 02 May 2025 06:00 UTC
Issued: Tue 29 Apr 2025 21:22
Forecaster: TUSCHY

A level 1 was issued for parts of SW/CNTRL Turkey mainly for isolated heavy rain, hail and gusts.

A level 1 was issued for parts of SE Turkey mainly for heavy rain, isolated large hail, strong to severe gusts and a low-end tornado threat along the coast.

SYNOPSIS

The stagnant pattern continues for this forecast period. For a more detailed SYNOPSIS please refer to the Day 1 outlook.

DISCUSSION

... Parts of Turkey ...

With not much net-motion of the main upper vortex anticipated, a persistent southerly flow continues to advect moist air onshore, which spreads far inland. Temporal diurnal heating supports a plume of 400-800 J/kg MUCAPE during the day. Not much capping is forecast beneath the upper low, so expect CI all day long with an increase during the noon/afternoon hours. However entrainment into growing updrafts could lower effective CAPE magnitude over the orography of CNTRL Turkey, so expect mainly a modest CAPE setup with decreasing values towards SW Turkey.

Slow moving and clustering convection brings heavy rain and isolated hail. The rainfall risk caused the issuance of a level 1 area for this extended outlook period.

Another level 1 was issued for the Gulf of Alexandretta and surroundings for an ongoing severe risk from the previous night. This activity weakens during the day and probably ends near sunset.

... Lightning areas ...

Either CAPE or shear or both parameters are too low for any organized severe risk.

Spain could be a candidate for a regional upgrade. During the daytime hours, a MUCAPE plume of 300-600 J/kg evolves over S- to N-CNTRL Spain, but strong subsidence should keep CI very isolated. In addition, any growing updraft has to fight against very effective entrainment of dry air at mid-levels.
During the night, the setup becomes more interesting as the wavy boundary starts to become cold-front dominant and affects S Portugal and SW Spain. It is this time-frame, where conditions for elevated supercells improve constantly with up to 800 J/kg MUCAPE and modest effective shear, depending on how deep the inversion will be. This activity could pose an isolated nocturnal large hail threat and the risk is augmented from Sevilla/Cordoba N towards Madrid. A hail-driven level 1 would be needed if EZ is right, whereas other models like ICON keep CI more damped until 06Z. This activity becomes one of the players for a rather substantial severe risk for most of S/E Spain during the following day (Day 3).

Another area of concern will be far S Portugal during the end of the forecast, where onshore moving thunderstorms could bring heavy rain and an isolated tornado threat. The tornado risk may be lowered due to a still stable/neutral BL stratification and hence no level 1 upgrade was performed for now.

A deepening depression over SW Russia may spark a few thunderstorms, but latest data indicates only meager CAPE so nothing severe is forecast for now. A low-end tornado risk may evolve in case of better diabatic heating and more robust LL CAPE build-up.