30-07-2024 23:46 | Estofex | m.b.t. 01-08-2024 t/m 02-08-2024
Extended Forecast
Valid: Thu 01 Aug 2024 06:00 to Fri 02 Aug 2024 06:00 UTC
Issued: Tue 30 Jul 2024 23:46
Forecaster: TUSCHY
A level 1 was issued for parts of CNTRL into W/NW Europe mainly for heavy rain and a few large hail and strong to isolated severe gust events.
SYNOPSIS
The blocking subtropical anticyclone over CNTRL Europe weakens and flattens into a more zonally aligned flow regime with numerous traversing waves. The persistent standing wave pattern over the far NE Atlantic into the Mediterranean with a trough just W of Portugal and the blocking ridge over the W Mediterranean weakens but remains in place during the forecast.
Elsewhere not much change is forecast with a deep vortex S of Iceland and an extensive area with rather low mid-level heights over W Russia, extending into the E Mediterranean area.
Once again, no synoptic-scale boundary impacts the DMC activity with convergence zones, laid out outflow boundaries, MCVs, numerous progressive low-amplitude waves and the orography dictating convective coverage and intensity.
DISCUSSION
... CNTRL to W/NW Europe ...
There is not much change to the moisture quality of this air mass although a slight downtrend is noted with TPWs more in the 35-40 mm range (and 30-35 mm over SE UK). BL moisture holds steady with mixing ratios around 14 g/kg. The main change to the SWODY 1 setup is the alrady worked-over airmass from the convective activity from the previous day/night. Hence a noticeable weakening trend of mid-level lapse rates is forecast which brings the MUCAPE more in the 1000-2000 J/kg range.
DLS remains weak for most places with values of 10 m/s or less. N-Italy could take profit of somewhat enhanced shear along the base of the passing waves with DLS in the 15 m/s range, but this depends on the intensity/geometry and track of those low-amplitude waves. Sadly the NWP guidance remains rather divergent regarding those waves, although most of them bring a stronger impulse into France during the day.
Once again the best approach for this setup in a SWODY 2 will be to issue a rather broad lightning/level area as many issues (e.g. clusters from the previous night, ongoing MCVs etc.) could impact the thunderstorm chances on a regional scale.
Initiating convection in areas with up to 2 kJ/kg MUCAPE could produce a few hail events with some large ones possible. However weakened lapse rates/lower CAPE should limit that threat. If stronger shear over N-Italy verifies we could see a few large hail events in this place and a confined level 2 upgrade is possible from far NE Italy into N Slovenia/SE Austria.
The main hazard (next to a few strong/severe downburst events) remains the heavy to excessive rain threat with slow moving/clustering convection.
(alleen de voor NL en aangrenzende gebieden relevante tekstdelen overgenomen, klik hier voor de volledige forecast, red.)
Hagel(-schade) | Onweer/blikseminslag | Verwachtingen/waarschuwingen | Wateroverlast/(zware) neerslag | Wind/storm (-schade)
