Storm Forecast Valid: Mon 05 May 2014 06:00 to Tue 06 May 2014 06:00 UTC Issued: Sun 04 May 2014 20:49 Forecaster: TUSCHY
A level 1 was issued for Greece and S-Bulgaria mainly for isolated large hail and excessive rain.
A level 1 was issued for NW Turkey mainly for an isolated large hail event.
A level 1 was issued for the CNTRL / E Ukraine mainly for an isolated large hail event.
...SYNOPSIS and DICUSSION...
A longwave trough is centered over Finland and Belarus with a weaker extension all the way to the Aegean Sea. Strongest synoptic forcing limits itself to Belarus/parts of W-Russia (W of Moscow) and the Aegean Sea/W-Turkey. The last-mentioned taps into residual moisture over the Aegean Sea. A plume of steep mid-layer lapse rates is displaced east over CNTRL Turkey, so not much CAPE to work with. Weak surface low over the N-Aegean Sea supports onshore flow of better moisture beneath 500 hPa temperatures of less than -20 °C. The same for the advection of moist air from the Ionian Sea to the SE. 400-800 J/kg weakly capped MLCAPE evolves over most of Greece to S-Bulgaria. Weak shear precludes organized convection, but slow moving and clustering storms likely pose an heavy/excessive rainfall threat, next to isolated large hail. An isolated waterspout event along the coasts is possible. W-Turkey struggles with meager BL moisture and weak mid-layer lapse rates. DLS exceeds 30 m/s, so any deeper updraft could gain rotation with an isolated large hail threat. The setup does not justify a level 1 due to ongoing uncertainties regarding CAPE. Only NW Turkey was upgraded due to higher confidence in a temporal CAPE/shear overlap mainly before noon.