CONVECTIVE FORECAST
VALID 00Z MON 27/09 - 06Z TUE 28/09 2004
ISSUED: 26/09 20:26Z
FORECASTER: GROENEMEIJER

There is a slight risk of severe thunderstorms forecast across central and eastern Romania, Moldova and parts of the Ukraine as well as the extreme north of Bulgaria

General thunderstorms are forecast across the Ukraine, parts of southern Russia, the central, eastern and southern Balkans, northwestern Turkey, Greece, southern Italy, the central Mediterranean Sea and southern parts of the western Mediterranean Sea.

SYNOPSIS

Monday at 06Z... a mid/upper level low pressure system is located over the Adriatic Sea. During Monday it will likely evelove into a NE-SW oriented trough over the Balkans. A ridge is located over southwestern Europe and a westerly jet moves into southern Scandinvia and the Baltic States.

DISCUSSION

...slight risk area...
On the eastern flank of the mid/upper-low / trough over the western Balkans a southwesterly jet (30 m/s @ 500 hPa per GFS12Z) is expected to develop. DCVA-related upward motion is progged in the left exit region of this jet over central Romania at 06Z. A baroclinic wave is expected to be developing there. Scattered storms are expected to be ongoing near and east of the wave and along its cold front over much of central and eastern Romania and northern Bulgaria during the early morning. The storms will likely move northeastward and affect the Ukraine during the late morning and afternoon. Deep-layer shear is expected to be 20-25 m/s, which is more than sufficient to allow for updraft rotation. East of the wave-tip, 0-3 km SREH of 250 m2/s2 is forcast per GFS, which should aid the formation of a few supercells, that in combination with anticipated low LCL heights, might produce one or two tornadoes. Otherwise, there is a risk of some large hail and of strong to severe winds, especially if a well-defined bow-echo develops along the wave's cold front, which seems a possibility.

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