Storm Forecast
Valid: Thu 23 Apr 2020 06:00 to Fri 24 Apr 2020 06:00 UTC
Issued: Wed 22 Apr 2020 22:59
Forecaster: GATZEN

A level 2 was issued across north-eastern Iraq, south-east Turkey, and north-west Iran for large or very large hail and to a lesser extent severe wind gusts, excessive precipitation, and tornadoes.

A level 1 was issued across eastern Turkey into Armenia and Iran for large or very large hail, severe wind gusts, excessive rain and tornadoes.

SYNOPSIS

High geopotential and associated subsidence expands towards France and the west Mediterranean in the wake of a cut-off trough that moves towards the east Mediterranean, where it merges to an amplified trough. Ahead of that trough, a very strong south-westerly jet spreads into Syria. At lower levels, dry air masses across most of Europe spread into the Mediterranean and northern France. Remaining moisture across western Europe will be associated with showers and some thunder, however, these areas are excluded from the thunder area due to high equilibrium level temperatures indicated by latest models.

DISCUSSION

East Turkey, Armenia, north-eastern Iraq, north-western Iran

Widespread storms have formed on Wednesday across northern Iraq and Iran. On Thursday, moist outflow of these storms is expected across most of the area. During the day, strong diurnal heating is expected across Syria in a dry air mass and a dry line will form across northern Iraq that slowly progresses east in the afternoon. At the same time, QG forcing will increase at the cyclonically sheared flank of the approaching jet streak, with impressive deep layer shear of 25 m/s that overlaps with up to 1000 J/kg MLCAPE east of the dry line. Initiation of storms is most likely over the mountain slopes of Turkey and Iran. However, a few storms may also initiate along the dry line given relatively weak CIN. Strong shear and dry mid levels will limit the potential of convection initiation. Storms that form will rapidly organize given Long and curved hodographs, wwith arounf 200 m²/s² SRH in the lowest 3 km and more than 150 m²/s² 0-1 km SRH across northern Iraq. Supercells with all Kinds of severe weather are forecast, including very large hail and damaging wind gusts. Tornadoes are not ruled out, however, high LCLs at 1200 m will limit the potential of tornadoes.

Farther north, less curved hodographs and weaker CAPE will limit the severe potential somewhat, however, given 20 m/s deep layer shear and some 100 J/kg MLCAPE, every storm that forms will have to potential to produce large or very large hail. Severe wind gusts are also forecast.

Storms are forecast to become elevated during the night in Response to boundary layer cooling, and severe potential will decrease. However, continuing QG lift is expected to result in ongoing storms especially across Iran with large hail possible.