Frontal system is spreading from Ukraine over Romania down to Albania and South Italy. Behind the front a distinct broad dark area exists, indicating cold, dry air sinking into the upper troposphere.
Over Bulgaria within the frontal zone, a large convective cell can be recognised. One convective cell appears over Greece and several small ones over Turkey. They develop on a pronounced WV boundary.
The development continues.
The development continues. Daytime convection induced by orography ahead of the front over Turkey intensifies.
Two big MCSs (Mesoscale Convective System) can be recognised within the front north-west of Turkey. The black stripes around the cells are typical features associated with MCS.
MCSs within the front are getting larger. The level of convection over Turkey decreases.
MCSs within the front merged in one big, bright cell. White colour e.g. high pixel values indicate cloudiness with high water content which extends through the whole troposphere. The level of convection over Turkey decreases.
Situation similar to the one an hour before.
Situation similar to the one an hour before.
From the begining, a spiral structure can be recognised over eastern Turkey. This structure cannot be seen in
the IR channel but only here in WV imagery. It is a sign
of upper level low, supported also by the geopotential field at 300 hPa. It will play an important role in future convective
development over eastern Turkey.
A frontal zone is reaching north-western Turkey. Very intensive white colours indicate high tropospheric moisture content. A small convective cell ahead of the front is recognised.
Convection ahead of the front continues.
Convection ahead of the front continues.
The level of convection in front of the front, close to Ankara, increases. Far ahead to the east (over Iran) the first sign of convection - small bright spot - can be recognised.
Convection in vicinity of Ankara increases. A dark stripe over the big cell can be noticed.
The cyclonic curvature presents itself as the dark spiral over south-eastern Turkey, Syria and Iraq. It will be clearer in the following time steps.
The development continues.
Convection close to Ankara decreases, as well as the convection within the frontal zone. The cyclonic curvature over south-east is still present and some bright spots indicating the new convection are embedded.
Convection close to Ankara decreases, as well as the convection within the frontal zone.
Typically, on a WV image, there are many well defined boundary features, and only some of them are associated with jet stream axes. The jet axis of the maximum wind speed is likely along the most contrast part of moisture boundary in the WV image, and a high amplitude upper-level trough consists of two branches. A jet stream branch coming from the upstream ridge, from the north-west (mid-Mediterranean - marked with A) and the second branch on the forward side of the trough, coming from south-west (from the eastern Mediterranean over west coast of Turkey further to the north-east - marked with B). Dark area indicates dry air on the cyclonic side of the jet.
The propagation of the system continues.
The frontal zone moves to the east with some bright area within frontal cloudiness. Again, the bright spots can be recognised over eastern Turkey as a sign of convection.
Convection over eastern Turkey becomes much more visible. It is connected with an upper level low (with the centre between lakes Van and Urmia to the north and river Tigris to the south, at the border of Iran, Iraq and Turkey). Bright spots can be recognized within the frontal zone - a sign of new convective development.
Convection over eastern Turkey is also associated with the jet streak coming from the east (marked with C). The intensification takes place at the left exit region of the jet.
Convective development within the front and over eastern Turkey continues. Several bright spots within frontal zone merged into one. At the leading edge of the front, on the WV boundary, convection also starts.
Most of the convective development occurs near the dark stripes. Intrusion of the stratospheric air from above makes the atmosphere less stable. When moisture is then added from below it provides favourable conditions for Cb development. The intensification of the convection within the front is also associated with the right entrance region of the jet on the leading side of the trough.
The development continues.
The development continues. Convection within the front and the prefrontal convergence line over central Turkey merged into one big convective system. The strong convection over eastern Turkey is still present.
The development continues.
The level of convection over eastern Turkey decreases.
The level of convection over eastern Turkey decreases but in the frontal zone convection is still present.
A several big convective cells can be recognised over north-eastern part of Turkey can be recognised. The level of convection over Eastern Turkey decreases. Gray shades in the image are indicative for the WV content in the upper part of the troposphere with intensive white colours indicating deep tropospheric moisture content.
Convective cells merged in one convective "zone" covering the big part of north-eastern Turkey.
The level of convection decreases.
The level of convection decreases.
The level of convection decreases.
The level of convection decreases.
The level of convection decreases.