Asian Summer Blocking High Pattern Omega Block/Rex Block.

Omega Block.

In the asian summer months from Around May to Late Sept there may be the weather experienced of Heatwaves and Long Spells of Hot dry weather. These are caused by Upper Wind Patterns at the Jet Level called omega blocks and are becoming more frequent in the Asian summer months due to warming in the North Polar Zones by a margin of 3 degrees warmer then 30 years ago in the northern summer.

Omega blocks are created when there are placed the Trough-Ridge-Trough Upper level pattern and within the Ridge region the upper level winds weaken that slow-down or stall the weather pattern over one area.

Then the area of High Pressure remains stalled/ultra slow moving as in over south korea and the sub-continent of North East Asia experiences Hot-Dry weather and as the weather remains in place the region experiences days and days in very hot weather with no prospects of rain and also a high pressure expectation of a blue dome series of days.

This pattern would be most uncomfortable in the Asian Mid Summer as this is when the summer months are peaking although these are sometimes present through the Asian summer.

Rex Block.

Lastly we discuss the next Upper Level Blocking pattern ie:The rex block that brings the same type of stalled Hot conditions to the continental area the High Pressure area stalls over (a few days in number). In the Rex block the High Pressure region sits in the north section of the Upper Level Wind pattern and south there is the Low pressure region. Also the trough axis is latitudinal from west to east. In our example a blocking High is placed over the Korea Peninsula and in the Taiwan/Taiwan channel Area they have stormy weather. Upper level blocking patterns strongly influence Asian weather patterns for days on end when the ingredients are in place and are influenced by the Westerly Jet in the asian summer months.

Therefore it becomes important to know beforehand of these blocking pattern arrivals so areas can prepare with

• Water supply restrictions (Applies more in a mega drought albeit Asia has the Tropical/Sub Tropical climate model).
• Air-conditioner maintannance.
• Purchasing of aids Fans, Sunscreen, Summer clothing.
• Heat preparedness.
• Vehicle preparation – replace fluids and topup, air cooling maintannance.
• Maintaining the electrical grid.
• Transport safety ie rail track inspections.
• Planning days at the beach-river ways in a safe way ie:Haeundae Beach Busan SK.