First of all, meteorological Autumn has begun on Sep 1st. Temperatures should start declining, but very slowly. And since humidity picks up in the UAE during September, a change in real feel temperature is not likely.
Anyway, looking ahead for the months of November to February during which westerlies start affecting Arabia, I will show below the corresponding seasonal forecast. With El Nino picking up, we might experience a different winter. Although not statistically proven, El Nino (particularly strong El Nino) years corresponds to wetter winters across Arabia. A great example is 1982 and 1995/1996 winters.
The US NWS/NCEP seasonal forecast predicts a wetter winter across most of Arabia and SW Asia with at least 50% above normal precipitation with the months of Jan-Mar being potentially 65-75% above normal in the UAE. Moreover the European ECMWF seasonal forecast also predicts a similar scenario with around 50-60% above normal precipitation across the Arabian Gulf countries, with the months of Nov-Feb being 60-70% above normal in the UAE. One more organization that issues seasonal forecasts is the IRI institute. Their forecasts predicts a drier winter, but I have seen them predicting such forecasts even for wet winters in the past few years. Maybe I like to believe what I want to believe. Temperature-wise, all seasonal forecasts predict warmer than normal weather (blame global warming).
What do I think? I expect a wetter winter and probably an early arrival of the westerlies and the arrival of jet stream.
Hi
I see 500 hpa maps of EU. Azore STHP expantion to western EU and formation of eastern med. trough is seen in such maps. If one suppose atmospheric rossby wave is stationary with zero phase speed relative to ground that i see in some literature, i expect more active cyclogenesis over med. sea. But these cyclones wont affect southern iran and most arabian countries now. Because of high altitude 500hpa system that is related to monsoon air sinking over the region. Here in Shiraz, It is warmer than normal now, e.g. temp is 17 33 but long term temp is 14 28 for these days. this is probably due to more strong air sinking that is seems due to med. activity along with monsoon.
Yes you are right. An an usual 500mb high sets over western Europe. At the same time, a weak trough over easten Meditteranean, with scaterred thunderstorms. Elsewhere over the Arabian Peninsuela, the semi-permanent subtropical high continues its influence with heat and sinking air.