Rainfall amounts average 25mm over a large section of KSA, with some areas nearing 50mm. Doha also reported 18mm of rain. It has been exceptionally cool in Riyadh on Tuesday with temperatures not exceeding 10c during a rainy Tuesday. Cool weather with rain also affected Bahrain and Qatar.

Rainfall accumulation up to Thursday Dec 1

Nov 26 – 27:

Cloudy weather will continue with isolated showers over parts of mid and eastern Arabian Gulf. Those showers might reach coastlines of Bahrain, Qatar, and western UAE.

Rain showers over Bahrain and Mid Arabian Gulf Nov 26.

Cooler weather will prevail over much of the region, bringing pleasant weather conditions.

Nov 19 – 24 Cold Front and Rain:

The subtropical high will move eastward, so will the mid-latitude low. While scatterred showers will linger over Kuwait, Iraq, and western Iran, a cold front will develop by Monday Nov 21 and will start moving eastward as well, bringing cooler air with it. While doing so, the area of scattered showers will gradually move from northen Arabian Gulf on Monday, to mid Arabian Gulf on Tuesday. This will cause scattered thunder showers over coastal Saudi Arabia, Bahrain, and then Qatar. Iraq and the mediterranean will dry up. By Tuesday the cold front will move further eastward to impact central Iran and eastern Arabian Gulf. On Wednesday some scattered showers “might” affect parts of coastal UAE and mountainous regions, northern Oman, and Gulf of Oman.

Most of the thundershowers affected UAE islands, with no noticable impact on UAE coastlines. Rainfall reached around 20mm over some UAE islands, and 44mm over Khassab in northern Oman.

Rain Radar on Wedneday Nov 23: Thunderstorms almost made it to UAE coastlines. But they still delivered rainfall to UAE islands.

Current Situation as of Nov 19:

Current temperautres accross the Arabian Gulf countries are above normal as a subtropical high pressure dominates much of the Arabian Peninsula. Meanwhile, a mid-latitude low has been affecting the eastern mediterranean with rain showers and thunderstorms. The areas of SE Iraq, Kuwait, and western Iran have been under this wedge of temperature gradient, under the oppsing air masses of the subtropical high and the mid-latitude low. With favorable surface convergence and upper divergence, clouds and scattered thundershowers have been occuring there as well over the last few days. But things are about to change.

A new tropical storm has formed over SE Arabian Sea. It will track NW during the next 3 days. When the storm reaches northern parts of the Arabian Sea, it is expected to weaken due to high wind shear and lower sea surface temperature. Yet, impacts over Arabian Sea countries can’t be ruled as of now. Stay tuned for more updates.

Water Vapor Satellite image shows the storm forming over SE Arabian Sea.

It seems that time will stop moving as the same weather keeps occuring everyday. Some will even feel we have moved backward in time!

Starting late Monday, a mid-level upper low will deepen over the eastern Medeiterranean, and an upper high will take dominance over the northern Arabian Sea.

500mb height lines expected for Nov 15. Contours represent the height in tens of meters. At these heights, the pressure is 500mb. High heigts (pressure) in the Arabian Sea with low heights in the Meditteranea,

The Rainy group:

Rain, showers, thunderstorms, and mountain snow will impact the Medeiterranean coasts of Lebanon, Palestine, Syria, Egypt, with some showers reaching parts of Jordan as well.

Meanwhile, a stationery front will form over the northern Arabian Gulf, with some rain and showers over Kuwait, nearby Saudi Arabia, and southern Iraq and Iran. The front will later develop into a cold front, bringing showers and thunderstorms again in the weekend. Some showers might reach Bahrain. But before all that, these same areas will heat up significantly, possibly to early 30s and late 20s.

The dry and warm Sector:

Much of Oman, the UAE, Qatar, and Bahrain will become suddenly warmer. But nights will remain mild even if days warm.. Daytime temperatures to be in late 20s to early 30s. Kuwait will also heat up until the rain arrives by Tuesday/Wednesday. However, the rest of the Arabian Gulf will remain dry. I guess Oman needs this dry break more than any country. The Arabian Sea will also see an end to its tropical season, giving Oman a much-needed break.

By the start of the next week, the upper low over the Mediterranean will move eastward and the cold front bring cooler air to western half of the Arabian Peninsula.

___
A fresh tropical system has formed in central Arabian Sea. it has reached tropical storm status. Easten coast of Oman is expected to get some light to moderate rainfall from this tropical low during the next 2-4 days. Some impact might reach SE Pakistan, which needs to keep an eye for any changing storm track.

Northern Oman has just received some thundershowers from the Arabian Gulf cold front. And one week back much of coastal oman had to deal with tropical storm Keila, which dumped a lot of rain and killed 14.

Infrared satellite image of the tropical storm on Nov 8, 2011.

Infrared Satellite image Nov 6, 2011. A fresh tropical system can be seen in the Arabian Sea.

Rain Radar as of 3:50AM GMT on Nov 7. Showers and some thunderstorms can be seen over the Arabian Gulf, UAE, and Qatar.

The weather has really cooled down over Kuwait and parts of Saudi Arabia with daytime temperatures in mid 20s.

After some rain over the Mediterranean, a developing mid-level low over SW Asia will help cause rain over Iraq from Firday to Sunday and Iran for the next 4-5 days. A weak cold front will develop over the Arabian Gulf. It will cause scattered thundershowers over Kuwait on Saturday and Sunday. The front is expected to slide southeastward over the Gulf, bringing the first rain of the cool season in the form of scattered thundershowers to coastal Saudi Arabia, Qatar, and Bahrain. Some showers might reach the UAE and Oman on Monday and Tuesday. A few thundershowers might bring gusty winds. Significant cooling in Kuwait and Saudi Arabia, with mild weather over the Arabian Gulf. Sea conditions will also get rough due to wind conditions behind the front.

Lightning strikes near Bahrain at 8 PM GMT on Nov 6, 2011.

Satellite image of Nov 5, 2011. Rain shower can already be seen over Kuwait and Saudi Arabia borders. This is the main boundary area that is expected to develop into a cold front.

Rainfall:

Rainfall exceeded 40mm over Masirah island. Other areas received between 5 – 30 mm of rain. With rain continuing for a few more days, several areas of coastal Oman might reach 50mm of rain.

Impact over Oman mainly:

Eastern coasts of Oman and possibly northeastern coast of Yemen are expected to receive some showers and over several periods between Sunday and Thursday. Showers could reach northerneastern Oman coasts. Other interior areas will experience cloudy weather. There will also be some clouds over parts of the UAE, but no rain is likely. And the Hajar mountains might receive some isolated afternoon showers as well.

Rain not part of the “cool” season

While these showers over Oman are arriving in end of October and early November, they are not the first rain of the cool season. It is part of the tropical activity of the Arabian Sea which goes through 2 windows of tropical activity. The first is in May and June, which produced violent cyclones in the past few years. The second is between October and November. The current low pressure is weak compared to tropical standards. But, it is expected to deliver much needed rain to Oman coastlines.

Where next?

There remains some uncertainty to the future behaviour of the low pressure. But most likely, it stall off the Omani coasts for 2-3 days, resulting in some prolonged rainfall over coastal Oman. Stay tuned for updates.

Infrared Satellite image shows convective clouds of the tropical low impacting Oman. Oct 31, 2011.

Infrared satellite image Oct 30 shows the low pressure getting closer to Oman.

Water Vapor image of the Arabian Sea Low. Oct 28, 2011.

Elsewhere, some showers and thunderstorms are expected in Iraq and western Iran during the next few days as an upper low approaches. Upper lows are forecasted to gain more momentum as we head into November and the winter months, and in some years November rainfall in parts of the Arabian Peninsula is quite normal.

Temperatures should go down slightly, and will be between 32-35 during the day starting on Saturday. Temperatures are dropping slightly as days are getting shorter. With November just around the corner, milder air is not that far away. But it will depends on the timing of first wave of cooler air sometime during the first 2 weeks of November.

Elsewhere in the Meditonerranean, a few showers are possible on Saturday Oct 15 and Sunday Oct 16, with temperatures staying mild and nice. Some showers are possible over northern Iraq on Saturday Oct 15.

A mid-tropospheric high pressure expected to build up