Monday Jan 30, 2012:

A long-wave upper air trough digs over the Mediterranean, with widespread rainfall over much of Jordan, northern Egypt including Sina’a, Syria, Lebanon, and Palestine. This time rain is likely to fall over interior areas that are usually dry.

Tuesday Jan 31, 2012:

Rain is expected to extend to northern half of Iraq and western Iran. A new surface low starts to form over northern KSA, with some thundershowers possible over northern red sea coasts of KSA. The low is expected to pull southerly winds ahead of its track, driving temperature upward over all the gulf countries of Oman, UAE, Qatar, Bahrain, KSA, and Kuwait. Dusty and gusty winds are possible over central and northern KSA, Kuwait, and northern Arabian Sea (along Kuwait and Iraq) which will become unusually rough. By Tuesday night, a rainy clouds start to develop over parts of KSA and Kuwait. Remaining wet over coastal Mediterranean.

Wednesday Feb 1, 2012:

February to start quite wet over Kuwait as moderate rainfall is expected to fall there including surrounding regions of KSA, parts of Iraq, with heavy rainfall over much of southwestern Iran. Arabian Gulf remains choppy, and remaining wet over coastal Mediterranean. Temperature cools down in Kuwait and northern KSA, but remaining warm over the rest of the gulf countries.

Thursday – Friday Feb 2-3, 2012:

Drying up as cooler northwesterly winds and a surface high gradually build up over KSA, Bahrain, and Qatar by Thursday, before reaching the UAE by Friday. Temperature fall to normal levels. This winter proves to be incredibly dry over the UAE as the impact of this low is minimal over the UAE.

Expected rainfall from Jan 29 to Feb 2, 2012

Synoptic weather:

After delivering rain to parts of the Mediterranean and northten Egypt, A mid-level low pressure is expected to move eastward towards southwestern Asian countries of Iran and afghanistan. With surface lows and fronts forming ahead and eastward of the upper lows, rain will fall over Iraq, Iran, then afghanistan, and Pakistan , with a cold front developing over the Gulf of Oman, northern Arabian Sea, southwestern Pakistan by Saturday Jan 21. Colder air along with a surface high will take over westward of the cold front, impacting much of the Arabian Peninsulua.

Colder Air Pushes Through:

Colder air will start making its way to the region by late Friday as windier conditions prevail , and it will be coldest in northern Arabia. Saturday and Sunday Jan 21-22 will be the coolest as daytime temperatures will fall 4-8 degrees below normal. Subsequent days will continue to be below normal, but less extreme. Kuwait and Riyadh daytime temperature on Saturday/Sunday will struggle to go above 12c with nights being quite chilly, possibly going below to -5 degrees. Bahrain and Qatar daytime temperatures will fall to mid-teens with some gusty winds on Saturday. In the UAE, daytime temperatures will be between 17-21 but with very windy conditions, and Muscat to be in early 20s.

A Lot of Winds For Some:

The Arabian Gulf will be the scene of very strong winds on Saturday with very rough sea conditions. Offshore winds will easily go beyond 60 Km/hr. UAE cities will be less extreme, but still gusty winds will blow over the northern coastlines. Winds will be between 40-50 km/hr with occasional gusts to above 50 km/hr. One area of concern is the east coast of the UAE where winds might gust beyond 60 km/hr. Open areas in northern UAE will be prone to localized dust, but coastal areas will experience fresh strong cool winds blowing from the sea. Winds will make it feel even cooler.

Unusual rain areas:

Southwest Pakistan, northern Arabian Sea, and Gulf of Oman will be under the influence of thunderstorms and rain on Saturday Jan 21.

Chance of showers for the UAE:

Small chance isolated rain showers over UAE coastlines between Saturday and Sunday. But the chance increases by Monday as a an upper air trough dives southward over the gulf, bringing some showers to northern UAE.

Clouds can be seen over upper Gulf. Jan 11, 2011.

It will generate some thundershowers while it slowly drifts southeastward and impact other Saudi Arabia cities along the Arabian Gulf coastlines. It might also bring chances of showers over Bahrain and Qatar, otherwise the front will dry up and end up bringing cooler weather on Saturday to mid sections of the Gulf before bring cooler air to the UAE on Sunday. The weather will cool siginifcantly accross KSA by Sunday and will end the recent warming. As for the warming, Jan 12-13 might bring the warmest day this winter over the Gulf countries of UAE, Bahrain, Qatar, and KSA. Many interior areas in the UAE and KSA will easily hit 30c. By Sunday, windy weather will prevail over the Arabian Gulf as cooler shamal arrives.

The upper low after moving eastward will generate wet conditions over eastern and southern Iran, afghanistan, and northern half of Pakistan.

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.

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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.

Weather-wise, the behavior of this tropical storm was not typical. Usually, tropical storms and cyclones pass by Oman in a span of 24 hours. But Keila stalled off the Oman coast for several days, something that increases the risk of persistent rainfall, leading to floods. Keila stalled due to weak steering currents which help direct storm movement. Most of Keila’s heavy rain was offshore, and only part of it reached SE Oman (see below map). Yet it managed to pull large tropical moisture to northern Oman as well.

Arabian Sea tropical storm Keila has been dumping exceesive rain over coastal Oman. Below image from NASA TRMM site shows accumulated rain up to 9 GMT on Nov 3, 2011. We can see most coastal areas receiving around 50mm, with some areas exceeding 100mm and well into 300mm of rain over SE Oman! Some rain also reached Gulf of Oman.

7-day Accumulated rainfall ending at 9GMT on Nov 3, 2011. See the extreme rainfall over SE Oman.

These are extreme amounts and are likely to be associated with deep convective thunderstorm clouds embedded with this tropical storm. Some gusty winds have been recorded as well. With the depression lingering offshore for at least 2 more days, rainfall amounts quickly rose up, reached northeastern Oman near Muscat, but focused more around the low’s centre near SE Oman. Even as the low starts to disorganize and weaken in 72 hours, abundant left-over moisture will ensure daily scattered to isolated thunderstorms for a few more days.

The weak upper low over SW Asia, although the first this season, is expected to reduce the impact of the upper high that usually suppresses convective thunderstorms. There will also be scaterred showers and thunderstorms over eastern half of Iran and afghanistan, marking the first rain of the season.

Later this week a high pressure takes over again over the Arabian Peninsuala as a low pressure impacts the Mediterranean.

Thunderstorms during the afternoon hours over interior UAE on Oct 8th, 2011.

Due to slight weakening of the subtropical high and slight cooling at lower levels, surface winds converging along the mountains should face less resistence to develop into isolated brief shower clouds. But October is typically a very dry month.