When the week began, the sun hadn't unleashed an X-flare all year long. In only two days, sunspot AR1748 has produced four. The latest X-flare from this active sunspot occured this morning at 0152 Universal Time. Although the sunspot is not yet directly facing Earth, this flare might have produced a CME with an Earth-directed component.
AR1748 has produced an X1.7-class flare (0217 UT on May 13), an X2.8-class flare (1609 UT on May 13), an X3.2-class flare (0117 UT on May 14), and an X1-class flare (0152 on May 15). These are the strongest flares of the year, and they signal a significant increase in solar activity.
Although AR1748 is not directly facing Earth, its strong flares have nevertheless affected our atmosphere. UV and X-radiation hitting the top of the atmosphere ionizes atoms and molecules, creating ion waves over the dayside of the planet. Sudden ionospheric disturbances -- "SIDs" for short -- make themselves known by the effect they have on low-frequency radio signals. When a SID passes by, the atmosphere overhead becomes an good reflector for radio waves, allowing signals to be received from distant transmitters. More SIDS are in the offing. (video)
even if you wish they were.**
LARGEST QUAKES -
Live Seismograms - Worldwide (update every 30 minutes)
This morning -
5.8 NEW BRITAIN REGION, P.N.G
Yesterday -
5/14/13 -
5.6 OFF W COAST OF NORTHERN SUMATRA
5.7 SOUTHERN PERU
5.0 NEAR EAST COAST OF KAMCHATKA
6.8 PAGAN REG., N. MARIANA ISLANDS
VOLCANOES -
Volcano Webcams
Mexico's Popocatepetl volcano has spewed a new column of ash with some of the material falling on three towns while glowing rocks landed on the towering mountain's slope. The volcano belched out a cloud of ash that rose four kilometres above its crater at 8:21pm on Tuesday (1121 AEST on Wednesday).
The ministry said "light quantities of ash" dropped on Paso de Cortes, a Mexico state community at the foot of the volcano, and the towns of Atlixco and Huejotzingo in the state of Puebla, some 23km away. Molten rocks were thrown one kilometre away, landing on the volcano's northern slope. The smoke was blowing toward the northeast. Mexico City is 55km northwest of Popocatepetl.
The volcano had already spewed some ash and rocks on Tuesday morning but a senior official later reported that it had calmed down. The disaster prevention centre reported low-level activity later on, including a 40-minute low-intensity tremor. The volcano has been rumbling and spewing steam, ash and rocks sporadically for days, prompting authorities to raise the alert level and prepare for possible evacuations last weekend.
Last week, Popocatepetl covered several towns in ash, including the capital of Puebla state. Authorities have raised the alert level to "Yellow Phase Three", the fifth of a seven-stage warning system, restricting access to an area of 12km around the volcano while preparing evacuation routes and shelters.
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TROPICAL STORMS -
In the Indian Ocean -
Tropical Cyclone Mahasen was located approximately 377 nm south of Calcutta, India.
Cyclone Kills 7 in Sri Lanka; Thousands Displaced - Cyclone Mahasen in the Bay of Bengal killed at least seven people in Sri Lanka. Mahasen, which brought heavy rains and landslides to Sri Lanka, was expected to hit Bangladesh and Burma later this week.
“Seven people have died and 10 people have got injured. There are 7,399 people from 1,947 families affected." 3,881 people have been displaced due to the cyclone. Three people were missing due to heavy rains and landslides. Officials at Sri Lanka's Department of Meteorology have said the center of Cyclone Mahasen is located 900 km off the island nation's eastern coastal town of Pottuvil.
On Tuesday, a boat carrying about 100 Rohingya Muslims capsized off western Burma and many were feared drowned at the beginning of a mass evacuation from low-lying regions ahead of a powerful storm. The tropical depression threatens areas of Myanmar where about 140,000 victims of ethnic and religious unrest are living in camps. The United Nations warned last week there could be a humanitarian catastrophe if people were not evacuated.
Mahasen is expected to hit northeast India in the next 72 hours with heavy rains and thunderstorms expected in the region. On May 16, the cyclone is expected to cross the Bangladesh coast. Bangladesh warned millions of people on Monday that the cyclone could barrel into their coastal homes later this week as authorities in Myanmar began moving potential victims to higher ground.
Fifteen of the twenty deadliest tropical cyclones in world history have been Bay of Bengal storms that hit Bangladesh, India, or Myanmar. The most recent of these horrifying storms was 2008's Cyclone Nargis, which killed 146,000 people in Myanmar.
The Bay of Bengal's notorious history is why hurricane forecasters are watching Tropical Cyclone Mahasen a little nervously today. Even though there has been little change to the 55 mph tropical storm over the past two days, the storm remains a potential threat to undergo rapid intensification into a dangerous major hurricane, although it is running out of time to do so. Ocean waters are an exceptionally warm 31°C (88°F), about 1°C warmer than average for this time of year. The warm ocean waters extend to great depth, and the Tropical Cyclone Heat Potential (TCHP) is over 90 J/kg/cm^2, which is favorable for rapid intensification.
The official forecast brings Mahasen to Category 1 strength before landfall occurs in Bangladesh near the Myanmar border on Thursday near 18 UTC. However, the model forecasts of Mahasen from the GFS, ECMWF, UKMET, GEM, NAVGEM, and FIM models continue to show wide disagreement on the future intensity, speed, and landfall location of the storm. It is possible that wind shear will keep the storm disorganized and below hurricane strength until landfall, as suggested by the ECMWF model.
Mahasen was approaching a trough of low pressure to its northwest that is expected to recurve the storm to the northeast into Bangladesh. There is a lot of hot, dry air to the storm's northwest over India, and if this dry air gets wrapped into Mahasen's circulation, it could put the brakes on rapid intensification.
Even a weakening Category 1 storm has the potential to bring a devastating storm surge to the coast of Bangladesh, and torrential rainfall will be a major flooding threat regardless of the storm's final intensity at landfall. The 00Z May 13 run of the HWRF model predicts that the Mahasen will dump a significant area of heavy rains of 16 - 30 cm (6 - 12") over Maynmar and Bangladesh. The storm surge, high winds, and heavy rains of Mahasen are a particular concern for the thousands of Myanmar refugees living near the coast in makeshift camps.
Mahasen spun up in response to an active phase of the Madden Julian Oscillation (MJO) that has been moving through the Indian Ocean during the past week. The MJO is a pattern of increased thunderstorm activity near the Equator that moves around the globe in 30 - 60 days. The strong MJO pulse coincided with a convectively coupled atmospheric Kelvin wave (CCKW), a wave of increased heat and moisture propagating along the Equator, which helped increase thunderstorm activity. The active pulse of the Madden Julian Oscillation is expected to reach the Western Caribbean (in a somewhat weakened state) May 21 - 25, and there will be a heightened chance of an early-season tropical storm forming in the Eastern Pacific and Western Caribbean during that time period.
HEALTH THREATS -
Six new Saudi coronavirus cases include 2 health workers. Two healthcare workers are among six new novel coronavirus (nCoV) cases reported in Saudi Arabia since late yesterday, suggesting that the virus might have spread from infected patients to hospital staff members.
