Sunday, May 15, 2011

15 May, 2011

If you haven't already, click 'LIKE' on the WEATHER & CLIMATE THROUGH THE EYES OF MARK VOGAN blog FACEBOOK PAGE for regular 'on-the-road' updates, links to be biggest stories, photos and video thoughout the day, 7 days a week on your local, national and international weather.

TODAY'S TOP WEATHER STORIES
On Weather & Climate Through the Eyes of Mark Vogan
 
MISSISSIPPI FLOOD OF 2011 latest
MORGANZA SPILLWAY OPENS, FLOOD WATERS ROAR ACROSS LOUISIANA'S CAJUN COUNTRY
 
 
Towns brace for flooding as Mississippi River spillway opens
CNN
 
Miss. River spillway opens, towns await flooding
CBS NEWS
 
Towns await floodwater from diverted Mississippi
NBC NEWS
 
Morganza Floodway opens to divert Mississippi River away from Baton Rouge, New Orleans
NOLA.COM


 
River Flooding: The Cause
THE WEATHER CHANNEL

TODAY'S WEATHER ACROSS AMERICA By Mark Vogan
 
Pattern remains slow-moving through next week, a miserable week for the East, Storm and trough digs into West

This video explains the pattern well...


TODAY'S WEATHER ACROSS UK & EUROPE By Mark Vogan

Scotland remains beneath canopy of clouds and showers while Alpine Europe sees heavy rains and mtn snows push out and eastwards, allowing higher pressure to build into the new week

While here in Scotland it remains cool, breezy, showery and downright rotten, we have cool conditions stretching all the way down into southern areas of the UK, northern France and across into the Low Countries thanks to the trough over NW Europe, but change is on the way for the better. 

Warmer times are ahead for central and southern England as the wave over us now, will flatten out as pressures build up from Spain and pushes the lowr pressures north from London, Bristol up over Birmingham and Manchester, however, that's where it stops, leaving us up here in Scotland remaining the way we currently are... 

This higher pressure building up into France and managing to get just across the English Channel into the south of England will get halted once up as far as the Midlands thanks to a trough stationed over Scotland, this deflects the higher pressures and ultimately keeps Scotland and the north of England very cool with highs really struggling to get much above 14C for much of the next week, while over London Monday is likely to reach 22C or higher. With a new disturbance creating some enhanced instability over southern and central Spain, from Seville to Barcelona, showers and some fairly decent thunderstorms will fire up, especially since highs will get into the 30s C in the south and mid to upper 20s C from Madrid to Barcelona once again like we've seen throughout the weekend.

This very heat will push north all the way to London as mentioned and then deflect east with the troughs presence further north. What will also help the north and northeast turning of heat will be the influence of a somewhat be the development of a potent upper-level low which will ultimately develop from the surface low which caused a lot of bad weather over the Alps. This upper low is and will progress east, spinning across Italy and Greece which will move down into the central Mediterrannean basin creating quite a stir here with strong, possibly gale-force winds.

Looking at the European model for today, Tuesday and Thursday.


today's upper pattern
 
Tuesday's upper pattern

Thursday's upper pattern

WEATHER TALK
By Mark Vogan

Why does the Morganza Spillway have to open, flooding millions of square miles and ultimately ruinning thousands of homes?

Mark Vogan explains this afternoon the reason for the Morganza Spillway opening!

How did such a flood happen?

The Mississippi River is North America's largest and most powerful, fed by hundreds of other rivers. One of those rivers which feed the Mississippi, the Ohio River, is another large and powerful one.

The surrounding valley of which the two rivers have carved out over the hundreds of thousands of years are relatively flat as major river plains do be.


THIS VAST RIVER NETWORK RUNS BENEATH ONE OF THE MOST HOSTILE WEATHER CONVERGENCE ZONES ON EARTH

This very year has illustrated all too well what happens when you get a year which sees abnormal warmth over the South and abnormal cold over the north. This spells DISASTER when you've got an active pacific jet stream and active storm train along it thanks to a La Nina pattern (abnormally cold Equatorial Pacific waters). Storms that have rode along this stronger than normal jet instigated by the abnormalities in both north and south air masses only mean one thing, extreme weather occurs as heat and cold don't mix without a fight breaking out.

After a strong La Nina winter, this often results in deep troughs favoring a western position which progress eastwards with lows dropping into them and deepening them, helping the entire trough move east. After these Pacific lows do their thing in producing low elevation rain, high elevation snow and some wind across the Intermountain West, it's really only once they push out from the Rockies and onto the Plains where they then get far enough east to then pull air up from the Gulf of Mexico. It just so hapoens that this vast 'Bay' of very warm water is sub-tropical and very warm.


ONCE PACIFIC STORM SYSTEMS ENTER THE PLAINS, IT'S AN OPEN DOOR TO BOTH THE TROPICS AND ARCTIC

The problem is, the geography of the USA is such that once Pacific lows do get out off the eastern face of the Rockies, they cross out onto low elevation Plains which literally stretch unbroken from the sub-tropics in the south, to the Arctic in the north, no real mountains stop these air masses from being tapped by eastward tracking Pacific lows. Once these systems mix, extreme weather occurs.  

With the trough containing colder air in the mid to upper levels than normal and the ridge which builds AHEAD of the storm which pulls hot, humid air north, the trough eventually pushes east and replaces the ridge over the Plains. This makes cold air flow over top of the hot, humid air underneath as the trough crashes into the ridge. The big problem is heat and humid air wants to rise and with that rise into very cold air above, it creates a major imbalance which needs to be corrected. This infusion of air means mega thunderstorm development along a trailing cold front that forms ahead and south of the low. This collision has been directly over the major river network which makes up the Ohio and Mississippi River system.

The type of pattern we've had in 2011 has meant... 

Extreme drought across much of Texas where back last month we saw the worst wildfire situation in state history. Further east where the very warm, moisture rich air flowing north from a La Nina induced abnormally warm Gulf of Mexico has meant, copious, endless supplies of moisture into cross-continental storms trekking east. The super heat and humidity flowing like a hose into the abnormally cold air to the north forced heavy, persistent rains directly over both the Ohio and Mississippi valleys. The flat terrain for hundreds of miles surrounding meant flooding of vast swathes of farmland. Where does all this water go? The rivers, where do all these rivers go? The Ohio and Mississippi...


Unfortunately, this network of smaller rivers flowing into larger ones can't cope.

To sum things up.

Larger population settling in the vast floodplain combined with a time of what Meteorologist Joe Bastardi of Weatherbell.com dubs, a time of climatic hardship, makes for a devastating result.


The period of climate in which we live in spells more violent weather when you've got an increasingly cooler Pacific, it's in it's cold phase of what is known as the Pacific Decadal Oscillation (PDO) and with a still warm phase of the Atlantic Multidecadal Oscillation (AMO), this makes for both colder than normal and warmer than normal weather colliding over the Plains, where all the air masses often meet one another. Bring abnormally warm and cold air masses together and you've got more extreme weather. That is why we've seen the tornado season we've had. The greatest problem we have is the swell in population in the WRONG AREAS, i.e. the great flood plains. Whether it's New Orleans which sits beneath sea level, the low lying Mississippi flood plain or the vast flood plain of Bangladesh, when we live in a time of great alteration in our planets climate, with the greatest ocean on earth cooling and the Atlantic remaining warm (for now), weather is naturally going to get worse. Correcting the imbalance created by these huge energy containers (the oceans, which contain far greater energy than the atmosphere and this energy is released into the atmosphere above).

WEATHER TALK AFRICA, MIDDLE EAST & W. ASIA By Mark Vogan

Noorpurhal, Pakistan tops 48C today as heat looks set to peak over next 3 days across Indian sub-continent


After some showers moved through Pakistan and India's Plains and Thar Desert holding temperatures to more tolerable levels of 46C, today saw clearer skies and this aided a temperature boost to 48C at Noorpurhal, Pakistan today. The next several days promises to be the hottest of the year with the Pakistan Meteorological Department as well as both the Pakistan Weather Portal and Vagaries of the Weather all suggesting Severe Heatwave conditions over all of North India and Pakistan settling into from Sunday through Wednesday next week. Showers and Thunderstorms are likely to roll into southern India while very powerful high pressures creates an enviornment where no clouds can form and a blistering sun which will roast much of northern India in temps between 44-48C, while Sindh province of India and Pakistan will likely reach between 47-51C over the next 72 hours. The very deepening of the thermal low towards the crucial 996 mb level may be the very tigger to kick off a pronounced southerly flow up from the Arabian Sea and Bay of Bengal, the vital component to kicking off an early monsoon.
 
THE EXTREMES OF THE DAY
 
TODAY'S US EXTREMES
COURTESY OF ACCUWEATHER

HIGH: 98 degrees at Bullhead City, AZ
LOW: 19 degrees at Bodie State Park, CA

TODAY'S UK EXTREMES
COURTESY OF THE MET OFFICE

HIGH: 63 degrees (17.3C) at Hurn (Dorset)
LOW: 37 degrees (2.9C) at Benson (Oxfordshire)

TODAY'S EXTREMES HERE AT MY HOUSE
 
HIGH: 54 degrees
LOW: 41 degrees
 
Thanks for reading.
-Mark

No comments:

Post a Comment


My Ping in TotalPing.com