Tropical Trouble

Just a quick update… more tomorrow. The tropics are on fire tonight as Hurricane Gordon moves into the Azores as it transitions to an extratropical low. Also 94L and 95L are of concern.

GORDON: CAT 1 85mph winds. Will move through the azores weakening as dry air, high shear and cold waters take their toll on him. Should be extratropicial be tomorrow night.

94L: Is a low pressure system roughly 1/2 way between Africa and America. It is likely to develop while moving W at 20 mph. THIS COULD BE A THREAT TO THE US IN A WEEK AND A HALF OR SO. LARGE UNCERTAINTY.

95L: Is a low pressure system in the W GOM. Some weak development is possible as it drifts around the Western GOM.

STAY TUNED!!!

-Jack

More climate forecasts; Fall 2012, Winter soon? winter late?

Well following in the shadow of my winter forecast I am coming out with my fall forecast. LAst year was the beast example I could give for “Early snow doesn’t always mean lots of snow” We had historic snows in October and virtually nil in the rest of the season.

Fall 2012: ENSO: Modiki holding steady though a weak El Nino could crop up later on raising temps and precip. MJO: (Madden Julian Oscillation) levels will be more negative than positive so a storm could form fairly easily from virtually nothing. NAO and AO: Weak to moderate negative trend means cooler temps and more precip.Temperatures will be about average for much of the time period so this means, snow likely early but might not accumulate till later.

Forecast for Eastern US for the next year (climate)

So new climate models came out today and here is what to look for for the eastern CONUS.

Winter 2012: Average for most areas. Slightly warmer with slightly more precipitation due to a Modiki type event. This is when there are above average SSTs in the equatorial East Pacific. Then comes the ice-cold Chilean current; underwater. The warm water heats up the air causing it to rise. Thunderstorms form in an area known as the ITCZ or Inter tropical convergence zone where opposing trade winds meet. These thunder storms cause an upwelling of water therefore bringing the cold chilean-current waters up to the surface. causing pools of warm water and cool water to swirl together. So in determining the ENSO (El Nino/Southern oscillation) event of this year because it is taken from averages ( cold + warm in average terms cancels to 0 there fore not El Nino (Warmer) or La Nina (Colder) but instead a modiki year which is very rare) becomes very difficult. Instead there is a different set of rules for a Modiki year.

Photo: current SSTs in the east pacific. Notice the bright reds and swirling pockets of blues.

 

Forecast: SNOWY and average temps For us on the east coast.

***SPECIAL WEATHER BULLETIN***

Issued for Coastal VA and surrounding areas
Valid from 200PM EDT – 800PM EDT AUG 15 2012

Severe weather will impact this region today with high winds and large hail. Be prepared for oncoming severe storms.

Climate forecast

Winter 2012-2013:

There will be a weak El Nino and a likely negative PDO. In more simple terms, an area of moderately warm waters off the coast off Peru (El Nino) and Cooler waters off the SW coast of Alaska(Negative PDO). So what does this mean for the US? It means that the eastern seaboard will see cooler temperatures so it will be a cooler than normal winter for the eastern third of the country. Also this set of conditions favors a pattern known as the Greenland block. This is when a ridge of high  pressure sits over Greenland and causes the jet stream (which is a “storm highway” and the divide between warm and cold) to dive south into the Eastern US. This ridging will vary from week to week this winter and will not be as strong as 2010-2011. The East will see Above-average precipitation (likely in the form of snow due to below average temperatures. In the Center of the country there will be the other counterpart to the Eastern trough, the high where the jet stream rises warm air and dry air into the nations heartland causing lower than average snow levels and worsening drought. In the Western US it should be a fairly average winter other than the fact that the Pacific storms will be more powerful and more frequent.

Stay tuned!

-Jack

Reliably hype-free weather info for Western Maine and New Hampshire from amateur forecaster Jack Sillin

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