Friday, July 9, 2010

9 July, 2010

Today's Top Weather Stories
On Weather & Climate Through the Eyes of Mark Vogan

Sizzling Temps to Ease at Tour de France; Showers Likely
The temperature in Gueugnon, France, was a sizzling 94 degrees F (34 C) as riders crossed the finish line after Stage 6.
AccuWeather News

Gravesend, Kent experiences UK's warmest of 2010 so far today with a high of 89 degrees!(See Weather Talk below)

Baked Britain: Babies and pensioners most at risk from soaring temperatures as mercury hits 31C

The Daily Mail



AMERICANO HOT: HOTTEST WEATHER OF YEAR 2010
Mark Vogan's Re-Capping thoughts of an historic heatwave which effected over 150 million Americans

Northeast's Worst heat in 10 years but Southeast and Pacific Northwest
heat also impressive!

By Mark Vogan

The Northeast

After a truely ferocious blast of heat over this past week where highs screamed well into the 100s from Richmond, Virginia to Boston Massachussetts and chocking humidity equating to Caribbean levels all the way to central Maine and northern Vermont to go with the blast furnace, the heat was certainly one for the records as highs not only were the warmest since August 2001, the last time Central Park and Philadelphia topped 100. Other spots such as Wilmington, Delaware, saw their hottest in OVER 40 YEARS, Baltimore, Maryland saw it's hottest day in 27 YEARS! Philadelphia, Pennsylvania not only sweltered in two straght afternoons above 100,it also endured it's hottest ever night with a low of 83 degrees and temps which were as warm as 94 degrees at 10.30pm and feeling like 100. The day Newark reached 103, it warmed remarkably fast that morning. It was an astonishing 95 degrees at 9AM and had topped 100 degrees at the site by 10.51am!.....

Philadelphia topped 98, then 102, first century mark temperature since August 9, 2001, after a toasty night which remained in the upper 80s most of the night, once again the thermometer rocketed, topping the century mark for the second consecutive afternoon, reaching an unbearable 103 degrees and with dew points high, it felt like a steam assisted oven. The 103 reading was the warmest there since 1995.

TYPICALLY COOLER CENTRAL PARK MATCHES NEWARK FOR HEAT!

New York City has 3 major or key recording sites. Newark International Apt, New Jersey to the SW of Manhattan. Central Park which is in the heart of Midtown, Manhattan and LaGuardia International Airport to the east, northeast across the East River in Queens. Both Newark and LaGuardia "typically" endure warmer temperatures day and night than Central Park thanks for a more urban environment, despite Central Park being in the core of Manhattan. The park as you'd expect has lots of greenery, grass, trees, foliage and several bodies of water. This environment supports cooler temperatures than the overwhelming mass on concrete, asphalt and other heat absorbing properties which of course heat the air from surface upwards. These heat absorbers collect heat throughout the day and then release it back to the atmosphere during the night as longwave radiation, therefore explaining why LaGuardia in August 2006 during a regional heatwave endured an overnight low of 87 degrees with most of the night staying in the 90s! Newark also endures hotter nights than many areas also. Central Park often cools suffiently as the greenery "reflects incoming solar radiation" rather than absorb it and therefore, nights cool easier. However, like in 2001, Central Park's reputation for being cooler wasn't on three days this week where highs topped 99, 103 and 100. The sheer intensity of the sun, thanks to the might of the upper-level ridge, wind direction etc allowed temps to heat up to within 3 degrees from the city's all-time record set back in 1936.



Drier than normal soils throughout the Northeast also played a massive role in not only aiding the easier heating of the air since there was less evaporating to do from the sun since soils had much less than normal moisture content. It also enhanced the compressional heating process transported by the W, NW wind flow blowing out of the Ohio Valley and Appalachains.

LOW OFF VIRGINIA WAS SAVING GRACE TO COAST, THEN CITIES

The saving grace to the Northeast heat was a storm off the east coast which allowed an eventual enhancement in the sea breeze which on day one of the I-95 consecutive 100s was non-existent as Boston topped 100, though it slowly crept to 90 only a couple of hours after maxing out there as winds did kick in off the ocean, as for coasts from Long Island to particularly the Jersey and Delware Shores, whilst NYC sizzled it was in the mid-90s with little breeze on the beaches, day 2 and Central Park again topped 100, Philly peaked with it's 103, whilst changes were occuring at the shore with highs dropping back to the 80s, despite the vast and intense heat gruelling just miles from shore. Interestingly, the low even by day two was close enough to kick in and penetrate east, northeast winds as far inland as Manhattan and Philadelphia as temps tumbled rapidly after the peak heating around 2pm.



By day 3, highs had fallen to only 90 degrees at Philly and 89 at Central Park, HOWEVER dew points and humidity levels were rocketing through the roof, making it feel just as bad on those scalding, shimmering city streets, the shear sweatiness and closeness off the air, combined with 90-degree heat made for such uncomfortable, tiring conditions. Dew points a few days earlier I noticed was 75 degrees in northern Maine and Vermont, this was thanks to a flow off the ocean as well as a surge pushing north from the eastern Gulf ahead of a eastward progressing frontal system. This and the east moving boundary off the ocean would squeeze the heat, but would lead to a blistering hot day for the Southeast whilst an increase in coverage and intensity of showers and thunderstorms as well as cooling relief for the Northeast!

ATLANTA TOPS HOTTEST OF 2010 WITH HIGH OF 97 DEGREES, 102 AT MONTGOMERY


The work of the two fronts moving towards each other, sent the heat south as well as briefly west of the I-95 into central Pennsylvania, down into central and western Virginia, bringing heat but also noticably warm nights. In fact Jesse Ferrell of AccuWeather.com in State College, Pennsylvania mentioned to me earlier today that they recorded a low of 74 degrees, warmest night since at least 2008. Bare in mind, State College is over 1,200ft in elevation and surrounded by mountains.

FOR GREAT LOOK-BACK INFO ON THIS WEEK'S HEAT WAVE, CHECKOUT THIS ARTICLE FROM ACCUWEATHER.

PACIFIC NORTHWEST ROASTS AFTER COLD, UNSETTLED SPRING AND EARLY SUMMER

Just look at how hot Seattle got yesterday (graphic above). High pressure has been shoved north of the Great Basin and downsloping west winds off the Cascades created compressional warming which allows Seattle the chance at reaching the mid-90s or higher. It's July and not really that much of a surprise to see 95 degree highs at this time of year in Seattle, however, it's the fact that Seattle, Portland and throughout the PNW has seen such a cool pattern that makes yesterday and indeed today's expected 90 in Seattle much more extreme. Afterall Seattle saw it's latest ever arrival of a 75 degree day this year. 

Highlights of the Great Eastern Heat Wave
AccuWeather News

While triple-digit heat in the Northeast is now a thing of the past and will soon break off in the Deep South, the great heat wave of early July 2010 will not be soon forgotten.



At least four locations had 100-degree heat for a four-day stretch: Newark, N.J.; Frederick, Md.; Selinsgrove, Pa.; and Shenandoah Valley, Va.


In Newark, N.J., spanning July 4 through July 7, the period tied the all-time streak for 100-degree temperatures set in 1993 and also in 1953, according to the National Weather Service.


Multiple cities had three days in a row of 100-degree heat including: Baltimore, Md.; Trenton, N.J.; Richmond, Va.; and Reading, Pa.
Fifteen killed in monsoon floods
BBC Weather


your america today forecast
by mark vogan

northeast & mid-atlantic
After days of 90s and 100s across the Mid-Atlantic and Northeast, a front now rules the picture across the reion, dropping highs to the upper 80s from NYC down to DC and showers and thunderstorms are likely to blossom as the air is still very sticky and bouyant. It will feel unpleasant whilst walking around downtown streets throughout the Northeast today and skies will grow dark and stormy and at anytime today but especially during the warmest hours of the day. This is when dangerous lightening, torrential downpours, strong to even damaging winds and even small hail can hit. Lows should fall into the 70s during the overnight hours tonight. 
southeast & florida
Today will be characterised by dominant showers and thunderstorms over the wester region whilst more sun and heat as well as humidity for the east side. Highs will range from 88 at Dallas to 92 down in New Orleans with showers and PM storms likely, whilst Atlanta to Charlotte will see mid to upper 90s! High around 95 at Atlanta to 98 at Charlotte. Florida should see showers and storms over the north and east, whilst on the west coast and towards Miami it should stay mostly dry, sunny, hot and humid, you know the drill! Lows tonight should be in the mid to upper 70s for everyone.northwest & southwest
A heat wave has simply brought mid-summer in with a vengence to the PNW on the heels of what has been a very cool, unsettled and dissapointing spring and early summer from Seattle to Portland and throughout the interior PNW. Highs today should top 90 for Seattle, 93 for Portland, whilst east of the Cascades, some areas are likely to top 100 degrees like we saw yesterday.
As for the Southwest. Highs range from 70s at the beaches, 80s for LA, 90s to low 100s from coastal valley to Inland Empire of California. Once out into the desert, highs easily top 100 degrees. Phoenix should warm to 113 degrees this afternoon, whilst Las Vegas should warm to around 106 degrees. Of course abundant sunshine will rule from the Mexican to Canadian border.. Showers and storms will be restricted to the mountains. Lows range from 50s and 60s from the beaches to coastal valleys, 70s throughout the deserts, 80s for large cities of Vegas and Phoenix.  
southern plains
I'm affraid nothing will change from Houston to Dallas to Oklahoma City. Highs range from 93 at Houston, 88 at Dallas to 85 at Oklahoma City. With perhaps the exceptions of the upper Texas coast down to San Antonio on west towards El Paso, most spots across the southern plains should see showers and thunderstorms pop up. 
northern plains
The Northern Plains from Williston, ND all the way to Chicago looks just great today with lots of sun and warm temperatures. Warmest will be found over the Dakotas where highs top 90 degrees at Bismarck, Minneapolis will be just beautiful with a high of 87 degrees under clear, sunny skies. Chicago, you too will enjoy 87 degrees with sunshine in abundance. Further south between Denver and Kansas City, across the St Louis, high will be in the mid to upper 80s but showers and thunderstorms are likely. Lows tonight range from 50s in the NW of the region (Dakotas), 60s and 70s from Minneapolis to St Louis, across to Chicago.

Weather Today across America
From AccuWeather



Record-Breaking Northwest Heat to End
AccuWeather

Heat Wave Breaks in the Northeast with Downpours, Thunderstorms
AccuWeather

Flooding Hits Oklahoma City, Tulsa, Amarillo, Victoria
AccuWeather

Weather Talk
By Mark Vogan


Hyde Park in Central London looking desert-like!

Image courtesy of the Daily Mail

UK DIVIDED BY TWO VERY DIFFERENT AIR MASSES

Today marked an impressive contrast in both sky and temperatures. As I followed the southeast of England temperatures this afternoon, my thermometer was reading 61 degrees. Glasgow as of the 3pm observation was 56 degrees and throughout much of the morning and early afternoon, skies had been very overcast with pockets of heavy showers in between more longlieved spells of fine, steady falling but soaking rainfall.

Amazingly, Glen Ogle, between Stirling and Crainlarich was reading a chilly 48 degrees at 3pm.. Amazing for July, yet at the same time, Gravesend, Kent, on the outskirts of southeast London was a sultry 89 degrees with a substantial humidity lingering over the southern half of Britain as a flow continues to be pumped from a tropical maritime source.

Whilst an area from the Midlands southward enjoys persistent "mostly sunny skies and warm temperatures", things become more and more unsettled the further north and west you go. Across Scotland persistent west flow aloft is continuing to usher in marine air of a more northerly origin, though I'm hesitant in saying it's a maritime polar origin as temperatures, though cool, aren't cold by any means.. A mugginess and mild temperatures are in existence in the north of the UK, with perhaps the exception of far northern Scotland.

A boundary seperates Britain. Sub-tropical air feeds warm and moist air across southern Britain and a fresh surge of heat is push into the south from the increasingly sweltering continent. The high baking interior Europe is nudging enough west to allow London upper 80s by day and sultry 70 degree nights and with air flowing off the warmer than normal Atlantic, south of the UK and colliding with hot air flow west off Europe, nighttime temperatures hold well into the 70s, beyond midnight in Greater London and perhaps city's suchg as Oxford. Meanwhile, a trough, cool pocket of air aloft and large low pressure spinning west and north of Scotland and Northern Ireland is continueing to hold pressure heights down, restricting warming as the air is coming from a cooler source and also propelling persistent unsettled, showery, windy weather.

Highs continue to struggle out of the 50s in many Scottish locales with places like Glen Ogle and other remote and sheltered spots perhaps barely making it out of the 40s, whilst a region from Birmingham to London and up to Norwich will see nights warmer than daytime highs across Scotland and highs which knock on the door of 90 degrees over the next 2-4 days.

It's only a matter of time, with the type of pattern, the persistency as well as the increasing intensity of warmth over southern Britain that with seasonal northward advancements of the jet, that warmer, drier and more anticyclonic pattern will reestablish itself over northern Britain. This may happen when England's south and central regions may be struggling with long, persistently hot days with highs in the mid-90s, perhaps as we look towrds the later part of July and into August! A hot August looming for not only England's south but all of the British Isles?

Related news item from the BBC

Hot weather prompts Met Office heatwave health alert

Stay tuned.
Vagaries of the Weather
India & Sub-Continental Asia Weather
By Rajesh Kapadia

What's Reaching Today's Blogs?

One for the Record Books
Joe Lundburg, AccuWeather

Ongoing Flooding in Mexico
Jesse Ferrell, AccuWeather

Weekend Western Outlook
Ken Clark, AccuWeather

Today's UK Extremes
Courtesy of the Met office

High: 89 degrees at Gravesend (Kent)
Low: N/A

Note: Warmest day in UK so far in 2010!
Today's Extremes here at my house

High: 61 degrees
Low: 55 degrees

TODAYS COND
Very unsettled, breezy with persistent light, fine and drizzly rains, some pockets of heavy showers... Cleared a little by afternoon.


Thanks for reading.
-Mark

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