Today's Top Weather Stories
On Weather & Climate Through the Eyes of Mark Vogan
Aiden Bernardo, 4, stops to enjoy one of the fountains at the Paseo Vista Park in Henderson Sunday afternoon. (Photo courtesy of the Las Vegas Sun)
Long Standing Heat Records fall across the American Southwest yesterday
Special Story By Mark Vogan
Las Vegas' high of 110 also, not only was a record high but was in fact the earliest 110-degree reading at McCarren International Airport (LV's official recording station) on record. Just getting in front of the last earliest 110 which was June 8th, 1955. Elsewhere across the low-lying hot spots of the Southwest, Palm Springs topped 107 degrees and as is often the case, at 282 feet below sea level and surrounded by the high and steep mountains, Death Valley recorded a high of 119 degrees with today expected to warm to 120 degrees (See Weather Talk below for more on Death Valley heat).
UPPER-RIDGE, FLATTENING AND PUSHING EAST
You'll find that the upper air pattern is changing slightly from what we have seen over the weekend, the ridge is flattening slightly over the Southwest as the jet straightens (becomes more zonal) as it enters the West Coast up by Oregon with an unusually active storm train has brought a months worth of rain in 4 days to the Pacific Northwest. This is lowering pressure heights over the desert, which in turn is cooling the 850mb level or upper levels by a degree or two from yesterday and this will trim those surface temps pretty much everywhere. Note Las Vegas will likely see 108, rather than 110 and Phoenix nearer 105 rather than 108, Palm Springs will likely be 105 rather than 107.
Death Valley may be the only spot to actually top yesterday's level as the air is trapped overnight from yesterday within the narrow valley and remains warm, this failure to release heat back to space overnight, has allowed a warmer base for today's daytime warming and once that sun climbs into the sky, highs are expected to climb through the 110s, finally topping out at around 120 degrees by late this afternoon. Also one must remember, that the warmer the air aloft is, the warmer it usually is at the surface and the greater the level within the atmosphere the air can sink from, the warmer surface readings should be. One must take into account that Death Valley has an extra 282 feet or more of atmosphere for the air to sink down to and you know the old rule of thumb is the lower in elevation you are the hotter it will become. The air also tends to be drier deep within this valley than surrounding valleys or basins, aiding in further heating the air here.
Folks who have enjoyed cooling coastal relief in the form of morning cloud/fog and afternoon sea breezes will see an increase in low cloud and fog along the coast which will get further and further inland through this week and may get into the inland vallays in the coming days as the pressures nearer the ocean fall as well as inland. Highs will be in the upper 60s to around 70 for the beaches, mid-70s for LA and 80s to low 90s for inland valleys and low 100s for the deserts today and over the next 5 days with a slight trimming of those numbers as the week progresses.
By midweek as the high is much weaker than it is now, we should see highs fail to top 100 for Phoenix, Vegas, Laughlin and Palm Springs with only upper 80s to upper 90s expected, even Death Valley may fail to top 100 for a day or two, but this never lasts for long this late into the season at and by next weekend the high will rebuild westward, rebounding temps from the desert to beaches by next weekend.
NORTHEAST US ENDURED HEAT AND SEVERE STORMS
By Mark Vogan
Severe Thunderstorms roamed Connecticut, Massachussetts as a strong cold front progressed from the Midwest to out over the Atlantic. This was the same front which brought death and destruction to the Midwest during the early part of the weekend and pressed across New England bringing, strong, damaging winds, lightening, drenching rains as well as the issuance of tornado watches and warnings, even in and around the Boston area. Highs were restricted to the 70s yesterday but it was sticky as humid air ran up ahead of the front and converged, north of NYC and thus brought the intense instability which indeed the atmosphere reacted producing powerful thunderstorms. Further south where skies were clearer and the warm, humid air was still in firm control and with the front still north and west it was a hot, humid Sunday!
Highs across the Tri-State area as follows.
Newark, NJ 94 degrees
LaGuardia, NY 93 degrees
Caldwell, NJ 90 degrees
Central Park, NY 89 degrees
JFK (Jamaica), NY 89 degrees
Islip (Long Is), NY 84 degrees (breaking the previous record by 5 degrees)
At 110 degrees, summer sizzles with record heat in Las Vegas
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Weather Talk
By Mark Vogan
Complexities of the American Southwest High Pressure Pattern
The American Southwest has always facinated me. If you live in the sunbaked Southwest, perhaps you'll wonder at times why in summer when strong high pressure builds and readings enter the 110-120 degree range across a large area, say from Death Valley, Calif to Las Vegas to Phoenix, AZ and Palm Springs, Needles and Laughlin with some spots topping over the 120 degree mark? This may occur when LA is likewise broiling with highs at the beaches in the upper 80s, Downtown LA is in the 98-102 degree range and it seems there's literally no relief anywhere....
Yet, there are other times when Palm Springs may be at 118 and Death Valley is nearing 130, only 150-200 miles away down along the beaches between San Diego and LA it may only be in the 60s and 70s and Downtown LA is only a mere 75-80 degrees...
Over the last 10 years of studying Southwest summer weather patterns I have seen both examples play out on countless occations. It's all to do with the Four high, it's size, heights (within the atmosphere), it's position, surrounding weather systems and there strength and movement around the high as well as the influence of the North Pacific high. When it's blistering hot from Pacific to Great basin like we saw in 2006 this is courtesy of an extremely powerful Four Corners high with pressures up around 600dc (The Everest of Upper-Level High's), at those levels (anything above 590dc) those are about as high as pressure heights will go, reaching into the very upper reaches of the atmosphere, warming it and allowing a maximum depth of sinking within the atmosphere, as air sinks it compresses and heat up. Some desert valleys and basins (Death Valley, Lower Colorado River Valley and Salton Basin) can also further heat the air near the surface as rising air off the surface may only go so high before dropping back towards earth, further heating the already scorching air. What happened in 2006 and in many cases gone by, those maximum pressures covered a larger area of the Southwest atmosphere, therefore allowing record, ferocious heat to cover a large area of the Western US. In 2006, It warmed to over 100 in LA, 118 in Woodland Hills, 121 in Palm Springs, a remarkable 125 in Laughlin, NV, 128 in Needles and 129 degrees at Death Valley.. Las Vegas topped 116 degrees and Phoenix 118 degrees.
Amazingly, we can also see instances where we see a bulging 590dc high over southern Nevada but pressures sharply dropping off around the "relatively small peak" i.e. the 590 high only rises to that levels for perhaps 200 miles or less, therefore, heights may be low enough at the southern California coast for daylong fog and low cloud at the beaches and highs of only 68 degrees at Santa Monica and only 75 degrees in Downtown LA... whilst 580dc heights are witnessed only 150 miles to the east in Palm Springs, producing a high there of 117 degrees. Las Vegas where the heights are strongest may be nearing the all-time 117 degrees and Death Valley which may be nearing 130 degrees. This was the case in 2005 with Vegas saw 5 days in a row topping 115 degrees and a peak which matches the all-time high there... Death Valley during that heat wave topped 129 degrees.
The contrast even with Phoenix and Vegas can be remarkable as highs can be the difference between 110 and 118, simply because of low pressure influencing nearby. Often lows pressing southeast from the Gulf of Alaska can either pump a Four Corners ridge, weaken it or displace it. LA and the beaches tend to heat when the Four Corners high pushes towards the Pacific, which ultimately shuts off the onshore flow and fog and stratus deck that floats in during the overnight, often it's way offshore and visible on sat imagery when the southwest high is further west than usual.
DEATH VALLEY, THE MOST FASCINATING PLACES FOR HOT WEATHER ON EARTH
For more information on Death Valley and why it's so dry and hot, check out these links below
Wikipedia (Look at the Climate Section)
National Park Service
What's Reaching Today's Blogs?
Another Northwest Storm/Wind and Cooling Southwest
Ken Clark, Western Expert, AccuWeather
A Short Term Reversal of Trends
Joe Lundburg, AccuWeather
Today's Extremes here at my house
High: 63 degrees (morning rain, giving way to afternoon outbreaks of sun)
Low: 56 degrees
Thanks for reading.
-Mark
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