Crazy Weather — Last Minute Changes

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The Palm Springs area is known for it’s beautiful weather, especially now during ‘the season.’ For most, today was no exception. For some it was nuts!

I planned on showing a telescopic image of last night’s asteroid fly-by. It’s cool show-and-tell. I got to do that at five, but it was quickly pushed off my agenda.

My forecast yesterday called for moderate to strong winds this afternoon. By 4:30 police had closed Gene Autry Trail in Palm Springs because of reduced visibility in blowing sand! I quickly worked up a graphic showing the gusts tonight.

As we went to air (and the road reopened) I got a photo of what looked like a funnel cloud. I hurriedly pushed that into my TriCaster and aired it a few minutes later.

It was probably a landspout. Conventional tornadoes come from mature storm cells. Landspouts are weak tornadoes that form early as storms are building.

This evening I got the video you see at the bottom of this entry. It’s the landspout near Desert Center (population around 150), a rural community surrounded by sandy wilderness. I showed it briefly at 9:00 and will feature it again at 11:00.

The landspout was unexpected, unforecast and unseen by Doppler radar! Luckily, It did no harm. It made for great TV.

A Definite Maybe

rtwrfdomainsSince last Wednesday I’ve been talking about the chance of the Palm Springs area getting a few sprinkles this Thursday. In most places caring about an iffy forecast for a tiny event so far in advance would be a non-starter. Not so in the desert where long time residents look forward to our few cloudy days!

So, here we are Monday. This is the sixth day since rain was first mentioned. I’m barely closer to knowing than I was then!

First, an admission. Without supercomputers no one could attempt a seven or eight day forecast. The atmosphere’s just too complex. But computer’s have shortcomings. I use the GFS model this far out.

The entire globe is covered by the GFS at a base horizontal resolution of 18 miles (28 kilometers) between grid points, which is used by the operational forecasters who predict weather out to 16 days in the future. Horizontal resolution drops to 44 miles (70 kilometers) between grid point for forecasts between one week and two weeks.

One point every 18 miles! At that resolution mountains disappear. Everything becomes a coarse approximation.

Later today Thursday will be seen in the much higher resolution CANSAC (California and Nevada Smoke and Air Committee) WRF model. CANSAC’s WRF only sees out 72 hours, but with 2km (1.2 mile) resolution.

For the geekiest reading, here’s the hardware CANSAC uses to run the WRF.

The CANSAC WRF real-time forecast system is operated on an SGI® ICE 8200 high-performance computer. Specifications are:

256 cores (Intel Xeon X5570)
384 GB RAM memory
20 TB disk space.

In the interim lots of human expertise is needed. The mountains west of the Coachella Valley are critically important. The models might not resolve them well, but I have to. They are a major reason we see less than six inches of rain in an average year (just over two inches since this year’s ‘wet’ season began in October).

I said Wednesday the coast was much more likely to see rain than Palm Springs. That still holds true.

If we get anything it will be tiny. In the desert that’s enough to perk ears.

Rain For SoCal, Again

Once again we’re right on the 3-hour flash flood line. I expect some flooding. Homes in burn areas will be threatened by mudslides. A few inches of rain probable through this region.

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Helaine saw the hashtag #stormageddon touted on TV a few minutes ago. SoCal is bracing… again. Is there some weird secret competition with the East on weather?

“Yeah… well… rain!”

Actually this storm looks very un-SoCalish. The radar from Vandenberg AFB shows a squall line out front. The HRRR agrees. The squalls remain intact as the line slides down the coast. Embedded thunderstorms are entirely possible.

We’ll have rain most of the day Friday though the bulk falls between 4-7 AM. We’re right on the 3-hour flash flood line, again. I expect some flooding. Homes in burn areas will be threatened by mudslides. A few inches of rain probable through this region.

wind15min_t410m_f0945The heaviest wind comes with the heaviest of the rain. Winds will gust out of the south. The wind map to the left highlights the higher ground where winds will be strongest.

If there’s snow for our two nearby tall peaks it will happen late in the storm. My second winter and no white so far.

Father north, San Francisco proper has gotten 2-4″ of rain with some windward mountainsides getting over 7″.

So far, this is the awful winter everyone was praying for!

Not The Worst Storm–The Worst Time

Travel on Wednesday will be demanding. Air travel will present its own special hell.

Model Analyses and Guidance

I continue to look at the numbers for Wednesday’s storm in the Northeast. Not the worst, but certainly at the worst time. Wednesday. Day before Thanksgiving. You get it.

By this time all the TV mets should be saying the same thing. The guidance is straightforward and consistent.

The exact numbers don’t matter. There will be enough to plow inland. On the shoreline slushier.

Rain then snow in DC before dawn. By sunrise I-95 will be wet from Ft. Lauderdale to Fort Lee!

In Connecticut the action begins in the morning. Schools and businesses might have to make decisions before there’s anything falling.

The snow (and mixed precipitation on the shore) will continue until around midnight before tapering to snow showers and flurries.

Travel on Wednesday will be demanding. Air travel will present its own special hell.

Our spare bedroom is available.

Do You Miss Buffalo?

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I was just on the phone with my dad. We talked about the weather a little. He’s in Milwaukee where it’s 29 with a wind chill of 22. My office window thermometer shows 72.

“Bet you’re glad you’re not in Buffalo,” he said.

I am.

766 Auburn Ave   Google Maps

I lived here, at 766 Auburn Avenue (Google streetview link) in the third floor apartment. It was a beautiful one bedroom with no insulation and enough water pressure to take a shower if no one in the other two apartments was! During the summer we were woken by squirrel races on the roof.

Those who live in Buffalo do so by choice. Anyone who wanted to leave left a long time ago. There is a survivor spirit among the residents.

It is a really nice, liveable city. Real estate is very reasonable. Summers are magical. Winters are hellish.

Starting in mid-November a thick veil of low clouds descends upon the city. This is the beginning of the process that spawns Lake Effect snow. It’s convection, like bubbles in a pot of boiling water. It will remain mainly cloudy with a handful of exceptions until spring.

This time of year the Great Lakes are warm and the flow through the atmosphere cold. Warm air near the lake’s surface is drawn up, condensing as it cools. Clouds form, often dropping snow.

Lake Effect season begins suddenly. The start is when the potential for big storms is greatest… as we saw this past week. Once Lake Erie freezes the process shuts down.

Lake Ontario doesn’t freeze. Sorry Syracuse.

For a real Lake Effect event, winds must be aligned through the atmosphere often parallel to a lake’s longest dimension.

These storms are VERY localized. The physics involved in Lake Effect snow is very similar to summertime thunderstorm formation. In fact, sometimes thundersnow is part of a Lake Effect storm.

Think “thunderstorm downpour” of snow… except instead of moving on, the storm continues for hours or days relentlessly.

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This graph is from East Aurora, NY. Under land use it’s marked, “Urban.” People live there. That’s over 30″ of snowpack with a water equivalent of 5″.

The edges of Lake Effect storms are well pronounced. You drive out of Lake Effect snow like you drive out of a summer thunderstorm. And these boundaries stay in place as long as the wind doesn’t shift.

No one can cope with this much snow. No one is equipped, even those areas that get as much as 200″ of snow a year!

“Yes, Dad. I’m glad I’m not in Buffalo.” But I don’t regret a day of living there.

Buffalo And The World’s Weirdest Weather

The photo at the top of this entry is Buffalo, Wednesday afternoon. The Sun is shining brightly.

Wondering where the snow is?

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The photo at the top of this entry is Buffalo, Wednesday Tuesday afternoon. It’s my old neighborhood on Elmwood Avenue. The Sun is shining brightly.

Wondering where the snow is?

robhimself793: I’m about a mile from the snow band, I have very little snow, maybe 6″. Just a mile south and people have 3 feet.

You’re seeing one of the more interesting aspects of Lake Effect snow. It is VERY localized. There’s heavy snow just a few miles from where this image was captured.

Lake Effect snow is the product of convection. Heat and moisture are transferred upward into the clouds from the relatively warm lake. You can see that in this time lapse of Lake Erie, one of the coolest pieces of weather video I’ve ever seen.

Heavy Lake Effect snow needs cold wind roughly parallel to the lake to get going. The resulting storm forms slender ‘streamers’ which reach out from the lake. They are often just a few miles wide, with flurries at the edges and white out conditions in the middle!

Near the Great Lakes it’s possible to drive from no snow to 4″/hour conditions in just two or three miles! These bands can stay stationary for hours, or even days!

Buffalo gets a lot of snow each winter, over 90 inches! Because of Lake Effect there are heavier snowbelts south of the city. People in Buffalo scratch their heads why anyone would want to live there, as we scratch our heads over Buffalo.

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