Friday, February 28, 2014

Impending Mid-Atlantic Wintry Mess and a (Very) Rare Stormy Southern California Day

The dazzling Sun appears balanced on the top of the building at the corner of 15th and L Streets NW, Washington, D.C., 10:23AM February 27, 2014.

Despite what I said in my previous entry, I rode my bicycle to work on Thursday morning.

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Friday evening update (mostly focused on the weather).

Upfront, let me say that I don't want this entry to go on too interminably (as my entries are wont to do) if only because I want to get to No. 9 reasonably early to see how goes the new downstairs / main level Friday night piano bar arrangement.

I rather doubt it will last very long -- this IS 2014 and in Washington, D.C., a city overrun with Millennials of all strips -- and the world of piano bars and actual jazz clubs is long gone (notwithstanding Twins Jazz). I suppose old gay men would like a piano bar but No. 9 is young and middle aged gay men. I just don't see it lasting.

I asked someone to go with me, but (of course) he never got back to me. As for Gary, he is away this weekend and Kristof, well, he and I rarely see each other, and increasingly he doesn't even return my text messages. So, all in all, I will be alone this weekend -- although I am supposed to go to Nick's birthday party tomorrow night at Bread Soda (Bread Soda?) up in Glover Park (a place I've never spent a Saturday night).


I may be late because I FULLY INTEND to be at home at 8PM to see the second half of the Wonder Woman episode "Judgment from Outer Space." I saw the first half last Saturday night on the Me-TV line up. It's a rather amazing episode in what it is trying to say. Tomorrow during the day, I'll go to the gym. I may also go on Sunday.

In general, though, I move alone through this life, and it will always be that way.

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The Weather ...

The weather from Sunday into late Monday looks to be a wintry mess. A system is forecasted to move toward the mid-Atlantic along a quasi-stationary boundary on Sunday with rain / freezing rain overspreading the Metro D.C. area and then turn to sleet and all snow by Monday as a large pool of Arctic air -- presently firmly entrenched -- returns after temporarily lifting northward.

Today's 18Z NAM 2-meter temperatures and winds valid at hour 51 / 21Z (4PM EST) Sunday, March 2, 2014.

The graphical output was created by the College of DuPage Meteorology Program (see below). It shows the D.C. area temperatures on Sunday afternoon rising to at least 60F. See below for temperature forecast 12 hours later.

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At this point, it's not clear how cold it will be during the event, but the 18Z operational runs of the GFS and NAM gave colder / snowier solutions. IF they verified, total snowfall would be in the 6 to 8 inch range, although depending on the snow-to-liquid ratios and the antecedent temperatures on Sunday (will it actually reach 60F or be much colder) will have a major impact on any accumulations.

Today's 18Z 2-meter temperatures and winds valid at hour 63 / 9Z (4AM EST) Monday, March 3, 2014.

This is 12 hours after the time step above and temperatures are now sub-freezing (in the 25F to 30F range) across the entire D.C./Baltimore region or down about 35F from 12 hours earlier. This is not just the diurnal cycle at play but the abundant Arctic air to the northwest has oozed into the region. (This temperature forecast is more of a depths-of-winter one -- and even then we've had winters where it hasn't been nearly this cold over such a wide swath of North America.)

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Wes Junker and Dan Stillman have a good write up on the Capital Weather Gang (link embedded): Wintry mess remains likely Sunday night-Monday; how much snow still a wildcard.

By the way, I have discovered just how comprehensive and colorful are the graphical outputs is the College of DuPage Meteorology Program's website for the NAM, GFS, UK MET, and other models. The main website is here.

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When It Finally Rains in Southern California ... (you can finish the rest)

The Santa Ana Mountains NWS radar (SOX) in base mode reflectivity at 1:24PM PST February 28, 2014 showing abundant rainfall moving into the Los Angeles area.

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The system itself will be related to a powerful storm that is presently slamming into California bringing heavy coastal / lowland rainfall and unusually heavy mountain snowfall to Southern California, breaking what has been one of the worst droughts ever across the entire state. This storm is very good -- although it will certainly cause flooding / mudslides, more general damage, and disruptions.

The broader Pacific Southwest sector radar mosaic at 2108UTC (1:08 PM PST) February 28, 2014 showing the weather system slamming into California.

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The storm system is a tremendously expansive and rather powerful extratropical cyclone with 977mb central pressure and broad occlusion sweeping north-south across the entire State of California.

NOAA/NASA colorized infrared satellite view from Feb. 27th (or possibly early on Feb. 28th) showing the vast extratropical cyclone with its telltale swirl of clouds wrapped around the occluding center.

Image from this Capital Weather Gang entry.

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NWS high-resolution surface map focused on California and adjacent Pacific waters valid at 21Z (1PM PST) Feb. 22, 2014 issued at 2222Z (2:22PM PST). The occlusion is quite impressive, extending in an elongated arc over 1,000 miles with the actual triple point just about over Long Beach.

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As an aside, my weather scenario dream is to be in Southern California as a once-in-a-couple-centuries event happens whereby a July or August hurricane manages to make it up from the tropical Pacific and slams into Los Angeles. There was a 1939 tropical storm that came ashore over Long Beach and, though poorly recorded, a hurricane in 1858 that slammed into San Diego.

It almost happened with Hurricane Linda in 1997.

San Diego NWS (SGX) county warning area (CWA) weather advisories as of 1:13PM PST February 28, 2014.

This is a rather unusual situation to have that many stormy weather advisories in effect in Southern California.

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Rainfall totals of 3 to 6 inches are possible in the L.A. basin down to San Diego and even more in the foothills while snowfall totals reach 12 to 18 to 36 to 48+ inches in the San Gabriel Mountains with the highest totals for elevations over 8,000 feet (right up to Mount San Antonio / Mount Baldy itself!).

Los Angeles / Oxnard NWS (LOX -- yes LOX, not LAX) CWA weather advisories as of 1:18PM PST February 28, 2014.

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This is the biggest storm to hit Southern California in years. While there was a smaller storm system a few days ago, this one tremendous and should drop more rainfall than sometimes falls in an entire year including L.A. itself where, depending on where you are, approximately 10 to 15 inches falls in an average year including 14.93" at USC downtown climate station (KLOX); 12.82" at Los Angeles Int'l Airport (KLAX); and 12.26" in Long Beach Airport (KLGB). (All of these are the current 30-year normal with wide interannual variability).

NWS point grid forecast for downtown Los Angeles valid Feb. 28 - March 3, 2014.

You just don't see this very often.

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Weather summary / overview with map issued by the San Diego NWS Forecast Office for the storm system currently hitting Southern California.

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This system will cross the Southwestern U.S. -- weakening substantially over the mountainous terrain of the southern Rockies -- and emerge into the Southern Great Plains, where it will meet up with the edge of the aforementioned Arctic frontal boundary. The intense thermal gradient / baroclinic zone along with upper level vorticity maxima moving out of Canada will all serve to re-energize the system as it approaches the East Coast.

The 18Z NAM showing sea level pressure (SLP) and 3-hour precipitation valid at hour 54 / 0Z March 3, 2014 as prettied up by the College of DuPage.

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While I'm uncertain if there will be a significant coastal storm, at the very least this is a good overrunning situation as a Pacific-originating storm system encounters / moves along a strong Arctic boundary as it approaches the East Coast. This portends a possibly icy / snowy situation for the mid-Atlantic including here in D.C. "Teleworking" is possible for me for Monday.

OK, I think that's all for now. I intend to update the blog tomorrow evening and then on Sunday (since I shall be avoiding the Oscars, which will be on EVERYWHERE and the only refuge is home).

But let's end with one more picture (tangentially related to the above California weather discussion):

A sunset image of downtown Los Angeles and the snow-capped San Gabriel Mountains (including Mt. Baldy) in the distance. This must have been an unusually clear day with a gusty breeze off the ocean. True, the smog situation in the L.A. Basin is vastly better than it was 40 years ago, but still...

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--Regulus

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