Saturday, January 30, 2010

Record Warmth and The El Nino Blahs

I should start by noting the return of much warmer than normal conditions after a few days of cooler conditions (see graph, with average highs and lows and observed temps). It is now certain that Seattle will beat its all time temperature record--we are now experiencing the warmest January in Seattle recorded history! Not a single day has had a mean temperature below normal. And this warmth has been observed over much of our region. The mean tempeature this month will come in close to 47F...that is warmer than an average March day (45.15F), but not quite April (49.4F). My garden is really responding right now...my grass is really growing and bulbs are pushing out of the ground.

The weather situation that we have been seeing this month, and which appears to be dominant in our future, is classic late-winter El Nino. In such a pattern there is unusual troughing offshore, with the jet stream..the current of strong winds...going south of us into California. They get more storms and precipitation. We get split flow and a dribble of weak systems. Really dead. Below I have put a graphics of the flow at 500 mb--roughly 18,000 ft for you to examine. The lines tell how high that pressure level is above sea level. Winds parallel the lines with higher heights to the right of the winds. The closer the lines are together, the stronger the winds. With all that said, you see the obvious--trough/low offshore and the main winds going to California.




We are running out of time for winter. In three weeks, we pass the unofficial end to NW winter...after which we rarely get major storms or flooding events. And our computer forecasts can see well 1/3 of the way and nothing is going happen here.

Finally, want to see a wonderful video of mountain wave clouds...lenticular clouds..downstream of the Olympics? Check this out!

http://www.drdale.com/lapse/lapse100128.mov

Wednesday, January 27, 2010

Inversions and Inverse Barometers

Well folks, there will not be any active weather for a long, long time. But there is always something meteorological that is interesting. Weather is like a fine wine...the subtleties are often the most rewarding. And a lot less expensive.

Take today. A high pressure area has been overhead, with relatively clear skies aloft and light winds. This time of year you know what that spells? Temperature inversions and fog.

Why? Under clear skies there is good infrared radiation cooling to space from the surface, allowing it to cool faster than air above. This produces an inversion in which temperature INCREASES with height. Want to see the effect in action? Look at the figure below from the Seattle Sand Point profiler near Magnuson Park in NE Seattle. In this figure you see temperature (in C) plotted with height for various hours (this is in GMT, 12 is 4 AM, 18 is 10 AM, etc). You can see a good inversion in the morning in the lowest 400m, which gets "burned off" when the sun finally got in to heat the surface. When the low-level air gets cooled to saturation we get fog.
Its just not fair...we get high pressure over us and it gets colder in the morning and some fog.

What about inverse barometers? I had number of emails and blog comments about the tide tables being WAY off last week--at some locations the water level was nearly TWO FEET higher than predicted! Here are two examples of this effect at Neah Bay and Astoria. The red line is observed and the blue is predicted. The green line is the difference.

Tide tables are normally pretty reliable, so what is going on? Fuzzy math? Nope...the answer has been the unusually low pressure this month. Take a look at the pressure at Seattle, Astoria, and Sea Tac in the plot below. From roughly the 15th to the 23rd the pressure was amazingly low...roughly 980 mb (mb is millibars, a unit of pressure). This is approximately37 mb below normal (1017 mb). So why is this important? It turns out that low atmospheric pressure results in a higher sea level. This is known as the "inverse barometer effect", with water level rising about 1 cm for every 1 mb drop in pressure (see the figure below). Thus, with a difference of 37 mb from normal, sea level would be 37 cm or 14.5 inches below normal. Thus, the extraordinarily unusual low pressure, something not considered in the tide models, resulted in the predicted water level height being much too low! There are also secondary factors, such as the sustained unusual winds offshore and higher than normal wave activity...but the pressure anomaly is the main driver.

Tuesday, January 26, 2010

The January Record

Will this month be the warmest January on record at Seattle Tacoma Airport? It is going to be a nail-biter but it appears we will make it.

A recap. The warmest January month until now was January 2006, when the average monthly temperature was 46.55 F. Where are we right now? Averaging all the days this month, including today, gives 47.1. Still above.

We have five days left.

Using the current NWS forecasts, the mean temperature of those days will be 45.9F.
Properly averaging this with the rest of the month gives a monthly-mean temperature of 46.9F. We make it with .35F to spare! Ok, I would like more of a margin, but it looks like the record will fall.

The east side is really cooking too! The monthly average temperature for Spokane so far is 35.2F which is 8.3F above their normal January temperature (26.9F). We are not going to beat 1953 (37.2F), but this January will come in second or third. A very respectable showing. What is missing in eastern Washington? The normal cloudy cold pool.

But what will really go down in the record books is the broad area of very, very low pressure over the western U.S. this month. Here is an amazing figure provided to me by Nate Mantua of the UW Climate Impact Group. It shows the pressure anomaly, the difference between the actual and climatological pressures, for January 15 through 23. An extraordinary anomaly reaching 21 mb (this is a large number for such things) over a huge area. I have never seen anything like it and probably won't see again for decades. There is reason that half the western U.S. set their ALL TIME low pressure records...records than have stood for 50-100+ years at these locations.

Saturday, January 23, 2010

Lawsuit Against Seattle Public Schools

On Tuesday, January 26th, at 8:30 AM, King County Superior Court Judge Julie Spector will consider an appeal by a group of Seattle residents (including yours truly) regarding the selection by Seattle Public Schools of the Discovering Math series in their high schools. Although this issue is coming to a head in Seattle it influences all of you in profound ways.

In this appeal we provide clear evidence that the Discovery Math approach worsens the achievement gap between minority/disadvantaged students and their peers. We show that the Board and District failed to consider key evidence and voluminous testimony, and acted arbitrarily and capriciously by choosing a teaching method that was demonstrated to produce a stagnant or increasing achievement gap. We request that the Seattle Schools rescind their decision and re-open the textbook consideration for high school.

By selecting the Discovering Math Series, the Seattle Public Schools chose a deficient mathematics program, based on the "reform" or "discovery" approach. In fact, they are using discovery math at elementary, middle school, and high school now. In this approach math is substantially dumbed down for "equity" reasons and students are asked to discover age-old principles on their own. "Direct instruction"--that is the teacher telling the students the best approach--is frowned on, calculators are brought in very early in elementary schools, group learning is pushed, and students are encouraged to play with objects (manipulatives). But most important of all...there is no evidence that this new age approach to math education works...and plenty to show it doesn't.

How bad are things in Seattle? Very bad. Below is a table of the 5-year average pass rate for the math WASL exam at three grade levels (thanks goes to David Orbits for preparing all the graphs and tables in this blog). And remember the WASL is an easy, dumbed-down exam to start with, with the 10th grade exam testing 7th or 8th grade material. You will notice a huge difference in the performance of minority and low-income students versus their white peers. And keep in mind that the 68% percent pass rate for the white kids is nothing to brag about. Many end up at the UW without the capacity to do college math. And less than 18% of the black children are passing the exam in 10th grade, and only about a quarter of the kids on subsidized meals are securing satisfactory scores. This table, and a graph based on it below, show another serious issue--student performance gets worse as they proceed through school--particularly for black and low-income students.


But if you think this is bad, take a look at the trends, and particularly the difference in the 10th grade WASL pass rate for white and black students. You will notice that with all the transition to discovery learning of the past decade the difference is increasing--black children are falling behind their white peers. In addition, their absolute performance declined the last few years.

As an aside,why the jump in 2005? Better teaching in Seattle Schools? Unfortunately, there is another explanation. This occurred when the District required those taking the WASL to have acquired at least 5 credits in Freshman year. Thus students who failed more than one class as 9th graders were not tested and the pass rate went up 15% by excluding those students (info from Dan Dempsey).

Remember, there is NO reason to expect the difficulty of the WASL exam was the same each year--in fact the evidence is against it! From 2000-2005 the State WASLed all at grades 4, 7, 10 and gave the IOWA standardized test to all at grades 3, 6, 9. WASL reading scores rocketed up at grade 7 during that period, but the IOWA test reading scores at grades 6 and 9 were flat the whole 6 years. The WASL was a lot more OSPI public relations tool than an assessment of instructional efficacy.

The initial rise period could also reflect the adjustment period to the exam--particularly for the well-off kids whose parents realized they either had to tutor them or pay others to do so.

So you think that with this record of failure, particularly with regard to minority kids, that the Seattle School District would change direction? No way...they went ahead and selected a very poorly reviewed reform math series...the "Discovering" Algebra and Geometry textbooks.

Before the School Board made the final decision last spring they and their curriculum committee had voluminous testimony warning them of a debacle ahead. For example,
Dr. Jack Lee, a well-known professor of mathematics at the UW, and someone known not to be an ideologue, wrote a long letter criticizing this series....some quotes:

Regarding Discovering Geometry

"I would strongly discourage the District from choosing this book. It represents a highly risky and experimental approach to teaching geometry, and I think the experiment, while well-intentioned, is unlikely to have the desired effect."

Regarding Discovering Algebra

"these books have far too much verbiage for students to read, and too little in the way of clearly stated mathematical principles. Definitions, computational algorithms, and formulas seem to be stated vaguely when they are stated at all.

The Washington State Board of Education hired mathematicians to review the Discovering Math series and others. Here in a quote from the Seattle PI is what they found:
Can you imagine? They were told the series was unsound and still decided to pick these books. Just astounding.

I could go on and on, but you get the idea. Seattle Public Schools picked high school math books that are not only bad for everyone, but they are PARTICULARLY bad for the disadvantaged who don't have extra cash for tutoring or whose parents don't have the time or backgrounds to help their kids (of course there are exceptions to this). And they were warned of this, time and time again. This is why we have filed the lawsuit and hopefully we will prevail. Seattle Public Schools have poor discovery books now at all three levels, making it nearly impossible for Seattle kids to get a good math education...a necessity in this technological world. Other districts are getting the message and dropping discovery math...such as Shoreline and North Shore. Issaquah wisely put the adoption of Discovering Math on hold.

Finally, to show you how confused the Seattle School District is in the matter of science and math education, they are about to vote (Feb 3) on a new disaster--making Cleveland HS a STEM (Science Technology Engineering and Math) school and spending millions of dollars to do so. Here they have an admittedly failing high school that is doing a poor job educating a nearly 100% disadvantaged population. Very few are doing well in math and science there. They are going to spend millions of dollars and make this a STEM magnet school in which all the kids will take advanced math and science. What will happen to the current kids? Few are ready for the calculus track. And they now going to bus kids in from all over the city (with all the added transportation costs) when the new district plan is to have neighborhood schools? So the district has basically decided to replace the kids! Other STEM high schools have failed in other cities with similar demographics (see comments by Dan Dempsey in the comments below).

The Seattle School Board is going to vote on whether to spend 800,000 dollars for some consultants to get the Cleveland STEM project going. A total waste of money. With the millions they are going to throw away on this, they could replace all of the bad math textbooks in the city with the good books recommended by the state superintendent of public instruction. They could jump to being the best! But they are determined to follow the same path of failure. Another gimmick. Just a tragedy. And an unnecessary one.

The only hope is that parents let the board know they have had enough. And the fact we have two new and very promising members of the school board (Betty Patu, Kay Smith-Blum), with a very capable chair (Michael DeBell), may make a big difference in overruling the current hapless bureaucracy. Keep your fingers crossed. But first there is Tuesday at 8:30 AM on the 8th floor of the King County Courthouse in Seattle.

Finally, how does this effect all of you? Bad math textbooks and curricula are found throughout the state and nation. This fight is going on throughout the country...and most Education Schools are on the wrong side...but that is another story.

Record Low Pressure


As readers of this blog can attest, I enjoy talking about record-breaking weather...and during the past several days records have been broken in spades with one of the most unusual West Coast weather situations in years.

I have talked about our torrid month here in the NW, with April temperatures in January. But even more amazing have been the extraordinary low pressures over the western U.S. and particularly the U.S. SW. Here is a sample from the National Weather Service:

...THE LOWEST PRESSURE EVER RECORDED AT PHOENIX SKY HARBOR OCCURRED AT 644 PM MST THURSDAY EVENING WITH A READING OF 29.20 INCHES OF MERCURY. THIS BREAKS THE PREVIOUS RECORD BY A FULL TENTH OF AN INCH.

Other ALL TIME RECORD low pressures:

LINDBERGH FIELD IN SAN DIEGO WITH 29.15 INCHES OF MERCURY AT 1222 PM PST...
LOS ANGELES INTERNATIONAL AIRPORT WITH 29.07 INCHES OF MERCURY AT 121 PM PST...
LAS VEGAS MCCARRAN AIRPORT WITH 29.03 INCHES OF MERCURY AT 514 PM PST.
YUMA WAS 29.12 INCHES OF MERCURY AT 259 PM MST

.Medford, San Francisco,and many others, also had record low sea level pressures.

I mean...this is really historic stuff. Perhaps your grandchildren will ask you about it someday....(maybe not).

The origin of these record low barometric readings? An extensive, very deep low over the western U.S. Below I have a sea level pressure map for Thursday afternoon...you can see this massive low. And also I have an upper level chart for the same...a massive trough over the West Coast with a strong jetstream (where the lines are close together) headed straight into the southwest.

The impact of this jet was profound: record precipitation into southern CA, Nevada, and Arizona. Heavy snow in Flagstaff and northern AZ.

Although we did not set pressure records in Washington in terms of the minimum, we did have very low pressure for an amazing length of time. Check out the plot of pressure at Sea Tac. I cannot remember an event in which our pressure stayed so low for so long (days below 990 mb).

I sometimes get calls from people suffering from arthritis, wanting to know about low pressure and big pressure falls--which they feel worsens their condition. I wonder if anyone noticed anything?
Finally, today will have a few showers and plenty of clouds....and a more serious system comes in tomorrow afternoon (Sunday). But absolutely nothing major happening. No threat of flooding in the Cascades as far as the models can predict. I think those worried about the Green River and Howard Hansen Dam can relax and go on vacation soon. After Jan 1 El Nino years rarely have major flooding and in any case, floods are very rare on west side rivers after Feb 20th...and our computer models show nothing significant for the next week. Plus, the dam water level is way low and there is room for a fairly major storm.

Wednesday, January 20, 2010

Warmest January in Seattle History?

It could happen...

Lets face it, the temperatures this month have been amazingly warm...we are experiencing April temperatures in mid January. Take a look at the plot of temperatures this month versus the daily average maxima and minima (plot).Many of our days have hit highs 5-13 F ABOVE NORMAL, and our minima have generally been higher than the normal maxes. Remarkable. The average temperature this month has been 47.55F--a month when the climatological average is
around 40F--7.5F above normal!!! The warmth this month is essentially due to the generally warm southwesterly flow, although for the last few days, downslope warming has added several degrees.

The warmest January on record was in 2006 when the daily average was 46.6F. So at this rate we are on track to beat it...IF...we stay warm. Unfortunately, temps will cool down to around normal (or perhaps a little warmer than that) this weekend, before a pineapple express heat wave strikes again midweek. We will come close...but no guarantee of being number one. But we will probably be in the top ten warm Januarys in any case. My garden is starting to react--bulbs are pushing up, a chorus of bird songs is rising , and the grass seems to be growing a bit.

Today was extraordinary....strong east winds in the Puget Sound lowlands and spring-like warmth. I went running during lunch to experience it all...there were strong easterly winds, with white caps on Lake Washington. Easterlies are pretty unusual in Seattle...and today's flow was moving right up and over the mountains. As this air subsides on the western slopes there is compressional warming that gives the temps an added boost. The Seattle profiler shows this easterly flow clearly...and the warming when it revved up earlier. The strong easterly flow tonight is keeping the temperatures up--when I biked home around 6:30 PM is was balmy and mild.



Sometimes I am too myopic about the west side..so let me say that the eastern side of the mountains are megawarm too....particularly since around January 10. Don't believe me? Check out the Spokane record below. Eastern Washington is really a bowl and during the winter it typically fills up with cold, cloudy air. The Tri-Cities is no vacation spot in January! (don't email me any complains about this--I am already getting too many comments from the pro-Jim Foreman crowd). This year the cold air was scoured out and warmth and sun has been enjoyed eastside. Is this good or bad for the fruit crops?

Monday, January 18, 2010

Its 9 PM and Its Getting Warmer Out!


Something very strange is going on right now (9 PM). It is getting warmer! I was just down in Kent and the temps felt nearly 60 (and there were modest winds from the east). As a drove through downtown Seattle it was 57F. Here is the temperature and wind trace (plus other goodies) at the UW. It has gotten warmer!
The sun is down..why is it getting warmer?

The east winds know!

The next major low system is moving up the coast right (see satellite image and forecast sea level pressure for 10 PM tonight).


Pressures are dropping (in fact they are really very low tonight...lower than last night). A fairly good pressure difference has developed across the Cascades and there is easterly flow at crest level. The result...easterly flow is moving through and down Stampede Gap (a weak area in the Cascades). Here is a model simulation of the winds at 10 PM. Some strong winds in the foothills and to the immediate west (sustained 20-35 mph, gust to 50 mph). One NWS spotter near Enumclaw clocked 80 mph.

There winds are influencing mainly the east side of the Sound from roughly Tacoma to north Seattle. (see graphic). Note how much colder it is northeast of Seattle (click on image to enlarge).

As the air sinks it is compressed by higher pressure and warms (see my book for more on this). So we are warming right now due to air compression.

I am a little tired now so I won't talk about all the exiting weather coming up with mega-deep lows passing off the S. Oregon coast bring storm-force winds there. Or the huge rainfall totals that will hit California and Arizona. That is why we have the NWS. Those folks are there three shifts a day, every day of the year. Their contributions are important and often unrecognized...but they are very good.

Summary From the NWS

PUBLIC INFORMATION STATEMENT

NATIONAL WEATHER SERVICE SEATTLE WA
1100 AM PDT MON JAN 18 2009
..THE FOLLOWING ARE MAXIMUM WIND SPEED REPORTS FROM AROUND WESTERN WASHINGTON SUNDAY NIGHT INTO MONDAY MORNING....

OFFICIAL LOW LAND AIRPORT OBSERVATION SITES.

SUSTAINED MAX WIND GUST

ARLINGTON 37 MPH 51 MPH
BELLINGHAM 36 MPH 61 MPH
BOEING FIELD 25 MPH 45 MPH
BREMERTON 23 MPH 38 MPH
CHEHALIS 30 MPH 41 MPH
EAST SOUND 21 MPH 54 MPH
EVERETT /PAINE FIELD 33 MPH 60 MPH
FRIDAY HARBOR 35 MPH 53 MPH
HOQUIAM 37 MPH 62 MPH
MCCHORD AFB 35 MPH 51 MPH
OLYMPIA 37 MPH 55 MPH
QUILLAYUTE 29 MPH 61 MPH
SEA-TAC 25 MPH 43 MPH
SEATTLE SANDPOINT OFFICE 25 MPH 43 MPH
SHELTON 20 MPH 49 MPH
TACOMA INDUSTRIAL AIRPORT 28 MPH 40 MPH
WHIDBEY ISLAND NAVAL STATION 40 MPH 63 MPH

NATIONAL WEATHER SPOTTER REPORTS AND MESOWEST

ANACORTES 54 MPH
CHERRY POINT 46 MPH 60 MPH
GLENOMA 45 MPH
LOPEZ VILLAGE 36 MPH 57 MPH
MT VERNON 51 MPH
PORT TOWNSEND 46 MPH 61 MPH SANDY POINT 41 MPH 59 MPH

MOUNTAIN OBSERVATIONS

CRYSTAL (NWAC) 71 MPH 113 MPH
HURRICANE RIDGE (RAWS) 68 MPH 127 MPH
HURRICANE RIDGE (NWAC) 44 MPH 87 MPH
MOUNT BAKER (NWAC) 45 MPH 65 MPH

MARINE OBSERVATIONS

ALKI POINT 44 MPH 59 MPH
DESTRUCTION ISLAND 64 MPH 70 MPH
POINT WILSON 36 MPH 58 MPH
SMITH ISLAND 49 MPH 61 MPH
TATOOSH ISLAND 63 MPH 69 MPH
WEST POINT 35 MPH 51 MPH

Sunday, January 17, 2010

This is serious now

The latest forecast models are in...and this looks worse and worse. Ground zero between midnight and 6 AM on the Washington coast. Here is the latest reports from buoy 46050 off of Newport....pressure falling rapidly and winds surging to 50 kts.



Take a look at the latest WRF 12-km model sea level pressure forecasts for 10 PM and 4 AM...an intense area of pressure change on the coast. I have the surface winds at 1 AM and 4 AM.
Sustained winds around 40 kts on the coast with higher guest. Also very strong winds developing in the Strait of Georgia. And it will be blustery elsewhere.

The Storm

A really interesting event is occurring--one the shows the strengths and weaknesses of weather prediction technology. Here is the latest infrared satellite image (for 5 PM) of the approaching storm. Can you see the swirl of clouds off of the Oregon coast? The low is closely associated with that swirl. However, there is some hint of a double center (the second one NW of the obvious one).

As the occluded front associated with the low moved up the CA and Oregon coasts there was a strengthening of the coastal winds, with 30-50 kts winds all over the place. At Cape Blanco, a normally windy spot (the ID is K92S), there were sustained winds of 67 knots with gusts to 80. This is hurricane force.

Now a big problem for the weather community is that many of the offshore weather buoys are A map of coastal buoys from NOAA

broken. All the NOAA buoys along 130W..which could have given us a good idea of what we are dealing with are broken! The further offshore buoy (46006) is broken. Every year this seems to happen...a few good storms and the buoys go kaput. A lot of the fishermen/women in Oregon and Washington are angry about this issue, but it is expensive to fix those offshore buoys and it doesn't seem to get done. Another reason why a coastal radar will be very helpful---it isn't taken out by rough seas.

A major forecast issue is then---where exactly is the low and how strong is it? Single or double? How good are this morning's numerical forecasts? My viewing of the imagery and what observations we do have suggest the storm is further south and west of the predicted location. (If had a radar on the Oregon coast we would know for sure!). That implies that the northern Oregon and Washington coasts are going to get hit harder...with more potential for the western interiors to pick up some winds.

Thankfully two close in buoys are still working! 46089 is due west of the Columbia River bars shows rapidly falling pressure and winds surging to nearly 45 kts. Buoy 46050, just west of Newport, is showing the same kind of thing.


Anyway, we will have a fun few hours this evening finding out what will happen. The strongest action won't be till after midnight along the north coast. A good night for a coastal storm party...but have plenty of flashlights and candles. The National Weather Service has a high wind warning out for the Oregon and Washington coasts. This is going to be a powerful wind event on the Washington coast--I expect some power outages and some downed trees.

Saturday, January 16, 2010

Coastal Winds

The new high resolution forecasts (4km grid spacing, initialed 4 AM) are in and the potential for a significant coastal wind event remains. Here are two plots of sea level pressure and surface wind speed for 4PM, 10 PM, and 4 AM, starting on Sunday afternoon. A deep low center moves up the coast and sustained winds on the coast are 45-50 kts. Gusts could easily be 15-20 kts higher.

Some of you have noted the tendency for coastal acceleration..and this does occur--in fact I just finished a paper on coastal windstorms where I talk about this effect. The interaction of onshore flow with the coastal terrain produces the speed up.


The Portland NWS has now put up a storm watch for the Oregon coastal waters. From their statement:
A STORM WATCH IS ISSUED WHEN THE RISK OF STORM FORCE WINDS OF
48 TO 63 KNOTS HAS SIGNIFICANTLY INCREASED...BUT THE SPECIFIC
TIMING AND/OR LOCATION IS STILL UNCERTAIN. IT IS INTENDED TO
PROVIDE ADDITIONAL LEAD TIME FOR MARINERS WHO MAY WISH TO
CONSIDER ALTERING THEIR PLANS.

The 10 am run is just in and the story has not been changed.
Here is the sea level pressure and precip chart for Monday
morning. One low after another rotating around. And California
is going to get hit hard with precipitation...a classic for El
Ninos.



Friday, January 15, 2010

The First Coastal Wind Event

The latest model runs have come in and the first major coastal wind event looks like it will hit southern Oregon/N. CA during the middle to late afternoon on Sunday (see graphic below of sea level pressure and wind speed at 4 PM Sunday. These are sustained winds (averaged over roughly 10 minutes)...not gusts, which can be considerably higher. The reds are sustained winds of 50 kts (hurricane strength winds are 64 kts or more). Certainly, the gusts will make that. These strong winds are associated with a tight low that moves up the coast, while weakening. By 4 AM the low and strong winds will reach Washington (see other graphic).


The Medford NWS folks have put out this statement:
LOW PRESSURE IS EXPECTED TO STRENGTHEN WEST OF THE COAST SUNDAY
AFTERNOON THROUGH SUNDAY NIGHT. WHILE THERE IS SOME UNCERTAINTY
WITH RESPECT TO THE STRENGTH AND LOCATION OF THE LOW...SOUTH
WINDS ARE LIKELY TO INCREASE TO NEAR WARNING LEVELS ALONG THE
COAST SUNDAY AFTERNOON. AT THIS TIME...THERE IS THE POTENTIAL FOR
SUSTAINED WINDS REACHING 30 TO 50 MPH WITH GUSTS 50 TO 70 MPH...HIGHEST
ALONG THE COASTAL HEADLANDS AND ALONG THE NORTHERN CURRY COUNTY.
COAST.

There are still at number of additional strong systems later in the week and
uncertainty is considerable.

Thursday, January 14, 2010

A Major Coastal Wind Event?

Friday Morning Update:

A strong current of S and SW flow is now hitting our region, with high winds aloft: check out the winds at the Seattle profiler...50 kts sustained a few thousand feet above the surface. (graphic) The rain over the past 24 h is shown in the second figure.
Intense rain is falling on and near the Olympics. Keep away from the Skokomish River!


Old Part

From Sunday night on, a very deep upper low will build over the eastern Pacific and a series of disturbances--some very strong--will move northward along the offshore waters. I mean four or more of them. Now our predictions have modest skill that far, but it looks like someone along the NW coast--between northern CA and Vancouver Is-- is going to get savaged. Want to see one of these storms? Or another? Or another? Or another? (graphics below with sea level pressure). Pretty impressive.

These are events that could bring hurricane force gusts to the coast. A multiple event with such strong components is not common. And heavy rain will strike the Olympics and N. Cascades through the weekend and then move into California. That is a story in its own--coastal CA and even the northern Baja should get very heavy rains if the current models are correct. The reason--a strong jet stream moving directly towards them with embedded disturbances.

Will be watching very carefully the next few days...


Friday Morning Update:
A strong current of S and SW flow is now hitting our region, with high winds aloft: check out the winds at the Seattle profiler...50 kts sustained a few thousand feet above the surface. (graphic) The rain over the past 24 h is shown in the second figure.
Intense rain is falling on and near the Olympics. Keep away from the Skokomish River!