Onshore Push

Update 7 AM Tuesday...the push was fairly strong last night---and still quite breezy this morning. The satellite picture below shows low clouds pushing to the crest of the Cascades. Want sun today? Simply go over the passes. A few miles more and you will be in bright sun. But remember that places like Ellensberg will get hammered by strong NW winds today...and golf at Suncadia will be, lets say, a challenge. (and see the new video link at the end of this blog)




My wind chimes are ringing right now and the trees are starting to sway as the wind increases. Such behavior after a warm day means only one thing...an onshore push has started.

Temperatures rose into the low 70s over much of the western lowlands today, but as we enjoyed the warmth an upper level disturbance has been approaching and the difference in pressure between the coast and interior has been rising. These changes are producing an onshore surge of marine air that will bring a substantial cooling tomorrow (by at least 10F) and the return of low clouds in the morning.

Meteorologists follow the pressure differences very carefully during such events. North Bend, Oregon minus Sea-Tac is one that is popular. I prefer Hoquiam minus Seattle. As shown below, this pressure different grew from near zero to around 2.6 mb today....enough for a modest push. For a strong one you look for 3.5 to 4 mb. The times below are in GMT (18 is 10 AM, 00 is 5 PM)


Here is the predicted upper level chart for 2 AM this morning. You can see the trough--centered over Vancouver Island-- moving towards us. Onshore pushes with northwesterly flow tend to be be on the weak side.


Perhaps the best way to see a push in progress is by looking at the wind and temperatures from the Seattle Sand Point profiler (below). Time is on the x-axis and height (in meters) on the y axis. If you can read the blue wind vectors, you can see that the winds are now from the southwest in the lowest 1000 meters (roughly 3000 ft) and increasing....a good sign of an onshore push.



And the low clouds offshore have thickened and started to push in! (see satellite picture below)

So get your sweater out for tomorrow...highs will be in the lower 60s, clouds will dominate, and there even could be some light sprinkles. By the afternoon there could be some cloud breaks and maybe a bit of sun.

Onshore pushes are the main forecast problems during Northwest summers---some call it our version of air conditioning.

Finally, a key point is that we are in a very different pattern from the last few weeks--it may not be hot, but endless days of clouds and rain are NOT in the forecast.

KUOW: Several listeners delivered the petition with nearly 5000 signatories to KUOW today and talked with their program manager Jeff Hansen. KCPQ-TV (Channel 13) covered it....and should be on at 10 PM. Here is the segment on KCPQ:

http://www.q13fox.com/videobeta/?watchId=38b0cbf5-7207-405f-8369-01a9125fab7b

KCPQ also gave me some time to talk about what I would have said on KUOW if I had been allowed. I am working on a detailed blog about my interactions with KUOW and particularly their reactions during the past few weeks. I really think KUOW has serious issues and I will try to analyze them in this work.

Climategate

Several of you have asked me during the past few weeks to comment on Climategate--the emails stolen from the University of East Anglia dealing with global warming issues. I will do so here, but I want to go beyond that situation to some of my own personal observations derived my own experiences doing climate-related research.

Let me start with my bottom line points:

Were some of the climategate emails inappropriate? Yes
Have some scientists exaggerated the implications of human caused global warming? Yes.
Are many global warming deniers unreasonable and expressing opinions that are not based in facts or rational thought? Yes.
Is the basic science of climate change now in question because of the climategate emails? No.
Has the whole business gotten too political? Surely.
Are scientists human and sometimes doing things out based on human emotion or group think? Yes.

Climategate emails: I read through more than a hundred of them...particularly the ones that have gotten big attention. These scientists were in circle the wagons mode. Clearly, they felt under pressure, if not threatened, by the global warming (GW) skeptics, and discussed ways of denying the critics information requested through Freedom of Information inquiries. They scientists talked about erasing emails, and not publishing in journals they felt were printing materials they disagreed with. Web sites like "Climate Audit" has become dirty words to some. (I personally love "Climate Audit"!). All of this was inappropriate.

In the famous "trick" email the east Anglia emails talk about replacing the proxy tree ring records with instrumental records for the past several decades (because the tree ring records disagreed with what the instrumental records were saying)--instead of just showing those records and noting the difficulty. Not quite open. Is there any major technical cover up evident in the emails?...not that I could see. Denier and skeptic types are claiming that these emails undermine the whole global warming business...and they are completely wrong about that. But there are some general issues we should talk about.

There is an almost tribal separation going on today between the scientific community and their "allies" (generally of a liberal persuasion) and the denier and critic crowd (many of them of a conservative bent). The denier folks have become angry, with conspiracy theories and accusations of far-left agendas. Whenever there is an article on climate change in newspapers, these people leaves large numbers of online comments. And few of them are well informed about the science. And there is a lot of misinformation on the "pro" global warming side as well. Scientists, unaccustomed to being on the firing line, have gotten defensive--and the emails from climategate really document this attitude.

This defensiveness has now gotten unhealthy for both the science and society. Scientists who attempt to publish material indicating that global warming due to manmade causes is not evident or weak, or who doubt the severity of the problem, are not treated well by some. I have had some first-hand experience with this. I am known as somewhat of a skeptic regarding global warming effects in the NW--although I do believe that greenhouse gases are a serious problem in the long-run. A group of us noted that the snowpack in the Cascades was NOT rapidly melting away, in contrast to some publications by some local climate scientists and publicized by Mayor Nickels. The reaction was intense. One of my colleagues, Mark Albright, who was the first to notice the lack of snowpack loss was fired as associate State Climatologist and the media went wild...we called it Snowpackgate...and it got national attention. I was told in the hallways to keep quiet about it...the denier types would take advantage of it!

We then wrote a paper on the subject (the main contributor being Mark Stoelinga) and submitted it to the Journal of Climate. I have published a lot of papers in my life (roughly 100) and I never had problems like we had with this paper. Very biased associate editor and some reviewers. Four review cycles and it was about to be turned down, until we appealed to the editor, who proved fair and reasonable. This paper has now been accepted for publication, but it really revealed to me the bias in the system. Here is the paper if you are interested:

http://ams.allenpress.com/perlserv/?request=get-pdf&doi=10.1175%2F2009JCLI2911.1
Poor papers with significant technical problems, but reflecting the "official" line, get published easily, while papers indicating the global warming is weaker or delayed, go through hurdle after hurdle.

I have heard case after case of similar treatment...so this is no anomaly.

The media tends to publish all kind of threatening predictions about global warming without really researching them. A good example is that suggestion that heavier precipitation will fall in the NW under GW...or is already happening. There is no evidence for this, but it gets repeated over and over again. On the other hand the denier types point to every cold wave or the fact there has NOT been a lot of warming in the last 5-10 years (which doesn't mean anything). And the glaciers! Some of the melting may well be due to man-forced warming...but the melting started early in the last century before CO2 effects were significant.

Another problem is that uncertainty of our climate predictions are often not clearly expressed in various publications--even semi-official ones put out by climate impacts groups of various types. It is sobering to note that the uncertainty in climate predictions has not declined over the past decades. Our models are much better now than thirty years ago, but key aspects of the modeling systems...like how they simulate clouds... are not as realistic as we would like...and this is very important for climate change work. I think people sense there is more uncertainty in the predictions than the official outlets tell them...and that may be part of the fuel of denier rage. The essential physics of warming is quite solid and well understood, but the details...like how clouds will react...are still under investigation.

So perhaps I have been confusing....but the bottom line is that this issue has been completely politicized and confused with both sides using problematic information at times....did this have to happen? If Gore hadn't taken up the mantle of stopping global warming, would things have been better? Can Climategate lead to a better approach and attitude among all parties?

Large Diurnal Temperature Range

An interesting aspect of the current weather regime is the large diurnal (daily) temperature range--the difference in temperature between the daily highs and lows.  At a number of Northwest locations we have seen highs in the 80s and 90s, while temperature have plummeted at night into the lower 50s and even some 40s, with some dropping into the 30s.   I am talking about surface air temperatures here, measured at roughly 2 meters. Some good examples:

Baker, Oregon--high of 90 and a low of 39F:  a diurnal range of 51F!
Olympia,WA--high of 85 and low of 44:  range of 41F

Or consider the Turnbull climate reference network site near Spokane that had  a 51 deg temperature range today with a low of  36 and a high of 87 on Tuesday.  What is really amazing is the range of surface (ground) temperature that on Tuesday jumped from 32 F to 114 F (82F!!) on Tuesday.  You read that right....from frost on the ground to 114F in one day.   That will crack some rocks!

 Here are graphs of temperature for the last two weeks--all of which show the huge range.  First, Sea-Tac, then Pasco, and finally Spokane.  All have a much greater range than normal.

So why such a big range?  Hint:  we often observe such big daily swings during late summer and early fall.

We start with fairly warm aloft and the sun being still fairly strong....that allows warming.
We have weak offshore flow aloft...that keeps the low clouds and marine influence at bay.
We have clear or nearly clear skies...that allows good infrared radiational cooling to space--and thus good temperature falls at night.
And nights are getting longer--that gives more time for nighttime cooling.  And the relatively equal time for heating and cooling at this time of the year is helpful

Put this all together and you get one big temperature range.  During the winter the range is far less in general, particularly because the cloud cover reduces heating during the day and infrared cooling at night.

Now for the controversial part of this blog.   There seems to be some difference in opinion whether a large temperature range is good for viniculture.   Does a big range help or hurt the quality of grapes used in wine-making?  Some online sources claim that such a range is good since it has the effect of producing high acid and high sugar content as the grapes' exposure to sunlight increases the ripening qualities while the sudden drop in temperature at night preserves the balance of natural acids in the grape.  Others, like the book by Gladstone, claims that a narrow temperature range is good.  Any wine experts read this blog?  What is the correct story?  I have always found the meteorology of wine making fascinating...and will climate change make eastern Washington wines even better?  Perhaps in another blog.

What is the warmest place on Earth? Warmest in the Northwest?

Perennially chilled Pacific Northwest folks are naturally interested in warmth and so I thought I might share some results of very interesting article in the Bulletin of the American Meteorological Society, which attempts to find the hottest place on earth and here in the NW.  (Article is by David J. Mildrexler, Maosheng Zhao, and Steven W. Running of the University of Montana)

Do a search on the warmest place on earth and you typically get El Azizia, Libya with a record air temperature (at 2 meters) of 136F measured in 1922.  Furnace Creek in Death Valley National Park comes close 134.1F.  But there is another way to measure temperature--- determining the temperature of the ground (the skin temperature) from space.  We can do this by measuring the amount of radiation emitted by the ground (sort of like a super ear thermometer that uses similar technology)  Now this satellite approach has the advantage that it measures the temperatures everywhere and there is a good chance there is no observation at the hottest locations (who would want to live or work there!).  On the negative side, this is not air temperature, which is generally less than skin temperature on hot, sunny days--sometimes a LOT less.

Anyway, these folks at U. of Montana used data from 2003-2009 from the MODIS satellite, which has a resolution of roughly 6 km (so it is probably missing the absolutely hottest points).

Ok, get your icy drink ready...here is the answer.  This graphic shows you the results.  The warmest location seems to be in the Lutt desert of Iran.  The second graphic shows you a blow up of the temperatures and an image of that desert.  Looks like hell.  It is like hell.

Several places come very close....but Lutt is the winner.

But what about the Pacific Northwest--where is the warmest ground to be found (I suspect there is going to be a stampede there in a few weeks)?  Here is the graphic. The left shows the temperatures and the right the land use (click on image to expand)..

Looks to me that the warmest location is on the Hanford reservation where there is no irrigated fields.  Such fields have a large impact on temperature, something you can see by comparing the temperature map (blown up version below), with a google maps satellite image (also shown).  Evaporation off irrigated fields can cool temperatures down several degrees (F).

No jokes about warming from the radiation at the Hanford facility...this is not the cause.  And there are a few warm locations just south of the state boundary as well.  Anyway, another reason to head to the Tri-cities during the spring and fall when it gets cool on the west side.  But don't try this during winter!---the lowest elevations of eastern Washington are cool and cloudy in midwinter, as cold, moist air settles into the terrain bowl in that area.

Wildfire Season

Due to the high snowpack from our La Nina winter and cools condition extending into July, wildfire season has been delayed over the Northwest; however, recently there has been a significant increase in fire activity, reflecting drier than normal conditions during the past month and belated warming over our region.  And you haven't seen anything yet.

Here is the latest Forest Service map of fire incidents over the region--all of the them are east of the Cascade crest, mainly in Oregon.

You can see several of the fires on today's MODIS satellite imagery (click to enlarge--necessary to see the smaller fires):

The most prominent smoke plume is not from the largest fire-- the High Cascades fire, which is now encompassing over 100,000 acres near Madras, Oregon--but from the Dollar Lake fire, 16 miles south of Hood River (roughly 3000 acres).  The winds are clearly from the east and you can see the smoke plume moving WNW towards Portland. If you look carefully you can see the smoke from a small fire over the Olympics.

Here is a nice shot of the smoke from north of the Gorge looking south and another near Mt. Hood.

Both of these fires were initiated by lightning strikes.

The local wildfire problem is probably going to get much worse during the middle and end of next week.  No rain is in sight and after a minor cooling on Monday and Tuesday, the heat should really rev up mid-week as the ridge over the western U.S. greatly amplifies into a huge atmospheric blocking pattern.  Here is a sample forecast for next Wednesday...wow.  And there is no end in sight.

 West of the Cascades we should see the entire region (away from the water) moving into the mid-80s, with a number of daily high temperature records falling.

A major concern is that the burnable surface materials ("the fuels") are drying out rapidly.  Here is a Forest Service figure showing you the moisture content of the "1000-hr" fuels---the bigger, thicker branches and debris. Darker red indicate seriously dry fuels and this is only going to get worse.

 

 A key feature in predicting fires is the thermal tough--a region of low pressure associated with warm air (I blogged about such features last week).   Right now I am doing an intensive study of West Coast thermal troughs with support from the U.S. Forest Service--understanding their generation and movement.  Thermal troughs are associated with a deep, warm air mass that is relatively unstable and enhanced fire danger occurs as such troughs move across the Cascades, with strong winds and upward motion right behind. During the middle of this week an amazing thermal trough is predicted by our high-resolution models.  Want to see?  Here is the predicted sea level pressure and temperature at roughly 2500 ft:

 In short, we are going into one of the warmest September periods we have experienced in a long time and fire danger is getting serious.  The only good thing is that there won't be much lightning. 

Upcoming Warmth

During the past few weeks we have had really decent weather--generally dry, with periods of above and below normal temperatures.

Such variability, centered around climatological temperatures, is what normal is all about.
There has been enough sun and warmth for a miracle to happen---I actually have red, ripe tomatoes!  Few pleasures in life are greater.  Here is the proof:

Well, another miracle is occurring...we are going into a warm up period through the weekend and then the heat really revs up on Tuesday and Wednesday as a monster ridge builds up over the western U.S.  And it just stays in place forever.

Right now a weak trough is moving through, bringing increased cloudiness over the region.  Tomorrow (Friday) we should wake up to clouds, but they should break up during the afternoon...low to mid 70s.   But on Saturday ridging aloft develops (see upper level chart) and the temps warm with more sun.  Perhaps a bit warmer on Sunday.

But early in the week ridging really develops (graphic) and temperatures could hit the mid 80s.

And do you see that features in the lower right...another hurricane.  The NWS GFS model has this storm approaching the East Coast late Friday (see forecast for Friday AM below) but the forecast will surely change.  The latest solution gets the hurricane/tropical storm close before it swings to the NE off of New England.

The NWS Climate Prediction Center is suggesting increased probabilities for above normal temperatures through next week. (see graphic).

No fried green tomatoes for me!

Just a reminder...will be starting my KPLU weather segment tomorrow (Friday) at 9 AM...right after birdnote.

NW Fog Season and Media Fog on Fox News

Well, if hurricanes are on one side of the meteorological spectrum, what is on the other?

Recent fog picture courtesy of the Seattle Times

You guessed it...fog, and folks the Northwest is entering fog season.  In fact, September and October are the foggiest time of the year around here, NOT the middle of the winter.

On Sunday I got to experience fog first hand--I was heading to Bellingham to do some kayaking near Lummi Island (Elakah kayak).  Seattle was densely fogged in, but every time we gained a few hundred feet elevation on I5 we escaped the shallow fog. This was quite shallow stuff...a few hundred feet at most.  On the water near Lummi we were in dense fog until it lifted around noon.  Here is the visible satellite picture before it burned off. 

One thing we have learned from satellite imagery is that fog burns in from the sides.

The irony is that REALLY dense fog, like on Sunday, is generally a good indicator of clearing later in the morning.

So why is the fall our big fog season?  The nights are getting long...that certainly helps, allowing more time for the air to cool to saturation (the dew point).  Relatively clear skies, since the storm season has not arrived yet.  Clear skies allows infrared radiation loss to space from the earth...giving us the needed cooling.  The atmosphere is relatively stable this time of the year, since the air aloft is relatively warm compared to the surface at night.  Warm air above cool, dense air is stable, and fog loves stability.

The least foggy time of the year here?  Spring!

And now a few comments and announcements.

First, the award for the absolutely dumbest opinion piece I have read in a long time--goes to foxnews.com for suggesting that the National Weather Service is unnecessary and should be sold off.  Here it is:
http://www.foxnews.com/opinion/2011/08/27/do-really-need-national-weather-service/

A sample of this foolish piece:  why do we need the National Weather Service when we can get our forecasts from the Weather Channel?   Folks, who do you think gathers all the observations and runs all the computer models?  Where do you think the Weather Channel gets this information from?  I could list a dozen more, but you get the idea.  We are talking completely brain dead.  How could Fox News publish such trash?

Second announcement: just a reminder I will start my new weather program on KPLU-FM at 9 AM this Friday.  And I plan to talk about hurricanes...OUR HURRICANES.  You can listen on the web, at 88.5 in the Puget Sound area, and additional frequencies at other locations (check their web site for the repeater stations--link to the right).

When Did Irene Stop Being a Hurricane?

On Sunday morning Anderson Cooper of CNN was asking about the strong winds that were being forecast and this brings up something that has really bothered me about the storm:  there is really no reliable evidence of hurricane-force winds at any time the storm was over North Carolina or moving up the East Coast.

First, what is a hurricane?  The official definition is that a hurricane is a tropical cyclone with SUSTAINED winds of 64 kt or more  (74 mph or more).  A gust of 65 kt  or more does not indicate a hurricane unless the sustained winds reach 64 kt.

I took a look at all the observations over Virgina, Maryland, Delaware, New Jersey, and New York.  Not one National Weather Service or FAA observation location, not one buoy observations, none reach the requisite wind speed.  Most were not even close.

Surely, one of the observations upwind of landfall, over Cape Hatteras or one of the other barrier island locations, indicated hurricane-force sustained winds?  Amazingly, the answer is still no.

Here is a map for reference.  The strongest winds I could find was at Cape Hatteras (CLKN7) where the winds got to 59 kt.

Or buoy 36, south of Cape Hatteras over the water...only got to 49 kt there.

Or plot the winds when the storm was just making landfall...no sustained winds even close (see graphic).  Solid triangle is 50 knots, big line is 10 kts, small line is 5 kts.  Look for a triangle, solid line and small line (65 kt), or more....none exist.

Yes, there were a handful of hurricane-force wind reports but none of them were from official stations and there is considerable doubt about their reliability.  Furthermore, satellite imagery clearly showed a poorly formed storm off of North Carolina--with little evidence of an eye.

The truth is that there was little chance of intensification of the system as it moved up the East Coast.   Storms derive their energy from warm ocean water and the second the storm made landfall half of the storm was over land--which saps the strength of the system.  The other half was over increasingly cool water.  This system was toast.   But as a tropical storm weakens and "goes extratropical" there is a tendency for the precipitation to swing to the W an NW of the storm.  That is exactly what happened .  The big threat was flooding, not winds.

I assume that upon further study the NWS will eventually downgrade this storm as it moved up the East Coast.  Considering the tendency for media to hype storms it it crucial for meteorologists to stick to the exact story and not overwarn in the hope of encouraging people to take effective action.  If the storm was known NOT to be a hurricane earlier might the Mayor of NY have held off closing the City down, thus saving billions of dollars?

Hurricane Irene Forecasts and Their Hurricanes Versus Our Hurricanes

The media is hitting Hurricane Irene really hard and some descriptions are going too far: "historical storm", "storm of the century", etc.  Folks, this a category 1 storm with sustained winds of 85 mph.  Serious, but not catastrophic.  We are already seeing local authorities overreact--like NYC cutting off bus and subway service at noon EDT.  At that time the winds at NY's Kennedy Airport were 8 miles per hour and there are only a few showers around.   The strong stuff will not happen until tonight, so why cripple people's ability to move around and for coastal people to evacuate?  Overreaction stemming from massive complaints about poor snow removal last winter?

A key reason for my field to improve forecasts is to reduce the overwarnings and overreactions--which undermine confidence in forecasts, resulting in calls of "crying wolf" and lessening public reaction when truly threatening situations are imminent.    Many of us worry about situations such as the SE tornadoes when forecasts are very good, but many people still die.  And more limited and surgical warning save money.  Big money.  The trouble, of course, is that the media loves to overhype storms...really good for viewership.

For those of us on the West Coast it is good to keep some perspective on storms.  We don't have tropical hurricanes, but our big storms are the equal of all but the strongest hurricanes. Take Irene..fairly large hurricane with sustained winds of 85 mph and a central pressure of 952 hPa (mb).  Here is a nice image of it:

Lets compare to our Dec 12, 1995 windstorm.  Here is an image:

Ours is just as big if not bigger.   Maximum winds?  Here is a nice analysis by storm-maven Wolf Read:

Gust to well over 100 mph on the coast!  Certainly, the winds from this storm are in the same league or greater than Irene.  Central pressure of our storm--953 hPa...virtually the same as Irene.  The 1995 storm is nothing compared to the 1962 Columbus Day Storm.
And the waves from our big storms generally eclipse those of the East Coast varieties.

A major difference between our storms and East Coast hurricanes is the coverage--for many reasons the WeatherChannel and East Coast media give relatively short shrift to our storms. 

But hurricanes do bring heavy rains and flooding, which is generally limited for our big windstorms.  The reason--hurricanes are tropical systems depending on warm water and the release of heat by condensation of water vapor.  Our storms derive their energies mainly from another source:  horizontal variations in temperature.  And the coastal areas of the east coast are more vulnerable to storm surges and coastal flooding--the biggest threats of hurricanes.

Mid-Level Convection

Yesterday was quite a meteorological treat, with interesting clouds and an amazingly colorful sunset.   But it was also a good example of mid-level instability--when the mid-levels of the atmosphere starts to break out into cumulus-like convective features.

Yesterday, a weak upper level disturbance was approaching, with upward motion aloft, producing an unstable layer  above the surface.

One sign of the upward motion was the development of cirrus, include some impressive fallstreaks (made of ice crystals).  Several of you sent me pictures you took of this beautiful feature and several others were shown on the web (see example below from George Tanaka of Bainbridge Island--courtesy of Scott Sistek's blog):

The curved ice crystal "tails" falling from the cirrus are often called "mare's tails."  Why are they curved?  The reason is that the wind speed change with height--usually decreasing below the main body of the cirrus--thus the curve.

But as the day progressed the air at mid-levels started to convect into small cumulus, actually altocumulus.  Some of these cumuli developed tower or turret shaped features--they are known as altocumulus castellanus.  Now that is name that will impress your friends!  Just say that casually at some party and it will turn some heads.

Here is a great video from the UW web cam that shows the destabilization of the mid-levels and the development of the convection, with some of it deep enough that rain started to fall out:

Click for video

http://www.atmos.washington.edu/images/webcam0/movies/20110824.mov

And you can catch the marvelous sunset.The instability clouds were apparent on the satellite pictures during the afternoon and afternoon:

An offshore band was particular impressive.

And an added features---Mt. Rainier developed a nice "cap" during the afternoon...a sign of moisture and lift aloft.

It is now clear that Hurricane Irene is going to savage the East Coast--a really serious storm. But for us, just the opposite.  The warm, perfect weather will continue through Sunday, with perhaps a slight cooling on Saturday.

And a reminder---I will be teaching Atmospheric Sciences 101 this fall if anyone is interested.  UW students, of course, and others who want to take it as non-matriculated students.  Retired folks can get in for practically nothing.

A Potential Breakthrough in Hurricane Forecasting

If you are a billionaire, a foundation leader, a powerful politician, or have a few million dollars to spare, I have an idea for you, one that might greatly improve the skill of hurricane forecasts.   No pressure--just a chance to make a huge difference in predicting storms that do billions of dollars of damage a year. But first lets talk hurricanes.

Today, Hurricane Irene is heading for the southeast coast of the U.S., and the current predictions of the National Hurricane Center suggest that the storm will make landfall either on the Outer Banks of  North Carolina or New England (or both).  The graphic below shows the NWS track forecast.  You notice they use a cone shape that increases in width in time, consistent with the loss of track accuracy in time.

 For three years the U.S. mainland has been spared a direct hit and we have become complacent.  When I was back in D.C. for a meeting at the NWS National Centers for Environmental Prediction there was lots of talk about massive cuts to the hurricane research budget.

Perhaps, things are about to change.

The interesting thing about hurricane forecasts is that we have gotten much better in some ways (predicting the track of the storm) and have barely improved in others (forecasting the intensity of the storm).

Want to see some sobering figures?  Here are the changes of errors over the past several decades for hurricane track and intensity.  A steady and impressive improvement in track forecasts.  For 48h forecasts the errors have gone from 300 nautical miles in 1970 to 80 nm today.  Huge improvement. But intensity forecasts have hardly changed--even gotten worse at 24h.

We understand why this discrepancy occurs.  During the past decades we have gotten much more observational data AROUND hurricanes from satellites and other sources and our numerical models have gotten better.  If you have a better handle on the environment of hurricanes you can secure a much better prediction of their track, because they are steered by the larger scale flow.   But to predict changes in their intensity, you have to know the details of their innards; you have to be able to specify their internal structure and have computer models with the very high resolution needed to get the fine-scale structure (eye wall, rainbands) correct.   Historically we have had neither.  Thus, our ability to forecast intensity is poor.

But the situation could be changed for the better.  Today, we have the computer power and models capable of doing the job--we are talking about running our computer models with grid spacings of 1-2 km (today we use 12 km).  Here is an example of what we are capable of--a simulation at 1.3 km grid spacing:

Beautiful simulation of the eye and rainbands. Amazingly realistic.   But we need to get data inside the storms at high resolution: data that can be used to start of initialize our great models.  That is where we need to improve.

One approach is to send manned aircraft, like the NOAA P3, with sophisticated radars and dropsondes (weather instruments that are dropped into hurricanes.)  This is good, but it is very expensive and we can't afford to have enough planes out there at all times to do the job.

A better idea would be to use unmanned aircraft to do the reconnaissance.  Today NOAA and NASA are experimenting with the use of Global Hawk drones that could fly high above hurricanes with downward-looking radars and the ability to release dropsondes into hurricanes.

This is very promising.  But we acutely need observations IN the hurricanes and particularly near the surface where the critical fluxes of heat and moisture are driving the storms.  We need unmanned aircraft that are tough enough to do the job, yet cheap enough that their loss would not be a disaster (Global Hawks cost millions of dollars!).

A local Washington company may have the solution: moderately expensive (tens of thousands of dollars) unmanned aircraft that could get the critical observations.  The company- Aerovel, located in the Columbia Gorge, is led by a brilliant Stanford-trained engineer named Tad McGeer.  He designed another unmanned aircraft that was the first to cross the Atlantic (I know about it, because I was the meteorologist for the mission.  The aircraft, Laima, is now in our Museum of Flight).  Aerovel has developed an aircraft that can take off like a helicopter, transition into level flight, fly thousands of km, return to base and land itself.

Don't believe me?  Check out a video of one of their recent test flights (click on image or link):

http://youtu.be/icsLzAj6Xis

Imagine a swarm of these unmanned aircraft densely sampling the lower structures of hurricanes, while the Global Hawks are observing from above.  The information would be sent back in real time to the National Weather Service, where high-resolution models use the information to make highly skillful hurricane predictions...far more skillful than we have today.

A dream?  No.  It is quite possible. But it will take several million dollars to test this out.  That is where we need someone or some group with sufficient resources to provide the seed money that will give this idea a real-life evaluation.

The New Coastal Radar Delivers!

A major change in weather is now occurring, with marine air pushing into western Washington, displacing the warmth of yesterday.   A front is approaching the coast, but will it rain?  How strong is the front?  Now we know--because of the new coastal radar.

This morning, Brad Colman, Meteorologist in Charge of the National Weather Service Seattle office, kindly sent me this image at 7:17 AM (they are getting the radar in real-time on many days):

 You can see a strong front offshore, stretching to beyond the Oregon border (yellow and red are heavy rain).   Here is an image two hours later (Courtesy of Kirby Cook, Science and Operations Officer, NWS, Seattle):

 This is a very strong front for this time of the year! The reds are heavy rain.  The northern part of the northern WA coast is getting hammered.  At 10 AM, the new radars estimate of precipitation at Quillayute was .64 inches, actual was .60 inches....very good!

Here is the image from the Camano Island radar:

It can't see the front beyond the entrance to the Strait of Juan de Fuca...the parts that will hit Seattle and south--because of blockage of the Olympic and distance.  But the new radar shows clearly the strength of the front extending out over the ocean...marvelous.

Or how about the Portland radar?  If you believed it, you would think that there were only a few sprinkles out there.

The winds are really picking up now, with some places getting sustained winds over 20 kts.  Here is the latest ferry weather winds.  Sustained 25 knots in the central Sound--and gusts would be higher.

The Seattle profiler at Sand Point, which shows winds above the surface, clearly indicates the strong southerly winds that have pushed in aloft....a very different day.  Temperatures aloft have declined by about 10C (18F).

The coastal radar, observations on ferries, the profiler...twenty years ago we didn't have any of them.  And we didn't have high resolution numerical models.   Progress is being made.

This event is associated with an unusually strong summer atmospheric river of moisture.  Let me show you an image of the integrated moisture in the vertical:

 

See that yellow and red filament heading right towards us?  That is the atmospheric river, and it has our name on it.  Much of the region should see significant rain, particularly those on the SW sides of regional terrain.  Take a look at the 24-h total rainfall predicted by the UW WRF modeling systems for the 24 hours ending 5 AM Tuesday.  1-2 inches on the windward slopes and 2-5 inches on the SW side of Vancouver Island.   This is heavy stuff for August.