Thursday, September 23, 2010
Yup, you guessed it, the rain is BACK in the forecast. We had different scenarios being forecasted by two different models. The American GFS model was forecasting dry and warm, with rain going right to the north of us, while the European ECMWF was forecasting rain. Naturally, we believed our own forecasting model, because we think that everything about America is way better than our inferior relatives across the pond. However, it's no secret that the ECMWF is a better forecasting model, especially for the long run. We just generally use our models because we have the amazing UW mm5 models for them, but yeah, long-range forecasting is the achilles heal of our models.
I'll have another, longer forecast later, I just have a bunch of hw to do.
Wednesday, September 22, 2010
As many of you have noticed, the U.S. hasn't been hit by a hurricane this year. We've come mighty close - one recurved off of the outer banks and one landed just south of Brownsville, but we have had no U.S. landfalls, which is phenomenal because this has been a very active hurricane season so far.
But we may get a hurricane landfall yet. There's another Cape Verde storm way out in the Atlantic, and it's not going to impact us. But there is an area of disorganized low pressure in the Caribbean, and this could very easily develop into something if conditions are favorable.
As the satellite image shows, there is a LOT of thunderstorm activity in the Caribbean. There is not much wind shear and there are warm water temperatures. The strongest hurricane on record occurred in the Caribbean in conditions like these back in 2005. It reached 882 millibars! The Columbus Day Storm, our strongest storm, was only a 960. Only a few storms ever go below 900, and no non-tropical storm that I know of has ever gone below 940. 882? That's crazy. It was Hurricane Wilma, and at peak intensity, it had the smallest eye on record, being 2 nautical miles in diameter. Most eyes are like 40 nm across.
See if you can make out the eye in this picture. It is visible, but barely. Wilma also occurred in mid-October when water temperatures were cooler. Evidently, they weren't cool enough to prevent hurricane formation. I'll keep you posted for updates on the situation in the Caribbean!.
Tuesday, September 21, 2010
Wednesday, September 15, 2010
Tuesday, September 14, 2010
Friday, September 10, 2010
Thursday, September 9, 2010
While the weather is still pretty boring, I thought it would be a good idea to go over some different topics that are still related to weather, even if they aren't my own forecasts for the upcoming days. I'll cover a couple notable storms each day, going in chronological order.
The first big windstorm to hit the Pacific Northwest since the arrival and settlement of white men was on January 9, 1880. This storm was rather unique because although we don't have detailed measurements from back then, we do have some observations and approximations, and
I've found two things. First of all, it is important to point out that this storm came in from the southwest onto the northern Oregon coast when cold air was already in place around the PacNW. The result, especially for places north of the center of low pressure (and therefore receiving northerly winds) was intense snowfall. Seattle got 2 feet of snow total. The second point is that the damage looks to have been highly localized. Look at the graphic above, and look at the comparison between Astoria and Fort Clatsop. "Light damage" at Astoria vs. a "terrific west wind" at Fort Clatsop. This clearly illustrates the localized nature of this storm, in no doubt helped and aided by our mountainous topography. This picture came from Wolf Read's "The Storm King" website @ climate.washington.edu/stormking. I love these guys' names. Wolf Read. Cliff Mass. Somehow Charlie Phillips doesn't seem to fit. Maybe Chuck Phil? Or as Adam Moshcatel likes to call me, C-Lips. Who knows.
I'll go over one more storm, the Olympic Blowdown of January 29, 1921. Again, reliable measurements were hard to come by in this age, but anecdotes and notes do exist and can give us an idea of what terrifying power this storm really beheld.
A weather bureau officer stationed at the North Head lighthouse (which recorded sustained winds of 113 miles per hour and a gust of 150, the strongest winds ever recorded in Washington excepting some occasional times on Naselle ridge) had this to say about the storm.
"The road from Ilwaco to North Head is through a heavy forest of spruce and hemlock timber for some distance. On the return trip shortly before reaching the heavy timber, the wind came with quite a heavy gust. We saw the top of a rotted tree break off and fall out of sight in the brush. About this time (near 3:20 p. m.) we were overtaken by a young man from the naval radio station at North Head who was driving a car. It is dangerous driving over this road under favorable conditions. We proceeded very slowly and with great care, passing over some large limbs that had fallen and through showers of spruce and hemlock twigs and small limbs blown from the trees. We soon came to a telephone pole across the roadway and brought our car to a stop, for a short distance beyond the pole an immense spruce tree lay across the road. We left the machines and started to run down the road toward a space in the forest where the timber was lighter. Just after leaving the car, I chance to look up and saw a limb sailing through the air toward us; I caught Mrs. Hill by the hand and we ran; and instant later the limb, which was about 12 inches in diameter, crashed where had stood. In three or four minutes we had climbed over two immense tree trunks and reached the place in which I thought was our only chance to escape serious injury or possibly death. The southeast wind roared through the forest, the falling trees crashed to the ground in every direction from where we stood. Many were broken off where their diameter was as much as 4 feet. A giant spruce fell across the roadway burying itself through the planks within 10 feet of where we stood. Three tops broke off and sailed through the air, some of the trees fell with a crash, others toppled over slowly as their roots were torn from the earth. In a few minute there were but two trees left standing that were dangerous to us and we watched every movement of their large trunks and comparatively small tops.
"Between 3:45 p. m. and 3:50 p. m. the wind shifted to the south and the velocity decreased to probably 100 miles or it may have been as low as 90 miles per hour. Shortly after 3:50 p. m. we started toward North Head. We climbed over some of the fallen trunks, crawled under others, and pushed our way through tangled masses of tops that lined the roadway. We supposed that all the houses at North Head had been leveled and the wireless station demolished for we knew that the storm was the most severe that had occurred in the vicinity of the mouth of the Columbia within the last 200 years. Mr. Seui, the young man from the radio station who was with us, hastened through the obstructions, and Mrs. Hill and I proceeded more slowly. About one-fourth of a mile from the station we were met by one of the men from the radio station, who had come to assist us had it been necessary. At 4:40 p. m. we arrived at the assistant lightkeeper's home where all the families of the Head had gathered for safety."
Wow. Yeah. That was a big one. The storm track for this was more typical of a region-wide windstorm, but it also was highly localized. Whereas several billion board feet of timber blew down on the coast, the inland areas escaped with light damage. But they would get their share of wind too. :)
And do yourself a favor and check out Wolf Read's website at http://www.climate.washington.edu/stormking/. That's where I'm getting these pictures and anecdotes from, and you'll find way more there than you will ever find here. Wolf Read is the man.
Wednesday, September 8, 2010
Have you ever looked at one eather forecast one day, seen it as forecasting rain, then seeing the forecast switch to sun, only to have it switch back to rain? That is what is happening in the models right now, and it is very, very hard to make accurate forecasts when models can't decide what path to take with a certain storm. It makes it particularly hard if all the models are doing this, which is what they have been doing.
Thankfully, they seem to be converging on a solution of sun Thursday and Friday, with light rain returning Saturday night and Sunday. This is September, so the sunshine won't be your July sunshine, and the storm won't be your typical November storm. Things will generally remain quiet and benign around here as summer transitions into fall. Fall transitioning into winter brings the big storms, and winter transitioning into spring often brings instability and heavy showers, but summer to fall (and spring to summer) are both fairly quiet as far as weather phenomena go.