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Regarding climate, it does not rain in Seattle as much as people think; Seattle is in the snow shadow of the Olympic Mountains. It doesn't rain much in summer at all. Seattle gets rather dry in July and August.
Regarding flooding, the Skagit and Snohomish rivers north of Seattle flood regularly experience flooding. Some of the land in the flood plain is used ...
18
Yes, if one takes the common meaning of the term "eye of the storm" to be the area of relatively low wind speed near the center of the vortex, most tornadoes can be said to have eyes. Cyclostrophic balance describes a steady-state, inviscid flow with neglected Coriolis force:
$$
\dfrac{v^2}{r} = -\dfrac{1}{\rho}\dfrac{\partial p}{\partial n}
$$
where ...
17
Catastrophic flash flooding is usually a sign of poor city/road planning in flat areas or due to torrential downfall of rain. The reality is that all the terrain in Washington allows water to drain, rather than be left standing (which causes flash flooding). And let's be clear, it doesn't rain hard in WA, it's usually not torrential downpour, bur rather a ...
10
It is likely snowing somewhere in these clouds and graupel exist transiently on their way to becoming hail, but its not likely that you will see either at the surface.
You can make a first order approximation of a pyrocumulus cloud by putting a very strong heat source at the surface in an environment otherwise favorable for severe convection. What you'll ...
9
Let us state the obvious reasons first:
Warm SSTs along the Timor Sea as well along the Queensland coast favour the formation of Tropical Cyclones -
The following two URLs show the SSTs along the Northern as well as Eastern Coast of Australia for the referenced periods.
a) http://earth.nullschool.net/#2015/02/15/2100Z/ocean/primary/waves/overlay=...
7
What is the synoptic/atmospheric setup that is causing the U.S. severe weather outbreak in May 2019?
Summarizing the comments I made above in this question and in this one - Does this weather pattern have a name ? I believe significant parts of the US are experiencing a Stationary Front for the past one month. There has been plenty of media coverage of this event and if you google the term "stationary front" under news one will receive a lot of links to ...
7
Hurricanes backtracking and looping seem to be quite common in the Atlantic (Nadine, Jeanne, Alberto, Dennis), and West Pacific (Ernie, Nari, Fung Wong, Parma, Roke) but not so much in the East Pacific (where the tracks are way more linear, with much less latitudinal change).
In general, tropical cyclones are steered by the global wind field. The ...
6
Looking at the southern hemisphere polar jet, there is a large trough (meander) in the jet stream bringing cold air a long way north from the Antarctic to south eastern Australia at present. The relevance of the position and shape of the jet stream is thought to be important for keeping cold polar air in place above the antarctic/arctic, with a strong jet ...
5
Is the ratio of IC to CG lightning relevant?
Yes. Primarily, severe storms tend to have very few cloud-to-ground (CG) strikes. Thus, the ratio of IC:CG is likely going to be very high.1 2 However, some severe storms do produce a significant amount of positive CG strikes. They would still have a high IC:CG ratio, but they would distinguish themselves by ...
5
It is mostly due to the Coriolis effect (aka Coriolis Force). (Another reference here) Because of the Coriolis Effect, parcels of air (think of boxes of air) in the northern hemisphere are deflected to the right. This means that air around the subtropical ridge over the Atlantic ocean circulates clockwise.
Think of a tropical cyclone as a parcel, or box of ...
4
Check out this beta data portal from the Cooperative Institute for Meteorological Satellite Studies / University of Wisconsin-Madison
CIMSS Tropical Cyclones
Data Archive http://tropic.ssec.wisc.edu/archive/ .
However, my favorite source of information is the Regional and Mesoscale Meteorology Branch (RAMMB) of NOAA/NESDIS http://rammb.cira.colostate.edu/...
4
In general, climate is the statistics of weather over a long period of time. In general, an individual weather event cannot be attributed to global change / global warming. An increase in the frequency of such events could be attributed to climate change. But considering how noisy weather and climate are, it takes a very long time series to measure an ...
4
We do get flooding in the Puget Sound lowlands, but it actually happens most often when a mid-winter warm front brings a moderate amount of rain to higher elevations, causing sudden, extensive snowmelt.
Those weather systems, like one in February 2020 that caused quite a bit of flooding, suddenly raise temps by 15-20 degrees C (20-30 °F), and raise the snow/...
3
Because soil drainage would be higher and the ground would take long to saturate Floods don't always happen in Rainy weather all the time because first the soil needs to be saturated (the point where it filled up with water) then the rain needs to continue, Flash floods are mostly produced this way.
So you would need lots of rain for a flood to occur in WA, ...
3
Although there is a superficial resemblance between tornados and dust devils, they are very different. There is no connection between the two. I have seen lots of dust devils in reality, but tornados only in videos. Whereas tornados are very large and usually very wet, dust devils are very small and very dry. They occur in deserts and very hot, dry ...
3
Cyclones generally drift in a westerly/north westerly direction due to the Beta Drift and Beta Effect
For atlantic hurricanes the forward speeds are summarized here by latitudinal range -Average forward speed of Atlantic Hurricanes and if there is recurve(turn more northerly) they can slow down or if they cross mid latitudes they may pick up speed by ...
3
Note: These inputs are of a meteorologist who has quite actively tracked severe
weather around the US for a couple
decades... but also hadn't spent as much time in or attention on the west and northwest of the country. So there could could theoretically be some degree of unintended bias. I've tried to use objective data where possible, but it's something ...
2
The characteristic funnel of a tornado is caused by condensed water. A tornado is a swirling mass of air with very high vertical vorticity and a corresponding drop in pressure. Large tornados can have pressure deficits on the order of 100 hPa, which is significant compared to synoptic horizontal pressure gradients. The drop in pressure causes air to ...
1
To add some concrete data to some of the great answers already here:
Seattle is actually not particularly rainy, especially compared to other parts of WA, but also compared to other cities in the US. According to this chart of the largest 51 US cities, Seattle is wetter than 18, drier than 31, and tied with 1. Yet, Seattle only has less rainy-days than 5 ...
1
You're definitely on the right path with wanting to dig into raw data yourself. RAP has always been a pretty solid source of useful basic data.
But in terms of making sense of the data, it indeed will take some practice. You can feel like you're not getting it at all, but suddenly pieces will start to click, much like riding a bike.
Basically, you need to ...
1
Here are some cities and locations
Average Annual Snowfall for the Following Cities and Locations (in inches)
Asheville, North Carolina: 9.9”
Waynesville, North Carolina: 14.1”
Milwaukee, Wisconsin: 46.9”
Madison, Wisconsin: 50.9”
Syracuse, New York: 123.8”
Buffalo, New York: 94.7”
Smugglers Notch, Vermont: 59.8”
Burlington, Vermont: 59.8”
Mount ...
1
I think what you are asking is there a way to do a research project that would look for a correlation between number of dust devils and tornadoes. Dust devils, being very local phenomena, are not tracked (as far as I know). So finding the data would be your first challenge. Even if you could get a dataset of dust devil occurrence you would have the ...
1
Extratropical cyclones are relatively well understood. They often follow the Norwegian Cyclone model, which was developed in the 1910's and 1920's. Because of their spatial extent, extratropical cyclones are often less intense than their tropical counterparts. Since they are so much larger and live longer over land, it is easy to get data about an ...
1
I don't think so. A large fire could generate a circulation with strong low-level convergence and upper level divergence that would cause subsidence as the air radiatively cooled. If the fire were stationary and huge, the Coriolis effect could make it's upper level outflow turn, but I don't think an intense hurricane-like cyclone could form unless the fire ...
1
Generally speaking, the types of data gathered outside a tornado can also be measured inside the tornado. Currently, forecasters try to estimate an area where tornadoes usually are. The forecasting time for tornadoes, or warn time, is about 13 minutes. There is still quite a bit we don't know about tornadoes, such as why some storms that look like they can ...
1
The shape of a tornado is due to the movement of air and not dust. The shape of a tornado is called a vortex. A vortex can occur in any fluid (air or liquid) where the fluid rotates about an axis line. Vortices are examples of turbulent fluid flow (air or liquid).
When vortices occur in liquids they are sometimes called whirlpools. Tornados are high energy ...
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