Levi Cowan has been tracking tropical systems since 2002, and is currently working on his bachelor's degree in physics at UAF.
By: Levi32, 1:51 AM GMT on April 26, 2007
As June rushes closer, conditions and patterns for the upcoming season are beginning to reveal themselves. Not surprisingly, some of the changes so far are different than what we expected a month ago. The La Nina which we thought would be so strong this summer may not end up as potent. As I stated in a blog a month and a half ago, several key factors were and still are not present to support a strong La Nina. A big one is the SOI, which instead of going positive, which is the normal case during a positive ENSO, is tanking negative, which we normally see during El Nino conditions. This is altering precipitation patterns across the equatorial Pacific regions, causing the ENSO Precipitation Index (ESPI) to rise (now nearing zero again). Here is a look at the latest SST anomalies:
Back in February, cold anomalies showed up in the central Pacific, where the ENSO is thought to make its strongest impression on the SSTs. However, these anomalies have been replaced by normal to warmer than normal waters, and the cooler anomalies reappeared in the eastern Pacific close to South America a month ago. This is not indicative of a coming strong La Nina to me. If there were, the central Pacific would be cold and not warm. To me, this looks more like a neutral pattern with a cold bias factor in the ENSO. This could be both a good and a bad thing for the upcoming hurricane season. On the good side, neutral to El Nino conditions generally increase wind shear and the number of upper-level lows and troughs in the Atlantic. We saw this last year, when the jet stream consistently dipped south and ripped apart many a potential storm during the entire season. The bad news is that a neutral pattern usually produces the most named storms on average in the Atlantic. The classic example of this was of course 2005, when we had 28 named storms. The ENSO was neutral that year. So, the key will be how the upper pattern sets up over the Northern Hemisphere over the next couple months. The position of the Bermuda High will be closely watched, as well as wind shear anomalies, which have been fluctuating up and down over the last several weeks. Another factor has been the ESPI, which moistened up the bone-dry Atlantic quite nicely last month when it went negative. But the ESPI has been trending back up for 2 weeks now, and the results are clear on the water vapor imagery. The Atlantic is bone dry again in most areas.
All these factors will come together during May and June to give us a picture of what the hurricane season could be like. Right now nothing much is certain. I don't believe we will have a strong La Nina this year, and as I said I think a more neutral pattern with a cold bias is likely. I'm sticking with my season predictions that I posted 2 weeks ago until I see a need to change them.
We shall see what happens!
Updated: 1:56 AM GMT on April 26, 2007
By: Levi32, 3:01 PM GMT on April 25, 2007
Today: Cloudy with areas of light rain this morning. Temperatures around 37 in the morning. Becoming mostly cloudy by afternoon with temperatures warming to 48. Winds SE at 10mph.
Tonight: Mostly cloudy, temperatures falling to 36, winds backing to the NE 15-20mph.
Tomorrow: Mostly cloudy, high near 49, winds NE 15-25mph.
Tomorrow Night: Cloudy with periodic light rain. Low around 38. Winds north 10-20mph.
NOTE: This is not the pathetic conservative NWS forecast lol. This is MY interpretation and not the whole "mostly cloudy with a chance of showers; chance of sun in afternoon; chance of precip 50%" whole kind of crap :) I should just do this from now on for my area lol. The NWS just doesn't know how to forecast anymore.....sad though I am to say it.
Updated: 3:19 PM GMT on April 25, 2007
By: Levi32, 10:30 PM GMT on April 13, 2007
Another severe weather outbreak is underway in northern Texas this afternoon. The SPC has posted a high risk region centered over the Dallas metro area. Shear profiles, low-level jet, upper-level support and moisture seem to be high enough to support a major outbreak. I do not have the time to look into this more thoroughly, but this will be a dangerous situation in northern Texas, especially for Dallas/Fort Worth. All residents should take extreme caution and watch the weather closely as the evening progresses. Strong to violent tornadoes are possible with these storms. Later all! We shall see what happens.
By: Levi32, 11:22 PM GMT on April 11, 2007
Well I did find some time this afternoon, so I will go ahead and share my findings for making nifty weather graphics.
I'm sure many of you have heard of or use Google Earth. In a nutshell it is an interactive view of the world from satellites. It contains some of the most detailed images that current technology can obtain. In the highest detailed areas, such as cities, you can even see houses and people. These images are not current however, and are taken within the last 3 years. The zooming and tilting features in Google Earth enable you to get some sweet views of wherever you want. Google Earth can be downloaded here.
Also as some of you may be aware of, images can be overlayed on Google Earth. I have recently experimented with putting weather images in it. It can sometimes be a hastle to line up the country borders to fit it on so it's aligned with the earth below, but once it's done you can get some nice views of it. However a couple days ago I discovered that I don't need to labor at putting in my own images. You may have seen on the NWS radar pages that there is a GIS link for putting radar images in GIS programs, such as Google Earth. These radar images take out the background image where there is no reflectivity, leaving just the radar colors. This allows you to see the surface of the earth where the radar isn't covering it up. You can get radar images for Google Earth here.
I went searching the web, and found that the NWS aren't the only ones experimenting with weather data in GE. This site has collected many overlays made by GE enthusiasts. Just browse the articles at the bottom of the page and you'll find all sorts of stuff. Some things I have found so far are GOES satellite images, Great hurricane trackers, Global IR composite(really good, covers the whole earth), historical hurricane tracks from 1850-present (the link to the rest of the years doesn't work, so here's the correct one), and much more. NOAA is also making data sets for GE in Geotiff. All this stuff is free, and I've already put most of it in my copy of Google Earth.
Each of those pages has a screen shot of the product, and here are two that I took today with my own computer of the severe storms in Alabama:
Here's one with radar and warning polygons:
And another one facing towards the gulf coast with SPC storm reports:
Click on each image for a larger version.
So, what do you all think? Personally I really like it, and the possibilities are endless. The National Weather Service will be implementing more and more products in the future, and more plug-ins are being created by individuals every day. I hope you enjoy, I know I will lol. I can't wait to try out those hurricane trackers this season. Have a great day everyone!
Updated: 11:24 PM GMT on April 11, 2007
By: Levi32, 4:24 PM GMT on April 11, 2007
Hey guys. I've been granted weather time on the computer for a couple hours a day to see how I do, so I won't be flying completely blind with the weather anymore. It's not much but I'll take it lol. Gotta learn to limit myself :)
I will be on here in bits and pieces, maybe a blog or two. Soon I'll be posting some really cool stuff that will allow all of us to make some swell graphics this hurricane season. I won't tell you what it is now...."Wink" :) I can guarentee though, you'll all love it if you haven't discovered it for yourselves aready.
Gotta go now, see you all when time permits.