19 year old freshman at UNC Asheville majoring in atmospheric sciences. I'm deaf and proud of it :) Twitter: @KyleNoel15
By: Bluestorm5, 1:33 AM GMT on May 24, 2014
UPDATE 2 (10:35 PM EDT 5/24/14):
Well, that escalated quickly. Since the last update 24 hours ago, Amanda went from young 60 mph tropical storm to rapidly intensifying Category 3 major hurricane with National Hurricane Center estimated max wind speed of 115 mph. This is what you're going to get when water is around 29-30 degrees Celsius, little dry air, high heat potential energy, and very calm shear wind. Mother Nature doesn't really care that it's May as long as the conditions are favorable, which it is right now and will be for one more day. As you can see, Amanda's eye is clearing out very good (Figure 1) which is why the current ADT update went nuts with Dvorak number of 5.8 with estimate wind of 109.8 knots (126.4 mph to us Americans) and pressure of 956.9 mb. Remember this is likely overdone, but still this is quite an impressive storm nevertheless. Because of the current state of rapid intensifying, I'm expecting Amanda to peak at 135 mph Category 4 in about 24 hours (Figure 2) before cooler water and higher wind shear will lead to Amanda's quick death. Maybe I'm not as quick with upcoming death of Amanda, but you get the idea. There's a chance that all of this leftover storm will give Mexico and Southern United States a much needed rainstorm considering the ongoing drought in these regions.
Figure 1: Satellite loop of Hurricane Amanda from 2100z to 230z (5 pm EDT to 10:30 pm EDT via University of Wisconsin). Note the eye clearing itself of clouds.
Figure 2: My forecast of Hurricane Amanda. As usual, credit to Weather Underground for background tracking map.
UPDATE 1 (10:56 PM EDT 5/23/14):
Yes. An update two hours after posting this blog post. National Hurricane Center (NHC) just bumped up Tropical Storm Amanda to 60 mph with max intensity of 100 mph Category 2. I think this is an aggressive move by NHC, but completely reasonable forecast too. Amanda continues to be a beautiful storm, structure wise, but it'll be interesting if she can build more thunderstorms for her inner core. Her slow movement is giving herself more time to take in warm water of Eastern Pacific as well as staying away from higher wind shear. I think this is jumping the gun, but could Amanda make a run at major hurricane status? We'll see!
FIRST NAMED STORM OF EASTERN PACIFIC HURRICANE SEASON
The last few days absolutely flew by me due to the fact I was busy working at a warehouse in a small, rural Carolinian town for 42 hours in four straight days. When I finally turn my computer back on yesterday, I discovered that there was an invest in Eastern Pacific (EPAC) for the past few days. Not long after I found out, National Hurricane Center (NHC) updated the storm up to tropical depression status. At 10:50 AM EDT, on the day of May 23rd, 2014, NHC updated the storm up to tropical storm status and gave her the name of Amanda (Figure 1). Despite the fact EPAC season opened on May 15th, Amanda is climatologically early for the first named storm of EPAC season as the first storm of season usually named by June 10th. This is only the beginning of what could be a hyperactive Eastern Pacific hurricane season due to an upcoming El Nino (explained my reasoning here).
Figure 1: Satellite loop of Tropical Storm Amanda as of May 23rd from 1800z to 2330z (2:00 pm EDT to 7:30 pm EDT) via University of Wisconsin.
As it is the case with majority of first named storms in either basin, this could be a tricky forecast to get right. Right now, Tropical Storm Amanda look very impressive for this time of year and got things going for it. Amanda is looking good and thunderstorms are firing all over the cyclone, especially near the center of the storm. Amanda also appears to be stacked pretty decently as well, although not it's perfect. Eastern Pacific is ridiculously soupy for this time of year at 29-30 degrees Celsius, which greatly favors Amanda in the next several days (Figure 2). Finally, the latest NOAA/NHC SHIPS product got the shear at about 10 knots, which is not too bad at all. Now, let's get to forecasting. First of all, Eastern Pacific's warmer than usual water is full of heat potential energy that could fuels Amanda over the next few days (Figure 2). With wind shear staying in check over the next 72 hours, according to SHIPS, I could see Amanda strengthening to at least an strong tropical storm. Potential is definitely there for Amanda to become EPAC's first hurricane as well. However, keep in mind this is the first storm of the season in late May and not one of those cursed I-named storms in early September. Bust potential is little high for this storm, in my humble opinion, but Amanda is putting up a show for a tropical cyclone in month of May. Now let's talk about the path of the storm. This storm appears to be slow mover which again favors Amanda's bid for hurricane status. Over the next few days, it'll move westward or west-northwestward until the steering in upper atmosphere force the storm northward or north-northeastward toward Baja California in Mexico, as you can see from 18z run of GFS ensembles (Figure 3). Higher shear in that area as well as cooling waters by 2-3 degrees could weaken and kill the storm eventually before reaching the land. Nevertheless, this could bring some rain to Mexico but not awfully much.
Figure 2: Sea surface temperature (top) and heat potential (bottom) of Eastern Pacific from WeatherBell.
Figure 3: 18z GFS ensembles from Levi Cowan's Tropical Tidbits website.
Let's take a look at computer models now. Naturally, I'll look at 12z ECMWF (aka Euro) first, and boy, that run is impressive as that model takes the storm down to 985.8 mb by Wednesday morning. Euro also took the storm on a similar track as 18z GFS enbembles I mentioned earlier. Next, I took a peak at high resolution 18z GFS. I thought 12z Euro was little crazy, but 18z GFS was even stronger with Amanda at 983 mb (Figure 4). But, Euro is actually not too far from GFS given that Euro initiation was slightly weaker. I'll consider the agreement between GFS and Euro models to be pretty decent to strong. There's also other models, but they don't make much sense with few of them taking storm to Category Two plus strength or delaying storm's run toward hurricane status until much, much later near Baja California (where cooler waters and higher shear is in the forecast).
Figure 4: 18z GFS run on May 23rd from Levi Cowan's Tropical Tidbits website.
Now, it's time to make a forecast (Figure 5). Given Amanda's impressive display of strengthening today as well as very promising environment in near future, I can see Amanda becoming a hurricane as soon as late Saturday evening. However, I decided to go slower with the strengthening since 18z GFS is being slightly unrealistic with Amanda becoming a hurricane by this time tomorrow night. However, it won't be surprising either if she does become a hurricane between 36 to 48 hours into future given how well Amanda is performing today. She need to set an inner core, which I believe Amanda is nearing doing so, and she could make a run at Category 2 status like both GFS and Euro are suggesting. I want to go as low as NHC at 80 mph given that this is the first storm of the season. and in the month of May too, but there's so much potential for this storm so I am forecasting the peak of 85 mph. I also think cooler waters and shear will start affecting the storm as soon as 96 hours into the future which is why I'm forecasting weakening at that time. My biggest concerns in my forecast are that I'm overestimating heat potential and warm water while underestimating climatology and physics of this planet's atmosphere. Two invests in Eastern Pacific had already busted so far this year as they didn't develop as forecasted which only add up to my concerns. This forecast is pretty aggressive for a tropical cyclone in the month of May, but environment look so good that I'm going to trust my gut that it'll be impressive. Nevertheless, the potential range of peak winds will be anywhere from only reaching "strong" tropical storm status to a Category 2 storm which make this a tough forecast. We'll see what happens, though!
Figure 5: My forecast of Tropical Storm Amanda. Thanks to Weather Underground for the tracking map.
I'll post updates for Tropical Storm Amanda on this blog post. I also won't be updating on Sunday since I'll be spending the day in Charlotte for a race :)
- Kyle Noël
Updated: 4:05 AM GMT on May 25, 2014
By: Bluestorm5, 8:39 PM GMT on May 06, 2014
UPDATE 2 (12:09 PM EDT 5/7/14):
While Invest 90E still look good (Figure 4), the circulation is still very broad and there's almost no more time left to tighten up the rotation to get tropcial cyclone status. It doesn't help that wind shear will increase across the area just before landfall in Mexico not too long from now. I don't think this storm will make it to tropical depression status, but we'll see. NHC still got this storm at 50% chance of developing in the next 48 hours and ATCF is still mostly the same except the pressure is now 1004 mb.
Figure 4: NOAA GOES satellite image at 1530z (11:30 EDT)
UPDATE 1 (4:57 PM EDT 5/6/14):
Well, that didn't last long. Minutes after posting this blog, National Hurricane Center decided to update their Tropical Weather Outlook to 50% of development in the next 48 hours. Honestly, I'm still skeptical of development into a tropical cyclone (whetever it's tropical depression or tropical storm) mainly because of climatology. It's still only May 6th, but we'll see. ATCF update at 18z (2 pm EDT) still got Invest 90E at 25 knots.
FIRST TROPICAL INVEST OF PACIFIC SEASON
Good afternoon, y'all. I hope everybody is enjoying this week because I know I am enjoying my first day of summer back home in Central North Carolina. It's absolutely beautiful outside with very few clouds and temperature of 85 degrees. Anyway, we finally got something to watch, tropical wise, in one of two basins. Bloggers on WU has been tracking a tropical disturbance (Figure 1) just off coast of southwestern Mexico for few days in hope of getting Pacific's first tropical storm of the season. Technically, Pacific hurricane season doesn't start until May 15th, but Mother Nature sometimes doesn't follow rules. Anyway, NHC marked this disturbance as an invest 12z (8 am EDT) this morning with the follow:
EP, 90, 2014050612, BEST, 0, 110N, 1070W, 25, 1009, DB, ..., INVEST
For those who aren't familiar with ATCF, basically we got an invest coded 90E (E for Eastern Pacific or L for Atlantic) with sustained winds of 25 knots and pressure of 1009 mb. This invest, according to ATCF, is located at latitude of 11 north and longitude of 107 west. Anyway, this invest marked the start of 2014 Pacific hurricane season unofficially. National Hurricane Center also followed up their declaration of invest with their first TWO (Tropical Weather Outlook) of the season as well by giving Invest 90E 30% chance of making it at least tropical depression (Figure 2).
Figure 1: Satellite image of Invest 90E from NOAA/University of Wisconsin as of 1745z (1:45 EDT).
Figure 2: 12z TWO from National Hurricane Center
FORECASTING INVEST 90E
There really isn't too much to talk about for our little invest. It's currently in the best environment over the next few hours, but it isn't going to last long at all. This storm will struggle to spin itself as it's pretty large and broad. Increasing wind shear over the next two days isn't going to help this large low pressure at all either. Building massive high pressure between Hawaii and California will steer the storm northward into mainland Mexico in about 48 hours, which isn't enough time for storm to develop into tropical storm in my opinion. However, you can't help but think there's at least a chance by looking at the satellite loop so this is why I am giving it 30% chance of ever developing into at least tropical depression (different from NHC because chance of development in my standard is for storm's lifetime rather than 48 hours). I also think this storm will peak at around 35 mph between now and landfall somewhere in Mexico while the environment is still decent (Figure 3).
Figure 3: My forecast for Tropical Invest 90E. As usual, background map credit to Weather Underground.
One last note: this is really more of a test blog as I usually don't do Pacific unless I got nothing to do, like right now. For this year, I will do a blog for a single storm and post updates on that blog post rather than posting a whole new one. Hopefully this will save me the energy of doing new blog posts and give me more motivation of doing more blog posts on Atlantic and Pacific cyclones. We'll see how it go :)
- Kyle Noël
Updated: 4:18 PM GMT on May 12, 2014
By: Bluestorm5, 3:04 PM GMT on May 03, 2014
Hey, y'all! I hope the year of 2014 is off to a wonderful start for y'all. Well, we're now in the month of May which mean the traditional start of 2014 Atlantic hurricane season on June 1st is quickly approaching. The month of May is also the best time to release a yearly hurricane season forecast as well. I know some bloggers on Weather Underground like to release their forecast a little earlier on March or April, but I prefer to release my forecasts as close to deadline as possible because of accuracy. First of all, no one should ever depend heavily on seasonal hurricane forecasts as we all found out the hard way last year. 2013 hurricane season was expected by many to be an active one with the number of storms, hurricanes, and major hurricanes to be above normal. However, we ended up with 14 storms, 2 hurricanes, and 0 major hurricane (normal season is 12 storms, 6 hurricanes, and 3 major hurricanes). My forecast last year was 14-18 storms, 6-8 hurricanes, and 2-4 majors. Technically because I got the number of storms correct last year, I was one of 15 winners out of 142 WU bloggers for trHUrrIXC5MMX's (now MaxWeather) contest. Last year, I chose to go against the consensus and predicted a calmer season. Even so, my forecast still busted horribly like nearly every tropical meteorologists, WU bloggers, and weather geeks did. The bust was so bad that the infamous Colorado State University hurricane forecasting research team nearly ran out of funds for their wonderful project that had been going for around 30 years now. Seasonal hurricane forecasts are not perfect, but that's the beauty of science. Even if we know that the forecast isn't going to be great, at least we're still trying so we can learn something new so we can become better at forecasting. As for myself, I've gotten a lot more forecasting practice since the first day of college last August. I spent about hundred days total forecasting in WxChallenge for eleven cities around this country. I did very well, finishing ranked 208th in nation out of 2,000 forecasters while winning a trophy for the best 8 days forecast for Grand Forks, North Dakota among 500-750 freshmen & sophomores. I also finished 4th out of 25 UNCA forecasters for the year as well. Doing WxChallenge forecasts almost everyday in college definitely help me become a better forecaster as well as picking up more meteorology knowledge and what to expect from computer models as well as recognizing trends from them. I am confident that doing these forecasts will help me with hurricane season forecast as well. Now that I got higher confidence in my forecasting skills, I believe I can do much better with this year's forecast than the last several years combined. Now, it's time to discuss what to expect for 2014 hurricane season in Atlantic basin.
LOOKING AT OCEANIC AND ATMOSPHERIC PATTERNS
I don't think many people realize how global the effects of oceans are to our planet's atmosphere, especially when it comes to weather in United States of America. Atmospheric patterns for certain locations on this planet heavily depends on how much warmer (positive phase) or cooler (negative phase) the oceans are comparing to normal. Meteorologists call them climate oscillations. Like the activity of almost all weather in USA, the activity of an Atlantic hurricane season depends on what the conditions are like for oscillations in several places. For this forecast, we'll focus on three oscillations: El Nino-Southern Oscillation (ENSO or El Nino), Pacific Decadal Oscillation (PDO), and Atlantic Multidecadal Oscillation (AMO). The most important one out of these three for Atlantic hurricane is the phase of El Nino-Southern Oscillation. During a year with positive ENSO phase (also known as El Nino event) when the water of equatorial Pacific is very warm, the air above the ocean will be warmer as well. Warm air over Pacific will rise up into the atmosphere because it's more dense than cold air. As result, we get more thunderstorms and the outflow from these storms will lead to higher wind shear across Gulf of Mexico, Caribbean Sea, and Cape Verde region of Atlantic Ocean. Higher wind shear is not healthy for tropical cyclones because it'll tilt the structure of the storm and kills it. Bottom line: El Nino events typically lead to less active than normal hurricane seasons in Atlantic Ocean. Now, it's time to discuss the current phase of El Nino-Southern Oscillation. It has been five years since we last got an El Nino event in Pacific heading into Atlantic hurricane season, the last one during the year of 2009. However, the end to the streak of non-El Nino years seem imminent heading into 2014 hurricane season. A strong westerly wind burst occurred over Pacific this past winter resulted in Kelvin wave been created in waters of Central Pacific. With an anomaly of 6° Celsius (Figure 1), this is the most impressive Kelvin wave ever observed. The anomaly of this current Kelvin wave is even warmer than the one in 1997 leading to "Super El Nino" event.
Figure 1: Climate Prediction Center's weekly ENSO update as of April 28, 2014
However, there was an episode of easterly winds during that temporarily stalled the eastward movement of Kelvin wave which lead to a stall in the warming of Pacific in ENSO region (Figure 2). Because of this, it's unlikely we'll see "super" El Nino similar to the one in 1997. However, westerly winds should resume at some point in May or June and this powerful Kelvin wave will move toward eastern equatorial Pacific. Once this wave start surfacing over there, El Nino event will start with a massive surface warming of equatorial Pacific that will release a lot of warm air into the atmosphere (Figure 3).
Figure 2: Official El Nino daily value from website TropicalTidbits run by WU blogger Levi Cowan. You can clearly see the stall during April.
Figure 3: Here's GIF of El Nino events of 80s and 90s from NOAA. Note how the warming started in eastern Pacific and spread out westward. If you can't get this GIF to work, just open this image in new tab and that should do the trick.
Now, let's move on to another oscillation: Pacific Decadal Oscillation (PDO). Why is this oscillation so critical to Atlantic hurricane season? Because having Pacific Decadal Oscillation in positive phase, when waters off coast of Alaska and British Columbia are warmer than usual, sometimes enhance El Nino to a stronger strength. PDO had been mostly negative since 2007, but it doesn't seem to be the case this year with all 3 months of 2014 showing positive number so far. In additional to that, there's a CFSv2 forecast (Figure 4) that shows PDO staying positive during this year's hurricane season as well as El Nino of at least moderate strength existing at the same time. Yet another oscillation to consider for 2014 Atlantic hurricanes season is Atlantic Multidecadal Oscillation (AMO). For most of the last 19 years since 1995, AMO had been positive resulting in few more active hurricane seasons than normal. While AMO is capable of staying positive for another few decades, it's undergoing a hiccup this year as it had turned negative in the past few months. It's negative because the water in Cape Verde region of Atlantic had turned colder than normal while subtropical waters off coast of New England region of United States of America had turned much warmer than normal (Figure 5). Waters between Canada and Europe is also much colder than normal which is yet another support why AMO is negative. Why is this so important? Because Cape Verde region is birthplace of some of the strongest and long-lasting hurricanes. Having cooler waters in that region reduce the chance of a formation of Cape Verde-type hurricane. Therefore, the number of storms, hurricanes, and majors get reduced in negative AMO years.
Figure 4: Here's the CFSv2 forecast from Climate Prediction Center for September 2014 to November 2014. Note how El Nino is at least of moderate strength while Pacific Decadal Oscillation (PDO) stay positive during this time period.
Figure 5: Sea surface anomaly from website TropicalTidbits run by WU blogger Levi Cowan.
In additional to oscillations, we could also look at Sahel region of Africa where tropical waves are produced every season. I've never thought about looking into the wetness or dryness of Sahel region determining Atlantic hurricane season until @webberweather pointed it out on Twitter back in March. The idea of using Sahel region to forecast the season: in a wet Sahel year, tropical waves are more powerful and this lead to more stronger storms for the season. Dry Sahel year, according to this theory, got an opposite effect. We have been in a period of dry Sahel region for a few decades now (Figure 6), but most of forecasts point to a wet Sahel region this time around for 2014 hurricane season which could promote at least some activity in Cape Verde region.
Figure 6: Most recent Sahel region rainfall graph from University of Washington/NOAA NCDC.
FORECASTING 2014 ATLANTIC HURRICANE SEASON
Now that I've explained current conditions of oscillations and planet's atmosphere, it's time to come up with a forecast. Obviously I want to have analogs that's the closest to this upcoming season so I got to start somewhere. Because of numerous of forecasts calling for at least moderate El Nino (value of 1.0+), I've decided to use all years since 1950 with El Nino having a value greater than 1.0. That'll give me 14 hurricane seasons to work with. In one of my atmospheric science classes this past spring semester, I found Excel to be extremely useful tool for number crunching so it's time to use my knowledge of that program for my hurricane forecast. For each of 14 hurricane seasons with at least moderate El Nino, I've added in how strong El Nino was, what was the phase of PDO and AMO that year, and whether if Sahel region was wet or not at the same time. Next, I did series of calculations using Excel to average out number of storms, hurricanes, and major hurricanes (Cat. 3 or stronger) for four different categories (strength of El Nino, phase of PDO, phase of AMO, and phase of Sahel). Now that I'm all set up with my large database, I know that this year could have a positive PDO, a negative AMO, and a wet Sahel region. Therefore, I used averages of these three categories and calculated them with averages of a moderate El Nino year, a strong El Nino year, or a super El Nino year. Based on my calculations, I came up with the average of 7.4666 storms, 3.7666 hurricanes, and 1.25833 majors if you combine all three final averages from each El Nino categories I've listed on Excel (Figure 7). It's worth noting that the average amount of storms decrease the stronger El Nino is, but it doesn't seem to affect number of hurricanes or major hurricanes.
Figure 7: Calculations that I did using an Excel spreadsheet. Database of 14 hurricane seasons with at least moderate El Nino strength included. Values of El Nino, PDO, and AMO are found using couple of sources linked. Sahel years are determined using a graph (Figure 6). Finally, calculations are done by me. Open the image in new tab for the absolute best quality.
Now I'm ready to release my forecast. The factors I looked at for this forecast included several forecasts that show this year will have at least moderate El Nino which could increase the wind shear across Atlantic basin effecting majority of Atlantic cyclones, a positive PDO possibly enhancing the strength of El Nino even farther, a negative AMO to reduce activity of Atlantic season thanks to cooler Cape Verde waters, a wet Sahel region to at least allow some stronger tropical waves to survive in Cape Verde region, weak vertical instability that should limit the strength of tropical cyclones in Atlantic, looking at analog years with at least moderate El Nino, and my Excel calculations above. Based on these numerous factors, here's my forecast for 2014 Atlantic hurricane season: 7-10 storms, 3-5 hurricanes, and 0-2 majors (Figure 8). Also based on these factors, I believe that most of activity for this year's hurricane season will be in subtropical region of Atlantic thanks to warmer than normal waters while Cape Verde region struggles due to higher shear from El Nino and cooler waters. Stronger tropical waves, thanks to wet Sahel region, should open up few windows in Cape Verde region, though. However, I am not expect for any storms to survive the infamous "Graveyard of Tropical Cyclones" of Eastern Caribbean Sea because almost none of them will be strong enough to handle higher shear that could be found in that area. While most of Gulf of Mexico should shut down due to higher shear from El Nino, northern half of the gulf could stay out of trouble and allow a strong storm or two to sneak into Southern USA (Figure 9).
Figure 8: My 2014 Atlantic hurricane season forecast.
Figure 9: My forecast of four regions where storms could peak in.
Just remember that seasonal hurricane forecasting is not a perfect science and these kind of forecasts shouldn't be taken seriously, especially my own forecast. Please pay attention to National Hurricane Center website once the season get rolling on June 1st. I wish y'all an another safe hurricane season and thank y'all for reading my long blog post. Feel free to leave any question, correction, or comment below :)
- Kyle Noël
Updated: 2:44 AM GMT on May 04, 2014