Climatologically, Wet Season began around June 1. Because of rapid climate change, historical data may be irrelevant. Regardless, looking at past data is currently the best scientific way to predict future weather.
Formula for Finding the Beginning
of Rainy Season
Warm Nighttime Temperatures (67-70° F)
+
High Humidities (dew points in the 70°s)
=
Rainy Season
Normally around June 1
Rainy Season Normally ends around October 15
(see more on this below)
Water level and flow meters at the Astor station on the St. Johns River currently report that the depth is .48 feet away from the channel. The flow at Astor is virtually non-existent. At the other end of Lake George there are tidal influences from the Atlantic Ocean pushing brackish water south toward the lake twice a day.
Beginning of the Wet Season for Orlando
Using data for the period 1949-2001 to look for the median date (half earlier, half later) when minimum temperatures were in the 67-70° range (19-21° C) and dew points were in the same range one can estimate the start of Orlando's Rainy Season. These dates almost always coincide with the onset of the Rainy Season. This combination of high nighttime temperatures and high humidities (dew points) usually occurs a few days before the start of frequent showers and thunderstorms.
Based on those data the start of the Rainy Season
for Orlando is: May 27
Beginning of the Rainy Season for Daytona Beach
For Daytona Beach data from 1935-2001 showed that there were more frequent intrusions of drier air after the apparent beginning of the Wet Season. Nevertheless,
Based on those data the start of the wet season
for Daytona Beach is also May 27.
A very low Wekiva River at Katie's Landing
It must be noted that a purely objective analysis is not possible because the exact onset of the Wet Season is difficult to determine in some years. There were classic years when dew points and minimum temperatures rose to around 70° in mid/late May, a rainy period ensued shortly thereafter and continued through the summer. Some years saw the start of showers/storms in late May, followed by several weeks of little/no rain, and then the onset of frequent rains once again in late June. Notably in 1998 neither occurred until late into July. It was in 1998 that much of Central Florida burned in wildfires.
This year dew points and nighttime temperatures are already high but a thermal inversion and semi-permanent high pressure have precluded any rainfall. A series of shortwave troughs are forecast to move through Florida the last week of May which should bring beneficial rains but not what we would consider rainy season rains (from sea breeze thunderstorms).
Me and my shadow, on another blazing hot May day on the shores of Lake George, Florida's 2nd largest lake.
Follow Phillip
on instagram
Attempts to objectively pick the date when dew points/minimum temperatures remained above 70° degrees failed, since many years had brief periods of readings in the 60°s through the month of June. This would have resulted in the median date for the onset of the Wet Season not correlating with a reasonable person's perception, and being much too late in the season.
Precipitable Water and Precipitation Rate
Can Determine the Start of the Rainy Season
Another method for determining the start of the Wet Season is inspection of two variables, Precipitable Water and Precipitation Rate. Using the 1960-2000 time period the areal average of these parameters was attained for a one degree of latitude by one degree area that covered Cape Canaveral, Orlando and Daytona Beach. There are approximately 69 miles in 1° of latitude.
A sharp upward trend in precipitable water starts historically about May 20. Precipitation Rates rise significantly beginning about May 22. This corresponds rather well with the median dates determined by looking at minimum temperatures and dew points. The small differences in the dates determined by the two methods is likely due to the different time periods examined.
Onset of the Wet Season at Daytona Beach and Orlando, Florida(Updated through 2010)
Daytona Beach Median Date = May 29
Orlando Median Date = May 27
RAINY SEASON DATA
UPDATED THROUGH 2010 REVEAL A
SLIGHTLY LATER START DATE
FOR DAYTONA'S WET SEASON
ORLANDO'S WET SEASON BEGINS MAY 27
Orlando Median Date = May 27
2004
|
6/1
|
6/3
|
2005
|
5/30
|
5/30
|
2006
|
6/11
|
6/11
|
2007
|
6/6
|
6/6
|
2008
|
6/10
|
6/9
|
2009
|
5/17
|
5/17
|
2010
|
5/30
|
5/30
|
We've Read:
The Wet Season
The Wet Season is typically considered to begin in the latter part of May and resembles "summer" across much of the remainder of the country. Warm temperatures (mid to upper 80s) begin earlier, but usually do not coincide with the beginning of frequent summer-like rains. The primary difference between summers in east central Florida and those at higher latitudes is that the heat and humidity are relentless (i.e. there are no synoptic scale fronts that bring significant cooling and drying). Though it does not rain every day during the summer, the frequency of rainfall usually begins to increase in late May. The start of the Wet Season is occasionally delayed until June and in rare cases, even as late as early July (e.g. 1998).
The Dry Season
The Dry Season usually begins in October as the first synoptic scale cold front brings drier and slightly cooler air into the area. This first front sometimes results in a significant rain event. Tropical systems, additional fronts and gale centers can bring periods of heavy rain through November, but the frequency of rain almost always decreases after the first significant frontal passage.
Fronts continue to push through the area during the traditional "meteorological winter" months of December, January and February. Cold frontal passages during this time period will sometimes be preceded by a line of showers and thunderstorms, but the occurrence of rainfall is much less frequent than the summer. The greatest coverage of rainfall during the winter months often occurs when one of these fronts moves back northward as a warm front. Some winters have more frequent frontal passages, which can result in much above normal rainfall. The most recent occurrence was the 1997-1998 winter when a strong El Nino resulted in significant severe weather episodes and flooding across the Florida peninsula, followed by severe drought the summer of 1998.
For east central Florida, late February through March might be the time period that most closely resembles typical Spring weather in the higher latitudes. Large swings in temperatures often occur along with occasional severe weather episodes, but rainfall is usually infrequent. April is often the driest month of the year as fronts become weaker and yield less rainfall, yet manage to pass through the area and reinforce the dry and stable air mass. Temperatures warm through May with average maximum readings reaching the upper 80s by the end of the month. Rainfall frequency increases compared to April, with the most notable increase usually beginning late in the month.
Climate Classification of East Central Florida?
Hard to Determine. . .but. . .
Cw = best fit
The Glossary of Meteorology defines a monsoon climate as one in which the wind flow reverses itself during the course of the year and there is a distinct winter dry season. Data indicate that there is a duality of seasons for east central Florida, with the cooler season being significantly drier than summer. Additionally, the mean wind during most of the east central Florida Wet Season is southeast (tropical) while the mean wind during much of the Dry Season is northwest to north (continental).
The Wet Season is marked by a daily inland progression of the Atlantic and Gulf of Mexico sea breezes as a low pressure trough develops across the peninsula due to surface heating. Showers and thunderstorms occur most days along the sea breezes and become numerous when these boundaries collide. While the low pressure trough that produces this sea breeze circulation is not on the same scale as the large heat lows that drive monsoon circulations elsewhere in the world, there is enough regularity to suggest some similarity. Some climatologists refer to the daily sea breeze circulation as a "diurnal monsoon."
The classic monsoon climate, of which India is the best example, has a "hot season" prior to the onset of the rains. Though this does not occur every year in east central Florida (and hence is not climatological), the hottest temperatures of the season sometimes occur in May or June, prior to when rainfall frequency increases. In fact, the hottest month on record in Melbourne occurred in June 1998 when the area was in the midst of a prolonged dry spell. India also has a secondary maximum in temperature right after the Rainy Season. This does not occur in east central Florida since there is a strong marine influence, and temperatures are modified in September/October as the prevailing wind flow becomes more easterly.
The Koppen Climate Classification System designates north/central Florida as a Subtropical Humid climate (Cf) with a year-round distribution of rainfall. This places east central Florida in the same climate classification as Memphis, Tennessee. Clearly, Memphis and Melbourne should not have the same climate classification.
The Cw classification is a Subtropical Humid Wet-Dry climate with a monsoonal influence (dry winter). This classification requires the climatologically wettest month to have ten times more rainfall than the driest month. East central Florida does not meet this requirement since the driest month averages around 2 inches, and there is no location in the state which averages 20 inches in a month! An alternate to the 10:1 ratio is that 70% of the yearly rainfall must occur during the six warm season months. Rainfall for Daytona Beach during the months of May-October is about 64% of the yearly total, while Orlando and Melbourne were 68%, and Vero Beach was 66%.
So it can be seen that east central Florida does not meet the strict definition of a Cw climate. However, during any given year, there is most always a month that is ten times wetter than another in east central Florida, since rainfall less than one inch is quite common during at least one of the Dry Season months. In fact, examination of Orlando rainfall from 1927-2001 showed that there were only 9 years when the 10:1 ratio was not met. This is the nature of statistics in which the average or "normal" conditions mask the extremes.
The Cs classification (Mediterranean Climate) occurs where there are dry summers and the wettest winter month has at least 3 times as much rain as the driest summer month. The climatologically wettest month in east central Florida has a little greater than 3 times the rainfall of the driest month. Therefore, east central Florida also does not meet the strict definition of a Cf climate.
The southern tip of Florida is an Aw (Tropical Wet-Dry) climate. The requirement for this designation is that the coolest month averages above 64.4 degrees Fahrenheit. East central Florida does not meet this requirement. However it is interesting to note that the rainfall requirements to receive a Tropical Wet-Dry designation are far less stringent when compared to the 10:1 ratio for the Cw (Subtropical Humid Wet-Dry) classification. The requirements are only that there must be a "marked seasonal rhythm" of rainfall and at least one month must have less than 2.4 inches. Both of these rainfall requirements are met for most of east central Florida.
A rainfall formula is used within the Tropical (A) classification to determine whether the climate is Monsoon (Am) or Wet-Dry (Aw). According to this formula, rainfall in east central Florida does not meet the Monsoon classification, but it does fit that of a Tropical Wet Dry (Aw) climate. As noted above, rainfall requirements for Humid Subtropical Wet-Dry (Cw) are not achieved in east central Florida. Therefore, the Wet-Dry sub-categories of the A and C climate classifications appear to have a discrepancy with regard to the rainfall requirements.
So while it cannot be technically stated that this area has a Monsoon or a Wet-Dry climate, most years exhibit a monsoonal influence with distinct wet and dry seasons. The east central Florida climate fits more closely with the Cw classification than it does with Cf.
The Tech You Need to Travel Better
While no product can guarantee a seat upgrade or make your delayed flight arrive on time, a few smart investments can make your next trip more comfortable, more relaxing and less stressful.
With airline seats getting smaller and highways more crowded, it’s a good thing there are plenty of high-tech, budget-friendly solutions to our travel woes. While there is no gadget that will make your seat wider or lessen traffic, there are some that will help you sleep better and stay relaxed on your next trip.
Here are a few suggestions you may want to invest in, with the help of our colleagues at Wirecutter, the product recommendations site owned by The New York Times.
Smart(er) Luggage
“Smart” luggage is luggage that will charge your phone or comes with location tracking so you won’t lose it. I have had the opportunity to travel with a smart bag, and it was nice to have a bag that would alert me if I walked too far from it or could charge my phone while I sat at a gate, far from an outlet, waiting for my now-delayed flight to board.
However, smart bags are expensive, and changing airline policies and confusion over how the bags (which often include lithium-ion batteries and other electronics) should be screened at security have crushed the industry. Companies like Away still make them, but our colleagues at Wirecutter suggest you save money and hassle and make your own luggage smart with a few simple additions.
The Travel Tips Issue
A collection of tips and techniques, from saving on travel to the tech gear you’ll need.
“When we first looked into smart luggage, we concluded that buying a suitcase that had a USB-battery pack, scale, and Bluetooth tracker embedded wasn’t worth it,” said Christine Ryan, an editor at Wirecutter. “We thought it smarter (sorry!) to buy those things separately and use them with the bag you already have, and hopefully love. Two years later, we stand by that decision, especially now that two of the major ‘smart bag’ companies have folded.”
For example, the addition of a USB battery pack that’ll fit neatly in your bag will keep your phone or tablet charged while you’re on layover or waiting for a delayed flight or train. A Tile Bluetooth Tracker can slide anywhere inside your bag and pairs with an app on your smartphone to let you know how far away your bag is at all times. A simple USB travel scale like the Balanzza Mini USB scale even lets you weigh your bag on the go, the same way smart luggage can.
Plenty of Portable Power
Speaking of batteries, you shouldn’t travel without an external battery pack (to keep all the other electronics in this list charged) and a portable surge protector to turn the only outlet in reach in your hotel room into two or three.
Ria Misra, another Wirecutter editor, called out the hotel/airport outlet problem: “Outlets aren’t always readily available or convenient when you’re traveling, particularly on international trips where you may also need an additional adapter to get the plug to work. I take a charged USB battery pack with me when I head out on the road, especially if I know I’m going to be using my phone’s GPS to navigate unfamiliar terrain, which can drain a battery fast. It’s also great to bring along when I plan to take public transport at my destination, so that I can charge up while in transit on a bus, train, or even on a long walk.”
Consider the Jackery Bolt or the Anker Powercore 20100, both Wirecutter favorites that are small enough to toss in a bag or backpack and will keep your phone topped off all day. The former comes with built-in cables, and while the latter requires you to provide your own cable (which we suggest you pack anyway), it offers more power in exchange.
If you want to be everyone’s best friend at the airport — or at least make sure no one in your party fights over the single outlet available at your departure gate — bring a portable power strip and surge protector. Wirecutter recommends the Accel Home or Away 3-port surge protector or the Tripp Lite Protect It 3-port surge protector. Both options turn a single power outlet into three surge-protected ones. You also get two USB ports, perfect for charging phones or e-readers while you use a laptop or other device. Also, don’t forget an outlet adapter, if you’re headed somewhere with different electrical outlets than here at home. Some of the best also work as port extenders, and even have USB ports, like this Ventev model.
White Noise Machine (or App)
If you have trouble sleeping, especially when you travel, a white noise machine may make a world of difference. At home I keep a fan on while I sleep, and I find the sound (and breeze) soothing. But when I’m on the road, I don’t have that luxury.
In that case, Wirecutter recommends the Lectrofan. It’s a stand-alone white noise machine that masks out barking dogs, snoring roommates or other mysterious hotel sounds. “I don’t need a noise machine at home, but having a white-noise app on my phone has been a life (well, night) saver when I’ve stayed in hotels with thin walls,” Ms. Ryan said. “I bring a Bluetooth speaker too, which helps the app drown out those outside sounds.”
It’s affordable, only about $50, and easy to use, even in the dark. If that sounds like $50 too much, I’ve had some luck recording the sound of my fan at home and then playing it back on my phone while I sleep, but Wirecutter also suggests a few apps for your smartphone that can create their own white noise.
myNoise, available for the Apple iPhone and iPad, and Noisli, available for devices running Google’s Android, are both great options. I’ve used Noisli with much success in the past, and its web app is great for helping you focus while working. myNoise is free, and offers additional sounds and features are available as in-app purchases, while Noisli is $2 with all of its features unlocked.
Google Chromecast (or Other Streaming Stick)
I don’t know anyone who pays for movies in hotel rooms, although I’m sure such people must exist. However, whatever broadcast, cable or pay-per-view hotels usually leave much to be desired. I like to travel with a Google Chromecast in my bag, although any streaming stick (Wirecutter likes the Roku Streaming Stick) will do. Streaming sticks are palm-sized, connect directly to a TV’s HDMI port and use Wi-Fi to stream media you control with your phone.
Not every hotel has HDTVs where you can access the ports, but many do, specifically for this purpose. With a Chromecast or Roku Stick in your bag, you get to choose what you watch on the hotel TV, and it’s great to log into your own Netflix account and continue the series you’ve been binge watching. Even better, if you’re traveling with children, you can pull up shows you know they enjoy, rather than try to find something from the TV’s on-demand or cable choices.
Noise Canceling Headphones
Frequent airline travelers know that a good pair of noise canceling headphones makes all the difference between a relaxing, pleasant flight, and one punctuated with engine noise, inconsolable children or overly chatty seatmates. At the very least, they dull the noise of the engines so you can get some sleep, or play your favorite tunes so you can enjoy that instead of the sounds of the people around you.
By virtually all accounts (including Wirecutter’s) the Bose QuietComfort 35 Series II are the headphones to beat. They can function in both wired and wireless modes, feature long battery life when you do use them wirelessly, and block out most external noise so you can sleep or enjoy your music, movies, or anything else in peace. They can be pricey though, generally about $350. For a more affordable option, consider the Audio Technica ATH-ANC7B, available for about a third of that price.
Low-Tech Stuff That Makes a Difference
A good sleep mask will help you sleep whether you’re on a long haul flight or at a hotel. Wirecutter likes the Nidra Deep Rest, which sports individual eye cups and sizable straps to block out the most light. Ms. Ryan uses Wirecutter’s additional selection, the Alaska Bear sleep mask, and praised it highly. “I went to Iceland last summer, right at the solstice, and if I hadn’t brought my Alaska Bear sleep mask, I’d have been terrible company,” she said. “First we were staying in a big-windowed camper van and then in an Airbnb with lovely, lacy, not-at-all-blackout curtains, so sleeping without a mask would have been … challenging.”
Also in the comfort department, a good pair of compression socks are great for any long day on the go but especially comfortable on long flights. They can boost circulation and are useful to prevent deep vein thrombosis, but are no excuse not to get up and stretch your legs on a long flight. “I know I’m supposed to get up and walk around the cabin when I fly,” Ms. Ryan said, “but if I’m sitting by the window, often I’ll just curl up and wait it out rather than try to crawl out over my neighbors. So I wear compression socks in the hopes that they’ll do something to counteract the sitting. They do feel good, at least.”
Similarly, a collapsible day pack is great for any shopping or souvenir-buying wherever you travel. The L. L. Bean Stowaway Day Pack is a great option that packs down and fits into a smaller bag when you don’t need it, but expands into a full backpack when you do. Also consider a set of packing cubes (I own a Wirecutter recommendation, the Eagle Creek’s packing cube system) to help keep the rest of your luggage neatly organized.
“Packing cubes make it easy to neatly compress your clothes to save space in your suitcase,” Ms. Misra said, “but, I’ve also found them especially useful in keeping my things organized throughout my travels. Even after I’ve dug to the very bottom of my suitcase in search of a lost item or two, my clothes are still tidily folded and zipped away.”
These last few things may not be apps, or gadgets you can plug in, but they’ll make sure your next trip is that much more manageable — and most importantly, less stressful.
 |
| A Skipper butterfly (Hesperiidae) on a Mexican Sunflower (Tithonia rotundifolia) |
Florida's Two Seasons
Florida does not experience the four seasons of Spring, Summer, Fall, and Winter as northern latitudes. There is generally an agreement that the seasons in Florida can be divided into two; the first extending from May through October, and the other from November through April. These seasons are sometimes referred to as warm and cool seasons or wet and dry seasons.
Successive years of below average rainfall have left our 700 acre lake mostly dry (below). Above looking northeast toward New Smyrna Beach in July of 2009 and below, the same image, same spot this week. Despite the storm clouds pictured here, rains have been much below average in 2016 and our lake is looking more like a forest than a wetland. It has been many years since I've had my jon boat out from its spot at the once-high water line.
Part of the problem of classifying Florida's seasons is from Florida's geographic location, which puts it squarely in a climatic transition zone. Climatology text books generally put south Florida and the Keys in the "wet and dry tropics" category and north Florida in the "humid subtropical" category, which also includes much of the southeast United States.
Central Florida Straddles Climate Regimes
Between 29° and 31° N. wet-dry seasons are more variable
As you move from extreme south Florida to extreme north Florida you transition from classic tropical wet and dry seasons to what is more aptly described as cool and warm seasons. This is because extreme north Florida is subject to more extratropical cyclone passages in the northern winter months, receiving more rainfall during that time while south Florida is experiencing its true "dry season." In addition, northern Florida's temperature difference between seasons is more noticeable compared to southern Florida. Central Florida is the transition zone between those two climate regimes.
In the image below a green lynx spider (Peucetia viridans) hangs onto sunflower top right of image.
Click on this or any other photo for a larger view.
The Florida peninsula south of about 30° north latitude clearly experiences wet and dry seasons on a consistent basis, while north of 30° experiences more variability in seasonal types from year to year. In north Florida, at the southern limit of the humid subtropical climatic region, some years could be more aptly described by wet and dry seasons and others by cool and warm seasons.
Formula for Finding the Beginning
of Rainy Season
Warm Nighttime Temperatures (67-70° F)
+
High Humidities (dew points in the 70°s)
=
Rainy Season
Normally around June 1
This year's rains have been sporadic, at best.
Read more about calculating beginning of
Florida's Rainy Season at
El Niño and Florida Rains
or lack thereof
The relationship between ENSO and rainfall is perhaps the most straightforward and statistically significant of all weather parameters leading to wet and dry season fruition in Florida. Daily thunderstorms on the sea breezes fueled by tropical moisture during Florida's wet season gradually end as the transition to the Florida dry season takes place in late October and November. This year, as a strong El Niño wanes in the Pacific Ocean, Central-South Florida, south of 29° N is experiencing predominantly hot and dry conditions when it should be wet. But maybe things are changing as the long term forecast is for wetter than normal conditions.
 |
| A Lubber Grasshopper (Romalea microptera) hangs onto some bamboo stakes in the garden. The lubbers are now grown and have shed their nymph bodies and black colorings. |
Occasionally a late season tropical system will bring excessive rainfall to Florida in November such as was the case with Tropical Storm Gordon in mid-November 1994. But generally, during the Florida dry season, substantial rainfall is only provided by passing extratropical disturbances in the westerlies or stalled frontal boundaries. See discussions on storminess and seasonal aspects of Florida climate for more details.
 |
| The current El Niño is now considered strong and may become historically strong by the time northern hemisphere winter arrives, when the El Niño should have its largest impact on Florida. |
These patterns are upended by strong El Niños. During strong EL Niños such as in 1982-83 and 1997-98, storminess is greatly increased over Florida and the Gulf of Mexico leading to well above average rainfall in winter and perhaps widespread flooding while El Niño summers can be extremely hot and dry.
The map below shows rainfall greatly exceeding normal (in the blue areas) over Florida and California for the month of February 1998 during one of the last strong El Niño events.
So based on past experience discounting climate change and its impacts Florida could expect a potentially stormy and wet dry season 2015-2016, but how much more heat and dry will we have to endure before then? It is anyone's guess until more data are available.
Michael Webster is definitely the guy with the best hair on Bondi Beach.
Personal trainer, ex-commando, and dog lover. . .from what we can make of his instagram feed. We like that he's letting the black hair go grey gracefully and accepting aging better than some might but think he might do better to slow the training and focus more on low-impact modeling. Just our thought.
No comments:
Post a Comment