There isn’t much left of what was Tropical Storm Emily. It’s remnants continue to move northeast, further out to sea. In its wake there is a weak area of low pressure, along an old frontal boundary in the eastern Gulf, that is creating an area of disturbed weather over portions of Florida. We aren’t expecting any tropical development with this feature, but we’ll monitor it closely in the coming days. In general, expect rain chances to fall through the rest of the work week.
Elsewhere across the Atlantic basin, there isn’t much activity to speak of other than a couple of open waves, one in the central Atlantic and one moving through the Lesser Antilles. Both of these have slim prospects of development thanks to an abundance of dry air in the area.
Below image courtesy: NOAA/University of Wisconsin
We’re getting into the time of year when just about any tropical wave coming off the coast of Africa has a chance of development, so you’ll want to check back often for updates as we head toward the peak of hurricane season.
Emily barely hangs on as a Tropical Depression Tuesday over the warm western Atlantic. The sheared disturbance combats drier air aloft and will stay disorganized as it heads northeast and out to sea. Wind shear near a stalled frontal boundary will take a toll on Emily and it will lose tropical characteristics mid week, if not sooner. It is no threat to land in the days ahead.
As we saw with Emily, any areas of convection sitting over Gulf of Mexico temperatures in the mid to upper 80s are always worth keeping an eye on. An area of disturbed weather has flared up early Tuesday over the central Gulf of Mexico. While there are no signs of tropical development, we will monitor this feature. An old frontal boundary across the north central Gulf could guide these showers and storms toward Florida in the days ahead.
Tuesday is the start of the third month of the Atlantic hurricane season. On average, the first hurricane in the Atlantic forms on August 10th. It is a month where tropical wave activity ramps up off the coast of Africa and moistens the Main Development Region between the Caribbean and Africa. The Gulf of Mexico, Caribbean, western Atlantic and central and eastern Atlantic are all fair game for tropical cyclone development. While on average only 8% of named storms form during July, 27% of named storms form in August.
We’re watching a few disorganized tropical waves in the south central Atlantic Tuesday. They are all situated just south of the most extensive dry Saharan air and are headed westward. Some gradual development of the tropical wave circled in white is possible over the next day or two.
Long-range computer models have been back and forth the past 2 days . A tropical wave in the next week/week and a half could strengthen as it approach the Caribbean. Below is the 0Z Euro for next Thursday. It shows a healthy tropical wave southwest of the Cabo Verde Islands. The latest GFS shows a disturbance enters the Caribbean mid-week next week and eventually dissipates. The bottom line is we are entering the time in hurricane season to be tropical weather aware, especially as storms enter the Caribbean.
Tropical Storm Emily made landfall on Anna Maria Island at 10:45 AM Monday morning with 45 mph winds. Strong rotation northeast of the center was spotted near the Sunshine Skyway Bridge during the time, which prompted a Tornado Warning for Manatee county, including Bradenton. As Emily moves further east away from the Gulf, it will weaken further Monday afternoon and evening.
Emily drenched the I-4 corridor southward early Monday. As of midday Valrico in eastern Hillsborough county saw over 8 inches of rain. St Pete had almost 6″ of rain and Bradenton had nearly 5″.The hardest hit areas were eastern Hillsborough, southern Pinellas, coastal Manatee and coastal Sarasota county. Wrap around moisture will fuel additional downpours through Monday evening as Emily moves east across the area. A Flood Watch is in effect until 8 PM for Hilllsborough, Pinellas, Manatee, Sarasota, Hardee, Desoto and Highlands county. Some rainfall totals may surpass 6″ through Monday evening.
The strongest winds were felt northeast and east of the center of circulation late Monday morning into midday. A wind gust of 57 mph was record at the fishing pier near the Sunshine Skyway Bridge. The Bradenton and Sarasota areas saw gusts near 50 mph, while further north in Tampa wind gusts were less than 20 mph. Wind gusts 30 mph+ are possible through Monday evening as Emily weakens over land and emerges back in the Atlantic early Tuesday.
The 11 AM advisory from the National Hurricane Center shows Emily weakening to a tropical depression Monday evening. It will re-strengthening to a tropical storm and accelerate northeast along a stalled frontal boundary over the warm Gulf Stream waters of the western Atlantic. Wrap around moisture and lingering tropical moisture will fuel scattered tropical downpours in Central Florida Tuesday and Wednesday.
Anytime an area low pressure sits over the Gulf of Mexico during the summertime tropical cyclone development can never be ruled out. Despite marginally favorable wind shear, the area of low pressure thrived off of the warm eastern Gulf waters and gained tropical characteristics early Monday. Tropical Depression 6 was quickly upgraded to Tropical Storm Emily at 8 AM. As of 8 AM max sustained winds are at 45 mph. Emily moves east at 8 mph. Tropical storm force winds extend out up to 60 miles for the center. As of 8:45 AM the center is less than 25 miles from the Sunshine Skyway Bridge. Tropical Storm Emily will cut across Central Florida Monday. Training/flooding is likely is spots, especially for Tampa Bay South near the coast. Winds 30-40 mph+ are possible in the strongest squalls. A Tropical Storm Warning is in effect for the Anclote River southward to Bonita Beach. Emily will weaken to a depression and move into the Atlantic early Tuesday.
Heavy rain/the potential for flooding is the primary threat from Tropical Storm Emily. A Flood Watch is in effect for Hillsborough, Pinellas, Manatee, Sarasota, Hardee, Desoto and Highlands county until 8 PM Monday. 3-6″ of rain are likely. Some coastal areas will pick up well over 6 inches of rain Monday.
At times it will be gusty, especially for Tampa Bay South Monday morning and afternoon. Wind gusts will be much lower than they are in a severe thunderstorm in the summertime. Gusts up 30-40 mph+ are possible through Monday afternoon. The strongest wind field is limited to an area around the center.
A well-defined area of low pressure churned in the Northeast Gulf of Mexico on Sunday. While it is non-tropical in nature, the potential for it to become subtropical or even tropical over the next 24-36 hours prompted its designation of Invest 98L. The National Hurricane Center is giving the low a 20% chance of becoming our next tropical depression over the next 48 hours, and a 30% chance in the extended term.
The low has formed along a nearly stationary frontal boundary that has stalled out across northern Florida. This has provided a decent pool of moisture for the low. However, upper level winds are only marginally conducive to development. Sea surface temperatures on the other hand are favorable for development as most of the Gulf is running 1°-2°C above average.
Regardless of development, the low and the associated frontal boundary will bring copious amounts of rainfall to Florida through the middle of the week. Bands of rain and storms will pile up along the peninsula over the next few days, and rain will be heavy at times. There will likely be a widespread 2″-4″ across Central Florida, but there could be some spots that see locally higher amounts.
A rare summer cold front settles into Central Florida Sunday and stalls late in the day. Low pressure will develop along this boundary in the Eastern Gulf and brings the threat for periods of heavy rain to Central Florida early this work week. Anytime low pressure sits over warm water temperatures in the upper 80s to near 90 it is worth watching for tropical development. The odds of this low gaining any tropical characteristics are low over the next 5 days. Wind shear is enhanced near this frontal boundary and upper level winds are only marginally favorable for tropical development. Development or not, this feature is a rainmaker for parts of the Sunshine State.
The Weather Prediction Center shows Central Florida, North Central Florida, and Southwest Florida will see the heaviest rainfall in the days ahead. The heaviest will fall where the frontal boundary stalls and lingers. 2-4″+ is expected in Tampa Bay, with isolated higher amounts near the coast. This will be spread out through mid-work week. Localized flooding is possible at times, especially when training sets up.
We are also watching a tropical wave southwest of the Cabo Verde Islands. Convection is disorganized Sunday with some dry air nearby. Slow development is possible in the days ahead as the disturbance moves west at 10-15 mph. Models aren’t too impressed with development of this feature. Officially as of Sunday morning there is a 30% chance of tropical cyclone development the next 5 days. The next name is Emily.
In general, activity in the Atlantic basin remains low as we get ready wrap up the month of July. However, a weak wave (Invest 97L) in the central Atlantic may see slow development in the coming days thanks to a semi-favorable environment.
Wind shear is minimal in the vicinity of this wave, but it is dealing with only marginally warm sea-surface temperatures around 80°, as well as a substantial pocket of dry air just to it’s north (Image below courtesy of NOAA/University of Wisconsin). While the formation of a tropical depression is possible as this wave moves west-northwest , this shouldn’t pose much of a threat to the Caribbean.
It’s looking more and more likely that July 2017 will wrap up with no additional named storms in Atlantic Basin. Only one named storm formed this month, Don. It was shredded apart by wind shear in the Caribbean and dry air kept it short-lived and weak. Dry air has a firm grip on the Caribbean and central Atlantic Tuesday, and there are no areas of interest for at least the next 5 days.
A fresh batch of Saharan air is situated over the south central and eastern Atlantic near Africa. All four tropical waves between the Lesser Antilles and Africa will stay disorganized due to this feature. The graphic below is courtesy NOAA/the University of Wisconsin.
Fast forward to the weekend and the Saharan Air Layer (SAL) remains quite active, especially in the Main Development Region. Dry, dusty stable air sticks around through at least next Sunday. Long-range computer models are pretty quiet. The 12Z Euro attempts to close off weak low pressure late next work week as a tropical wave approaches the eastern Caribbean. The latest GFS shows absolutely no tropical cyclone formation for the next 2 weeks+. Activity will likely ramp up at some point in August. Once dry air erodes, there is the potential for stronger storms to thrive off of warm sea surface temperatures.
The eastern Pacific is especially active. 5 named storms have formed over the past two weeks. On Tuesday there are three named storms: Hurricane Hillary, Hurricane Irwin and Tropical Storm Greg. All three will stay over the open Pacific waters. Greg could dissipate by Wednesday but Irwin and Hillary strengthen. Due to proximity, Hurricane Irwin and Hurricane Hillary will interact with, and possibly rotate around each other later this work week. This is called the Fujiwara Effect. Irwin may eventually be absorbed by Hillary southwest of the Cabo Peninsula over the weekend or early next week.
The second month of the 2017 Atlantic hurricane season winds down. On Saturday, dry African Saharan air keeps convection limited with a few tropical waves in the Atlantic and Caribbean. Saharan air outbreaks are very common in July. No tropical cyclone development is expected for at least the next 5 days.
As we shift to August and September all eyes are on the Main Development Region between the Caribbean and Africa. Water temperatures run 1-1.5 C above average. This could aid in a more active period as we approach the peak of the season (September 10th). Most computer models keep the Atlantic basin quiet for the next week. On average, the first hurricane in Atlantic forms on August 10th, therefore, it’s pretty common for July to wrap up on a quiet note.
Tropical Storm Don dissipated over the last 24 hours and it’s remnants are slowly moving through the southern Caribbean. With that system out of the way, we turn our eyes to a weak tropical wave (Invest 96L) in the Central Atlantic. As of Wednesday afternoon, the National Hurricane Center gives this only a 30% chance of development over the next few days as it moves west-northwest.
Like Don, high wind shear and dry air aloft will ultimately keep Invest 96L from developing into anything of consequence, but nonetheless we’ll keep an eye on it through the rest of the week.
It is still a bit early in the season for these Central Atlantic waves to develop into strong tropical systems, but as we head into the months of August and September, expect things to get more active. In fact, on average since 1950, 61% of named storms have formed over the next couple of months.