A Nationwide Heat Wave Leads To A Severe Weather Risk On Wednesday

Hey, hey—it's a story about heat that's not just about the west! Aren't we special? A large ridge of high pressure building over the central United States will intensify the heat most of us are feeling this week. Highs will soar into the 100s in the northern Plains while unbearably humid conditions spread over the central and the southern states. The edge of the ridge could foster a risk for severe thunderstorms in parts of the Midwest and Mid-Atlantic on Wednesday.

The pattern over the U.S. this week is the classic, putrid mess that we have to go through at least once every summer. 

Source: Tropical Tidbits

A big ridge of high pressure parked over the center of the country will send temperatures soaring, which is no small thing given how high humidity levels are right now. Some communities could see a dew point around 80°F, which is near the upper end of how muggy it can feel without actually diving into a boiling pot of spaghetti.

If you're looking for relief, the only spots to find it outside of the mountains will be the Northeast and parts of the Great Lakes, where temperatures will gradually cool off toward this weekend as an upper-level trough settles into the region. 

For everyone else, though, it's going to feel just awful.

Source: CDC

Heat advisories and excessive heat warnings festoon the National Weather Service's alerts map like an art project, warning of temperatures and humidity levels that could quickly lead to heat-related illnesses if you're not careful.

Adults don't need to be told to stay inside and take it easy, of course, but it's really easy to underestimate how much of a toll the heat and humidity take on your body. Even a healthy, physically-fit person can fall victim to heat exhaustion or heat stroke in short order when it's this hot out. 

As with any summertime heat wave, there's a risk for severe storms along and near the outer edge of the ridge responsible for the hot temperatures.

The Storm Prediction Center highlights a risk for severe weather from the Dakotas straight down to the D.C. area, with the greatest risk for severe weather existing over the Upper Midwest.

Overlaying Wednesday's severe weather outlook with Wednesday's high temperature forecast does a great job illustrating how the threat for severe weather follows the edge of the ridge, which appears as a temperature gradient:

This kind of a heat wave is ripe for the formation of a squall line, with a risk for damaging straight-line wind gusts. A squall line that's particularly intense and lasts for a long time can be called a derecho. Don't worry whether or not it'll be a derecho. Just know that there's a risk for severe weather and plan accordingly, charging up your devices and keeping flashlights handy so you can find your way around without draining your phone battery.

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GOES-17 Is Back Online After Engineers Resolve A Computer Error

Some good news on the satellite front: GOES-17 is going to be just fine.

The weather satellite, which covers the Pacific Ocean and the western half of the Americas, came back online a little before 9:00 a.m. Eastern today after a 31-hour outage caused by an onboard computer error. 

From NOAA's NESDIS:

NOAA’s GOES-17 is out of safe-hold mode and engineers expect its six instruments to return to normal operations soon. The probable cause of yesterday’s anomaly appears to be a memory bit error in the spacecraft computer. The engineering team says the computer has been responding correctly to commands. 

Earlier this morning, the Advanced Baseline Imager and Magnetometer were restored and data are flowing. The remaining four instruments are expected to come online later this morning.  The team expects some minor, short-term data quality issues while the instruments are being recalibrated, but GOES-17 is on track for a full recovery with no lasting effects to the satellite.

Whew.

Just about all of the products you'd ever need are up and running again.

The above image of actinoform clouds over the Pacific Ocean is from just a little while ago. (The clouds are mesmerizing to watch on a loop if you've never had the pleasure.)

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GOES-17, A Fighter Among Weather Satellites, Faces Yet Another Health Hiccup

The weather satellite that monitors the Pacific Ocean and western North America went into safety mode and stopped transmitting data early Thursday morning. There's no public word on what's troubling GOES-17, which is also called GOES-West, aside from a statement that engineers are "aggressively troubleshooting" the issue and working toward a fix.

The satellite is the 17th member of the Geostationary Operational Environmental Satellite (GOES) program, and it serves alongside its twin GOES-16, which monitors the Atlantic Ocean and the eastern side of the Americas as GOES-East.

GOES-West and GOES-East work in tandem to provide breathtaking images that are a tremendous boon to meteorologists monitoring the skies above and what lies beyond the horizon.

We can get high-resolution images of a small area every 30 seconds, national images every 5 minutes, and full-hemisphere images every 10 minutes. The resolution and turnaround time are a vast improvement over past GOES generations.

GOES-West's view of North America on July 21, 2021. (NOAA)

GOES-17 is the little satellite that could. The spacecraft launched in March 2018 with a major flaw that threatened its existence before it even had a chance to shine.

We get our satellite imagery from a device called the Advanced Baseline Imager (ABI). This sensor uses visible and infrared radiation to create the vibrant images we see online and on television every day.

A geostationary satellite orbits at the exact same speed at which Earth rotates, giving the satellite the same view of Earth for its entire service life.

This fixed orbit exposes the ABI to hot sunshine when it's nighttime here in North America. While it's very cold in space, a hard-working mechanical device basking in direct sunshine gets dangerously hot and it needs a robust cooling system in order to function properly.

After reaching orbit, engineers discovered that one of the cooling pipes that served the ABI was clogged, preventing the sensor from cooling off effectively during times of peak heating.

An example of the interference in infrared satellite imagery caused by excess heat given off by the ABI. (NOAA)

This flaw causes the sensor to grow so hot that it gives off radiation that matches the wavelengths of some infrared and water vapor products, significantly degrading many of the products generated by the ABI during moments of peak warmth.

Engineers had to develop some significant workarounds to get the satellite working in the face of this unfixable flaw. There are still certain times of the day and year where the satellite's performance is degraded.

This isn't the first time GOES-17 unexpectedly shut down. A software glitch in August 2019 knocked the ABI offline for about 11 hours. Engineers solved the problem with the old "turn it off and on again" trick.

NOAA announced last month that they plan to launch GOES-18 in December and designate the new satellite as GOES-West in early 2022, sending GOES-17 into a well-earned retirement.

Fortunately, the previous generation of satellites stands by in case any of the operational satellites feel under the weather.

If GOES-17 requires prolonged downtime between now and the launch of the next satellite, the satellite that previously served as GOES-West (GOES-15) can be swapped in as an emergency substitute.

While the image resolution and speed at which we get new images would fall a bit from what we've grown used to, the substitution would still fill the gap and help meteorologists perform their jobs effectively.

[Top Image: The last satellite image transmitted by GOES-17 before it went down last night, via NOAA]

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Another Week Of Summer, Another Record-Breaking Heat Wave

Oh, look. It's another story about extreme heat breaking records somewhere. What a novel story angle.

It's hard for heat to become news. It's consistent. It's brutal. It claims a huge toll. But it's not sexy. There's no zhuzhing up week after week of hot temperatures.

This is what's made the recent spate of heat waves morbidly fascinating—it's been so hot, and the heat's broken so many records, that we couldn't escape the story even if we wanted to focus on rollicking thunderstorms or a swirly cloud in the Atlantic.

Lytton, British Columbia, witnessed Canada's hottest temperature ever recorded three days in a row. The town broke the national record by hitting 115.9°F on June 27, 118.2°F on June 28, and 121.1°F on June 29. Most of the town burned down in a wildfire on June 30.

Portland, Oregon, broke their all-time record high three days in a row, hitting 108°F, 112°F, and 116°F during the same heat wave. That 116°F record is 9°F hotter than the previous hottest-ever reading there.

Seattle, Washington, shattered its hottest-ever temperature two days in a row, hitting 104°F and 108°F, ultimately breaking its previous record high by 5°F. 

So far this year, Las Vegas, Nevada, has tied its all-time record high of 117°F once and they've seen a second-place high of 116°F twice.

Death Valley, California, tied its second-highest temperature on record when it hit 130°F on July 9, which might be the hottest temperature ever reliably recorded on Earth. (The two official records, a 134°F reading in Death Valley and a 131°F reading in Tunisia, are both routinely questioned for their accuracy.)

Two days later, Stovepipe Wells, another station within Death Valley, recorded a high temperature of 129°F and a low temperature of 108°F. This pairing gave the station an average daily temperature of 118.5°F, which is preliminarily the hottest average daily temperature ever recorded on Earth.

This image from the GFS weather model shows an upper-level ridge building over the U.S. and Canada early next week. SOURCE: Tropical Tidbits

During a year when so many notable records have fallen, it's going to be hard to keep attention on the ongoing bursts of heat plaguing the much of the U.S. and Canada.

A strong upper-level ridge building over the Plains and Prairies will send temperatures soaring over next week, with several days in the 100s not out of the question in eastern Montana. Triple-digit readings are also likely in parts of the Intermountain West, California's Central Valley, and the desert Southwest.

Here's the NWS temperature forecast for Sunday, July 18:

And the same for Monday, July 19:

Those are just two of many hot days ahead. The National Weather Service's forecast for Glasgow, Montana, for the next seven days shows high temperatures of 97°F, 102°F, 101°F, 103°F, 105°F, 104°F, and 102°F. Six consecutive days at or above 100°F would tie Glasgow's longest such streak on record, originally set back in August 2003.

The ongoing record-breaking heat is a health hazard for folks who are susceptible to heat-related illnesses, those who work outside, and people who don't have access to air conditioning. It's awful news for farmers who are watching their crops slowly wither and burn in the unrelenting summer sun. It's worrying for the prospect of an already-awful wildfire season across the west.

I think we're close to running out of ways to describe it so it doesn't sound like it's a run-of-the-mill thing now. It's no good! It's bad! It's hot! It's not sustainable! It's got to break, or it's just going to keep getting worse.

[Satellite image (via NOAA) shows prolific wildfire smoke spreading over North America on July 15, 2021.]

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Hurricane Elsa Approaching Tampa, Florida, As Storm Closes In On Landfall

Elsa is a hurricane again as it draws closer to its inevitable landfall north of Tampa, Florida, in the early morning hours on Wednesday. Strong winds, heavy rain, and tornadoes are likely across the Florida Peninsula and parts of the southeastern United States over the next couple of days as the storm pushes inland.

The National Hurricane Center's latest advisory found maximum sustained winds of 75 MPH near the center of the storm, bringing the storm to hurricane strength once again.

Hurricane warnings are in effect ahead of the storm's landfall. Tropical storm watches and warnings stretch inland to the South Carolina Lowcountry.

It's important to remember that there's little practical difference between a 65-70 MPH tropical storm and a 75-80 MPH hurricane. They can each produce roughly the same wind/rain/tornado impacts.

Forecasters expect the hurricane to make landfall north of Tampa along Florida's Big Bend on Wednesday morning. Conditions will begin deteriorating around Tampa Bay on Tuesday evening as the core of the storm approaches from the south. The radar image above shows Elsa west of Punta Gorda around 7:30PM on Tuesday.

Elsa will pick up speed as it heads northeast through coastal portions of the southeastern United States, emerging off the Mid-Atlantic coast by the end of the week. The system could reach tropical storm strength again and swipe Cape Cod on Friday as it races toward Atlantic Canada. From there, the nor'easter-like storm will bring heavy rain and gusty winds to the Canadian Maritimes and Newfoundland this weekend.

Flash flooding from heavy rain is the greatest risk from this storm as it pushes inland. A moderate risk for flash flooding is in effect for a chunk of western Florida—including the Tampa area—as Elsa passes through.

Several inches of rain are possible across Florida, eastern Georgia, and eastern parts of the Carolinas through Thursday. If the storm nudges even a little farther to the west, the I-95 corridor into the Northeast would see greater odds of heavy rain and gusty winds on Friday.

Strong winds along Elsa's path inland will lead to some wind damage near the core of the storm. Falling trees, scattered power outages, and light debris blowing around are the biggest threats from the wind. Stay mindful of any trees or tree limbs that loom over your house. Avoid those areas during the strong winds. Trees and limbs falling into homes is a major cause of injuries and deaths during a landfalling storm.

Tornadoes are a risk with any landfalling tropical cyclone. The wind shear on the eastern side of the storm can cause thunderstorms in the outer bands to turn into mini-supercells that can produce tornadoes. Tropical tornadoes happen quickly and the lead time is usually lower than it would be during a "normal" tornado threat.

One peek at Elsa's structure and it's not hard to see why the storm made the short leap from a strong tropical storm to a minimal hurricane. The system consolidated thunderstorms around the center of circulation and it's traversing the steamy waters of the eastern Gulf of Mexico.

The only thing that's prevented further strengthening today is southwesterly shear that's trying the best it can to tear the thunderstorms away from the circulation. The wind shear almost prevailed a few times—as evidenced by the center peeking out a few times during the day—but the storms have held tight, and Elsa's persevered as a result.

[Top Image: NOAA | Satellite Loop: College of DuPage]

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Flooding Rain, Tornadoes Likely As Tropical Storm Elsa Heads Toward Florida

Tropical Storm Elsa is on track to make landfall along Florida's west coast on Wednesday morning. The storm will bring strong winds and flooding rains to communities in its path, as well as the risk for a storm surge along the coast as it nears landfall. Much of the Florida Peninsula will also see a risk for tornadoes as Elsa passes through the region.

Elsa's Track

The National Hurricane Center's 5:00 PM advisory found that Tropical Storm Elsa had 50 MPH winds as it moves over Cuba southeast of Havana. The storm is heading northwest at 14 MPH as it rounds a ridge of high pressure over the western Atlantic.

Funny enough, even though it's over land, the storm looks better on satellite now than it has in a few days. Elsa seems to be trying to consolidate itself somewhat as it pushes over Cuba. Satellite imagery reveals that thunderstorm activity appears to be tightening up around the center of the storm, which could help it maintain strength and recover faster once it emerges in the Gulf overnight Monday into Tuesday.

Forecasters expect Elsa to regain a little bit of strength as it approaches landfall in Florida's Big Bend on Wednesday morning, but moderate southwesterly wind shear could limit how quickly it intensifies. There's an outside chance it'll regain hurricane strength before making landfall, but please remember there's little practical difference between a strong tropical storm and a minimal hurricane.

Elsa will gradually pick up speed after entering the Gulf of Mexico on Monday night. The storm will then start curving northeast as it approaches Florida's west coast on Tuesday and Wednesday. Elsa will move over coastal portions of Georgia and South Carolina after crossing Florida, eventually falling apart in the northwestern Atlantic by the end of the week.

There's a chance that the storm could track closer to the East Coast than what's currently predicted, a scenario firmly within Elsa's cone of uncertainty. If this happened, heavy rain and gusty winds are possible closer to the I-95 corridor later this week.

The Rain

The potential for flash flooding from heavy rain is, as usual, the most widespread threat associated with Tropical Storm Elsa as it makes landfall in Florida and scoots up the southeast coast. 

The Weather Prediction Center expects several inches of rain to fall through midweek, with the greatest totals expected along and to the right of Elsa's track. The heavy rain will pose a risk for flash flooding from the southern tip of Florida northward to around Myrtle Beach, South Carolina. 

Elsa is moving at a steady clip and its speed will increase as it rounds the ridge over the western Atlantic. This forward march will limit the amount of time any one downpour can sit and drench a community. However, tropical systems produce high rainfall rates, and it won't take long for a downpour to lead to localized flooding issues.

The Storm Surge

A storm surge is possible along Florida's west coast as Elsa approaches the area on Tuesday and Wednesday. A maximum storm surge of 3-5 feet is possible along coastal communities from Tampa Bay north through the Big Bend if the storm surge coincides with high tide.

The potential for a five-foot storm surge isn't anything to sneeze at. It'll be lower for most communities, but any inland push of seawater is dangerous for homes and businesses close to beaches and coastal waterways.

The Tornadoes

Tornadoes are possible on Tuesday across most of the Florida peninsula as Tropical Storm Elsa's wind and rain begin to overspread the state.

Tropical tornadoes are an ever-present hazard with landfalling storms. Thunderstorms in the outer bands can turn into miniature supercells by tapping into the storm's own wind shear. Tropical tornadoes usually happen quickly, which can reduce the warning lead time. Make sure you have a way to receive tornado warnings the moment they're issued, and have a plan to take cover if you go under a warning.

The Wind

Strong winds of 60+ MPH will be a problem for towns near the center of the storm. The winds and gusts of a strong tropical storm can easily knock down trees and toss around loose objects outside. Power outages are likely in some areas.

Remain mindful of trees and limbs that loom near your home, and stay away from those rooms during the high winds. A significant number of non-water injuries and deaths during landfalling storms are the result of trees and tree limbs falling through walls and roofs. 

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Tropical Storm Warnings Issued In Florida As Elsa Chugs Through Northern Caribbean

A tropical storm warning is in effect for the Florida Keys as Tropical Storm Elsa slowly gets its act together in the northern Caribbean Sea. The storm quickly ramped up into a hurricane over Barbados last week, but it moved so fast that it shredded itself apart as it approached Hispaniola. The system will move over Cuba on Monday before entering the southeastern Gulf and aiming for Florida by midweek.

Elsa's Track

The National Hurricane Center found that Elsa had 60 MPH winds late Sunday morning as the core of the storm passed just north of Jamaica. The system will follow the western periphery of a strong Bermuda High parked over the western Atlantic Ocean, steering the storm over Cuba on Monday before entering the Gulf of Mexico on Tuesday.

If the system survives its trip over the mountains of Cuba, it's likely that Elsa will reach Florida's west coast as a strong tropical storm by Tuesday night or Wednesday morning. Depending on how quickly it recovers from its land interaction, there's a chance it could become a minimal hurricane by the time it reaches Florida. However, there's not much practical difference between a strong tropical storm and a minimal hurricane.

Elsa's Impacts

The greatest impact from this storm will be its heavy rainfall.

The latest forecast from the Weather Prediction Center shows a swath of 2-4 inches of rain falling across the Florida Peninsula over the next couple of days. The agency shows a slight risk of flash flooding on Tuesday and Wednesday as the storm moves across the state.

A few inches of rain are possible across coastal communities in Georgia and the Carolinas by the middle of the week.

Some good news is that Elsa will keep moving and pick up speed as it curves to the north and northeast, limiting the amount of time it can produce drenching rains over one area. Tropical downpours are notorious for producing high rainfall rates, though, so it wouldn't take much to lead to localized flash flooding.

There's a risk of a storm surge along the Florida Keys and Florida's west coast as the storm approaches landfall this week. The surge shouldn't be too high—possibly a few feet above sea level in vulnerable spots—but any coastal flooding from a storm surge is dangerous for communities along the coast.

Winds of 60+ MPH could cause tree damage and power outages. Stay mindful of large trees and limbs that loom near your walls and roof, and, if possible, avoid those parts of the house during the highest winds. Many people are injured during landfalling storms when trees and tree limbs fall on homes.

The risk for tornadoes is an ever-present threat when tropical cyclones make landfall. Much of southern and central Florida will probably see a risk for tornadoes on Tuesday and Wednesday. Tropical tornadoes are fast and can touch down with reduced warning lead time. Make sure you have a way to receive warnings the moment they're issued and you're ready to take swift action to stay safe.

Elsa's Unusual Journey

This has been a...strange...storm for early July.

The system became a tropical depression and a tropical storm while it was out in the tropical Atlantic, something you wouldn't expect to see until August or September.

Elsa became the earliest fifth named ("E") storm on record, beating Edouard last year.

The storm unexpectedly intensified into a hurricane as it passed over Barbados on Friday, becoming the farthest east we've ever seen a hurricane so early in the year.

Elsa hauled tail across the Caribbean like it was trying to beat the yellow light. Strong easterly winds around the south side of the Bermuda High hustled the storm west toward the Greater Antilles. The system maintained hurricane strength for almost 24 hours despite a forward speed of about 30 MPH. 

Storms usually don't last long when they move that fast. A speedy storm will eventually outrun itself, so to speak, with the low-level circulation decoupling from the thunderstorms above. In addition to weakening, this internal disconnect can sometimes lead to the cute li'l naked swirl we see on satellite imagery.

Elsa's high-stakes lifestyle caught up with it Saturday morning. The relative wind shear caused by its speed started chipping away at the thunderstorms near the center of the hurricane. You can see its lopsided, slightly ragged appearance on the satellite image above. Elsa weakened slightly to a strong tropical storm as its wind and rain reached Hispaniola and Jamaica.

Sunday morning saw the storm slow down by about half, allowing the system to attempt to recuperate before it traverses central Cuba on Sunday night and Monday. Elsa looks much healthier on satellite imagery now than it did 24 hours ago. Storms are attempting to wrap around the center of circulation again, and we're seeing that swirling, rippling upper-level outflow above the storm that's indicative of intensifying thunderstorms.

[Satellite Images: NOAA]

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