East Coast NCAA Football weather

Firsthand Weather has discussed doing this in the past, so I figured that with the relative calm before the next Tropical system comes into play, that we should give this a shot and see how you guys like it.   Hopefully we got some college football fans out there.

East Coast NCAA Games

To begin, Friday

Wade Wallace Stadium in Durham North Carolina.

Duke (4-0) will be attempting to take down #14 Miami (2-0) in this ACC contest.

Game time conditions should be partly cloudy with temperatures in the mid to upper 60s, after a day with highs in the mid 70s.

 

For Saturday’s games,

1  We start at Dowdy-Ficklen Stadium in Greenville, North Carolina

#18 South Florida (4-0), who will need to stay perfect to have any shot at the playoffs, will be taking on East Carolina (1-3)

Game time conditions should be partly cloudy with temperatures in the low 70’s with daytime highs reaching the mid 70’s

2. Ben Griffin Stadium in Gainesville, Florida

Vanderbilt (3-1) will try to get their season back on track against #21 Florida (2-1).

Game time conditions should be partly to mostly cloudy with a risk of Thunderstorms.  Temperatures should be in the low to mid 80s.

3.  Lincoln Financial Field in Philadelphia Pennsylvania

Temple (2-2) will be hosting Houston (2-1)

Game time conditions feature the risk of a passing shower with sun and clouds and temperatures in mid 60’s

4. Heinz Field, in Pittsburgh Pennsylvania

Pittsburgh (1-3), which is off to a disappointing start,  will be hosting Rice (1-3)

Game time conditions should feature partly cloudy conditions with temperatures in the mid 60s

5. Bobby Dodd Stadium in Atlanta Georgia

Georgia Tech (2-1), looks to stay in contention against underperforming North Carolina (1-3)

Game time conditions should be partly cloudy with temperatures in the mid to upper 70s

6.  Carter Finley Stadium in Raleigh North Carolina

NC State (3-1), fresh off their huge statement against Florida State, look to not drop off against Syracuse (2-2)

Game time conditions look to be partly cloudy with temperatures in the mid 70s

7.  Alumni Stadium in Chestnut Hill Massachusetts

Boston College (1-3) is still favored to win, despite their lousy start, while hosting Central Michigan (2-2)

Game time conditions will feature showers with temperatures in the 50’s

8.  Beaver Stadium, University Park Pennsylvania

#4 Penn State (4-0) continues its quest for the playoffs by hosting Indiana (2-1)

Game time conditions feature a slight chance for shower with temperatures in the mid 60’s

9.  BB&T Field, Winston-Salem North Carolina

Florida State (0-2) was knocked out of the top 25 last week, comes to take on undefeated Wake Forest (4-0)

Game time conditions should be partly cloudy with temperatures in the mid 70s

10. High Point Solutions Stadium, Piscataway New Jersey

#11 Ohio State (3-1) travels to play Rutgers (1-3)

Game time conditions should feature the risk of passing showers with temperatures in the mid to lower 60s

East Coast Game of the week

Lane Stadium, Blacksburg Virginia

#2 Clemson (4-0) will take on #12 Virginia Tech (4-0) in a contest of the best the ACC has to offer

Game time conditions should be clear with temperatures falling through the upper and mid 50’s

 

Rob

64.58 Inches of Rain Falls With Harvey!

Hurricane Harvey was the first major hurricane to make landfall in the United States since 2005, but its winds were not the only historic variable associated with Harvey. Millions were impacted by deadly flooding, and on Wednesday, the National Weather Service (NWS) officially confirmed that 64.58 inches of rain fell with Hurricane Harvey near Beaumont, Texas (in Nederland). This is a new record for the heaviest rainfall ever recorded in the United States during a tropical cyclone. The previous record occurred in Hawaii in which 52 inches was recorded. To show the magnitude of Harvey, the NWS confirmed that at least seven weather stations recorded more than 51 inches of rainfall with Harvey in Texas.

Rainfall Estimates

Was Harvey Caused By Climate Change?

Many people on social media have made statements along the lines of: “this is because of climate change” and “Harvey was caused by climate change”. But, this is not the appropriate way to view Harvey and its impacts. Climate change reflects a change in the background state in which all weather exists. Climate change, in itself, does not cause an individual tropical cyclone. Climate change can make impacts of a tropical cyclone worse. A few ways in which climate change can make the impacts worse are: I) rising sea levels due to melting ice, II) warming ocean waters, and III) more atmospheric moisture. I) As ice melts, the sea levels will rise. This can cause sea water inundation to be a bigger threat for coastal areas during a storm surge. II) As the atmosphere warms, and warms the ocean waters, it can increase the intensity of tropical cyclones. This is because the warm waters are food for the hurricanes (but one of many ingredients needed for a tropical cyclone to develop and intensify). And III), as the atmosphere warms, it can hold more moisture. This can allow for more moisture to be evaporated and more rain to fall with tropical cyclones. So, to blame the development of Hurricane Harvey, and its impacts, solely on climate change is not the appropriate.

The impacts of climate change on tropical activity continue to be heavily researched and are not fully conclusive.

Finally Feeling Like Fall?

Fall officially began a few days ago, but the jet stream is well north across the eastern United States. This ridge has caused temperatures to soar well into the 80s and 90s for areas east of the Mississippi. These warm temperatures will remain through Wednesday before the transition to near-normal temperatures begins.

By Wednesday, the trough that is responsible for mountain snow across the West will slowly shift eastward. This will send a cool front into the Great Lakes and the South-Central region. This front will eventually move towards the East Coast by early Friday, which will put an end to the summer-like warmth that has engulfed the eastern United States. High temperatures will be 10-20 degrees cooler by the upcoming weekend with the most significant temperature drop near the Great Lakes.

Trough across the West with ridge across the East (Today)

Ridge across the West with trough across the East (Saturday)

Temperatures will still be near to slightly below average, but compared to temperatures that are currently well above average, this will be a very noticeable change. Highs will drop into the 60s and 70s for much of the Midwest, Great Lakes, Northeast, and Mid-Atlantic. Lows will dip into the 40s with a few 30s near the Great Lakes by the weekend. High temperatures across the Southeast will fall into the upper 70s and low 80s. Lows are expected to be in the upper 50s and 60s.

Temperature anomalies (Saturday Afternoon)

The cooler temperature will continue through the weekend before a slight modification occurs by next week. The numerical guidance is hinting at a more amplified upper-air pattern, which would cause more cool fronts to move into the United States over the next few weeks.

Watching Hurricane Maria Closely Along The East Coast

Hurricane Maria made landfall in Puerto Rico early Wednesday morning as a strong category 4 hurricane, leaving the entire island without power and a path of destruction. Maria underwent an eye wall replacement cycle last night, which resulted in the maximum sustained winds lowering from 175 mph to 155 mph before landfall. However, this also resulted in an expansion of the wind field, which may have caused the Virgin Islands to be more heavily impacted. The passage of Maria over Puerto Rico disrupted the system, bringing it down to category 2 strength, but with time, Maria should regain strength and become better organized once again.

Over the last several days, Maria has been able to thrive in a low-shear environment, which is one of the reasons why this system underwent rapid intensification. In the immediate term, wind shear should remain relatively low. Currently, wind shear is heightened to the west, north, and east of Maria; however, this can mostly be attributed to the outflow that is coming off of the hurricane and will actually enhance further strengthening of Maria. It is worth mentioning that an upper-level shortwave located just to the southeast of Florida could be responsible for some of the wind shear to the west of Maria, but Maria is far enough to the east that it is not being negatively impacted by this shear. The shear tendency analysis confirms that shear has been on the increase in locations all around Maria, but shear has tended lower in the immediate vicinity of Maria. Again, this is mostly due to outflow coming off of the system, and this configuration of low/high shear values over and around the system should remain predominant over the next couple of days.

hurricane maria shear

The steering flow near Maria is not particularly strong, but the system will generally move northwestward before making an even more northward turn over time. On the steering flow analysis, the features that are most noteworthy are the outflow coming off of Maria, the building ridge over the eastern United States, the weak trough moving off the East Coast, the longwave trough over the western U.S., and Jose. Many of these features could potentially have an impact on the future strength and movement of Maria.

steering flow maria

Through the rest of the week and into the weekend, Maria should be able to strengthen, given that wind shear should remain relatively weak in the short term. However, a positively tilted, mid to upper-level trough will be positioned over the southeast underneath the building, deep-layer ridge over the northeast. This only gives Maria about a 3-day window to really begin to regain strength before being more heavily influenced by the southwesterly shear on the east side of the trough. Before that occurs, Maria will be moving through a region where sea surface temperatures currently run from 29-30°C, which will provide the necessary energy for additional strengthening. The National Hurricane Center has Maria reaching category 3 strength again with winds topping out at 115 mph, but if Maria can recover quickly enough from being negatively impacted by Puerto Rico, it may have enough time to get a bit stronger than that. However, Maria shouldn’t get close to the peak intensity that it reached on Tuesday.

sea surface temperatures

upper level map hurricane maria

The big question that remains is whether or not Maria will actually make a landfall along the East Coast or get close enough to be impactful. Tropical Storm Jose should manage to keep a well-established weakness in place between the building ridge over the northeast and the ridge near Bermuda, allowing Maria to safely move between those two features in the short term. Also, the positively-tilted trough mentioned above should also have an influence on keeping Maria away from Florida, Georgia, and probably even South Carolina. However, as Jose weakens significantly this weekend, Bermuda ridging and the ridge over the northeast could actually merge, which could allow Maria to make a northwestward jog towards the East Coast sometime next week. The timing of a longwave trough that will be digging into the eastern United States later next week and whether or not the two ridges merge will determine just how close Maria gets to the East Coast. If the longwave trough makes it eastward quickly enough, this would steer Maria safely out to sea, but it’s not guaranteed that this will occur before Maria makes it pretty close to the coast. Residents from the North Carolina coast to the Massachusetts coast need to monitor Maria closely. The good thing is that the sea surface temperatures are very cool along and just off the Mid-Atlantic and Northeast coasts, so if Maria managed to get close, weakening most definitely would occur. This still doesn’t mean that there wouldn’t be some major impacts to those areas, if this scenario unfolds. Again, the second scenario is a safe passage out to sea.

hurricane maria projected path

Bullet-Point Summary:

  • Maria could recover enough to regain additional strength over the next 3 days, but weakening should begin to occur afterwards.
  • Maria will generally travel northwestward before making a more northward turn in the short term.
  • Maria could make a jog northwestward next week as Bermuda ridging and ridging over the Northeast potentially merge.
  • Residents from the North Carolina coast to the Massachusetts coast need to monitor Maria closely. If this occurs, impacts would occur mid next week.
  • The second scenario is that Maria will go safely out to sea with little to no impact, so don’t panic.

Tropical Storm Watches issued from Delware to Massachusetts

Tropical Storm Watches are in effect from Fenwick Island, Delaware, to Sandy Hook, New Jersey, including Delaware Bay South, and from East Rockaway Inlet, New York, to Plymouth, Massachusetts, including Long Island Sound, Block Island, Martha’s Vineyard, and Nantucket.

Tropical Storm

Jose effects on the Outer Banks

Hurricane Jose is currently located a little more than 300 miles southeast of Cape Hatteras.  With his movement straight north, Jose will pass off shore of the Outer Banks.  Current sustained winds are 90 miles per hour with Tropical Storm Force winds extending just over 200 miles from the center.  Tropical Storm force gusts may occur in some of the heavier showers over the Outer Banks, but sustained conditions are not expected in area, so there are no Watches at this time.  Some tropical showers and thunderstorms are already being seen on the Morehead City Nexrad radar.  These showers will continue to develop as Jose moves closer.  Here is the current Satellite view.

Tropical Storm conditions further North

The best chances for sustained Tropical Storm conditions begins in Delaware and goes up the coast into Massachusetts.  The Mid-Atlantic coast could avoid sustained conditions, but widespread tropical storm conditions should be expected as the wind field expands.  Even as Jose weakens, the tropical storm force winds will continue to expand as the transition to an extra tropical system takes place as seen in this forecast below.  This model does keep the sustained winds off the coast, but the watches are in effect due to the risk of those winds moving slightly further west.  It will not take much westward movement to bring these sustained winds onshore in the Mid-Atlantic on Tuesday.

As seen above, the tropical storm force winds are expected to move well ashore in New England and  over Long Island.  The closest pass to the Island of Nantucket, seen below, will occur Wednesday afternoon.

This image shows sustained tropical storm force winds nearly reaching Boston.  I would expect that Watches will be extended further up the East coast of Massachusetts in further advisories.  Tropical Storm force wind gusts could be seen up into Central New England in the heavier showers and thunderstorms of the outer bands.  While the majority of the rain will fall closer to the center of the system, the precipitation shield associated with Jose will be expanding by the time it reaches New England.

We should not just pay attention to the forecast for the center of Jose during this time.  The location of the center only matters in terms of positioning for the overall storm.  The key factor from Delaware north will be the rate of expansion of the wind field and precipitation shield as the system starts its transition from tropical to non-tropical.  Even if Jose is still a Tropical Storm by the time he passes southeast of New England, the transition will have been happening in at least some capacity.

Robert Millette

 

Hurricane Jose track shifting towards U.S.

Hurricane Jose, currently a little more than 600 miles South Southeast of Cape Hatteras, is moving toward the Northwest at approximately 10 miles per hour. Jose’s maximum sustained winds are at 75 miles per hour, barely qualifying as a category 1 hurricane. Intensification is forecast for a short time while Jose remains in a low shear environment and moves over warmer water, but water temperatures begin too cool towards New England and additional shear is expected by the end of the weekend.

Hurricane Jose track

Hurricane Jose

Tropical Storm Watches possible in North Carolina

Hurricane force winds remain very close to the center of Jose at this time, but Tropical storm force winds extend 140 miles from the center. Due to the amount of distance those winds span, and the expected enlargement of the storm, Tropical Storm Watches are possible in North Carolina over the next couple of days. You can see how close the current forecast brings tropical storm conditions to the Outer Banks below. A direct hit is not forecast in the region, as can be seen, but winds along the periphery of Jose could be strong enough to reach Tropical Storm status. A Tropical Storm Watch or Warning does not mean that you will face a direct hit from a Tropical Storm, just that tropical storm conditions are likely in your area as the storm passes off shore. We here at firsthand will be monitoring this closely over the weekend.

Jose heads North

Towards the middle of next week, the closest pass and the current area most likely to receive a direct hit if landfall occurs, is Southeastern New England. Models have been trending west with the system as time goes by and The cone of uncertainty extends as far west as Eastern New York at this time. The latest run of the GFS, shown below, shows a landfalling tropical system on Cape Cod.

Firsthand Weather will be with you every step of the way as Hurricane Jose makes his approach. Please begin some of your preparations if you are in the Outer Banks or New England this weekend. Do not be one of the people left trying to buy supplies when items are low. Buying in advance also allows stores to restock items which allows a greater supply for everyone. It is best to have your supplies ready a head of time and have them around to use than to not have them should the storm miss then to need them and not have them available. Stocking up on survival food to ensure that your family can eat when the hurricane hits is advisable. You should also test flashlights and check other equipment, like medical kits, vehicle emergency kits, and generators ahead of time to ensure they are in good order. While large evacuations are not anticipated with Jose, checking on the location of your nearest shelter would not be a bad idea if you were to lose power.

 

Robert Millette

Old Farmer’s Almanac: Cold and Snowy Winter

Enjoy the cold and snow? Well, you’re in luck according to the 2018 Old Farmer’s Almanac, which is predicting a cold and snowy winter for much of the continental United States. This is based on a 225-year-old formula used by the Almanac, which boasts an 80% accuracy rate.

According to the Almanac, the 2017-2018 winter will be much colder than last winter. The Northern Plains will see temperatures slightly above average, but cold outbreaks and snow are still likely periodically in this region. Much of the Southern region can expect cold and wet conditions, which increases the possibility of some of the precipitation falling in the form of snow. The Great Lakes and Northeast should also prepare above average snowfall. The Pacific Northwest will cold but drier than average, which is much different than last winter when record rainfall and snowfall occurred in this region. The Southwest may see above average precipitation to aid in some drought relief.

2017-2018 Winter Outlook (Old Farmer’s Almanac)

Based on the Almanac, here’s a regional breakdown for the upcoming winter:

Southeast:
Temperatures: Average to slightly above (east), below average (west)
Precipitation: Above average

Northeast:
Temperatures: Average
Precipitation: Above average

South-central:
Temperatures: Average to slightly above
Precipitation: Above average

North-central:
Temperatures: Below average (south), above average (north)
Precipitation: Above average (south), below average (south)

Southwest:
Temperatures: Below average
Precipitation: Above average

Northwest:
Temperatures: Below average
Precipitation: Below average

Please note: this is not Firsthand Weather’s 2017-2018 winter outlook, and this does not necessarily reflect our views on the upcoming winter season. A lot of our followers enjoy the Almanac and thus this article is for their enjoyment. Firsthand Weather will have a final winter outlook in October, so keep checking back for details!

To see the entire forecast from the Old Farmer’s Almanac, click HERE!

Irma To Bring Widespread, Significant Impacts To Southeast

Hurricane Irma made landfall earlier today in the Florida Keys (as a category 4) followed by a second landfall near Marco Island, Florida. Winds have gusted as high as 100 mph in Miami with reports of 130 mph wind gusts on Marco Island. Regardless of the two landfalls today, Hurricane Irma is still a strong category 2 with sustained winds of 115 mph. Irma is expected to skirt the western coast of Florida over the next 24 hours–bringing a devastating storm surge, widespread hurricane force winds, heavy rainfall, and tornadoes. Impacts will eventually be felt well inland as Irma moves northwestward out of Georgia into western Tennessee.

Hurricane Irma Cone Through Thursday Afternoon (NHC)

Florida (now through Monday evening):
All of Florida will see hurricane conditions over the next 24 hours; this includes damaging winds, flooding, storm surge, and tornadoes. Wind gusts in excess of 100 mph are possible for all of Florida with the west coast of Florida and the Florida Panhandle potentially experiencing gusts in excess of 130 mph. Flooding is another major threat with Irma: Florida will see an additional 4-14″ of rainfall. The heaviest rain will occur across the western and northern parts of the state. Dangerous storm surge is occurring and will continue to occur along coastal areas of Florida and for low-lying areas further inland, too. Cape Sable to Captiva may see a storm surge of 10-15 feet. Isolated tornadoes are likely.

Georgia, South Carolina, and eastern Alabama (late tonight through Tuesday):
By Monday afternoon, Irma will move into south-central Georgia. Irma should still be a strong cyclone, thus, damaging winds, heavy rainfall, and isolated tornadoes can be expected for much of the Southeast through Tuesday. Tropical Storm force winds extend outward up to 220 miles and hurricane force winds extend outward up to 80 miles. This has prompted Hurricane Warnings (winds of 50-110 mph) for much of southern Georgia; Tropical Storm Warnings (winds of 40-70 mph) for the rest of Georgia, eastern Alabama, and southern South Carolina; and, High Wind Warnings (winds of 35-60 mph) for western South Carolina and northeastern Georgia. Widespread 3-8″ of rainfall is possible with isolated 10-12″ amounts in southern Georgia. Isolated tornadoes are possible.

Mississippi, Tennessee, and North Carolina (Monday night through Wednesday):
Lesser impacts will be felt across these states. Gusty winds are likely across eastern Mississippi, Tennessee, and North Carolina from Monday afternoon through Tuesday night. The higher terrain of Tennessee and North Carolina could see wind gusts up to 55 mph. A High Wind Warning is in place for southern parts of North Carolina. Heavy rainfall is possible with 2-4″. Locally higher amounts, 4-8″, are possible in southeastern parts of Tennessee and on the windward side of the ranges in North Carolina. The greatest tornado threat in these states will occur in North Carolina on Monday and Tuesday.

All three of these area, especially the first two (I: Florida, II: eastern Alabama, Georgia, and South Carolina), have a chance to see power outages associated with the vast wind field of Irma. Please plan accordingly and listen to local officials in case evacuations/curfews are issued.


Tropical Storm Force Wind Speed Probability Through 5 Days (NHC)

Severe Potential–Tornadoes Sunday (SPC)

Severe Potential–Tornadoes Monday (SPC)

Severe Potential–Tornadoes Tuesday (SPC)


Rainfall Forecast Through 7 Days (WPC)

The remnants will continue northwestward through Tennessee before being ‘picked up’ and moving northeastward towards the Ohio Valley.

Hurricane Irma Update (Important)

First and foremost, I want to thank each and every one of you who have provided very useful information on Firsthand Weather for those trying to evacuate. Feel free to continue using Firsthand Weather as a way to get beneficial information out to the public.

As expected, Hurricane Irma has strengthened once again and is just barely below category 5 strength with sustained winds of 155 mph. I have become increasingly concerned that some people have let their guards down due to the fact that Irma weakened some from an 185 mph hurricane. Please don’t do that. Only FOUR hurricanes have ever hit the state of Florida with sustained winds of 150 mph or greater. Two of those hurricanes were Andrew (1992) and Charley (2004), which were much smaller in size. You must keep in mind that Irma became one of the strongest hurricanes ever recorded in the Atlantic and was the strongest hurricane ever recorded outside of the Gulf of Mexico and Caribbean Sea. Try to keep that into perspective.

Hurricane Irma is actually moving due west now. Admittedly, Irma is being influenced by the Bermuda ridge a bit longer than I originally anticipated. That could be good or bad for the U.S. The bad news is that a delayed turn northward will likely result in this system tracking northward through the peninsula of Florida, instead of along the East Coast of Florida. This is one of the two scenarios that I said would likely occur; however in my last article, I said that I was leaning more towards Irma riding along the Florida East Coast and then possibly making a second landfall in Georgia or South Carolina. You should be aware that likely WON’T occur now. Unfortunately, it appears that Irma could have impacts from the west coast to the east coast of Florida and across regions in between. That’s not good news at all. Residents across the state including along the Florida Peninsula need to continue to prepare for this hurricane.

The good news about a more westward track is that the odds are greater that Irma COULD weaken due to interactions with Cuba; however, I wouldn’t bank on that. It will all come down to how quickly we see that northward turn. On the other hand, Irma is moving into even warmer waters. If this system is not negatively impacted in any way by Cuba, expect Irma to be a 145-150+ mph hurricane at landfall across southern Florida. I still don’t think Irma will come into the Gulf of Mexico from the west, as I have mentioned for several days ago. If anything, it would be worth watching to see if it briefly goes over Gulf of Mexico waters as it moves up the Florida peninsula, but I don’t anticipate Irma actually going due west into the Gulf of Mexico before making the turn northward. Of course, I will keep an eye on things.

It’s alarming to me the number of people who have let their guards down due to being removed from the projected path of Irma. DO NOT DO THAT. This is a very large storm and impacts will occur outside of the projected path, especially on the eastern side of the storm. This includes storm surge, which could become a major issue along the Georgia and Carolina coasts, depending on how quickly Irma turns northward. Residents across Georgia, the Carolinas, and even into parts of Alabama and Tennessee need to remain vigilant and watch for the latest forecast trends.

As a meteorologist and someone who has been following the weather closely for a long time now, I can almost always decipher between weather events that are going to be difficult to forecast and those that are not. Hurricane Harvey, for example, was not as challenging of a forecast. We knew that this system was going to stall, and regardless of where it actually hit along the Texas coast, we knew if we had a general idea of where it would hit, we would be able to pinpoint the general area that would receive copious amounts of rainfall. Hurricane Irma is not one of those cases and will be difficult to forecast through the extent of the event for various reasons. One of those reasons is the fact that Irma will be moving northward into Florida. The south Florida coastline pales in comparison to the length of the Texas coast. The exact timing of the turn northward is dependent on the very minute differences in strength of the Bermuda ridge. When the timing of this turn north could potentially change the forecast significantly, this makes forecasting such an event challenging to the very end, and the forecast becomes prone to larger errors. I told you this would be the case over a week ago. So as a precautionary measure, you should be preparing for a potentially significant, high-impact weather event if you’re located in Florida, and residents should be making preparations across the additional states that I mentioned, just in case those plans need to go into effect.

To conclude, I am going to continue watching Irma very closely. In a lot of ways, we’ll be doing a lot of nowcasting and short-term forecasting and will be relying pretty heavily on observations either from in-situ observations or remotely sensed observations from satellites. I’ll be sharing all of that information with you along the way. I am currently in the same boat as many of you are with trying to tell my family and friends what they should do and how they should prepare. I hope that you have found our information and forecasts to be helpful, and we will continue to provide this service as this event unfolds.

Hurricane Irma Should Be Monitored For Possible U.S. Impacts This Weekend/Next Week

As of 8 pm ET, Hurricane Irma is still a strong category 5 hurricane with maximum sustained winds of 185 and gusts up to 225 mph. It has unbelievably maintained that same strength since yesterday, despite some fluctuations in minimum central pressure. It is moving west-northwest at 16 mph and will be skirting the northern coast of Puerto Rico soon.

Forecast Discussion:

The biggest challenge to forecasting Hurricane Irma’s track through early next week remains the various features that either have or will impact its steering. Bermuda ridging over the Atlantic has kept Irma on a westward course, and this feature will continue to play a role on Irma’s movement. This ridge has strengthened and has even built southwestward with time; however, there are two main features to watch that could act to break down the westward extend of the ridge closer to the end of the week.

First, a longwave trough has established itself over the eastern United States with a ridge back to the west. For what it’s worth, this is actually the pattern that is responsible for bringing less humid and cooler air across the eastern half of the United States. Unfortunately, it appears that the trough is going to move out too quickly for it to actually steer Irma safely away from the U.S. east coast; however, as the trough lifts and then propagates eastward with time, it will keep a weakness established between the Bermuda ridge out east and a ridge that will center itself over the Four Corners region and extend into west Texas by this weekend. Once Irma gets far enough west, this should result in Irma taking a hard turn northward. This is actually well-advertised in the model guidance, but there has been a bit of spread over the last few days between the models on when that northward turn will occur. Some models take Irma into the eastern Gulf of Mexico, some northward through the peninsula of Florida, and some skirting Florida along its east coast before taking Irma into Georgia and South Carolina.

latest irma forecast models

Figure 1: This is the latest model representations of where Irma could go.

Although Bermuda ridging may build southwestward over the next day or two, this feature should become less of a dominant steering mechanism at least long enough for Irma to start making the turn northwestward/northward towards the end of the week or early weekend. The second feature to watch will be Hurricane Jose. It’s difficult to say if that will have any influence on the southern extent of the Bermuda ridge as Jose treks in a northwestward direction, but it’s most certainly something to watch closely.

To complicate matters even further, the current ridge that is established over the western U.S. which extends northward into western Canada is going to actually break (imagine a wave in the ocean crashing), which will result in the formation of a cut-off low (the same trough I was referring to earlier). Another, weaker shortwave will be moving southeastward towards Mississippi and Alabama, and ridging may begin building over the northeast by this weekend. All in all, this continues to be a super complex forecast.

Aside from all of these features to monitor, the angle that Irma will be coming in relative to the coast makes for additional challenges. A jog fifty miles west or east can be the difference between major hurricane-force winds along the coast or barely tropical depression/storm-force winds.

Where I Think Irma Could Go And Who Should Be Preparing:

Now that you’ve listened to me spend quite a lot of time talking about the complexity of this forecast, I’m actually going to attempt to make a forecast. We still have the three scenarios on the table that I presented close to a week ago in my earlier articles. Irma could barely make it into the eastern Gulf of Mexico and ride along Florida’s west coast, Irma could ride up or along the eastern Florida peninsula into Georgia or the Carolinas, OR Irma could move just east of Florida and out to sea.

The least likely scenario is for this system to go into the eastern Gulf of Mexico. While Bermuda ridging will certainly continue to influence Irma’s steering, it likely won’t extend far enough westward. With a weakness established between the two ridges and with the possible influence of the eastern U.S. trough (even with it lifting out), this should open the door for Irma to make that turn northwestward and then northward before getting into the Gulf. There was quite a bit of talk in the meteorological community about how if Irma stayed below a certain latitude that it would increase the odds of an entrance into the Gulf, and while that may be true, Irma should gain enough latitude over the next couple of days for this scenario not to unfold. I still advise those along the Florida panhandle and west coast of Florida to closely monitor the latest forecasts regardless, due to the complexity of the forecast.

irma sea surface temperatures

Figure 2: Hurricane Irma remains over warm waters.

Based on what I am seeing, the most likely scenario is for Irma to make the turn northwestward and eventually northward before reaching the Florida Keys. This would result in Irma riding along the Florida east coast, possibly causing tropical storm to hurricane-force winds for regions closer to the coast. It’s too soon to say if these winds will be tropical storm/low-end hurricane strength or closer to major hurricane-force winds. I’m not saying that because I’m predicting Irma to weaken considerably before reaching coastal regions of Florida, but because a slight difference in track west or east will make a significant difference in impact. That’s why all residents from the Keys to the east coast of Florida need to prepare for this event. Also, residents located in the Bahamas need to prepare to possibly be impacted by a major hurricane.

As Irma rides close to the coasts of Florida and Georgia, the upper-level low over the Southeast, the ridging over the Northeast, and the Bermuda ridge could cause Irma to eventually make a landfall somewhere between the north Georgia or South Carolina coasts. The strength of these features will ultimately play a role in how this evolves. Residents along the Georgia and Carolina coastlines (including North Carolina) need to monitor this situation very closely, and if model guidance begins to consistently support this forecast and the reasoning behind it, vacation plans for late this weekend and early next week will need to be canceled.

Irma Impact Map

Figure 3: These are states that could be impacted by Hurricane Irma. Note: the black line represents the NHC’s latest projected path; however, the buffer around the black line is not the NHC’s cone of uncertainty, just a 2 degree buffer.

Bullet-Point Summary:

  • The Bahamas need to prepare to potentially be impacted by a major hurricane. The Florida Keys to the east coast of Florida could be impacted by tropical storm to hurricane-force winds. A fifty-mile difference in track could result in huge differences in impact. Given that we’re about five days before Irma reaches Florida, it’s too soon to make a forecast with that kind of precision, given Irma will trek parallel to the state. In fact, it actually could prove to be a challenging forecast even 24 to 48 hours beforehand.
  • While it can’t be ruled out that Hurricane Irma will go into the eastern Gulf of Mexico, it’s highly unlikely. Residents from the panhandle to the west coast of Florida still need to be aware of the latest forecasts in case anything changes.
  • Residents along and inland from the Georgia and Carolina coasts need to prepare to possibly be impacted by a hurricane very late weekend into early next week. While it should be understood that this forecast remains to be complex, planning for this event should be ongoing.
  • While some weakening could occur, Irma is expected to remain in an environment that will support little weakening through at least the end of the week. It seems unlikely that Hispaniola will majorly impact Irma’s strength.
  • We will address other states that could be impacted by Irma over the next day or two.
  • Again, as has been stated numerous times, this forecast is complicated. Modifications will have to be made, but there is nothing wrong with preparing for this event, despite the uncertainty that remains.

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