Columbus (WCMH) – Tropical Storm Harvey is back in the Gulf, and is setting up for a third landfall soon. Many here in Central Ohio are wondering, are we going to see any of Harvey’s heavy rainfall?
What we do know about Harvey:
- It will start to finally move this week
- It will get weaker and eventually become a depression, and a remnant low
- It will bring large rainfall totals inland as it moves through the southeast
- The official forecast track has it turning to the north-northeast, tracking the Mississippi river
- When Harvey starts moving, he is going to keep on moving
That last point is a very important one. The major problem with Hurricane/Tropical Storm/Tropical Depression Harvey has been is crazy slow to almost a stalled motion. Also, this storm has had crazy close proximity to a very warm, very large body of water that could continue to feed this system.
Sadly for our friends to the south in Texas/Louisiana is that Harvey is not going to really get going for a few days still. That means a foot of additional rain in spots is easily possible.
On a positive note, Harvey should not get much stronger even though it is going back over the Gulf
As Harvey enters into the Gulf again, a few things are working against it from becoming a hurricane again. First, upwelling, or the process by which deeper, colder waters are circulated or churned up to the closer to the surface. Hurricanes and tropical systems feed of warm oceans, and upwelling provides the storm the opposite.
The other main thing working against Harvey tonight, dry air that is getting pulled into this system.
In the image above, you notice in red the drier air that is getting pulled in from the left side of the storm and now is getting wrapped around what is the center of Harvey.
The spread of forecast models confirms this with low end tropical storm strength until its third landfall by midweek.
The forecast models by mid to late week begin to show what is left of Harvey moving north-northeast
The steering currents in the mid/upper levels will eventually pull Harvey. The majority of the forecast models eventually come into line with each other.
How will Harvey most likely impact us in Ohio?
What is interesting is that we are going to be watching an upper level trough (that U shaped thing over Lake Superior) late week, and additional disturbances pivoting around it.
I think at this point, one of these disturbances pivoting around the trough may be able to tap into and draw up some of that moisture from Harvey into the weekend, but again, it is going to be moving.
So yes, this may enhance rainfall rates for a brief period of time on Saturday/Saturday night, but it should be moving out quickly. Right now Harvey is encountering upper level winds (think steering currents) of almost none to maybe 15 miles per hour around it.
By the weekend, winds at the same height will be in excess of 65 miles per hour in our area, and to our immediate north on Sunday morning, we could have 115 mile per hour winds with that jet streak.
Bottom line, the remnants of Harvey are not sticking around long enough to be a flooding potential for us.
Here is the latest forecast from the Weather Prediction Center at NOAA:
This is total precipitation forecast for the next 7 days across the county.
Notice that most of the state is somewhere in the half inch to inch and a quarter range for the next week. For reference we should see about 4/5th of an inch of rain per week this time of year, and we are currently sitting 85/100ths of an inch below normal for rainfall for August.
This forecast mirrors what looks likely to happen is that the upper winds in a few days will begin to pull a somewhat drier, and much weaker Harvey to the south of our area, and eventually exit it off to the east.
We will get the bulk of our moisture from a few disturbances from the northwest.
In case you were wondering about that heavy rain up the east coast…
Those heavier numbers are due to what is now Tropical Depression 10, which should become Tropical Storm Irma before hitting the Outer Banks, and then riding up the east coast.
There is another strong wave coming off of Africa, that we will be watching for a 2nd week of September rain maker along the Atlantic coast of the US. Right now, it is not forecast to hit land, but the proximity to land in a forecast 384 hours out leaves plenty of uncertainty….stay tuned.
If you have any questions about Harvey, the tropics, or any other weather, email me, firstname.lastname@example.org