HERMINE AND THE NOREASTERS !!
STARDATE 201609. 1
There is SOOOOOO much information that offer that I don't even know where to begin with the tropical storm Hermine. I am not going to detailed overview of Hermine as it develops in the northeast Gulf because end up there are so many places on the Internet where you can get that information. But more importantly the purpose of this website and my company is to convey weather information to you as the individual... a business owner ... or organization before you read about it or get it from someplace else.
We have received a lot of positive e-mail / feedback today when we saw the massive changes going on in the track of the development of the system for the Labor Day weekend and altering the forecast before anybody else. I suppose this is probably going to come across as bragging or patting my self on the back but keep in mind that it is just me. I don't have $10 milion advertising department.
I do agree that is likely Hermine becomes a hurricane before landfall. But I do have some serious problems with the forecast from the Hurricane center as well as NWS and some of the local media with regard to what's going to happen in the Middle Atlantic states COASTAL area this Labor Day weekend.
As we begin lets go over some KEY points that you need to keep in mind throughout this entire discussion.
1 The further inland you are the LESS s rain you will see and the less rain duration you will experience. So if you are in the Shenandoah Valley ...far southwest Virginia ...western Maryland ...West Virginia you are NOT going to see a lot of rain - I dont think any of those areas will see rainfall amounts over 1 inch and some of this weekend will be pretty decent. Obviously therefore as you get closer to the coast the rain amounts will go up very rapidly and some areas just inland from the coast over eastern North Carolina Southeast Virginia and the Delmarva region could see anywhere from 4 to as much as 8 inches of rain depending on how this thing develops and where the LOW stalls
3 in case you forgot September 2 a NEW Moon. This will lead to the increased title flooding.
4 A lot is going to depend on where the coastal storm forms and stalls. If the new European and WRF models are correct ..the system is going to stall off the southeast coast of Virginia.. or off the lower Virginia eastern shore on Sunday. Tthe winds will stay strong ( 20-40mph gusts to 50mph on the coast) and these strong northeast winds will not allow the tides to go out. Thus when the next High tide comes in and you still have winds of 20 to 40 mph with higher gusts on the coast .. the water will pile up and the tidal flooding will increase.
This is what we are REALLY concerned about. The areas from NJ coast to Nags head as well as the open mouth of the Chesapeake bay need to take the coastal flooding threat very seriously. Keep in Mind SEPT 2 is also a New Moon so this will enhance Tidal floodiing.
If on the other hand the wretched GFS and HWRF is correct there will be some tidal flooding but the winds on the coastal will be a lot less and the impact will not be nearly as severe. We do not think this scenario is going to verify and we strongly support the scenario of the coastal storm stalling off the lower Virginia eastern shore (also known as the Virginia capes).
5. Next you NEED to understand that Hermine will NOT NOT be a tropical storm when it comes north up the coast. It will track just inland as it comes up the coast and take track from say Savannah George into Nofrolk Virginia and off the lower southern Delmarva peninsula As it does so it will transform from a tropical system into a coastal storm or a classic nor'easter. Here is WHY --
As Hermine comes up the coast it is going to mutate into a coastal storm or nor'easter and that is why most of the global models show significant deepening once again it reaches eastern NC/ Hatteras. When Hermine is in the Carolinas it will be pulling cooler air from a large HIGH to the north. So as the Hermine pulls in cooler air on its nw side.... the eastern side will stays warm/ tropical . At that point it becomes baroclinic -- it will develop cold fronts and warm fronts and it will no longer be tropical
That being said the 11:00 PM advisory from NHC with regard to day 4- is pretty bad. I means its wretched Apparently NHC seems to be following the GFS and the HWRF -- which explains why their extended forecasts track Sucks
The HWRF is obviously NOT the model to use that ths point since Hermine will no longer be a tropical system. The numerous flaws with the GFS model system compounds the problem -- while it true that the GFS does stalls the system often Middle Atlantic Coast... the GFS model flaws has it closing off at the upper levels and stalling much too far to the east .
I suppose this is why the 11:00 PM advisory has the nor'easter or hybrid storm stalled south of New England when the obvious synoptic pattern shows the system stalling out east of the Delmarva. This is supported by the Wednesday 12Z operational European the European ENSEMBLE and the 0z Thur NAM / WRF which stalls the TC/ Noreaster mix at 60 to 84 hours to east of Delmarva. It should be noted that all of these models of course have a much more refined resolution then the GFS and handle Nor'easter significantly better than the HWRF
As it is almost always the case with large powerful coastal nor'easters... the European model this far out as clearly the model of choice. This is the Wednesday afternoon or 12z European model run and this first image shows the position of the tropical storm becoming a Noreaster as of 8am on Saturday and 8:00 PM Saturday. Clearly by 8:00 PM on Saturday the system is now a full nor'easter and it is parked just east of Hampton roads.
In this next image we can see where the coastal storm is located as of 8am Sunday and 8:00 PM on Sunday evening. As you can see it has moved very little and the system is parked due east of the Salisbury MD coast or southeast of Cape May NJ. This is significantly closer than the last few operational GFS model runs. The reason for this is that the inferior physics package and data assimilation of the GFS model allows the system to stall further to the east away from the coast.
This next image shows the position of the system on Monday morning September 5 which is Labor Day. As you can see the LOW has done a counterclockwise loop or stall off the Delmarva Coast. This sort a long slow movement is going to really cause problems with the coastal tidal flooding from New York City all the way down to Nags Head in NC
The rainfall amounts are impressive as hell and many believe that the rainfall amounts are overdone. They probably are and we are yet prepared to tell you that Central North Carolina / Raleigh or Roanoke Rapids and Emporia in Virginia will see 10 to 12 inches of rain. But if the European model is correct and system does stall like this Sunday night and Monday off the Delmarva coast those rainfall amounts cannot be ruled out. Also notice on this graphic how the rainfall amounts are dramatically lighter as you go further west. For example Charlottesville sees about 1.5 inches of rain while Roanoke Virginia sees less than that.
Here are the Wednesday afternoon European Ensembles and as you can see there remains firmly committed to the idea of the system stalling off the Delmarva Coast and NOT off the New Jersey coast or or south of Connecticut. By Sunday morning the LOW is located due east of Norfolk and southeast of Salisbury Maryland. Again this is further south and closer to the coast then what the operational GFS and GFS ensembles are showing.
Amazingly by Monday morning the European Ensembles keep this system close to the coast and have it trapped fairly far to the south right through Tuesday morning. Obviously would keep the northeast winds along the coast fairly strong and prevent that the rides from going out which would worsen the tidal floodiing for all areas of the Mid Atlantic Coast from New York City down to Nags head North Carolina.
Finally we can take a look at some of these rainfall plots from the European Ensembles as of Wednesday afternoon. For example this first one is from Richmond Virginia. The different color bars represent rainfall forecast amounts of all 51 members of the European Ensembles - so the dark RED color is about 4 " of rain and the brown color bands represent rainfall amounts of 5 inches. At the bottom of the image you can see the regular European vs. the European Ensembles mean. Notice that the regular European for Richmond gives it about 3.5 inches of rain where is the Ensembles mean shows rainfall amounts around 2.5 inches.
If we take a look at NORFOLK we see a lot of the color bars showing that dark brown color which represents 5 "+ rain. And the operational run which has NORFOLK getting 5.5 while the Ensemble man is gets 3.5 inches
One final note. The Wednesday afternoon European model keeps this system stalled off the Midlantic Coast and about 300 miles due east of the Delmarva or due south of the eastern tip of Long Island NY right through next Wednesday and Thursday. At that point the euro has the system drifts southward.... crosses the Gulf stream ...RE energizes into a tropical system... then possibly becomes a hurricane once again .. and drifts SW towards Hampton Roads and Nags Head NC !!
This is the most amazing development I have seen on the European model in quite some time. This is unlikely but cannot be ruled out given the overall upper level patterns over North America. So rather than forecasted this type of extreme scenario ...I will simply pointed it out and follow the European model and the other global models to see if they pick up on this trend of this Noreaster lingering off the Middle Atlantic Coast for most of next week and possibly drifting south again towards the lower Middle Atlantic Coast line by September 9 or 10.