Dorian

9-9 - Finally have time for a wrap up.
Once Dorian became mobile, it started the process of restrengthening and regained major hurricane status briefly before making landfall on Cape Hatteras as I think a cat one.  
It cruised east of JAX at about 6kts.

Moved along the coast past Charleston

Almost hits Cape Fear

Looks like it hits Cape Lookout, but not officially landfall until OBX

The eye went over a "buoy"  - Hatteras Station

By sunset it was moving off the coast, restrengthening again.

But Dorian wasn't done. As it headed to Nova Scotia, it caused TS force winds along the MD, DE, NJ, NY, MA and RI coasts.

 


9-3  Morning - eyewall currently having issues and open to the SW.  If this continues, it will not gain strength once it escapes its current environment.  Then it will encounter some shear until it heads NE.

NAM is the only model without a landfall, or at least that the center doesn't clear some land.

Otherwise the strike zone is N Myrtle Beach to Cape Lookout.  I'd go with Cape Fear right now.
HWRF skips right over the three capes.

GFS is right off Myrtle Beach and hits Cape Fear - takes on CL and CH too.

NAM 3k isn't far enough out, but looks further west than its parent NAM and will hit Cape Fear

Euro keeps the core barely off the coast at MB but hits CF, CL and CH.  Like the NAM, its unclear if the actual center crosses, though the Euro is a little closer in than the NAM.  The 0z run is similar hitting CL.

Point of all this is that there is little variability in the models.  In the big picture, the track is set.  Its just minor details that matter.  If it comes inland earlier, does it stay inland and decline.  If it stays off the coast does it hold strength or increase?   Below is the gust map from the Euro - just a 30 mile shift can cause much more or much less pain.

9-2 Afternoon

Dorian still over Grand Bahama, devastating it. Videos from there heartbreaking.
Dorian underwent an eye wall replacement and used up a lot of the warm water at the surface, so its declining now.  Unsure if it will ramp back up, but as it weakens, the wind field spreads.

The damage is extensive and ongoing.  Links to videos below.

 https://twitter.com/MorrisMedici/status/1168570843754049538

 https://twitter.com/julmisjames/status/1168540891583307780


9-2  Morning

Not much has changed with the track and the fear of it moving west past Grand Bahama has abated. Now it will sit for a while before lifting either N or NW.

Whether the eye crosses land in FL is questionable and I still have no prediction.  I'm leaning no though.  GFS has hurricane winds along the coast though, which warrant monitoring.  All models have it coming really close to Cape Canaveral, then hugging the coast all the way to Cape Hatteras.  Definitive landfall looks likely from Myrtle Beach north to Hatteras, but the entire coast to OBX is subject to hurricane force winds, either sustained or gusts, along with storm surge.

Euro 6z upped the gusts along FL coast.  As you can see in the map, a few miles makes a difference. Gusts of 107kts or 120mph on Canaveral.

Precip looks again the worst along the immediate coast were a few miles makes a difference.  Once it gets in to the NC area, it should be more inland as the storm weakens and expands.

Late afternoon. 
A look at the 5 main deterministic model runs from this afternoon.  No they are not the same.  Some do have hits grazing either FL or the Carolinas.  But the consensus is astonishing as is that its now in line with climatology. 

8-30 Early afternoon update.

Back to 50/50 on landfall in FL.  May be SC/NC instead.  What is incredible is this run by the Euro that ultimately hits Nova Scotia.

 Much like Matthew, but Matthew was already going north when it got to FL.

Very impressive on the satellite

8-30   Morning update.

A little more confident of a Florida strike, leaning 65/35 now.  Will also have to start paying attention to its remnants for the Mid Atlantic through Maine/NS

Wind map says it all track wise.  Euro and GFS

Euro

GFS

 Dorian continues to intensify and borders a major hurricane as of 8am (3mph away from Cat 3, with some obs over 110mph not being counted).  Its also slow enough that the the upper level features that we think may guide it, may not.  But, it doesn't appear at this time that the Keys are any longer in play.  Miami to Daytona is my broad guess.  West Palm to Cocoa Beach is a more narrow guess.  NHC predicts 140mph at landfall now...I'm going to go with 115mph. 

8-29  Its been awhile...

Dorian shocked the weather world by not only missing Hispaniola but pretty much glancing or missing Puerto Rico as well.  Today its moving kinda slowly away, not gaining too much strength as some dry air, a touch of shear and proximity to Hispaniola/PR is still having an affect on its flow.

Dorian is full of surprises.  Here is  the 8am advisory having it hit DR.

And here is the advisory for 11am the next day, pretty much as its hiting the USVI

That's quite a surprise.

I ran a history of tropical cyclones that went through the area that Dorian was in this morning.  Historically speaking, its rare that a 'cane hits Florida from this position, traveling in this direction.  Its even more rare for a 'cane to be in this spot after hitting Barbados. There's one storm that's highlighted, and it killed 51 people.

So historically, storms have curved away from Florida - typically this is due to a well timed front/trough.  Like the one that is going through the EC today.  If Dorian were at that X, it would likely curve out to sea.  But its not.

One small feature that pops up is a tiny upper low to its west.  You can barely make it out on the water vapor loop earlier today, just north of Turks and Caicos.

That ULL (upper level low) heads west, and Dorian is expected to follow it as a ridge builds in after the passing of the trough as depicted on the Euro for sake of ease. You can also see the ridge above it until the last 2 frames...that's where it gets interesting.

Right around 84-96 hours, the ridge begins to breakdown. Earlier on the GFS, later on the latest HMON.  You can also see the distance between the ULL and the storm increases so its influence is lost, and a ridge should technically be between the two by hour 96.  This leaves Dorian without any steering.  Thus, you have solutions all over the place.
Again the Euro stalls it and moves it up the coast, not terribly windy, but slow and rainy.

Or the GFS and CMC which bring it directly into FL and THEN swing it up.

Or the HMON, which takes it down to the Keys as a really bad major storm.

Or you can look at the HWRF (the other US hurricane model) which has it hitting Cocoa Beach (no real loss there) with 115-120mph winds.

Last option is the NAVGEM which curves it back out before hitting FL.  The Carolina's aren't safe with this solution though.

So to wrap it all up - if you think they know where landfall will be, you're crazy.
I'm at 50/50 if it hits Florida vs curving out, just based on climatology and there's that strong ridge.  While I doubt the Keys are really in play, Miami to Jax is.  Sorry, can't pin it down more at this point.

End of March

3-19  Trended west from yesterday.  No real reason. Looking like mostly rain and from 1.5" to 2.5" of it with 30-35mph winds at the coast and gusts inland to 40mph. Just a nasty spring noreaster.

 

 

GFS and Fv3 on board with it being a coastal hugger too. This would still have brought us rain in January.

CMC is off on its own with a 966 low off NJ and hurricane force winds.

 

 I really don't see how much further back it can go.  Wouldn't surprise to see if bump east a bit.
Noting how the GFS starts it later.  Still need to watch when this thing starts to deepen.  I think the NAM is weird in that with the cold air coming in, as well as the upper level vorticity and negative tilt that it doesn't deepen the low, at least in the 18z run. It goes from 1010 to 1003 in 6 hrs (45-51) then as the upper energy hits it, to 1001,999,995,992,992,990 every three hrs.  Or from 1010 to 990 in 24 hrs.  Should be more.

As of now, it s 80% chance rain, 20% chance of any snow for the tristate. 

Then there's the 26th

3/18

All hands on deck - as the day progressed, so did the development of this storm.  Just as it should with an upper low coming down.  The saving grace for snow haters is that it will be pretty warm ahead of it.  Also, its trending further west.

Todays Euro runs.

The problem with the Euro is that while the 1000-500 thickness shows snow for us, its the boundary layer that's warm (thickness is a description of the temperature from surface to 18,000 ft).  If the storm develops faster then there's a chance CT and RI get some snow out of this.

 GFS just came on board...

FV3 had backed off the snow idea





UKIE was still farther east.  Usually it overdoes phasing, this time it misses it. It really should be further west by the upper low.

A bunch of things can happen -it can keep drifting west, which I'm skeptical of based on where the upper low is coming in.  It can form quicker or further south as the NAM is indicating, which might result in a rain to snow situation.  It can bump out to sea and graze us, which might also bring some rain to snow. But I like today's maps.  I think if the upper levels arrive when and where they do as depicted today, then the low forms closer into them.  If those upper levels flatten out or are slower, then maybe more west, but if its too slow, not at all.  If they push faster or further east, then it goes out to sea.

NAVGEM is furthest east by the UKMET which is a red flag for the UKIE.  Otherwise models look lined up nicely.

3/17
We had two events to watch this week.  The first was a light clipper that comes through on the 18th.  Moisture is limited, but could put a dusting to an inch down in places anywhere from Baltimore to Hartford.  Lately its been more focused south towards Baltimore.

The second one is more interesting.  The evolution on the models is a textbook demonstration as to how hard being a meteorologist is.   I started looking at this one when the long range EPS (euro ensemble) put forth this forecast run on the 10th.  Upper low coming into the midwest with a storm coming up the coast .

It further developed it to the strongest storm of the season

 

It then muddled around in different forms...

Then it simply disappeared for a few days until this run on the euro operational brought it back yesterday

 What happens when a trough enters the US in the Great Lakes and pushes down is that a storm usually forms just in advance of it.  As depecited above.  Now timing and placement would still need to be ironed out, but it should happen.   But then there's this mornings Euro run which is just a frontal passage with no storm at all.

Meanwhile the old GFS went from frontal passage to storm.  Now note the storm is offshore, but the trough axis is pretty far back which doesn't seem right.  Below is the trend showing how its developed in the last day.

Then there's the new GFS-FV3 which buries us.  Its trended to the strongest storm of the season.

Leading to this result

Being 5 days out, what do you forecast.....  right now snow showers is a good bet with frontal passage.  But the GFS and CMC have a storm off the coast which is out of touch with the trough. NAVGEM is furthest east where it belongs.

Mar 4

Results
We had 12" in Newtown, with some getting 14" in CT.  All snow!

2-28  The time frame has split into thirds.  3/1 light snow, 3/2 storm, 3/4 storm.  This may NOT be the last of the snow either before it warms up for St Patricks day (hopefully).

Much of this was mixed in with the 3-2 post, which has now developed into its own nor'reaster. 

This is from my post at  WX Disco

Storm moves fast.  Enters south of San Fran on Saturday.   Its a pretty zonal flow ahead and confluent to the north.  Argues for it to move W-E

24 hrs the Upper Low (in Red) is halfway across, slightly south of entry.  Surface low forms in Blue over AL.  No ridge in front.
Normally you'd look for energy behind it to form a deeper trough, forcing it to move north.  But that energy is strung out and not diving down. There's not much forcing the storm north.

By the end of the run the surface low is off NJ.  The Upper low is barely recognizable over KY.  Its just a bit north of the latitude it entered.  Something has moved it a bit  north, I just cant see what.
Surface low in blue is over SNJ.  The troughs aren't lined up and while the NWS in Upton says that there is phasing, to me it seems that the energy in the northern stream stays separate.
The green lines are various trough axis.  The northern trough is positively tilted. The middle trough more neutral, but this is more of an opinion than fact.
You can argue there is some negative tilt in the middle trough, but my point is more that they aren't aligned very well.  This may change.  But I wonder if you play this out a few more frames does that energy in the upper midwest push the storm further east, or does it dive further down and bring the storm further north.  It looks to me with the trough orientation that it pushes it out.

Things that can go wrong:  Our main energy hits CA in 40 hrs.  How accurate is that without sampling? 
The energy on the SE side of the green line by the lakes is actually over Canada now.  The energy behind the green line over MN/ND and Canada isn't sampled yet. How much influence does that have if its not correctly modeled. 
The adage that the latitude a storm enters it exits is appropriate due to the zonal flow.  In this case its a little off at the 500mb level.  Ideally it would be exiting over the DelMarVa.  
Lastly does the Saturday system muck things up ahead of this.  If that develops further, what happens?  There's also two shortwaves at hr 45 - one near Idaho the other over the lakes that can throw things off a bit.