ATL: EARL - Post-Tropical - Discussion

[Hammy]

Earl is butting up against strong wind shear associated with a TUTT. That wind shear isn't going anywhere the next few days, and Earl cannot penetrate it and survive. GFS is likely WAY too aggressive with strengthening, given the high shear in its path. EC may be too aggressive, too.

http://wxman57.com/images/EarlShear.JPG

If that the case, then every single model is wrong — the GFS, Euro, CMC, ICON, HWRF, HMON, and HAFS all have pretty much the same track and intensity solutions through 5 days. I just don’t see everything busting and over-estimating Earl. If it was just a few models showing a hurricane while others showed Earl dissipating, like how the models were a few days ago before it was named, then a bust would be more believable. But every model with such an excellent consensus getting this wrong? That would be an anomaly.

Euro and UKMET solutions from 48 hours ago might be valid.

It's already a decent bit stronger than those runs had at this point.

[Nimbus]

Sheared LLC is NNW of PR.

Stair step motion overnight bucking the shear.
See the GFS shear map WXman57 posted to see why the positions of the trough and the two upper level highs create a challenge to forecast.
Stronger hurricane could have made the highs bridge shunting the trough north, and if Earl continues creeping west as a TS the shear might kill him before he gets under the eastern side of the high further the west.

[HuracanMaster]

There is an absolutely insane amount of lightning over Puerto Rico right now looking at Weathernerds Satellite data.

Two dead in salinas PR reported while jetskiing, struck by lightning.

[Iceresistance]

There is an absolutely insane amount of lightning over Puerto Rico right now looking at Weathernerds Satellite data.

Two dead in salinas PR reported while jetskiing, struck by lightning.

Yep, I was afraid of that.

[cycloneye]

Here, the autorities since yesterday told the people not to go out to beaches and rivers but some people didn't follow the warnings.

 https://twitter.com/CycloforumsPR/status/1566560633667174400

[aspen]

If that the case, then every single model is wrong — the GFS, Euro, CMC, ICON, HWRF, HMON, and HAFS all have pretty much the same track and intensity solutions through 5 days. I just don’t see everything busting and over-estimating Earl. If it was just a few models showing a hurricane while others showed Earl dissipating, like how the models were a few days ago before it was named, then a bust would be more believable. But every model with such an excellent consensus getting this wrong? That would be an anomaly.

Looking at the Euro shear map my assumption is that the shear axis gets into a position to vent Earl. Nothing else makes sense IMO.

Yeah, this is probably the reason. Wind shear alone, unlike dry air, isn't really a death sentence for storms; directions of shear really matter.

That’s probably why none of the models kill Earl. Once it starts recurving during the next 12-24 hours, it starts moving in the same or similar direction as the shear, instead of running right into it. Then it looks like the trough helps to ventilate Earl as relative shear drops starting Wednesday afternoon or evening, and it goes bonkers from there.

[WiscoWx02]

There certainly is still some shear impacting Earl, but I’ve noticed that the upper level cirrus outflow is starting to spread out more in all directions…with the models showing intensification from here on out I’m wondering if shesr is starting to finally relax.

Edit: it also appears the mid level center is still displaced to the north of the low level center, so it still has a little ways to go.

[aspen]

There certainly is still some shear impacting Earl, but I’ve noticed that the upper level cirrus outflow is starting to spread out more in all directions…with the models showing intensification from here on out I’m wondering if shesr is starting to finally relax.

Edit: it also appears the mid level center is still displaced to the north of the low level center, so it still has a little ways to go.

The GFS and hurricane models show Earl being a lopsided system impacted by shear up until Wednesday, but by then less net shear and a favorable trough interaction allows it to build up an inner core. We’ll probably continue to see bursts of convection reign in the LLC closer to the MLC before being displaced again, like what happened today.

[Sciencerocks]

[ElectricStorm]

Would love for this to become an OTS major, hopefully this misses Bermuda though

[Jelmergraaff]

New NHC intensity forecast has it strengthening rather quickly, starting around Thursday. Last forecast time (+120 h) shows an intensity of 120 mph. Earl probably has quite a good chance of becoming the first major hurricane. Model average is also around 100 kt for T+120h.

FORECAST POSITIONS AND MAX WINDS

INIT 05/0300Z 20.2N 65.4W 45 KT 50 MPH
12H 05/1200Z 21.3N 65.6W 50 KT 60 MPH
24H 06/0000Z 22.5N 65.7W 55 KT 65 MPH
36H 06/1200Z 23.6N 65.8W 60 KT 70 MPH
48H 07/0000Z 24.5N 65.9W 65 KT 75 MPH
60H 07/1200Z 25.4N 65.8W 70 KT 80 MPH
72H 08/0000Z 26.4N 65.5W 75 KT 85 MPH
96H 09/0000Z 28.7N 64.4W 90 KT 105 MPH
120H 10/0000Z 32.0N 61.5W 105 KT 120 MPH

[Hammy]

Based on ASCAT and microwave imagery, it looks like the main center--while still elongated to the southwest--is migrating closer to the convective burst rather than being decoupled. Note the small curl around 65W and just north of 20.

[aspen]

Looks like Earl is up to 50 kt according to recon. Pressure might be down a few mbar too.

[kevin]

Looks like Earl is up to 50 kt according to recon. Pressure might be down a few mbar too.

Quite impressive, the first pass had 994.7 mb and 53 kt SFMR + 49 kt estimated surface winds. Looks like so far Earl is following NHCs forecasted continuous intensification despite the high shear.

[tolakram]

Floater: https://weather.cod.edu/satrad/?parms=meso-meso1-02-96-1-100-1&checked=map&colorbar=undefined

[BobHarlem]

Interesting bits from the Bermuda Weather service:

http://weather.bm/ForecastDiscussion.asp

SHORT TERM FORECAST (Tuesday-Wednesday)
The general consensus in the short term is for narrow upper ridging
to develop across the area in advance of vertically stacked Earl
approaching from the S. Essentially, weak high pressure at the sfc
(1016-1018mb) dominates through the period, although there are now
signs in all the model guidance of pressure beginning to fall on
Wednesday night. With the high pressure regime comes mostly light
winds, mainly out of the S. At the end of the period, they are progged
to back into the E and increase towards moderate. Aside from some
isolated diurnal or homegrown daytime showers, conditions promise
to be largely fine and dry with plenty of sunshine. There is then
a transition to cloudier skies and scattered showers on Wednesday
night in advance of Earl. Seas are expected to build towards rough
on Wednesday as the area begins to feel the effects of long period
swell from Earl. With conditions expected to deteriorate beyond this
time period, the main warning that will likely need to be considered
is a TS Watch in concert with Earl.

LONG TERM FORECAST (Thursday-Friday)
The pattern in the upper levels is for the ridging to break down
as vertically stacked Earl moves into the area, with an expected
passage to the E of the Island on Friday. At the sfc, pressure falls
as Earl (now likely to be an intensifying hurricane) approaches.
There is some model disagreement that will likely prove quite significant
down the road… the UK and EC models stall Earl to the near E/NE at
the end of the period, having failed to be caught up by upper troughing
and the upper W’ly flow. However, the CMC and GFS are much more bullish
in Earl being caught by the upper trough and accelerated away towards
the NE. NHC are following some form of middle ground right now, and
the local forecast tries to represent this as much as possible at
the time of writing. However, further adjustments will likely be
necessary which is not uncommon for a tropical system. At any rate,
conditions are forecast to deteriorate markedly for the end of the
week with increasing shower activity, possibly thundery and strengthening
winds. The current forecast now calls for sustained TS winds into
Friday as Earl makes a close passage to the E of BDA. Swells are
likely to build rough to very rough, possibly high. A TS Warning
seems quite likely and even a possible hurricane watch, should the
current forecast trend continue.

[cycloneye]

[cycloneye]

AL, 06, 2022090512, , BEST, 0, 215N, 652W, 55, 998, TS

https://ftp.nhc.noaa.gov/atcf/btk/bep122022.dat

[Sciencerocks]

[aspen]

A NOAA-P3 mission
that was in the storm this morning indicated the low-level wind
field in the northern semicircle of the storm had also intensified,
with several dropsondes indicating boundary layer mean winds in the
55-65 kt range and one reported a surface wind gust of 57 kt. These
values match the twin Doppler radar (TDR) onboard of the aircraft,
with peak 0.5 km winds above 64 kt. The peak SFMR winds from the
mission were 58 kt, with 700-mb flight-level winds at 63 kt. The
satellite presentation this morning though remains somewhat ragged,
with the low-level circulation partially exposed, though TDR
analysis suggest the vertical tilt between the low- and mid-level
centers has decreased compared to yesterday. Based partially on the
these aircraft observations, the intensity has been set at 55 kt for
this advisory, which also agrees with the latest TAFB intensity
estimate.

Some measurements already support an intensity of around 60-65kt. If Earl gets a bit better organized today, maybe it could become a weak hurricane a little earlier than forecast.