Hurricane Maria

[hawkeye_wx]

While current conditions are pretty good for Maria, sufficient for gradual strengthening, they are not perfect.  The western half of the core has been lacking convection this morning.  The core convection, rather than pinwheeling around the center, looks a bit like it is chasing the center.  I suppose this will improve as the system slows a bit.

[forecasterjack]

Maria is quite a big system which may slow intensification a little bit. Nevertheless, everything is improving on satellite. Strengthening storm for sure. Loop: https://weather.us/satellite/572-w-160-n/top-alert-superhd-15min.html#play 

[hawkeye_wx]

The NHC mentions the current, temporary, issue with the core in the 11am disco.

The cloud pattern has not changed much since the last advisory.
There appears to be a dry slot working into the western side of
Maria, and the low-level circulation seems to be peaking out from
under the western side of a persistent CDO feature.

[Windspeed]

The NHC mentions the current, temporary, issue with the core in the 11am disco.

 

The cloud pattern has not changed much since the last advisory.There appears to be a dry slot working into the western side ofMaria, and the low-level circulation seems to be peaking out fromunder the western side of a persistent CDO feature.

 

The longer it struggles with structure as a developing cyclone, perhaps the longer it will delay RI or avoid RI altogether prior to land interaction. Unfortunately there is still plenty of time for it to do so.

[jpeters3]

There was ~ 20 kt of deep-layer shear, which looks to be dropping off now.  This probably contributed to the restricted outflow.

Edit: I thin the cirrus clouds moving northward off the South American coast is evidence of this shear.

 

[Windspeed]

26 minutes ago, jpeters3 said:

There was ~ 20 kt of deep-layer shear, which looks to be dropping off now.  This probably contributed to the restricted outflow.

Edit: I thin the cirrus clouds moving northward off the South American coast is evidence of this shear.


 
 

Yes, the westward motion of the TUTT over the central Caribbean is faster than Maria's forward motion. In fact, one of the reasons for the high percentage chance of rapid intensification is due to the impressive upper environment and outflow pattern that evolves on modeling. There is a large anticyclonic pattern right over Maria through Thursday or at least as far out in modeled range as I would trust. The 200 mb anticyclonic flow around Maria is just bananas.

[hawkeye_wx]

The dry air has really gotten to Maria this morning.  The core convection has collapsed.

[purduewx80]

it had collapsed but is quickly redeveloping in N/E quads. http://weather.cod.edu/satrad/exper/?parms=meso2-02-24-1-100

[jpeters3]

5 minutes ago, hawkeye_wx said:

The dry air has really gotten to Maria this morning.  The core convection has collapsed.

Shear associated with the upper trough to the system's west. 

[Heisy]

CMC brings Maria into the SE Coast, GFS was farther SW, but heads NNE up the coast and out to sea. 

[salbers]

This really seems like a hurricane billiards game in the 00Z GFS. The upper level high in the Atlantic with Jose and Maria being the players. Will be interesting to see how the models continue to evolve. 

[AfewUniversesBelowNormal]

Maybe if it evolves quickly into a Cat 3/4, a further south track will happen. Nothing in the area at this time of the year has intensified so quickly, moving so far north. Big storms create momentum, and at this is a time of deep cyclones, for some reason, models aren't attuned (example1: Irma went south of Florida entirely, 75% of strong storms do the same thing- go with basic steering patterns vs 500mb influence). I think also there is a Moderate La Nina influence happening right now that is mostly being missed. 

[Amped]

Feeder band coming up from the south now established.  Should limit future dry air problems.

[Windspeed]

Maybe if it evolves quickly into a Cat 3/4, a further south track will happen. Nothing in the area at this time of the year has intensified so quickly, moving so far north. Big storms create momentum, and at this is a time of deep cyclones, for some reason, models aren't attuned (example1: Irma went south of Florida entirely, 75% of strong storms do the same thing- go with basic steering patterns vs 500mb influence). I think also there is a Moderate La Nina influence happening right now that is mostly being missed. 

Tropical cyclones still need luck or a lack thereof if you are in their way. Yes, the moderate La Nina has relaxed the overall sub-tropical jet across the basin. But you still have TUTTs and cutoffs that evolve and interact in the upper levels. Maria's forecast track just happens to be positioned perfectly for strong divergence versus shear. Position Maria 10 deg longitude either west or east right now and it's sheared out. Lee is struggling.

[Chinook]

Here is the 00z European EPS spaghetti plots for Tropical Storm Maria. I am very concerned that this will cause damage and loss of life on several Lesser Antilles islands, Puerto Rico, the Dominican Republic, and The Bahamas.

[AfewUniversesBelowNormal]

having fun...

https://www.wunderground.com/hurricane/atlantic/1999/Hurricane-Jose
Analog 1, happened a month later, not as deep. 

analog 2, westward track from north
https://www.wunderground.com/hurricane/atlantic/1998/Major-Hurricane-Georges

Hugo, moving west and earlier intensification 
https://www.wunderground.com/hurricane/atlantic/1989/Major-Hurricane-Hugo

earlier intensification
https://www.wunderground.com/hurricane/atlantic/1979/Major-Hurricane-David

https://www.wunderground.com/hurricane/atlantic/1964/Major-Hurricane-Cleo

https://www.wunderground.com/hurricane/atlantic/1963/Hurricane-Edith

Best analog:
https://www.wunderground.com/hurricane/atlantic/1950/Major-Hurricane-Dog

 

3 storms since 1935 strengthened rapidly where Maria is expected: Cleo, Edith, Dog

(All 7 are ENSO cold cycle times)

[David Reimer]

986 MB measured by dropsonde. NHC estimated it was at 994 MB. Peak FL winds in the NW quad just under 60 knots. 

[Windspeed]

12z ECMWF is very similiar to last night's 00z. Incredible block over Nova Scotia/North Atlantic forces stalled out Jose off Mid-Atlantic. Eventually weakens and breaks down 500mb vort and fills in weakeness. Begins to increase heights over Mid-Atlantic. However, it does so with Maria further east this time. This looks like a similar stall setup as Jose between Bermuda and the CONUS. And being so far out will likely continue changing/evolving with each run depending on small adjustments with Jose's interaction.

[Superstorm93]

ATCF is up to 65 knots for Maria. 

I could see how winds are a bit higher in the NE quad. 

[Hoosier]

12z Euro looks like Jose's remnants leave a weakness behind around West Virginia, and Maria is trying to interact with it, at least partially, at 216 hours.

[Windspeed]

12z Euro looks like Jose's remnants leave a weakness behind around West Virginia, and Maria is trying to interact with it, at least partially, at 216 hours.

 

Sitting over ocean east of Mid-Atlantic and south of New England in 240 hr La La Land. 500 mb ridge backed east. Surface ridge over Quebec. Probably results in New England landfall, but again, the op will probably change with every run for many days until it gets a better handle on how Jose breaks down. EPS is your friend and null and void beyond 144 in such a wild setup.

 

[hawkeye_wx]

Second recon pass found 984 mb, but still sub-cane wind.

[Hoth]

Looks like Josh is planning to chase. 

[AfewUniversesBelowNormal]

The 500mb pattern is so good to keep it south. Actually, more classic for Gulf coast hurricanes than east coast. I give Maria a 75% chance of hitting Florida or going into the Gulf. Jose remnants less likely to bring it north. (it may not be that strong though unless going really far south)

[Amped]

CDO has formed and improved nicely the past few hours.  Recon might find something near 980 and close to hurricane force on the next pass. Still no signs of an eye.

[Windspeed]

The 500mb pattern is so good to keep it south. Actually, more classic for Gulf coast hurricanes than east coast. I give Maria a 75% chance of hitting Florida or going into the Gulf. Jose remnants less likely to bring it north. 

 

 

A 75% chance 5 days before the Bahamas? lol... I wouldn't be comfortable with a 25% chance unless Jose gets kicked OTS like the ECMWF 00z run showed on Thursday night. I might give it a 50% chance of any CONUS impact at best this far out if Jose were streaming into the Maritimes. But you would still need a solid 500mb ridge extending into the SE interior to increase Florida's odds of landfall. Having a moderate 500mb vort east of the Mid-Atlantic opens the door for Maria to gain latitude near the Bahamas. It's more a question of timing right now and Jose's 500mb vort. That really is the key for any potential CONUS landfall. But, of course, this is all out in 144+ hour fantasy land. The talking points about chances and odds with respect to any CONUS impacts are subject to a high degree of uncertainty and will most likely change by mid week.

 

 

 

[hawkeye_wx]

The zoomed-in, GOES-16 one-minute image visible loop(awesome) shows deep convection continuing to bubble up on the north and west sides of the center.

http://rammb.cira.colostate.edu/ramsdis/online/loop.asp?data_folder=goes-16/mesoscale_02_band_02_sector_05&width=1000&height=1000&number_of_images_to_display=100&loop_speed_ms=80

[Amped]

Quote

ZCZC MIATCDAT5 ALL
TTAA00 KNHC DDHHMM

Hurricane Maria Discussion Number   6
NWS National Hurricane Center Miami FL       AL152017
500 PM AST Sun Sep 17 2017

A burst of deep convection developed over Maria's center since the
last advisory and has continued to expand in size.  The Air Force
Hurricane Hunter aircraft investigating the cyclone found maximum
flight-level winds of 63 kt and SFMR surface winds of 64 kt.  The
crew also noted the formation of an open eyewall.  Based on these
data and observations, Maria is upgraded to a 65-kt hurricane.

The initial motion remains west-northwestward, or 283/13 kt.  Maria
is expected to maintain this trajectory for quite some time, but it
will likely slow down during the next 36 hours as it approaches the
Lesser Antilles.  Overall, the track guidance is tightly clustered
for the entire 5-day forecast period, which increases confidence in
the NHC track forecast.  The updated official forecast is slightly
south of the previous one for the first 36 hours, mainly due to the
update of the initial position found by the aircraft, but it is
right along the previous track after 36 hours.  This solution is
between the GFS and ECMWF models and very close to the HCCA
solution.

The aircraft data indicate that Maria has a compact circulation,
which could make it a prime candidate for significant
intensification in an environment of low shear and warm SSTs.
Rapid intensification indices are not especially high, but
nonetheless, Maria is forecast to continue strengthening and
potentially reach major hurricane by 48 hours.  If that occurs,
some fluctuations in intensity could occur due to eyewall
replacements and land interaction, but Maria will likely remain as
a major hurricane on days 3 through 5.  Because of Maria's small
size the chance of significant strengthening is higher, and the NHC
intensity forecast is near the high end of the guidance, closest to
the HWRF and HCCA models.

FORECAST POSITIONS AND MAX WINDS

INIT  17/2100Z 13.8N  57.5W   65 KT  75 MPH
 12H  18/0600Z 14.3N  59.0W   75 KT  85 MPH
 24H  18/1800Z 15.1N  60.5W   85 KT 100 MPH
 36H  19/0600Z 15.8N  61.8W   95 KT 110 MPH
 48H  19/1800Z 16.5N  63.1W  105 KT 120 MPH
 72H  20/1800Z 17.8N  65.8W  110 KT 125 MPH
 96H  21/1800Z 19.0N  68.5W  110 KT 125 MPH
120H  22/1800Z 21.0N  71.0W  105 KT 120 MPH

$$
Forecaster Berg

NNNN

 

 

[Windspeed]

The zoomed-in, GOES-16 one-minute image visible loop(awesome) shows deep convection continuing to bubble up on the north and west sides of the center.

 

http://rammb.cira.colostate.edu/ramsdis/online/loop.asp?data_folder=goes-16/mesoscale_02_band_02_sector_05&width=1000&height=1000&number_of_images_to_display=100&loop_speed_ms=80

 

The slower core organization of Maria developing a closed eyewall may turn out to be a blessing for Dominica, Guadeloupe and Montserrat getting a hurricane versus major hurricane. Of course Montserrat has the bonus threat of mudflows off of Soufriere Hills volcano.

 

[Hurricane Agnes]

She's officially upgraded (as noted in an earlier post) -