Philippe | 50 mph 999 mb Peak | Being a weirdo storm

[Iceresistance]

1. Central Tropical Atlantic (AL90):
Shower and thunderstorm activity associated with an area of low 
pressure located about 600 miles west-southwest of the Cabo Verde 
Islands continues to show signs of organization. Further development 
is expected, and a tropical depression is likely to form during the 
next couple of days while the system moves generally westward at 10 
to 15 mph. The system is then expected to turn west-northwestward 
early next week as it moves over the central tropical Atlantic.
* Formation chance through 48 hours...high...70 percent.
* Formation chance through 7 days...high...90 percent.

 

Edited October 1, 2023 by StretchCT

[Iceresistance]

Now TD 17

[StretchCT]

TD17 highly likely to be named, maybe later today. SHOULD  recurve before it makes its way to the Islands or Bermuda as there is a lot going on to it's north and none of it involves a strong ridge/high.  But some ensemble members still want to take it further west. 

FORECAST POSITIONS AND MAX WINDS

INIT  23/1500Z 15.6N  38.8W   30 KT  35 MPH
 12H  24/0000Z 15.7N  41.0W   35 KT  40 MPH
 24H  24/1200Z 15.8N  43.7W   35 KT  40 MPH
 36H  25/0000Z 15.9N  46.2W   35 KT  40 MPH
 48H  25/1200Z 16.2N  48.5W   40 KT  45 MPH
 60H  26/0000Z 16.6N  50.2W   40 KT  45 MPH
 72H  26/1200Z 17.1N  51.6W   45 KT  50 MPH
 96H  27/1200Z 19.5N  54.0W   50 KT  60 MPH
120H  28/1200Z 23.0N  54.5W   55 KT  65 MPH

 

Edited September 23, 2023 by StretchCT

[StretchCT]

[Iceresistance]

Philippe is a challenging tropical cyclone to analyze this morning. 
On one hand, the overall satellite presentation has improved since 
yesterday, and a 0907Z SSMIS microwave pass shows a possible 
mid-level eye.  Yet the 1-min GOES16 imagery reveals a weak 
low-level swirl southwest of the main convective blob, and ASCAT-B 
near 12Z showed a disorganized inner core with less wind than one 
might expect (albeit very contaminated with rain).  Overall, 
intensity estimates have risen since the last advisory, so the 
initial wind speed is set to 45 kt, similar to the TAFB/SAB values, 
but this should be considered fairly uncertain.

More weird storms, perfect for 2023 though...

[StretchCT]

Models in the 5 day frame are undecided when the recurve happens

Euro is off compared to the GFS with the current strength

That has ramifications down the line as the GFS develops more and recurves, Euro keeps it weak and sends it limping into the Bahamas.

 

[StretchCT]

Phillipe is a mystery storm. NHC said it looked good this morning on the 11am disco.

Spoiler

1100 AM AST Wed Sep 27 2023
 
Visible, infrared and microwave imagery depicts that Philippe is a 
slightly better organized system this morning. A burst of deep 
convection continues near and east of the center. In addition,  
earlier AMSR and SSMI/S microwave passes show that a convective 
band has been developing on the eastern side of the circulation. 
However, visible satellite images within the past hour depict that 
the low-level center is becoming partially exposed on the western 
edge of the convection. Subjective and objective satellite 
intensity estimates have increased this cycle, with a TAFB Dvorak 
data-T number of 3.0, 45 kt. Given the developing banding feature 
and satellite intensity estimates, the initial intensity is raised 
to 45 kt for this advisory.  This is also in agreement with a 
recent ASCAT-B pass.

Then it didn't

Spoiler

500 PM AST Wed Sep 27 2023

Philippe's convection continues to oscillate this afternoon. Shortly 
after the previous advisory, the convection waned and has become 
less organized. An ASCAT-C pass showed that the center of the system 
has become more ill-defined, with the low-level center difficult to 
pinpoint this afternoon. Convection continues to redevelop back to 
the east, with the expected mean center on the west side of the 
convection. This was further supported by an AMSR microwave 
overpass depicting and overall lack of organization. Subjective 
Dvorak data-T numbers have come down with the current intensity 
estimates remaining at 3.0. Given the earlier ASCAT-B pass and the 
CI intensity estimates, the initial intensity will is held at 45 
kt, but this could be generous.

I can't  see a low level center of circulation but there seems to be a mid level CoC 

Here's how it looked earlier

[StretchCT]

Doesn't seem like Philippe wants much to do with Rina afterall.

GFS develops it down to the 950s, harmlessly at sea.

FORECAST POSITIONS AND MAX WINDS

INIT  01/0300Z 16.1N  57.0W   45 KT  50 MPH
 12H  01/1200Z 16.5N  57.7W   45 KT  50 MPH
 24H  02/0000Z 17.1N  58.6W   50 KT  60 MPH
 36H  02/1200Z 17.8N  59.4W   55 KT  65 MPH
 48H  03/0000Z 18.6N  60.3W   60 KT  70 MPH
 60H  03/1200Z 19.6N  61.0W   60 KT  70 MPH
 72H  04/0000Z 21.1N  61.2W   65 KT  75 MPH
 96H  05/0000Z 24.8N  61.1W   75 KT  85 MPH
120H  06/0000Z 28.5N  59.2W   80 KT  90 MPH

Edited October 1, 2023 by StretchCT

[StretchCT]

Crazy how Philippe hasn't changed much - this is the 5am advisory from Friday

500 AM AST Fri Sep 29 2023
 
...PHILIPPE LIKELY TO LOITER JUST EAST OF THE NORTHERN LEEWARD
ISLANDS FOR ANOTHER 3 TO 4 DAYS...
 
 
SUMMARY OF 500 AM AST...0900 UTC...INFORMATION
----------------------------------------------
LOCATION...18.5N 55.2W
ABOUT 520 MI...835 KM E OF THE NORTHERN LEEWARD ISLANDS
MAXIMUM SUSTAINED WINDS...45 MPH...75 KM/H
PRESENT MOVEMENT...SW OR 235 DEGREES AT 2 MPH...4 KM/H
MINIMUM CENTRAL PRESSURE...1003 MB...29.62 INCHES
 

It's gone down to 998mb and later that friday up to 50mph, but otherwise still sheared, still 50mph.  It will hang around a little longer before moving north and becoming a hurricane.

Spoiler

Tropical Storm Philippe Discussion Number  36
NWS National Hurricane Center Miami FL       AL172023
500 AM AST Mon Oct 02 2023
 
The overall structure of Philippe has changed very little during the 
past day or so.  Deep convection remains confined to the 
southeastern portion of the circulation due to moderate to strong 
northwesterly vertical wind shear.  There is no significant banding 
features, but the cloud tops within the main convective mass are 
quite cold.  Radar imagery from Barbados shows very heavy rainfall 
is occurring just east of the Lesser Antilles.  The initial 
intensity is held at 45 kt in deference to the earlier aircraft 
data, and the latest subjective Dvorak intensity estimates which are 
unchanged from before.  The next Air Force Reserve reconnaissance 
aircraft mission is scheduled to investigate Philippe later this 
morning.
 
Center fixes during the past 6-12 hours indicate that Philippe has 
turned northwestward (315 degrees) and is moving a little faster, 
around 6 kt.  Philippe is forecast to move around the southwestern 
portion of a mid-level ridge over the subtropical Atlantic during 
the next couple of days.  After that time, Philippe should turn 
northward between the aforementioned ridge and a mid- to upper-level 
trough over the southwestern Atlantic.  Around day 5, there is 
increasing uncertainty as to whether Philippe will turn 
east-northeastward or continue on a more northerly trajectory ahead 
of a large trough moving into the eastern United States. Little 
change was made to the previous forecast through 72 hours, but after 
that time the track was adjusted northwestward closer to the GFS 
ensemble mean.  The new track is not as far west as the latest ECMWF 
or the multi-model consensus aids.
 
Strong westerly vertical wind shear is expected to prevent 
significant strengthening for about another 12-24 hours.  After that 
time, Philippe is expected to encounter a more favorable upper-level 
wind pattern as it moves northward over the Atlantic. This should 
allow for steady strengthening, and much of the guidance predicts 
that Philippe will become a hurricane in 3 to 4 days.  The NHC 
intensity forecast follows suit, and is a blend of the HFIP 
corrected consensus model and the multi-model (ICVN) intensity aid.
 
 
KEY MESSAGES:
 
1. Tropical storm conditions are possible across portions of the
northern Leeward Islands through tonight while Philippe passes near
or just northeast of the area, and a Tropical Storm Watch is in
effect for Antigua and Barbuda.  Interests elsewhere in the northern
Leeward Islands should continue to monitor this system.
 
2. Heavy rainfall from Philippe could produce isolated to scattered
flash flooding, particularly across Barbuda and Antigua, through
Tuesday.
 
 
FORECAST POSITIONS AND MAX WINDS
 
INIT  02/0900Z 17.1N  60.0W   45 KT  50 MPH
 12H  02/1800Z 17.7N  60.7W   45 KT  50 MPH
 24H  03/0600Z 18.6N  61.4W   45 KT  50 MPH
 36H  03/1800Z 19.8N  61.8W   50 KT  60 MPH
 48H  04/0600Z 21.2N  62.2W   50 KT  60 MPH
 60H  04/1800Z 22.7N  62.3W   55 KT  65 MPH
 72H  05/0600Z 24.6N  62.2W   60 KT  70 MPH
 96H  06/0600Z 28.3N  60.8W   70 KT  80 MPH
120H  07/0600Z 31.7N  58.9W   75 KT  85 MPH
 
$$
Forecaster Brown

 

Fortunately there's not much rain over the islands or this stationary system would cause major problems with landslides, flooding. 

[StretchCT]

Still pretty far out to make any call on this, but Nova Scotia isn't out of the woods with Philippe. Maine should watch.

Ukie merges it with a front after this.  CMC has the front faster and kicks it out.

JMA similar to the ukie

[StretchCT]

I like the description 🙂

The Icon demonstrates why we should watch this.  Most of the 12z models have a separate storm forming to it's west, also seen here with Philippe heading out to sea or landing in Canada. HAFS A dissipates it completely. 

UKIE

Euro

 

[StretchCT]

It's moisture shield has pushed through the Leewards

Can't really tell where the CoC is anymore.  Wondering if they declassify soon.  This storm is baffling.

Recon has a midlevel center I guess

 

 

[StretchCT]

There's a surface low that will form in the vicinity of Philippe and mess with it.  Some models absorb Philippe into that low, or that low into Philippe, a few have them separate. HAFS A demonstrates this interaction.  

 

 

HWRF keeps them completely separate, sends P ots but sends the new, TS strength storm into Maine. 

So Maine and Atlantic Canada should still watch this, though it shouldn't be any stronger than a Noreaster. 

[StretchCT]

NAVGEM takes Philippe into Maine

 

GFS plays games with the other low I mentioned earlier but flings Philippe into Maine/NS

CMC eastern NS

UKIE looks like a hit in New England but then it swings east and hits NS

 

 

[TLChip]

The pattern is wet in the NNE lately with tropical systems, will it continue? Hard to bet against it a few days out.

[StretchCT]

The ECMWF AI Experimental models https://charts.ecmwf.int/

These are 850 mb charts - Pangu

FourCast

GraphCast

[StretchCT]

NHC has put Maine into the cone of uncertainty. The Cape too.

[Mainiac]

The NHC found my house and decided put put an extratropical low with tropical storm forced winds on top of it. I guess this means peak foliage is probably going to be short lived.  

[StretchCT]

Funny clip on how unpredictable Philippe is.

[MaineJay]

The last time a storm named Philippe was involved in a storm up here, it caused the most power outages ever in Maine, even surpassing the ice storm of 1998.

  It is known at the Sou'Easter and hit October 29, 2017. I lost power for 5 days.  I don't see this being a repeat, gladly.

  Haven't seen measurable rain since Sept 19 when I got 2.78".  Looks like another deluge, followed by a fairly dry spell up this way.

[MaineJay]

Small spatial differences in the location on the incoming front, Philippe, and the degree of interaction are gonna wreak havoc on localized rainfall amounts.  

  There appears to be a "wedge" of lower QPF in many models between the two players, NAM most pronounced, flanked by hefty totals.  

 

[Mainiac]

I thought we were doing well drying out the past few weeks, but NWS Caribou posted this graphic showing that we're in the 98th percentile in root zone saturation. 

 

That left hook is getting more distinct. Interesting to see if it keeps trending west after landfall. 

[StretchCT]

Yay. more rain

Edited October 5, 2023 by StretchCT

[Mainiac]

WPC showing a large swath of 2"-4". I love how Mount Katahdin is such an outlier that it pops up in precipitation maps. 

[NHSparky]

13 hours ago, MaineJay said:

The last time a storm named Philippe was involved in a storm up here, it caused the most power outages ever in Maine, even surpassing the ice storm of 1998.

  It is known at the Sou'Easter and hit October 29, 2017. I lost power for 5 days.  I don't see this being a repeat, gladly.

  Haven't seen measurable rain since Sept 19 when I got 2.78".  Looks like another deluge, followed by a fairly dry spell up this way.

I remember that the wind was crazy that night lost power and the whole ten yards.