ATL: FRANKLIN - Remnants - Discussion

[Aric Dunn]

What a strange last 12 hours with this system.. but it looks like it might explode once in the BOC. Took a little bit of land friction to help tighten of the core. should be back offshore in about 6 hours.

Also its far enough north the land is very flat so wont disrupt it all too much . well no large peaks gradual increase.

[Digital-TC-Chaser]

there are no signs of dry air in the core of this TC. Not all lack of convection is due to dry air

What do you suppose it is, then?

simply a TC that does not have a core. They take time to build

Think It looked to be @ about 60% into the process building the core.

[Hammy]

Forecast no longer calling for hurricane intensity, but instead increased shear and possibly weakening as it approaches the second landfall.

[Alyono]

Forecast no longer calling for hurricane intensity, but instead increased shear and possibly weakening as it approaches the second landfall.

I am fairly sure that isn't going to happen. Again, this is an over reliance on SHIPS/LGE by NHC, similar to what we saw last year with Matthew and Nicole. Nearly every dynamical model makes this a hurricane in the Gulf

[Hammy]

Forecast no longer calling for hurricane intensity, but instead increased shear and possibly weakening as it approaches the second landfall.

I am fairly sure that isn't going to happen. Again, this is an over reliance on SHIPS/LGE by NHC, similar to what we saw last year with Matthew and Nicole. Nearly every dynamical model makes this a hurricane in the Gulf

Doesn't SHIPS have possibly the worst track record with the shear forecasts?

[Alyono]

Forecast no longer calling for hurricane intensity, but instead increased shear and possibly weakening as it approaches the second landfall.

I am fairly sure that isn't going to happen. Again, this is an over reliance on SHIPS/LGE by NHC, similar to what we saw last year with Matthew and Nicole. Nearly every dynamical model makes this a hurricane in the Gulf

Doesn't SHIPS have possibly the worst track record with the shear forecasts?

it's the GFS shear forecasts. And we all know I wouldn't trust the GFS for much of anything. EC slowly intensifies Franklin up until landfall. A small area of 70-75 kt winds when the center makes landfall

[GCANE]

Franklin's convection is much better over land than over water.
I wonder if the elliptical structure of 500mb vort may contribute to this.
850 and 750mb vorts look circular and 200mb is clear.

[GCANE]

Nothing dry with the air around Franklin

[GCANE]

If the "open wave" idea (elliptical vort) at 500mb is a valid hypothesis, that is inhibiting strengthening of Franklin; then, the forecast at 24 hrs shows this closing off which would allow Franklin to spin up.

[GCANE]

COAMPS forecasts Cat3 at landfall

[GCANE]

Nearly off-scale latent heat flux is forecast just before landfall.
Very likely this could RI at or near landfall.

[GCANE]

Enthalpy flux (a measure of the energy of a system) is nearly off scale as well.

[Digital-TC-Chaser]

06 cycle run

[GCANE]

Here's a good illustration of the open-wave or elliptical-vort pattern at 500mb.

[tropicwatch]

Franklin appears to still have decent structure. Doesn't look like Yucatan will disrupt it much.

[cycloneye]

BULLETIN
Tropical Storm Franklin Advisory Number 8
NWS National Hurricane Center Miami FL AL072017
1000 AM CDT Tue Aug 08 2017

...FRANKLIN EXPECTED TO MOVE INTO THE BAY OF CAMPECHE LATER TODAY...


SUMMARY OF 1000 AM CDT...1500 UTC...INFORMATION
-----------------------------------------------
LOCATION...19.6N 89.6W
ABOUT 60 MI...100 KM ESE OF CAMPECHE MEXICO
MAXIMUM SUSTAINED WINDS...45 MPH...75 KM/H
PRESENT MOVEMENT...WNW OR 290 DEGREES AT 13 MPH...20 KM/H
MINIMUM CENTRAL PRESSURE...1001 MB...29.56 INCHES

Tropical Storm Franklin Discussion Number 8
NWS National Hurricane Center Miami FL AL072017
1000 AM CDT Tue Aug 08 2017

Franklin's center continues to move over the land mass of the
Yucatan Peninsula. Since this area is relatively flat, only slow
weakening is likely occurring. The morning sounding from Merida,
located over northwest Yucatan, showed winds near 40 kt just above
the surface. Assuming that these winds are coming down to the
surface somewhere within the circulation, the initial intensity is
estimated to be 40 kt. Some additional weakening should occur as
long as the center remains over land. A restrengthening trend is
forecast to begin when the center moves into the Bay of Campeche
later today or tonight. Even though Franklin will be moving
over very high SSTs while over the Bay of Campeche, the global
models show northerly shear affecting the cyclone as it nears the
southwest Gulf coast of Mexico. Although this shear could impede
intensification, Franklin could be near hurricane intensity when it
nears the coast late Wednesday. Therefore, it is prudent to
maintain the Hurricane Watch.

The motion continues to be west-northwestward, or 290/11 kt. A
mid-tropospheric ridge is forecast to remain in place to the north
of Franklin over the next couple of days. This should cause the
tropical cyclone to move west-northwestward to westward until its
second landfall. The official track forecast is similar to the
ECMWF solution and to the previous NHC forecasts.

FORECAST POSITIONS AND MAX WINDS

INIT 08/1500Z 19.6N 89.6W 40 KT 45 MPH
12H 09/0000Z 20.0N 91.1W 35 KT 40 MPH...OVER WATER
24H 09/1200Z 20.3N 93.3W 50 KT 60 MPH
36H 10/0000Z 20.4N 95.4W 60 KT 70 MPH
48H 10/1200Z 20.3N 97.6W 50 KT 60 MPH...INLAND
72H 11/1200Z...DISSIPATED

$$
Forecaster Pasch

[cycloneye]

TCPOD for Wednesday that includes the Global Hawk.

Code: Select all

000
NOUS42 KNHC 081422
REPRPD
WEATHER RECONNAISSANCE FLIGHTS
CARCAH, NATIONAL HURRICANE CENTER, MIAMI, FL.
1020 AM EDT TUE 08 AUGUST 2017
SUBJECT: TROPICAL CYCLONE PLAN OF THE DAY (TCPOD)
         VALID 09/1100Z TO 10/1100Z AUGUST 2017
         TCPOD NUMBER.....17-069

I.  ATLANTIC REQUIREMENTS
    1. TROPICAL STORM FRANKLIN
       FLIGHT ONE -- TEAL 72
       A. 09/2330Z, 10/0530Z
       B. AFXXX 0607A FRANKLIN
       C. 09/2030Z
       D. 20.4N 95.4W
       E. 09/2300Z TO 10/0530Z
       F. SFC TO 10,000 FT

    2. OUTLOOK FOR SUCCEEDING DAY....NEGATIVE.
    3. REMARKS: THE GLOBAL HAWK (NA872) WILL FLY A 23 HOUR MISSION
       OVER FRANKLIN THIS EVENING DEPARTING ARMSTRONG AT 09/0200Z.
       FLIGHT LEVEL: 55,000 TO 60,000 FT. ON-STATION TIME: 09/0600Z
       TO 09/2000Z. ANTICIPATING 86 DROPS.


[Alyono]

it's really taken a beating during the last few hours. No convection again in the core, all on the periphery. This does not bode well for rapid intensification in the BOC

[lrak]

Will the surface low close to the western edge of Houston have any effect on Franklin's track? It looks to be slowly drifting south. And could this low do the same thing like Emily?

The swell forecast is looking dangeroushttp://polar.ncep.noaa.gov/waves/viewer.shtml?-gwes-latest-hs-gmex-, may have to wait until the surf drops a bit...getting too old darnit.

[Portastorm]

Will the surface low close to the western edge of Houston have any effect on Franklin's track? It looks to be slowly drifting south. And could this low do the same thing like Emily?

The swell forecast is looking dangeroushttp://polar.ncep.noaa.gov/waves/viewer.shtml?-gwes-latest-hs-gmex-, may have to wait until the surf drops a bit...getting too old darnit.

Unlikely. Take a look at the latest water vapor loops ... the mid-level ridge is holding strong in the Gulf. Also that mesoscale-induced low in east central TX is supposed to retrograde west per NWS discussions.