EPAC: NORBERT - Post-Tropical

[hurricanes1234]

The season is on steroids.

[somethingfunny]

This looks better than Tropical Storm Dolly does... it doesn't appear to have a closed center yet, but its' overall structure looks like this will be a healthy cyclone as it spins itself up.

[cycloneye]

100%-100%

TROPICAL WEATHER OUTLOOK
NWS NATIONAL HURRICANE CENTER MIAMI FL
500 AM PDT TUE SEP 2 2014

For the eastern North Pacific...east of 140 degrees west longitude:

Showers and thunderstorms have recently increased near a low
pressure area producing gale-force winds, located about 200 miles
southwest of Manzanillo, Mexico. If current trends continue,
advisories will be initiated on a tropical storm later this morning.
This system is expected to move slowly northward and then
northwestward near the southwestern coast of Mexico and the southern
Baja California peninsula during the next few days, and interests in
these areas should monitor the progress of the disturbance. Locally
heavy rains could cause life-threatening flash floods and mud slides
over portions of southwestern Mexico during the next few days.
* Formation chance through 48 hours...high...near 100 percent.
* Formation chance through 5 days...high...near 100 percent.

&&

For additional information on the low please see High Seas Forecasts
issued by the National Weather Service...under AWIPS header
NFDHSFEPI and WMO header FZPN01 KWBC.

$$
Forecaster Blake

[Yellow Evan]

EP, 93, 2014090212, , BEST, 0, 169N, 1068W, 35, 1004, LO, 34, NEQ, 30, 50, 0, 0, 1009, 120, 25, 0, 0, E, 0, , 0, 0, INVEST, M,

[xtyphooncyclonex]

So... Norbert?

[Yellow Evan]

6z GFS pretty much the same as the 0z GFS. HWRF now with the Euro on track. NOGAPS same track, but fluctuating in intensity.

[cycloneye]

Yes!

PACIFIC REQUIREMENTS
1. NEGATIVE RECONNAISSANCE REQUIREMENTS.
2. SUCCEEDING DAY OUTLOOK: POSSIBLE FIX NEAR 21N 110W
AT 4/1730Z.

[cycloneye]

BULLETIN
TROPICAL STORM NORBERT ADVISORY NUMBER 1
NWS NATIONAL HURRICANE CENTER MIAMI FL EP142014
800 AM PDT TUE SEP 02 2014

...NORBERT FORMS OFFSHORE OF SOUTHWESTERN MEXICO...


SUMMARY OF 800 AM PDT...1500 UTC...INFORMATION
----------------------------------------------
LOCATION...17.5N 106.5W
ABOUT 180 MI...285 KM SW OF MANZANILLO MEXICO
ABOUT 435 MI...695 KM SSE OF THE SOUTHERN TIP OF BAJA CALIFORNIA
MAXIMUM SUSTAINED WINDS...40 MPH...65 KM/H
PRESENT MOVEMENT...NNE OR 20 DEGREES AT 14 MPH...22 KM/H
MINIMUM CENTRAL PRESSURE...1004 MB...29.65 INCHES


WATCHES AND WARNINGS
--------------------
THERE ARE NO COASTAL WATCHES OR WARNINGS IN EFFECT.


DISCUSSION AND 48-HOUR OUTLOOK
------------------------------
AT 800 AM PDT...1500 UTC...THE CENTER OF TROPICAL STORM NORBERT WAS
LOCATED NEAR LATITUDE 17.5 NORTH...LONGITUDE 106.5 WEST. NORBERT IS
MOVING TOWARD THE NORTH-NORTHEAST NEAR 14 MPH...22 KM/H. THE
CYCLONE SHOULD TURN NORTHWARD BY TONIGHT AND THEN WEST-
NORTHWESTWARD BY TOMORROW. ON THE FORECAST TRACK...NORBERT IS
EXPECTED TO REMAIN OFFSHORE OF SOUTHWESTERN MEXICO.

MAXIMUM SUSTAINED WINDS ARE NEAR 40 MPH...65 KM/H...WITH HIGHER
GUSTS. SOME STRENGTHENING IS FORECAST DURING THE NEXT 48 HOURS.

TROPICAL STORM FORCE WINDS EXTEND OUTWARD UP TO 60 MILES...95 KM
FROM THE CENTER.

THE ESTIMATED MINIMUM CENTRAL PRESSURE IS 1004 MB...29.65 INCHES.


HAZARDS AFFECTING LAND
----------------------
NONE


NEXT ADVISORY
-------------
NEXT COMPLETE ADVISORY...200 PM PDT.

$$
FORECASTER BLAKE


TROPICAL STORM NORBERT DISCUSSION NUMBER 1
NWS NATIONAL HURRICANE CENTER MIAMI FL EP142014
800 AM PDT TUE SEP 02 2014

The area of low pressure located a couple of hundred miles southwest
of Manzanillo now has enough organized convection to be considered a
tropical cyclone. Although moderate northeasterly shear is present,
banding features are in the southern semicircle of the cyclone along
with bursts of convection near the center. The initial wind speed
is set to 35 kt in accordance with earlier ASCAT data.

Norbert has been moving toward the north-northeast or 020/12.
Almost all of the guidance show Norbert turning sharply northward
and west-northwestward within 24 hours due to the cyclone leaving
the ITCZ and becoming steered by a mid-level high over Mexico. The
NHC prediction during this time is on the right side of the guidance
envelope, mostly because of the initial motion. After that time,
there is some uncertainty in the strength of the ridge over
northwestern Mexico, which causes some spread in the model tracks of
Norbert while it approaches the southern Baja California peninsula.
While the NHC forecast is close to the model consensus after 24
hours, it would not be surprising to see later forecasts be
adjusted a bit to the north at longer range, given model trends.

The environment near Norbert seems mostly favorable for
strengthening during the next few days with the cyclone forecast
over warm waters with moderate shear. Given this environment, it
is a little surprising that none of the more reliable models makes
Norbert a hurricane. Since there is some possibility of land
interaction and higher shear, the NHC prediction will be a little
above the model consensus, but below the highest guidance.


FORECAST POSITIONS AND MAX WINDS

INIT 02/1500Z 17.5N 106.5W 35 KT 40 MPH
12H 03/0000Z 18.6N 107.0W 40 KT 45 MPH
24H 03/1200Z 19.3N 108.4W 45 KT 50 MPH
36H 04/0000Z 19.6N 109.6W 50 KT 60 MPH
48H 04/1200Z 20.1N 110.5W 50 KT 60 MPH
72H 05/1200Z 21.8N 112.8W 50 KT 60 MPH
96H 06/1200Z 23.0N 115.5W 45 KT 50 MPH
120H 07/1200Z 23.5N 117.5W 40 KT 45 MPH

$$
Forecaster Blake

[Yellow Evan]

Interesting they say no land threat, yet the NHC disco mentions land interaction.

[cycloneye]

@RyanMaue · 1m
Only 50-knots maximum intensity for newly named TS Norbert in Eastern Pacific. I'll take the over @EricBlake12

‏@BigJoeBastardi · now
@RyanMaue @EricBlake12 me too, should go to cat 2 or 3. SST as warm as I have seen them there!



The posts in this forum are not official forecasts and should not be used as such. They are solely the opinions of the poster and may or may not be backed by sound meteorological data. For official information, please refer to NHC or CPHC products.

[Yellow Evan]

Ryan Maue ‏@RyanMaue 18m

HWRF 06z took Norbert down to 983 mb in 72hrs --sufficient for Cat 1 hurricane ... I'd guess 85-knots max intensity. pic.twitter.com/gLOrNs1zYf

Worth noting he also nailed the peak intensity of Marie:

Ryan Maue @RyanMaue · Aug 21

NHC takes 13E (Marie) to 95 knots in 5 days. GFS 00z goes to 937 mb in 4 days. I'm happy with my 140-knots forecast

[Yellow Evan]

EP, 14, 2014090218, , BEST, 0, 181N, 1064W, 35, 1004, TS, 34, NEQ, 30, 50, 0, 0, 1009, 120, 25, 0, 0, E, 0, , 0, 0, NORBERT, M,

[Kingarabian]

And so the NHC conservative approach continues with these EPAC storms. In my opinion, I think it'll reach Cat.1.

The posts in this forum are NOT official forecast and should not be used as such. They are just the opinion of the poster and may or may not be backed by sound meteorological data. They are NOT endorsed by any professional institution or storm2k.org. For official information, please refer to the NHC and NWS products.

[Yellow Evan]

I'm surprise the NHC has refused to adjust for their mistakes. They undercasted every system, including Amanda, Cristina, Julio, Marie, Lowell, and Iselle. I guess you could blame the guidance as well.

[cycloneye]

BULLETIN
TROPICAL STORM NORBERT ADVISORY NUMBER 2
NWS NATIONAL HURRICANE CENTER MIAMI FL EP142014
200 PM PDT TUE SEP 02 2014

...TROPICAL STORM WATCH ISSUED FOR BAJA CALIFORNIA SUR...


SUMMARY OF 200 PM PDT...2100 UTC...INFORMATION
----------------------------------------------
LOCATION...18.5N 106.5W
ABOUT 150 MI...240 KM WSW OF MANZANILLO MEXICO
ABOUT 375 MI...605 KM SE OF THE SOUTHERN TIP OF BAJA CALIFORNIA
MAXIMUM SUSTAINED WINDS...40 MPH...65 KM/H
PRESENT MOVEMENT...N OR 360 DEGREES AT 9 MPH...15 KM/H
MINIMUM CENTRAL PRESSURE...1004 MB...29.65 INCHES


WATCHES AND WARNINGS
--------------------
CHANGES WITH THIS ADVISORY...

THE GOVERNMENT OF MEXICO HAS ISSUED A TROPICAL STORM WATCH FOR BAJA
CALIFORNIA SUR FROM LA PAZ SOUTHWARD AROUND THE SOUTHERN TIP OF THE
BAJA CALIFORNIA PENINSULA NORTHWARD TO SANTA FE.

SUMMARY OF WATCHES AND WARNINGS IN EFFECT...

A TROPICAL STORM WATCH IS IN EFFECT FOR...
* LA PAZ TO SANTA FE MEXICO


TROPICAL STORM NORBERT DISCUSSION NUMBER 2
NWS NATIONAL HURRICANE CENTER MIAMI FL EP142014
200 PM PDT TUE SEP 02 2014

Satellite images suggest that Norbert has become a little better
organized during the day since the center is no longer partially
exposed and banding features have become somewhat better defined.
Intensity estimates, however, are about the same as 6 hours ago, so
the wind speed is kept at 35 kt. Except for moderate northeasterly
shear, environmental conditions appear favorable for strengthening
for the next couple of days. Intensity guidance is a bit higher
than 6 hours ago, with the HWRF now calling for Norbert to become a
hurricane. The new NHC forecast will follow the trend of the
guidance and shows a higher peak intensity than the last one,
between the intensity consensus and the Florida State Superensemble.

Norbert has turned northward and has slowed, with an initial motion
of about 360/8. The leftward turn should continue overnight, with a
west-northwestward track expected in about 24 hours as Norbert comes
under the influence of a mid-level high over Mexico. This high
weakens somewhat in a couple of days, which could then force Norbert
on a more northwestward track. While the bulk of the guidance still
shows the center of Norbert passing south of the Baja California
peninsula, there has been a northward trend noted in much of the
guidance. The NHC forecast is adjusted to the north and now lies
north of the model consensus, but is still south of the latest ECMWF
forecast.

The new NHC track forecast suggests an increasing chance of
tropical-storm-force winds in southern Baja California Sur, and a
tropical storm watch has been issued for the extreme southern part
of the state.

FORECAST POSITIONS AND MAX WINDS

INIT 02/2100Z 18.5N 106.5W 35 KT 40 MPH
12H 03/0600Z 19.4N 107.2W 40 KT 45 MPH
24H 03/1800Z 20.0N 108.5W 45 KT 50 MPH
36H 04/0600Z 20.5N 109.6W 50 KT 60 MPH
48H 04/1800Z 21.1N 110.5W 55 KT 65 MPH
72H 05/1800Z 22.6N 112.7W 50 KT 60 MPH
96H 06/1800Z 23.6N 114.8W 45 KT 50 MPH
120H 07/1800Z 24.0N 116.8W 35 KT 40 MPH

$$
Forecaster Blake

[Yellow Evan]

Good call SMN on the TS watch. Core should remain well offshore though.

[cycloneye]

BULLETIN
TROPICAL STORM NORBERT INTERMEDIATE ADVISORY NUMBER 2A
NWS NATIONAL HURRICANE CENTER MIAMI FL EP142014
500 PM PDT TUE SEP 02 2014

...NORBERT GETTING BETTER ORGANIZED AS IT MOVES NORTHWARD...


SUMMARY OF 500 PM PDT...0000 UTC...INFORMATION
----------------------------------------------
LOCATION...18.9N 106.5W
ABOUT 145 MI...230 KM W OF MANZANILLO MEXICO
ABOUT 355 MI...570 KM SE OF THE SOUTHERN TIP OF BAJA CALIFORNIA
MAXIMUM SUSTAINED WINDS...45 MPH...75 KM/H
PRESENT MOVEMENT...N OR 360 DEGREES AT 9 MPH...15 KM/H
MINIMUM CENTRAL PRESSURE...1003 MB...29.62 INCHES


WATCHES AND WARNINGS
--------------------
CHANGES WITH THIS ADVISORY...

NONE.

SUMMARY OF WATCHES AND WARNINGS IN EFFECT...

A TROPICAL STORM WATCH IS IN EFFECT FOR...
* LA PAZ TO SANTA FE MEXICO

A TROPICAL STORM WATCH MEANS THAT TROPICAL STORM CONDITIONS ARE
POSSIBLE WITHIN THE WATCH AREA...GENERALLY WITHIN 48 HOURS.

FOR STORM INFORMATION SPECIFIC TO YOUR AREA...PLEASE MONITOR
PRODUCTS ISSUED BY YOUR NATIONAL METEOROLOGICAL SERVICE.


DISCUSSION AND 48-HOUR OUTLOOK
------------------------------
AT 500 PM PDT...0000 UTC...THE CENTER OF TROPICAL STORM NORBERT WAS
LOCATED NEAR LATITUDE 18.9 NORTH...LONGITUDE 106.5 WEST. NORBERT IS
MOVING TOWARD THE NORTH NEAR 9 MPH...15 KM/H. NORBERT IS FORECAST
TO TURN TOWARD THE NORTHWEST OVERNIGHT AND THEN TURN TOWARD THE
WEST-NORTHWEST BY LATE WEDNESDAY INTO THURSDAY. ON THE FORECAST
TRACK...NORBERT SHOULD BEGIN MOVING AWAY FROM THE COAST OF
SOUTHWESTERN MEXICO OVERNIGHT...AND APPROACH THE SOUTHERN TIP OF THE
BAJA CALIFORNIA PENINSULA ON THURSDAY.

MAXIMUM SUSTAINED WINDS HAVE INCREASED TO NEAR 45 MPH...75 KM/H...
WITH HIGHER GUSTS. SOME ADDITIONAL STRENGTHENING IS FORECAST DURING
THE NEXT 48 HOURS.

TROPICAL STORM FORCE WINDS EXTEND OUTWARD UP TO 60 MILES...95 KM
FROM THE CENTER.

THE ESTIMATED MINIMUM CENTRAL PRESSURE IS 1003 MB...29.62 INCHES.


HAZARDS AFFECTING LAND
----------------------
WIND...TROPICAL STORM CONDITIONS ARE POSSIBLE WITHIN THE WATCH AREA
BY THURSDAY AFTERNOON.

RAINFALL...NORBERT IS EXPECTED TO PRODUCE RAINFALL AMOUNTS OF 2 TO
4 INCHES OVER COLIMA AND WESTERN PARTS OF MICHOACAN AND JALISCO IN
SOUTHWESTERN MEXICO THROUGH WEDNESDAY.


NEXT ADVISORY
-------------
NEXT COMPLETE ADVISORY...800 PM PDT.

$$
FORECASTER BRENNAN

[Yellow Evan]

EP, 14, 2014090300, , BEST, 0, 189N, 1067W, 40, 1003, TS, 34, NEQ, 30, 50, 0, 0, 1009, 130, 25, 0, 0, E, 0, , 0, 0, NORBERT, M,

[supercane4867]

TROPICAL STORM NORBERT DISCUSSION NUMBER 3
NWS NATIONAL HURRICANE CENTER MIAMI FL EP142014
800 PM PDT TUE SEP 02 2014

Norbert has continued to slowly become better organized over the
past few hours. Deep convection has increase near the center in a
CDO-like feature, and a curved convective band extends into the
western semicircle. The initial intensity of 40 kt is based on a
blend of the latest subjective and objective Dvorak estimates, and
this could be a bit conservative. The SHIPS model shows some
moderate northeasterly to easterly shear over the cyclone for the
next 2 to 3 days, but otherwise conditions appear favorable for
strengthening. There is a fair bit of spread in the intensity
guidance, in part due to variability in the track forecast. The
HWRF model now shows the cyclone moving over the Baja peninsula, and
has trended a bit weaker. On the other hand, the SHIPS model now
shows Norbert becoming a hurricane in 36 to 48 hours. The new NHC
track takes Norbert over warmer SSTs closer to the Baja peninsula in
2 to 3 days and the NHC intensity forecast has been adjusted upward,
showing Norbert becoming a hurricane in 48 hours. This forecast is
close to the SHIPS model and the FSU Superensemble. Gradual
weakening is forecast at days 3 through 5 as the cyclone moves over
cooler waters.

Norbert has turned toward the left during the past few hours, with
an initial motion estimate of 330/07. The dominant steering
mechanism through the period will be a mid-level ridge centered over
the southern United States, which should generally steer Norbert
northwestward during the next 72 hours and then west-northwestward.
Much of the track model guidance has shifted well to the right, or
north, for this forecast cycle, especially at 48 hours and beyond.
The GFS, GEFS ensemble mean, HWRF, and GFDL are now north of the
ECMWF, which was previously along the right side of the guidance
envelope. This shift appears to be due to a deeper representation of
Norbert and more erosion of the subtropical ridge to the north.
The NHC track has been shifted to the right this cycle, and now
lies south of the multi-model consensus aid TVCE. The NHC track is
close to a blend of the GFS and ECMWF through 36 hours and is a
little south of that model blend afterward.

Given the large shift in the guidance and the large spread,
confidence in the track forecast is lower than normal and additional
adjustments may be needed in future forecast cycles. The rightward
shift in the track increases the threat to the southern part of the
Baja California peninsula. A tropical storm or hurricane warning
could be needed for this area tonight or early Wednesday.

FORECAST POSITIONS AND MAX WINDS

INIT 03/0300Z 19.2N 106.9W 40 KT 45 MPH
12H 03/1200Z 19.8N 107.8W 50 KT 60 MPH
24H 04/0000Z 20.4N 108.9W 55 KT 65 MPH
36H 04/1200Z 21.1N 109.8W 60 KT 70 MPH
48H 05/0000Z 21.9N 110.7W 65 KT 75 MPH
72H 06/0000Z 23.5N 112.8W 60 KT 70 MPH
96H 07/0000Z 24.5N 115.0W 50 KT 60 MPH
120H 08/0000Z 25.3N 117.0W 40 KT 45 MPH

$$
Forecaster Brennan

[Yellow Evan]

Big shift north. This is starting to remind me of Paul 12 with the E shifts. Yesterday, I was confident on an OTS track, but now it is bring memories back of many other Baja TC's. However, I stress that this is only one run, and things can chance back W easily.

This system is developing faster than was expected by global models, so in future posts, I will consider that when commenting on possible track.