EPAC: NORBERT - Post-Tropical

[CaliforniaResident]

All I ask is that Norbert send Southern California (L.A. metro Area) some sweet and rare summer rain!

[Steve820]

All I ask is that Norbert send Southern California (L.A. metro Area) some sweet and rare summer rain!

I know right? But I doubt it's going to affect California; Norbert might just instead remain offshore like Lowell.

[Yellow Evan]

All I ask is that Norbert send Southern California (L.A. metro Area) some sweet and rare summer rain!

I know right? But I doubt it's going to affect California; Norbert might just instead remain offshore like Lowell.

Except models are trending east. Not all hope is lost.

[Yellow Evan]

0z GFs a little more west and a little weaker than the 18z.

[wxmann_91]

Norbert is consolidating pretty well now with a nice CDO evident. 0Z Euro continues to shift right and now hits takes Norbert inland over Ensenada. Taken verbatim, would be a significant flooding event for SE CA.

[cycloneye]

TROPICAL STORM NORBERT DISCUSSION NUMBER 4
NWS NATIONAL HURRICANE CENTER MIAMI FL EP142014
200 AM PDT WED SEP 03 2014

The convective cloud pattern of Norbert has improved significantly
since the previous advisory. A pronounced CDO feature has developed
with two distinct convective bands wrapping into the center. A 0432
UTC AMSU microwave indicated that a small mid-level eye feature
could be trying to form. Satellite intensity estimates from TAFB
and SAB were a consensus T3.0/45 kt at 0600 UTC, and UW-CIMSS ADT
values have been steadily increasing and are now T3.7/59 kt. Based
on these intensity estimates, the continued improvement in the cloud
pattern, and the small radius of maximum winds, the advisory
intensity is conservatively set at 50 kt.

The initial motion estimate is still northwestward or 305/07 kt.
Norbert is forecast to move in a general northwestward direction
around the southwestern periphery of a deep-layer subtropical ridge
that stretches westward across northern Mexico and Baja California.
This motion, accompanied by a slight decrease in forward speed, is
expected to persist throughout the forecast period. The NHC model
guidance has shifted slightly to the right again, but the size of
the guidance envelope has decreased, showing much less spread on
this cycle. The official forecast track is similar to the previous
advisory track through 36 hours, and then is somewhat to right of
the previous forecast after that.

The combination of the small radius of maximum winds, 29.5C SSTs, a
moist mid-level environment, and vertical shear decreasing to
around 10 kt suggests that Norbert should at least intensity at the
typical rate of 20-25 kt per day for the next 36 hours or so.
However, if thew shear decrease more than currently expected, then
rapid intensification during the next 24 hours is a very distinct
possibility. By 96 hours and beyond, Norbert will be moving over
SSTs less than 26.5C, which should induce slow weakening. NHC
intensity forecast is above the previous forecast, and closely
follows the SHIPS intensity model.

FORECAST POSITIONS AND MAX WINDS

INIT 03/0900Z 19.6N 107.6W 50 KT 60 MPH
12H 03/1800Z 20.0N 108.5W 55 KT 65 MPH
24H 04/0600Z 20.6N 109.4W 65 KT 75 MPH
36H 04/1800Z 21.4N 110.1W 75 KT 85 MPH
48H 05/0600Z 22.3N 110.9W 75 KT 85 MPH
72H 06/0600Z 24.0N 112.7W 65 KT 75 MPH
96H 07/0600Z 25.1N 115.1W 60 KT 70 MPH
120H 08/0600Z 26.2N 117.0W 55 KT 65 MPH

$$
Forecaster Stewart

[xtyphooncyclonex]

Impressive rate of intensification. No surprise this should be a major...

[somethingfunny]

Does the Mexican weather service issue their own forecasts or do they retransmit NHC products (or both)?

[Yellow Evan]

Does the Mexican weather service issue their own forecasts or do they retransmit NHC products (or both)?

They do the latter. Have a modified warning system though.

[Yellow Evan]

000
WTPZ34 KNHC 031153
TCPEP4

BULLETIN
TROPICAL STORM NORBERT INTERMEDIATE ADVISORY NUMBER 4A
NWS NATIONAL HURRICANE CENTER MIAMI FL EP142014
500 AM PDT WED SEP 03 2014

...NORBERT TURNS WEST-NORTHWESTWARD...


SUMMARY OF 500 AM PDT...1200 UTC...INFORMATION
----------------------------------------------
LOCATION...19.7N 108.3W
ABOUT 245 MI...395 KM SSE OF THE SOUTHERN TIP OF BAJA CALIFORNIA
MAXIMUM SUSTAINED WINDS...60 MPH...95 KM/H
PRESENT MOVEMENT...WNW OR 295 DEGREES AT 8 MPH...13 KM/H
MINIMUM CENTRAL PRESSURE...999 MB...29.50 INCHES


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

NONE.

SUMMARY OF WATCHES AND WARNINGS IN EFFECT...
A TROPICAL STORM WARNING IS IN EFFECT FOR...
* LA PAZ TO SANTA FE MEXICO

A TROPICAL STORM WATCH IS IN EFFECT FOR...
* NORTH OF SANTA FE NORTHWARD TO CABO SAN LAZARO MEXICO

A TROPICAL STORM WARNING MEANS THAT TROPICAL STORM CONDITIONS ARE
EXPECTED SOMEWHERE WITHIN THE WARNING AREA WITHIN 36 HOURS.

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

A HURRICANE WATCH COULD BE REQUIRED FOR PORTIONS OF THE SOUTHERN
BAJA CALIFORNIA PENINSULA LATER THIS MORNING.

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


DISCUSSION AND 48-HOUR OUTLOOK
------------------------------
AT 500 AM PDT...1200 UTC...THE CENTER OF TROPICAL STORM NORBERT WAS
LOCATED NEAR LATITUDE 19.7 NORTH...LONGITUDE 108.3 WEST. NORBERT IS
MOVING TOWARD THE WEST-NORTHWEST NEAR 8 MPH...13 KM/H...AND THIS
GENERAL MOTION SHOULD CONTINUE TODAY... WITH A TURN TOWARD
THE NORTHWEST EXPECTED ON THURSDAY. ON THE FORECAST TRACK...THE
CENTER OF NORBERT IS EXPECTED TO APPROACH THE SOUTHERN TIP OF THE
BAJA CALIFORNIA PENINSULA ON THURSDAY.

MAXIMUM SUSTAINED WINDS REMAIN NEAR 60 MPH...95 KM/H...WITH HIGHER
GUSTS. STRENGTHENING IS FORECAST DURING THE NEXT 48 HOURS...AND
NORBERT IS EXPECTED TO REACH HURRICANE STRENGTH BY THURSDAY.

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

THE ESTIMATED MINIMUM CENTRAL PRESSURE IS 999 MB...29.50 INCHES.


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

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.

SURF...LARGE SWELLS WILL AFFECT PORTIONS OF THE SOUTHWESTERN COAST
OF MEXICO TODAY AND THURSDAY...AND PRODUCE DANGEROUS SURF CONDITIONS
AND RIP CURRENTS. LARGE SWELLS WILL GRADUALLY SPREAD NORTHWARD INTO
THE SOUTHERN GULF OF CALIFORNIA AND AFFECT THE SOUTHERN PORTIONS OF
BAJA CALIFORNIA SUR BY THURSDAY.


NEXT ADVISORY
-------------
NEXT COMPLETE ADVISORY...800 AM PDT.

$$
FORECASTER BLAKE

[Yellow Evan]

EP, 14, 2014090312, , BEST, 0, 197N, 1084W, 55, 995, TS, 34, NEQ, 50, 50, 40, 40, 1007, 130, 15, 0, 0, E, 0, , 0, 0, NORBERT, D,
EP, 14, 2014090312, , BEST, 0, 197N, 1084W, 55, 995, TS, 50, NEQ, 20, 20, 0, 20, 1007, 130, 15, 0, 0, E, 0, , 0, 0, NORBERT, D,

[Yellow Evan]

6z GFS a bit stronger and closer to Baja

[TropicalAnalystwx13]

The shear that was plaguing Norbert has weakened (which the SHIPS did not forecast, oddly enough), and so it looks like rapid intensification may continue throughout the day today. I could definitely see this being a Category 2 or even a major hurricane at peak intensity. It looks 60-65kt right now (T4.1 from CIMSS ADT but T3.5 from SAB/TAFB).

[TropicalAnalystwx13]

Transient eye:



Sun's up:

[mrbagyo]

[cycloneye]

Peak at 8 AM PDT advisory is 90kts.


BULLETIN
TROPICAL STORM NORBERT ADVISORY NUMBER 5
NWS NATIONAL HURRICANE CENTER MIAMI FL EP142014
800 AM PDT WED SEP 03 2014

...NORBERT EXPECTED TO BECOME A HURRICANE LATER TODAY...


SUMMARY OF 800 AM PDT...1500 UTC...INFORMATION
----------------------------------------------
LOCATION...19.6N 108.8W
ABOUT 240 MI...385 KM SSE OF THE SOUTHERN TIP OF BAJA CALIFORNIA
MAXIMUM SUSTAINED WINDS...65 MPH...100 KM/H
PRESENT MOVEMENT...WNW OR 295 DEGREES AT 9 MPH...15 KM/H
MINIMUM CENTRAL PRESSURE...995 MB...29.39 INCHES


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

NONE.

SUMMARY OF WATCHES AND WARNINGS IN EFFECT...
A TROPICAL STORM WARNING IS IN EFFECT FOR...
* LA PAZ TO SANTA FE MEXICO

A TROPICAL STORM WATCH IS IN EFFECT FOR...
* NORTH OF SANTA FE NORTHWARD TO CABO SAN LAZARO MEXICO

A TROPICAL STORM WARNING MEANS THAT TROPICAL STORM CONDITIONS ARE
EXPECTED SOMEWHERE WITHIN THE WARNING AREA WITHIN 36 HOURS.

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

A HURRICANE WATCH COULD BE REQUIRED FOR PORTIONS OF THE SOUTHERN
BAJA CALIFORNIA PENINSULA LATER TODAY.

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


DISCUSSION AND 48-HOUR OUTLOOK
------------------------------
AT 800 AM PDT...1500 UTC...THE CENTER OF TROPICAL STORM NORBERT WAS
LOCATED NEAR LATITUDE 19.6 NORTH...LONGITUDE 108.8 WEST. NORBERT IS
MOVING TOWARD THE WEST-NORTHWEST NEAR 9 MPH...15 KM/H. NORBERT
SHOULD TURN TOWARD THE NORTHWEST LATER TODAY AND CONTINUE THAT
GENERAL MOTION FOR THE NEXT DAY OR TWO. ON THE FORECAST TRACK...THE
CENTER OF NORBERT IS EXPECTED TO APPROACH THE SOUTHERN TIP OF THE
BAJA CALIFORNIA PENINSULA ON THURSDAY...AND MOVE NEARLY PARALLEL TO
THE PACIFIC COAST OF THE PENINSULA ON FRIDAY.

MAXIMUM SUSTAINED WINDS HAVE INCREASED TO NEAR 65 MPH...100
KM/H...WITH HIGHER GUSTS. NORBERT IS EXPECTED TO BECOME A
HURRICANE LATER TODAY...AND CONTINUE STRENGTHENING FOR THE NEXT DAY
OR TWO.

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

THE ESTIMATED MINIMUM CENTRAL PRESSURE IS 995 MB...29.39 INCHES.


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

RAINFALL...NORBERT IS EXPECTED TO PRODUCE RAINFALL AMOUNTS OF 3 TO
5 INCHES OVER THE SOUTHERN PART OF THE BAJA CALIFORNIA PENINSULA
THROUGH FRIDAY.

SURF...LARGE SWELLS WILL AFFECT PORTIONS OF THE SOUTHWESTERN COAST
OF MEXICO TODAY AND THURSDAY...AND PRODUCE DANGEROUS SURF CONDITIONS
AND RIP CURRENTS. LARGE SWELLS WILL GRADUALLY SPREAD NORTHWARD INTO
THE SOUTHERN GULF OF CALIFORNIA AND AFFECT THE SOUTHERN PORTIONS OF
BAJA CALIFORNIA SUR BY THURSDAY.


NEXT ADVISORY
-------------
NEXT INTERMEDIATE ADVISORY...1100 AM PDT.
NEXT COMPLETE ADVISORY...200 PM PDT.

$$
FORECASTER BLAKE



TROPICAL STORM NORBERT DISCUSSION NUMBER 5
NWS NATIONAL HURRICANE CENTER MIAMI FL EP142014
800 AM PDT WED SEP 03 2014

Norbert has become significantly better organized this morning.
The central dense overcast has become more symmetric with more
prominent banding around the center. Microwave images also show
that the inner core is becoming better defined, with the likely
first stages of a primitive eye. The initial wind speed is set to
55 kt, at the top end of the subjective Dvorak estimates, although
the latest objective numbers are higher. With the improvement in
the inner core, light-to-moderate shear, and very warm waters,
future strengthening seems quite likely. In fact, rapid
intensification is a distinct possibility, with the SHIPS-RI
showing about a 1-in-3 chance of Norbert becoming 30 kt stronger in
the next 24 hours. Considering the environmental factors and the
low bias of the deterministic guidance so far, the new NHC intensity
forecast is raised considerably from the previous one, about 5 kt
above the highest guidance through 48 hours. After that time,
cooler waters and a more stable atmosphere are expected to weaken
the cyclone. The NHC forecast is blended with the previous
forecast and the intensity consensus at long range.

With recent microwave and visible imagery, it appears that Norbert
has been moving westward over the past few hours. However, a more
representative long-term motion is 295/8. Mid-level ridging is
expected to weaken later today over northwestern Mexico, which
should cause Norbert to turn more to the northwest. While all of
the reliable guidance keeps the center of the storm offshore of Baja
California Sur, Norbert should come close enough to bring tropical-
storm-force winds to the state. The models have shifted somewhat
southward since the last cycle, and with the recent westward motion,
it makes sense to adjust the NHC forecast a little farther south for
the first day or so. There hasn't been much change to the guidance
beyond day 3, so the new forecast is basically an update to the
previous one.

FORECAST POSITIONS AND MAX WINDS

INIT 03/1500Z 19.6N 108.8W 55 KT 65 MPH
12H 04/0000Z 20.1N 109.6W 65 KT 75 MPH
24H 04/1200Z 20.9N 110.3W 80 KT 90 MPH
36H 05/0000Z 21.8N 111.0W 90 KT 105 MPH
48H 05/1200Z 22.6N 111.9W 90 KT 105 MPH
72H 06/1200Z 24.4N 113.9W 70 KT 80 MPH
96H 07/1200Z 25.6N 116.2W 55 KT 65 MPH
120H 08/1200Z 27.0N 117.5W 40 KT 45 MPH

$$
Forecaster Blake

[Ntxw]

Got its act together quick, should be a hurricane soon if not already.

[CrazyC83]

I would have gone with 60 kt at the extreme high end due to the deep CDO and occasional eye.

[cycloneye]

Plane for Thursday departs at 7:45 AM EDT. For sure it will be a interesting mission.

II. PACIFIC REQUIREMENTS
1. TROPICAL STORM NORBERT
FLIGHT ONE -- TEAL 71
A. 04/1730Z
B. AFXXX 0114E NORBERT
C. 04/1145Z
D. 21.5N 110.5W
E. 04/1715Z TO 04/2100Z
F. SFC TO 10,000 FT

2. SUCCEEDING DAY OUTLOOK: POSSIBLE FIX NEAR
23.2N 112.2W AT 05/1730Z.

[Alyono]

12Z GFS has this very near the US/Mexico Border as a coherent system