ATL: ALBERTO - Post-Tropical

[stormhunter7]

Nailed landfall yesterday. I was in dead center of Laguna Beach. Amazing structure to see first hand. Also, i disagree with NHC on landfall timing by an hour. I had winds go from 20-30mph to near calm right at 3pm CDT. Then the winds picked backed up and by 340pm were blowing pretty hard. Almost in a different direction. Lowest pressure i got on my Note 8 phone sensor was 994mb at 3pm. Also noticed an American Airlines flight from MIA to PNS came by just after landfall, unique view to look up and see that small jet. LOTS of drier air in and over COC, and I could see the tower convection to my NW that was continuing to blow up. Pretty cool! First Subtropical Storm intercept!

[Steve]

Based on those verification scores, who would have thought the CMC and UK would be the two best performing models with Alberto and Euro one of the worst?

Not surprised by UKMET, theyve been coming on strong lately. A model that must be given equal weight to now.

3 days, even the BAM models are usually okay to watch. Fact remains that in the mid-term, it was an eastern outlier. It has had that distinction many times in the past. IMHO, sometimes it's good, sometimes it isn't. That certainly can be said for all the models, but I'm just sure when to guess that it is a correct outlier or just out to lunch - which it often is. But nice job on the 3 days. It's 5/6 day verifications have to be pretty poor for most of the runs.

[tolakram]

Interesting that the GFS ended up being one of the better performing models with Alberto. Got to see how it behaves with future storms if there is any improvement from the previous version.

The GFS has always done better in this area at this time of year when shear is high. wxman57 pointed this out numerous times. The GFS is better at predicting center reformations, apparently, which makes it's track more accurate in these situations. Without shear, later in the year, I suspect the Euro or possibly the UKIE would be best for track. If the UKIE did well here for the same reason the GFS did then expect worse performance for other storms. How worse??

Speaking for myself only, this is why it's so maddening to see people blindly follow a single model because it's 'more accurate'. It demonstrates a complete lack of knowledge about how to use models IMO.

Sorry, not picking on you here.

[Kazmit]

Alberto before landfall:

[HeeBGBz]

Alberto has an interesting "tail" out to the east and south (The area south of Cuba in particular)

Thank goodness that is off the east coast of Florida, if that was over us we'd be looking at some significant flooding

The Mississippi coast is supposed to get the tail on Wednesday.

[EquusStorm]

Core has held together really well, even now. Woke up to breezy and rainy weather, and some rather impressive gusts in the final band wrapping around the center when the center passed a few miles to our NE here in Jasper AL. Noticed some street flooding and tree branches broken. A little less impact than Harvey here, but more than Irma or Nate. And now I'm realizing just how many storms have impacted us here in the last nine months... wow.

There is certainly more rain to fall in east AL in the core of where flooding has been forecast, even as Alberto continues northward, but to this point it's been interesting to see that the heaviest rain has fallen to the west of the center in heavy bands on that side. Flash flood watches were not in place west of Birmingham until last night, when I assume it had to be added as the core bands stayed west of center. Alberto's structure has been, and continues to be, fascinating, and I await the endless debate on exactly how much subtropical vs tropical characteristics the storm exhibited in its final day or two. Might be some interesting studies.

[aperson]

Interesting that the GFS ended up being one of the better performing models with Alberto. Got to see how it behaves with future storms if there is any improvement from the previous version.

The GFS has always done better in this area at this time of year when shear is high. wxman57 pointed this out numerous times. The GFS is better at predicting center reformations, apparently, which makes it's track more accurate in these situations. Without shear, later in the year, I suspect the Euro or possibly the UKIE would be best for track. If the UKIE did well here for the same reason the GFS did then expect worse performance for other storms. How worse??

Speaking for myself only, this is why it's so maddening to see people blindly follow a single model because it's 'more accurate'. It demonstrates a complete lack of knowledge about how to use models IMO.

Sorry, not picking on you here.

Thanks a ton for this post, I often see people talk about "not just relying on the models" but I rarely see model-to-model comparisons that let us understand what features different ones are strong or weak at.

I would love to see / help create some kind of table that has strengths/weaknesses/features of each model. Stuff like "not ocean coupled", "better in high shear environments", etc... would be extremely valuable heuristics to know.

[cycloneye]

BULLETIN
Subtropical Depression Alberto Advisory Number 19
NWS Weather Prediction Center College Park MD AL012018
400 PM CDT Tue May 29 2018

...CENTER OF ALBERTO MOVING OVER NORTHWEST ALABAMA...
...HEAVY RAINFALL THREAT CONTINUES...


SUMMARY OF 400 PM CDT...2100 UTC...INFORMATION
----------------------------------------------
LOCATION...34.7N 87.3W
ABOUT 100 MI...160 KM SSW OF NASHVILLE TENNESSEE
MAXIMUM SUSTAINED WINDS...30 MPH...45 KM/H
PRESENT MOVEMENT...N OR 350 DEGREES AT 18 MPH...30 KM/H
MINIMUM CENTRAL PRESSURE...998 MB...29.47 INCHES


WATCHES AND WARNINGS
--------------------
Flash Flood Watches in effect for portions of Alabama, Georgia,
Tennessee, Kentucky, Illinois, North and South Carolina, Virginia
and West Virginia.


DISCUSSION AND OUTLOOK
----------------------
At 400 PM CDT (2100 UTC), the center of Subtropical Depression
Alberto was located near latitude 34.7 North, longitude 87.3 West.
The depression is moving toward the north near 18 mph (30 km/h) and
forward speed of the low center is forecast to increase over the
next 24-48 hours.

Maximum sustained winds were near 30 mph (45 km/h) with higher
gusts. Gradual weakening is forecast.

The estimated minimum central pressure was 998 mb (29.47 inches).


HAZARDS AFFECTING LAND
----------------------
RAINFALL: Additional rainfall of 2 to 4 inches, with isolated
higher amounts, will be possible from northern sections of
Alabama/Georgia northward across western and Middle
Tennessee, Kentucky and southern Illinois. Heavy rain is also
forecast across the Appalachian Mountains from the Carolinas to
Virginia/West Virginia. Flash flooding and rapid water rises on
creeks and streams across these areas will remain a possibility
through tonight.

Rainfall totals from Alberto are summarized at:
www.wpc.ncep.noaa.gov/discussions/nfdscc5.html.

WIND: A few gusts to tropical-storm force are possible across
portions of northern Alabama and Middle Tennessee through this
evening.

SURF: Swells generated by Alberto will continue to affect the
eastern and northern Gulf Coast through Thursday. These swells are
likely to cause life-threatening surf and rip current conditions.
For more information, consult products from your local weather
office.


For more information on rainfall totals please see the Storm Summary
available at www.wpc.ncep.noaa.gov/discussions/nfdscc5.html


NEXT ADVISORY
-------------
Next complete advisory at 1000 PM CDT.

$$
Forecaster Carbin/Hayes/WPC

FORECAST POSITIONS AND MAX WINDS

INIT 29/2100Z 34.7N 87.3W 25 KT 30 MPH
12H 30/0600Z 37.2N 88.2W 25 KT 30 MPH...INLAND
24H 30/1800Z 40.6N 87.3W 20 KT 25 MPH...INLAND
36H 31/0600Z 44.8N 85.5W 20 KT 25 MPH...POST-TROP/REMNT LOW
48H 31/1800Z 48.8N 82.2W 20 KT 25 MPH...POST-TROP/REMNT LOW

NNNN$$

[Hammy]

In my opinion, Alberto would've easily have been a hurricane if it wasn't for the dry-air continuously wrapping into the system.

Likewise, had it formed out over the open Atlantic--I don't recall the last time I've seen something remain this organized this far inland that wasn't simply a result of moving quickly.

[South Texas Storms]

Glad the heavy rainfall predictions didn't really pan out. It seems like Cuba and the western Bahamas saw the heaviest rain, with the really heavy totals staying out over the water. This storm could've been much worse than it actually was.

[cycloneye]

BULLETIN
Tropical Depression Alberto Advisory Number 20
NWS Weather Prediction Center College Park MD AL012018
1000 PM CDT Tue May 29 2018

...CENTER OF ALBERTO MOVING OVER WESTERN TENNESSEE...
...HEAVY RAINFALL THREAT CONTINUES...


SUMMARY OF 1000 PM CDT...0300 UTC...INFORMATION
-----------------------------------------------
LOCATION...36.3N 87.5W
ABOUT 45 MI...75 KM WNW OF NASHVILLE TENNESSEE
MAXIMUM SUSTAINED WINDS...35 MPH...55 KM/H
PRESENT MOVEMENT...N OR 360 DEGREES AT 16 MPH...26 KM/H
MINIMUM CENTRAL PRESSURE...999 MB...29.50 INCHES


WATCHES AND WARNINGS
--------------------
Flash Flood Watches in effect for portions of Alabama, Georgia,
Tennessee, Kentucky, Illinois, Indiana, North and South Carolina,
Virginia and West Virginia.


DISCUSSION AND OUTLOOK
----------------------
At 1000 PM CDT (0300 UTC), the center of Tropical Depression Alberto
was located near latitude 36.3 North, longitude 87.5 West. The
depression is moving toward the north near 16 mph (26 km/h) and this
motion is expected to gradually increase.

Maximum sustained winds are near 35 mph (55 km/h) with higher gusts.
Some weakening is forecast during the next 48 hours.

The estimated minimum central pressure is 999 mb (29.50 inches).


HAZARDS AFFECTING LAND
----------------------
RAINFALL: Additional rainfall of 2 to 4 inches, with isolated
higher amounts, will be possible from northern sections of
Alabama/Georgia northward across western and middle
Tennessee, Kentucky and southern Illinois. Heavy rain is also
forecast across the Appalachian Mountains from the Carolinas to
Virginia/West Virginia. Flash flooding and rapid water rises on
creeks and streams across these areas will remain a possibility
through the overnight.

WIND: A few gusts to tropical-storm force are possible across
portions of middle and western Tennessee through the overnight.


For more information on rainfall totals please see the Storm Summary
available at www.wpc.ncep.noaa.gov/discussions/nfdscc5.html


NEXT ADVISORY
-------------
Next complete advisory at 400 AM CDT.

$$
Forecaster Hayes

FORECAST POSITIONS AND MAX WINDS

INIT 30/0300Z 36.3N 87.5W 30 KT 35 MPH
12H 30/1200Z 38.4N 87.7W 25 KT 30 MPH...INLAND
24H 31/0000Z 42.3N 86.3W 20 KT 25 MPH...INLAND
36H 31/1200Z 46.6N 83.5W 20 KT 25 MPH...POST-TROP/REMNT LOW

NNNN

$$

[CyclonicFury]

Since it is now listed as tropical per WPC, does this mean the storm itself would be called TS Alberto or SS Alberto?

[CrazyC83]

Since it is now listed as tropical per WPC, does this mean the storm itself would be called TS Alberto or SS Alberto?

SS Alberto for now I believe, but I kinda think it will be reclassified as tropical at landfall (even if the landfall intensity decreases a bit).

[WeatherGuesser]

Center (as identified by well defined rotation on radar animation) currently over Princeton, KY

[WeatherGuesser]

In about an hour, that center has moved from SE of Princeton to NW of Madisonville, a distance of around 30 miles.

[arlwx]

BULLETIN
Tropical Depression Alberto Advisory Number 21
NWS Weather Prediction Center College Park MD AL012018
400 AM CDT Wed May 30 2018

...CENTER OF ALBERTO MOVING ACROSS WESTERN KENTUCKY...
...HEAVY RAINFALL THREAT CONTINUES...


SUMMARY OF 400 AM CDT...0900 UTC...INFORMATION
----------------------------------------------
LOCATION...37.2N 87.9W
ABOUT 55 MI...90 KM SSW OF EVANSVILLE INDIANA
MAXIMUM SUSTAINED WINDS...35 MPH...55 KM/H
PRESENT MOVEMENT...N OR 10 DEGREES AT 15 MPH...25 KM/H
MINIMUM CENTRAL PRESSURE...998 MB...29.47 INCHES


WATCHES AND WARNINGS
--------------------
Flash Flood Watches are in effect for portions of the southern
Appalachians and Lower Ohio Valley.


DISCUSSION AND OUTLOOK
----------------------
At 400 AM CDT (0900 UTC), the center of Tropical Depression Alberto
was located near latitude 37.2 North, longitude 87.9 West. The
depression is moving toward the north near 15 mph (25 km/h) and
this motion is expected to become more north-northeasterly with
some further acceleration today and tomorrow as it moves up the
Wabash River Valley and through the Lower Peninsula of Michigan.

Maximum sustained winds are near 35 mph (55 km/h) with higher gusts.
Minimal change in strength is expected on Wednesday. Some slight
weakening is possible on Thursday.

The estimated minimum central pressure is 998 mb (29.47 inches).


HAZARDS AFFECTING LAND
----------------------
RAINFALL: Additional rainfall of 2 to 4 inches, with isolated
higher amounts, will be possible from western Kentucky northward
near the Illinois/Indiana border into the Lower Peninsula of
Michigan. Heavy rain is also forecast from central Alabama
northeast into the Appalachian Mountains from the Carolinas to
Virginia. Flash flooding and rapid water rises on creeks and streams
will remain a possibility across these areas.

WIND: A few gusts to tropical-storm force are possible across
northwest Tennessee, western and central Kentucky, and
southwest Indiana this morning.


For more information on rainfall totals please see the Storm Summary
available at www.wpc.ncep.noaa.gov/discussions/nfdscc5.html


NEXT ADVISORY
-------------
Next complete advisory at 1000 AM CDT.

$$
Forecaster Roth

FORECAST POSITIONS AND MAX WINDS

INIT 30/0900Z 37.2N 87.9W 30 KT 35 MPH...INLAND
12H 30/1800Z 39.8N 87.3W 30 KT 35 MPH...INLAND
24H 31/0600Z 43.5N 85.5W 25 KT 30 MPH...POST-TROP/EXTRATROP
36H 31/1800Z 48.0N 82.6W 25 KT 30 MPH...POST-TROP/EXTRATROP

NNNN
$$

[cycloneye]

BULLETIN
Tropical Depression Alberto Advisory Number 21
NWS Weather Prediction Center College Park MD AL012018
400 AM CDT Wed May 30 2018

...CENTER OF ALBERTO MOVING ACROSS WESTERN KENTUCKY...
...HEAVY RAINFALL THREAT CONTINUES...


SUMMARY OF 400 AM CDT...0900 UTC...INFORMATION
----------------------------------------------
LOCATION...37.2N 87.9W
ABOUT 55 MI...90 KM SSW OF EVANSVILLE INDIANA
MAXIMUM SUSTAINED WINDS...35 MPH...55 KM/H
PRESENT MOVEMENT...N OR 10 DEGREES AT 15 MPH...25 KM/H
MINIMUM CENTRAL PRESSURE...998 MB...29.47 INCHES


WATCHES AND WARNINGS
--------------------
Flash Flood Watches are in effect for portions of the southern
Appalachians and Lower Ohio Valley.


DISCUSSION AND OUTLOOK
----------------------
At 400 AM CDT (0900 UTC), the center of Tropical Depression Alberto
was located near latitude 37.2 North, longitude 87.9 West. The
depression is moving toward the north near 15 mph (25 km/h) and
this motion is expected to become more north-northeasterly with
some further acceleration today and tomorrow as it moves up the
Wabash River Valley and through the Lower Peninsula of Michigan.

Maximum sustained winds are near 35 mph (55 km/h) with higher gusts.
Minimal change in strength is expected on Wednesday. Some slight
weakening is possible on Thursday.

The estimated minimum central pressure is 998 mb (29.47 inches).


HAZARDS AFFECTING LAND
----------------------
RAINFALL: Additional rainfall of 2 to 4 inches, with isolated
higher amounts, will be possible from western Kentucky northward
near the Illinois/Indiana border into the Lower Peninsula of
Michigan. Heavy rain is also forecast from central Alabama
northeast into the Appalachian Mountains from the Carolinas to
Virginia. Flash flooding and rapid water rises on creeks and streams
will remain a possibility across these areas.

WIND: A few gusts to tropical-storm force are possible across
northwest Tennessee, western and central Kentucky, and
southwest Indiana this morning.


For more information on rainfall totals please see the Storm Summary
available at www.wpc.ncep.noaa.gov/discussions/nfdscc5.html


NEXT ADVISORY
-------------
Next complete advisory at 1000 AM CDT.

$$
Forecaster Roth

FORECAST POSITIONS AND MAX WINDS

INIT 30/0900Z 37.2N 87.9W 30 KT 35 MPH...INLAND
12H 30/1800Z 39.8N 87.3W 30 KT 35 MPH...INLAND
24H 31/0600Z 43.5N 85.5W 25 KT 30 MPH...POST-TROP/EXTRATROP
36H 31/1800Z 48.0N 82.6W 25 KT 30 MPH...POST-TROP/EXTRATROP

NNNN

[cycloneye]

Imagine if this was in GOM waters but is in Indiana.

[gfsperpendicular]

They actually raised wind speeds, wow

[TheStormExpert]

They actually raised wind speeds, wow

Not to mention it's not "Sub"-Tropical anymore.