ATL : TROPICAL DEPRESSION ALEX - MODELS

[cycloneye]

I wont be crazy looking at models until there is a well defined LLC.

[Ivanhater]

[srainhoutx]

I wont be crazy looking at models until there is a well defined LLC.

I agree Luis. We have all season to stay up half the night watching every turn of the models. HPC offers some interesting thoughts in Final Disco. A strong Polar front in the NE? Hmmm...

EXTENDED FORECAST DISCUSSION
NWS HYDROMETEOROLOGICAL PREDICTION CENTER CAMP SPRINGS MD
216 PM EDT MON JUN 21 2010

VALID 12Z THU JUN 24 2010 - 12Z MON JUN 28 2010


PRELIMINARY UPDATE...

USED THE 00Z/21 ECENS MEAN TO UPDATE THE PRELIMINARY FRONTS AND
PRESSURES FOR DAYS 3 THROUGH 7. THE ECENS MEAN HAS BEEN STABLE
FOR FOUR CONSECUTIVE RUNS...AND IS WELL CORRELATED WITH BOTH THE
00Z/21 GEFS MEAN AND CMCE MEAN. THE ECENS MEAN HAS MAINTAINED A
STRONG EDGE OVER THE OTHER GUIDANCE AT THE MEDIUM RANGE FOR MONTHS
NOW...AFFORDING A YARDSTICK OF SORTS FOR AT LEAST PMSL ACROSS THE
NATION. THE 00Z/21 MEAN DEPARTS MOST SIGNIFICANTLY FROM SOME OF
THE DETERMINISTIC MODELS WITH THE HANDLING OF THE LOW OVER THE
GULF OF MEXICO DURING THE SECOND HALF OF THE PERIOD...KEEPING THIS
CIRCULATION CLOSER TO THE YUCATAN PENINSULA. WILL RELY ON THE
MIDDAY COORDINATION WITH TPC FOR THE FINAL FORECAST POSITIONS OF
THE LOW.

FINAL...

THE 12Z/21 GEFS MEAN...GEM GLOBAL...AND UKMET ARE LARGELY
SUPPORTIVE OF THE UPDATE PACKAGE...PARTICULARLY OUT AT DAY 6...SO
MADE NO CHANGES FOR THE FINAL ISSUANCE. THE PARALLEL VERSION OF
THE GFS CLUSTERS BETTER WITH THE PREFERRED GUIDANCE THAN THE
OPERATIONAL VERSION...THOUGH BOTH MODELS HANDLE THE ENERGY OVER
THE GULF OF MEXICO DIFFERENTLY THAN THE TPC COORDINATED TRACK OF
THE TROPICAL LOW. THE POLAR FRONT WILL BE ABOUT AS SHARP AS PEAK
SUN ANGLE CAN SUPPORT...WITH BLISTERING HEAT FROM THE MID ATLANTIC
SOUTHWARD...AND COOL...DRY AIR OVER THE SAINT LAWRENCE VALLEY AND
INTERIOR NEW ENGLAND LATE IN THE PERIOD.


CISCO

[stayawaynow]

Ivanhater. That is a great graphic. What site is it from?

[TexasF6]

hardcoreweather.com looks like our website, but nowhere near the cailber...

[sphelps8681]

Where on the Texas coast could it be heading if anything developes? I do understand things change regularly. Or maybe I should ask which model shows it heading to Texas and where?

Thanks

[HURAKAN]

Where on the Texas coast could it be heading if anything developes? I do understand things change regularly. Or maybe I should ask which model shows it heading to Texas and where?

Thanks

Way, way, way too early to say anything about where it could end up. At this moment, your guess is as good as the computer models'.

[gatorcane]

I wont be crazy looking at models until there is a well defined LLC.

For pinpointing track, yes, but I should be able to look at models to determine if they think a tropical system is going to form or not. Right now none of them think one will form out of this.

BTW to all:

Here is a link to the UKMET, a good model for forecasting cyclogenesis and long-term large-scale steering patterns. It shows NADA out through 120 hours. Note the big Western Atlantic ridge over Bahamas, Florida, and Eastern GOM holding strong at 120 hours still.

To see what I mean, go to this link, scroll down to the bottom of the page where it says "Tropical Plots" row "500mb Heights/PMSL" and click the X under the 120 hr column.

http://raleighwx.easternuswx.com/models/ukmet.html

[KWT]

Actually a very strange run from the 12z ECM, because it heads due north as the trough approaches, then as the trough axis moves to the north of the system, for some unthinkable reason the system buckles due west again, one of the two of those is an anomaly on this run, probably the due north jump given the upper ridge present.

12z ECM far closer to what you'd expect and also to its own ensembles, in fact its nearly a splitting image of the 0z ECM runs.

Still the SHIPS see favourable conditions, so alas needs watching still IMO...

[Weatherfreak000]

Also, its worthy to note the 18Z runs supposedly arent the most reliable. 00Z runs have the best data input.


Is this correct? I was under the impression it was.

[Aquawind]

Yes the 12Z and 00Z runs have fresh data..

[CourierPR]

I wont be crazy looking at models until there is a well defined LLC.

For pinpointing track, yes, but I should be able to look at models to determine if they think a tropical system is going to form or not. Right now none of them think one will form out of this.

BTW to all:

Here is a link to the UKMET, a good model for forecasting cyclonesis and long-term large-scale steering patterns. It shows NADA out through 120 hours. Note the big Western Atlantic ridge over Bahamas, Florida, and Eastern GOM holding strong at 120 hours still.

To see what I mean, go to this link, scroll down to the bottom of the page where it says "Tropical Plots" row "500mb Heights/PMSL" and click the X under the 120 hr column.

http://raleighwx.easternuswx.com/models/ukmet.html

Well, AccuWeather seems to believe there is a possibility of 93L developing by week's end and something developing near the Bahamas after that. I guess they pulled that out of a hat. By the way, what is "cyclonesis"?

[Aquawind]

Cyclogenesis
(Abbrev. CYCLGN) - The formation or intensification of a cyclone or low-pressure storm system.

[CourierPR]

Cyclogenesis
(Abbrev. CYCLGN) - The formation or intensification of a cyclone or low-pressure storm system.

I am well aware what cygclogenesis is. If you look at the quote it is written as CYCLONESIS.

[Ivanhater]

18z NAM for the records

[lonelymike]

Also, its worthy to note the 18Z runs supposedly arent the most reliable. 00Z runs have the best data input.


Is this correct? I was under the impression it was.

To note the EC is run twice daily with fresh data.

[HouTXmetro]

I remember a few years back like 2003 I think Hurricane Claudette was barreling NNW towards TX/LA border then ran smack into a HP Ridge and immeditaley turned west and made landfall in the Central TX coast.

[cycloneye]

For information only.18z GFDL has the full 126 hours in this run and ends in the central GOM.

WHXX04 KWBC 212323
CHGQLM
ATTENTION...NATIONAL HURRICANE CENTER

NCEP COUPLED GFDL HURRICANE MODEL FORECAST MADE FOR

TROPICAL DEPRESSION INVEST 93L

INITIAL TIME 18Z JUN 21

DISCLAIMER ... THIS INFORMATION IS PROVIDED AS GUIDANCE. IT
REQUIRES INTERPRETATION BY HURRICANE SPECIALISTS AND SHOULD
NOT BE CONSIDERED AS A FINAL PRODUCT. PLEASE SEE THE TPC/NHC
OFFICIAL FORECAST.


FORECAST STORM POSITION

HOUR LATITUDE LONGITUDE HEADING/SPEED(KT)

0 13.2 67.6 290./11.1
6 14.3 68.8 311./15.8
12 15.0 69.6 314./10.3
18 15.8 71.4 293./19.1
24 16.4 72.6 295./13.1
30 16.8 73.6 296./10.6
36 17.5 75.0 297./15.2
42 18.1 76.2 294./12.4
48 18.5 77.3 294./10.9
54 19.1 78.1 305./ 9.3
60 19.3 79.0 283./ 9.4
66 19.7 80.0 293./10.0
72 20.2 80.7 306./ 7.9
78 20.7 82.0 291./13.8
84 21.0 82.8 291./ 7.8
90 21.5 83.6 304./ 9.1
96 22.0 84.6 292./10.1
102 22.4 85.2 309./ 6.9
108 22.8 85.8 302./ 7.2
114 23.4 86.4 315./ 7.9
120 23.9 86.6 335./ 5.5
126 24.3 86.7 351./ 4.3

[HURAKAN]

18z GFDL

[cycloneye]

18z GFDL Animation