evening ivan forecast... rightward shift

LowMug · #21 Postby **LowMug** » Mon Sep 13, 2004 8:48 pm

Derek Ortt wrote:Low Mug,

you have every right to be critical. It shows that you care in what we are attempting to do, and it shows that you are monitoring the situation closely enough to notice these things and are on top of the storm.

dont let your guard down though, this is still a significant threat to you and is not all that far from you, well within the margin of error

Derek,

Was not trying to be critical in a negative way. I only was asking for the reasoning behind the shift. I thank you for your time and explanation and look forward to the next forecast...

AL Chili Pepper · #22 Postby **AL Chili Pepper** » Mon Sep 13, 2004 8:49 pm

Read the coordinates NFL....not the graphic. It hasn't been updated.

#23 Postby **PurdueWx80** » Mon Sep 13, 2004 8:50 pm

Evening upper air maps for your enjoyment:

http://www.rap.ucar.edu/weather/upper/upaCNTR_200.gif
http://www.rap.ucar.edu/weather/upper/upaCNTR_300.gif
http://www.rap.ucar.edu/weather/upper/upaCNTR_500.gif

Edit: Don't pay quite as much attention to the stuff added to these maps (height lines, etc.) as they are model-generated. They generally fit very well w/ the obs though.

#24 Postby **tronbunny** » Mon Sep 13, 2004 9:03 pm

derek, you mentioned some bad data.
I just read the 1Z recon text.

NOUS42 KWNO 140123

ADMNFD

SPECIAL NCEP DISCUSSION

CENTRAL OPERATIONS/NCEP/NWS/WASHINGTON DC

0120 UTC TUE SEP 14 2004

140120Z...00Z NCEP PRODUCTION IS RUNNING

ON TIME..

RAOB REPORT..

AMA/72363 - 10142

OAK/72493 - PURGED ALL HGTS AND TEMPS...BAD

DATA...PURGED WINDS 240MB AND UP...TOO

STRONG

Is that the bad data you referred to?

Derek Ortt · #25 Postby **Derek Ortt** » Mon Sep 13, 2004 9:04 pm

there was some shift right before landfall.

It may have been a garp problem as well. those obs just didnt make total sense

Derek Ortt · #26 Postby **Derek Ortt** » Mon Sep 13, 2004 9:05 pm

ah,

maybe the ncep does make some sense. I was wondering why the weakness would still be a relative 500mb ridge

rainstorm · #27 Postby **rainstorm** » Mon Sep 13, 2004 9:05 pm

hurricane warning needed for tampa?? and along east coast?

AL Chili Pepper · #28 Postby **AL Chili Pepper** » Mon Sep 13, 2004 9:07 pm

Uh huh. So the models ran with bad data too? This is getting interesting!

#29 Postby **PurdueWx80** » Mon Sep 13, 2004 9:08 pm

tronbunny wrote:derek, you mentioned some bad data.
I just read the 1Z recon text.
NOUS42 KWNO 140123

ADMNFD

SPECIAL NCEP DISCUSSION

CENTRAL OPERATIONS/NCEP/NWS/WASHINGTON DC

0120 UTC TUE SEP 14 2004

140120Z...00Z NCEP PRODUCTION IS RUNNING

ON TIME..

RAOB REPORT..

AMA/72363 - 10142

OAK/72493 - PURGED ALL HGTS AND TEMPS...BAD

DATA...PURGED WINDS 240MB AND UP...TOO

STRONG

Is that the bad data you referred to?

OAK is San Francisco...that is hardly affecting the heights over the Gulf. AMA is in TX..but it doesn't say what is up there.

Guest · #30 Postby **Guest** » Mon Sep 13, 2004 9:21 pm

Derek Ortt wrote:we have shifted back to the right as we may have had some bad 12Z upper air obs that went into the 12Z forecast

http://www.nwhhc.com/atl092004forecast.html

Derek, I certainly respect what you do, however, I have direct access to the Coastal Weather Research Center @ the University of South Alabama, a paid service offered to local and coastal businesses. They have been using a model that has been developed at the university. That model accurately forecasted Andrew,Danny & George up to and through landfall. The current forecast is for direct landfall on AL/MS line, and that doesn't include any bad data. Good luck with your forecast, I'm putting my bet on Dr. Aaron Williams, he has always been accurate. 8-)

cind52 · #31 Postby **cind52** » Mon Sep 13, 2004 9:24 pm

Sean in New Orleans wrote:Good news for New Orleans and a small sigh of relief as we watch....

Sean how can you say good news for New Orleans all models point to the mouth of the river

Derek Ortt · #32 Postby **Derek Ortt** » Mon Sep 13, 2004 9:25 pm

as I said, it may have been garp. we got every ob just a few minutes after 0z.

DO NOT EXPECT ANY MORE MAJOR SHIFTS FROM HERE ON. Anyone between Grand Isle and Panama Ciyt remains at risk for a direct hit, and all of those areas are within the margin of error

rainstorm · #33 Postby **rainstorm** » Mon Sep 13, 2004 9:28 pm

i am scared now. ne right up the east coast as a cat3?

Stormsfury · #34 Postby **Stormsfury** » Mon Sep 13, 2004 9:28 pm

Code: Select all

MODEL DIAGNOSTIC DISCUSSION
NWS HYDROMETEOROLOGICAL PREDICTION CENTER CAMP SPRINGS MD
125 PM EDT MON SEP 13 2004
 
VALID SEP 13/1200 UTC THRU SEP 16/0000 UTC
 
MODEL INITIALIZATION...

COMPARED TO LATEST WV IMAGERY.. THE ETA AND NGM ARE TOO
SLOW WITH THE S/WV IMPULSE MOVING INTO THE PACIFIC NW WHILE
THE FASTER GFS LOOKS BETTER.

ALONG THE ALASKA COASTLINE... THE GFS WAS BETTER INITIALIZED
WITH THE SFC LOWS WHILE THE ETA AND NGM WERE TOO FAR TO THE
SOUTH.

THOUGH DIFFICULT TO TELL DUE TO THE LACK OF UPPER AIR DATA
OVER THE CENTRAL GULF.. BASED ON WV IMAGERY AND THE WAY THE
MSTR IS MOVING OVER THE REGION.. IT LOOKS LIKE THE GFS IS
BETTER INITIALIZED WITH THE UPPER RIDGE THAT EXTENDS FROM
TEXAS ACROSS THE GULF AND INTO FLORIDA.

THE GFS IS ALSO DOING A BETTER JOB DRAWING FOR THE UPPER LOW
OVER WRN TN THAN IS THE ETA.

MODEL TRENDS...

ALL THE MODELS ARE SHOWING GOOD CONTINUITY WITH THE COLD
FRONT PUSHING THRU THE UPPER MS VLY... THOUGH THE ETA IS JUST
SLIGHTLY SLOWER.

ALONG THE PAC NW COAST... THE ETA IS FARTHER SOUTH THAN ITS
PREVIOUS RUN WITH THE SYSTEM MOVING ONSHORE INTO SWRN B.C.
BY THE END OF THE PERIOD. THE GFS IS CONSISTENT WITH THIS
SYSTEM.

MODEL DIFFERENCES AND PREFERENCES...

BOTH THE ETA AND GFS ARE FARTHER SOUTH WITH THE FRONT OVER
THE CENTRAL PLAINS COMPARED TO THE NGM AND ARE THE
PREFERRED SOLUTIONS.

OFF THE NW COAST... THE ETA IS FASTER THAN THE GFS IN BRINGING
THE NEXT SYSTEM INLAND AND ACROSS SRN BRITISH COLUMBIA. AS
THE GFS HAS BEEN MORE CONSISTENT WITH THIS SYSTEM... WE
PREFER THE GFS.

OVER THE UPPER MS VLY... THE GFS IS STRONGER WITH THE S/WV
TROF LIFTING UP TOWARDS THE GREAT LAKES THAN THE ETA. AGAIN..
THE GFS IS MORE CONSISTENT WITH THIS SYSTEM AND IS THE
PREFERRED MODEL AGAIN.


ROBSON

LowMug · #35 Postby **LowMug** » Mon Sep 13, 2004 9:37 pm

Yea well that is not good for me given the latest GFS run has it over the AL-MS border...

So what gives

Ripopgodazippa · #36 Postby **Ripopgodazippa** » Mon Sep 13, 2004 9:44 pm

NHC shifted to the left. Mobile Bay.

Ixolib · #37 Postby **Ixolib** » Mon Sep 13, 2004 9:47 pm

In looking at this thread, I'm now quite confused (although I'm not nearly close to being knowledgable enough to even be reading it

).
Anyway, these are the questions my confused mind has conceived:

1. Is the Ortt forecast valid on this run, or was it the last forecast with "bad" data?
3. What does it mean there will be no more shifts?

LowMug · #38 Postby **LowMug** » Mon Sep 13, 2004 9:47 pm

Ripopgodazippa wrote:NHC shifted to the left. Mobile Bay.

I just saw that...thanks Ripoa;lfjl;fa;fhljfloue...whatever all that is

pvbeach · #39 Postby **pvbeach** » Mon Sep 13, 2004 9:51 pm

Confused here too - I apologize, I'm new - but this thread doesnt make sense. I'm reading everything from Mobile to Cedar Key to up the East Coast??? Derek, do you have a graphic for your forecast? Thank you!

#40 Postby **PurdueWx80** » Mon Sep 13, 2004 9:51 pm

Derek didn't make this forecast...the forecaster is always listed at the bottom of the page. Derek makes an assumption that there was bad data based on his observations. This is a subjective yet educated opinion, not based on any fact though. Iloxib - I think he means there will be no wild shifts in the NWWHC's forecast tracks from here on out - he is referring to the jump made based on the presumption of bad data and observations of the trough pulling Ivan NNW this afternoon/evening.

evening ivan forecast... rightward shift

Re: evening ivan forecast... rightward shift

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