Dunkman Posted August 30, 2011 Share Posted August 30, 2011 Great, thank you for your response (and everyone else, as well). Are there statistics somewhere which would show how accurately the global models or hurricane models forecast the strength of these ridges and troughs? I think you could find statistics for how they track tropical cyclones, and statistics for how they perform as a whole. This is a good place to start. http://www.emc.ncep....TATS/STATS.html http://www.emc.ncep.noaa.gov/gmb/STATS_vsdb/ Link to comment Share on other sites More sharing options...
Juliancolton Posted August 30, 2011 Share Posted August 30, 2011 So, how to properly pronounce Katia? The official pronunciation is described as "KAH-tyah" - my mind still wants to read "Katie-ah" though... Link to comment Share on other sites More sharing options...
hurricaneschwartz Posted August 30, 2011 Share Posted August 30, 2011 NHC pronunciation guide says ....ka TEE ah Glenn Link to comment Share on other sites More sharing options...
Juliancolton Posted August 30, 2011 Share Posted August 30, 2011 NHC pronunciation guide says ....ka TEE ah Glenn Glenn, Where did you find that info? The list I've been using (http://www.nhc.noaa.gov/pdf/aboutnames_pronounce_atlc.pdf) says it's "KAH-tyah", which still makes no sense... ka-TEE-ah would be easier on the tongue. Link to comment Share on other sites More sharing options...
hurricaneschwartz Posted August 30, 2011 Share Posted August 30, 2011 Glenn, Where did you find that info? The list I've been using (http://www.nhc.noaa....nounce_atlc.pdf) says it's "KAH-tyah", which still makes no sense... ka-TEE-ah would be easier on the tongue. Interesting. I printed out the pronunciation guide in June. Could they have made a correction? I've never seen it change like that. Now I don't know what to say on-air. I've been saying ka-TEE-ah all day. Glenn Link to comment Share on other sites More sharing options...
gymengineer Posted August 30, 2011 Share Posted August 30, 2011 Glenn, Where did you find that info? The list I've been using (http://www.nhc.noaa....nounce_atlc.pdf) says it's "KAH-tyah", which still makes no sense... ka-TEE-ah would be easier on the tongue. How does KAH-tyah make no sense? It's a common female name across several different languages (Spanish, Russian, etc.). This particular spelling is just one variation. Link to comment Share on other sites More sharing options...
Juliancolton Posted August 30, 2011 Share Posted August 30, 2011 How does KAH-tyah make no sense? It's a common female name across several different languages (Spanish, Russian, etc.). This particular spelling is just one variation. I meant WRT choosing the proper pronunciation. Link to comment Share on other sites More sharing options...
Juliancolton Posted August 30, 2011 Share Posted August 30, 2011 Well, we have more time to ponder it. SINCE THAT TIME THE CURVED BAND HAS DISSIPATED...AND THE CONVECTIVE PATTERN HAS DEVOLVED INTO MORE OF A SHEAR PATTERN. A SMALL BURST OF DEEP CONVECTION HAS DEVELOPED OVER AND JUST WEST OF THE CENTER...BUT ONE THUNDERSTORM DOES NOT MAKE A TROPICAL STORM. THEREFORE...THE INTENSITY IS BEING HELD AT 30 KT FOR THIS ADVISORY. Link to comment Share on other sites More sharing options...
NickD2011 Posted August 30, 2011 Share Posted August 30, 2011 I know someone named Katia who pronounces her name Ka-TEE-ah Link to comment Share on other sites More sharing options...
Torontoweather14 Posted August 30, 2011 Share Posted August 30, 2011 No TS at 11 p.m. NHC 11 p.m. update Link to comment Share on other sites More sharing options...
TheWeatherPimp Posted August 30, 2011 Share Posted August 30, 2011 Interesting NHC discussion on Tropical Depression 12 tonight. They are leaning towards the future Katia moving more West than Northwest at the end of the forecast period. "THIS CHANGE IN THE STEERING FLOW SHOULD KEEP THE CYCLONE MOVING ON A WEST-NORTHWESTWARD TRACK FOR THE NEXT 4 DAYS...AND THEN SLOW DOWN AND POSSIBLY TURN MORE WESTWARD BY DAY 5 AS A NARROW RIDGE DEVELOPS TO THE NORTH AND WEST OF THE SYSTEM. SINCE THE DEPRESSION IS BASICALLY ON TRACK...THE NEW NHC FORECAST IS JUST AN UPDATE AND EXTENSION OF THE PREVIOUS ADVISORY TRACK." Link to comment Share on other sites More sharing options...
st80ugfd80 Posted August 30, 2011 Share Posted August 30, 2011 No TS at 11 p.m. NHC 11 p.m. update Perhaps by 0600? Ive been watching the sat loop, saw some pretty good flare up but since has dicipated. Link to comment Share on other sites More sharing options...
jburns Posted August 30, 2011 Share Posted August 30, 2011 Perhaps by 0600? Ive been watching the sat loop, saw some pretty good flare up but since has dicipated. God, I hate it when I dicipate. Link to comment Share on other sites More sharing options...
Floydbuster Posted August 30, 2011 Share Posted August 30, 2011 Does anybody know the exact set-up for Frances? Was the there just not enough time for the trough to cause a second weakness or was the ridging just ultra-dominant? Link to comment Share on other sites More sharing options...
OHweather Posted August 30, 2011 Share Posted August 30, 2011 Just a couple of thoughts on TD 12… Given the generally well agreed on large scale pattern shownon models in a week to 10 days, TD 12/Katia needs to gain as little latitude as possible before getting to 65-70W. The PNA, which was positive while Irene was making a run at the east coast and contributed to shortwaves amplifying west of the east coast given short wave lengths, is expected to become neutral if not negative per the NAEFS during the coming days and is currently modeled to remain in that state through day 14, at least. While there is a chance this changes in the coming days, the GFS/ECM ensembles are both in relatively good agreement in heights becoming higher than normal over the western Aleutians, forcing a trough off the west coast that shifts ridging east well into the western CONUS/Canada. This in turn forces below normal heights near the east coast, as opposed to Irene when the ridging was along the west coast and forced shortwaves to amplify over the Great Lakes given the short late summer wavelengths. The GFS, and ECM ensembles both reflect this well at D10: 12z Euro ensembles: 12z GFS ensembles: In addition, there will not be higher than normal heights over the Davis Strait/Greenland to force a sharper trough over the eastern US/Great Lakes which would potentially draw a hurricane farther west if in place (like with Irene). This all may change, but the ensembles are both in pretty strong agreement on these main upper level features at this time. Given this, I believe the chances of recurve—likely between the US east coast and Bermuda given likely troughing along the east coast—are at around 85% if this system passes north of 25N, 70W. It’s not necessarily the normal benchmark (20N, 60W) but I believe it works better in this situation given where it looks like the troughing may be located and how amplified it might be in the 1-2 week timeframe. The other 15% would be something unforeseen like an unexpected weakening of the trough or a much weaker system. Now, working backwards, what are the odds this system doesn’t gain too much latitude in the short term? TD 12 is currently at a low latitude, south of 10N. However, there is a weakness in ridging between 40-50W that the system is approaching. This should result in a WNW over the next couple days as TD-12 approaches this weakness. However, the global models agree on weakening this weakness and strengthening ridging over the subtropical Atlantic north of TD 12 over the next couple of days, and by day 4 the 12z Euro showed solid ridging to almost 70W. This should result in a continued WNW motion. However, note how the heart of the ridging is located to the east of the cyclone per the ECM. This general trend is modeled to continue. The ridging will attempt to build west, however troughing will remain along the east coast with shortwaves continuing to move east (as discussed above) which will keep the western Atlantic ridging noticeably weaker than the eastern Atlantic ridging. This should continue to allow TD 12 to continue gaining latitude for the forseeable future. I’m by no means expecting an early recurve, however given what will likely be a strong system within a few days and weaker ridging over the west Atlantic, it will be hard for TD 12 to be far enough south when it gets to 60-70W to avoid being recurved by likely troughing along the east coast. A track between the goal posts seems to be a good first guess. Link to comment Share on other sites More sharing options...
donsutherland1 Posted August 30, 2011 Share Posted August 30, 2011 Perhaps the most ominous part of the 11 pm discussion is: THIS CHANGE IN THE STEERING FLOW SHOULD KEEP THE CYCLONE MOVING ON A WEST-NORTHWESTWARD TRACK FOR THE NEXT 4 DAYS...AND THEN SLOW DOWN AND POSSIBLY TURN MORE WESTWARD BY DAY 5 AS A NARROW RIDGE DEVELOPS TO THE NORTH AND WEST OF THE SYSTEM. It will be interesting to see if the 8/30 0z Euro shifts farther to the south and west relative to the 8/29 12z run. I took a further look at the region in which TD 12 developed, looking at all storms that formed in the vicinity of 7.4N-11.4N/21.3W-31.3W since 1950. 13/19 (68%) of storms grew into hurricanes. 11/13 (85%) of the hurricanes were major hurricanes. 9/13 (69%) of the hurricanes reached Category 4 or 5 with 4/13 (31%) reaching Category 5. 6/19 (32%) of the storms made U.S. landfall and all 6 storms were hurricanes. Hence, of the storms that grew to hurricane status, 46% made U.S. landfall. 6 hurricanes recurved, 3 tropical storms recurved, and 3 tropical storms fizzled out. 1 hurricane made Canadian landfall. In contrast, less than 14% of tropical cyclones that formed east of 30W made U.S. landfall. Overall, odds of TD 12's (future Katia) making U.S. landfall are greater than the climatological norm for Cape Verde storms. If the satellite guidance is right, TD 12 is close to tropical storm status. My guess is that it will become TS Katia at the 5 am advisory somewhere in the vicinity of 31W. Afterward, based on a blend of the computer guidance and historic statistics for hurricanes that formed in the region in which TD 12 originated, TD 12 should grow into a hurricane by the time it reaches an area in the 39.5W-44.5W vicinity. Development into a hurricane at the slower part of the range (farther west) does not necessarily mean that the storm wouldn't grow into a Category 4 or 5 storm. Cleo (Cat. 5), Donna (Cat. 5), Frederic (Cat.4), and Ivan (Cat. 5) all reached hurricane status 12° or more West than when they became tropical storms. Link to comment Share on other sites More sharing options...
Torontoweather14 Posted August 30, 2011 Share Posted August 30, 2011 Perhaps by 0600? Ive been watching the sat loop, saw some pretty good flare up but since has dicipated. I think we should have a TS by 11 a.m. tomorrow, if not earlier. Link to comment Share on other sites More sharing options...
Torontoweather14 Posted August 30, 2011 Share Posted August 30, 2011 Latest Early 00z Hurricane models FWIW: Track: http://euler.atmos.c...rack_early1.png Intensity: http://euler.atmos.c...sity_early1.png It lists it as Tropical Storm 12 which is kind of funny, as that name is a mix of a Tropical Depression and a tropical storm, with the tropical storm title, but no name. I guess they got confused! Link to comment Share on other sites More sharing options...
Big Jims Videos Posted August 30, 2011 Share Posted August 30, 2011 Don S, as always thanks for posting great information. Lets just be glad the cable news anchors/producers dont understand model readings...because the hype machine will sure to start up again. Link to comment Share on other sites More sharing options...
Torontoweather14 Posted August 30, 2011 Share Posted August 30, 2011 Latest Early 00z Hurricane models FWIW: Track: http://euler.atmos.c...rack_early1.png Intensity: http://euler.atmos.c...sity_early1.png It lists it as Tropical Storm 12 which is kind of funny, as that name is a mix of a Tropical Depression and a tropical storm, with the tropical storm title, but no name. I guess they got confused! If direct link doesn't work, copy and paste the link into another tab or window and then enter it. Should work then. Link to comment Share on other sites More sharing options...
QVectorman Posted August 30, 2011 Share Posted August 30, 2011 Don thanks for the stats!!! In regards to the ECMWF trends I have noticed it keeps building the ridge farther west with each run and as you stated is trending the TC a little more SW with each run. We have a couple hundreds runs to go til show time Waiting to see the 0z trend Link to comment Share on other sites More sharing options...
donsutherland1 Posted August 30, 2011 Share Posted August 30, 2011 Don thanks for the stats!!! Thanks Jim and QVectorman. Link to comment Share on other sites More sharing options...
st80ugfd80 Posted August 30, 2011 Share Posted August 30, 2011 Sat. imagery showing some very decent blossoming! Looking real nice up to 0415UTC Link to comment Share on other sites More sharing options...
GaWx Posted August 30, 2011 Share Posted August 30, 2011 - I found 48 TC’s from the period 1960-2010 that had formed by 28W and which were located between 8-17N near the longitude where TD #12 was declared (26.3W). Of these 48, 10 (21%) went on to hit the CONUS. - Of the other 38, 11 (23%) dissipated over the ocean prior to a recurve (the category often neglected in discussions), 27 (56%) recurved, and none moved into MX or C.A. - Five of the ten hits were from TC’s near the 10-11N range, two were near 12-13N, and the other three were near 14N. So, all were within ~10-14 N. A respectable six of the 20 (30%) within the 8-12N range, where TD #12 was located, later hit the CONUS. So, the low lat. helps TD #12/Katia’s CONUS hit chances, which is intuitive. - However, the hit chances are reduced substantially when considering TD #12’s heading between ~25 and 30W: 1) The range of headings for the 48 TC’s was from ~250 deg. (WSW) to ~315 deg. (NW). ALL ten hits were from TC’s with headings of ~260-280 deg.! There was only one TC of the 48 that was less than 260 (with it at ~250). I count 25 TC’s with headings of ~260-280 deg. So,a whopping 40% of the 25 TC’s with a 260-280 heading hit the CONUS! Also, three others of the 260-280 group made it further west than 70W. A respectable 8 of the 26 TC’s (31%) with headings within ~250-280 deg. dissipated. So, only 8 of the 26 (31%) with headings of 250-280 recurved. 2) OTOH, there were 22 TC’s within the ~281-315 deg. interval with 21 of these 22 within ~281-300. NONE of those 22 got any closer than ~500 miles from the CONUS or made it to 70W! (The closest was Luis of 1995.) That is in stark contrast to the 13 of the 25 in the 260-280 group making it at least to 70W. A whopping 19 of the 22 (86%) recurved, which is almost three times the % of those with headings of 250-280! 3) TD #12 is on a heading of ~290 deg. (WNW) per the 11 PM EDT 8/29 NHC advisory discussion. I count only seven of the 48 TC’s with headings of ~290+. The furthest west/closest to the CONUS any of these seven got was 65.9W/~700 miles (Igor of 2010). 4) Therefore, despite the low lat. of TD #12, I feel comfortable maintaining a high (say ~90%) chance that TD #12/Katia will not hit the CONUS, especially considering that the GFS/Euro still show/suggest a recurve due to a lack of sig. high pressure over the W Atl. If the lat. had not been so low, I may have already gone with ~95% chance of no hit. I will update my %’s over the days to come. Link to comment Share on other sites More sharing options...
st80ugfd80 Posted August 30, 2011 Share Posted August 30, 2011 Im somewhat new to the tropic side of weather, but it sure looks like the storm is developing some good outflow? Im refering to the cloud formations off the outer edge of storm that would eventually give the storm the "Buzzsaw" look. Am I right or way off? Link to comment Share on other sites More sharing options...
Shawn Posted August 30, 2011 Share Posted August 30, 2011 8/30//29//2011 00z Euro: Ruins an SC track, but there's still a chance.. (long chance) of a East coast impact. The problem with this once again is it's 240 hours out and the NHC speaking of a due West track 5 days from now is even more omnious. Either way, (: For anyone who wants to see these models themselves and who don't know where to find them, they are located at Allen's site here: Allen's Site! Link to comment Share on other sites More sharing options...
st80ugfd80 Posted August 30, 2011 Share Posted August 30, 2011 nearly 300 miles wide already Link to comment Share on other sites More sharing options...
phlwx Posted August 30, 2011 Share Posted August 30, 2011 Officially Katia. 11.8/31.7, WNW 17. Five day takes it to 100 kt Link to comment Share on other sites More sharing options...
jconsor Posted August 30, 2011 Share Posted August 30, 2011 Links to tropical cyclone ensemble forecasts: http://ruc.noaa.gov/hfip/tceps/2011/ http://ruc.noaa.gov/tracks/ ECMWF ensembles out to 5 days for Katia: Link to comment Share on other sites More sharing options...
am19psu Posted August 30, 2011 Share Posted August 30, 2011 Perhaps the most ominous part of the 11 pm discussion is: THIS CHANGE IN THE STEERING FLOW SHOULD KEEP THE CYCLONE MOVING ON A WEST-NORTHWESTWARD TRACK FOR THE NEXT 4 DAYS...AND THEN SLOW DOWN AND POSSIBLY TURN MORE WESTWARD BY DAY 5 AS A NARROW RIDGE DEVELOPS TO THE NORTH AND WEST OF THE SYSTEM. It will be interesting to see if the 8/30 0z Euro shifts farther to the south and west relative to the 8/29 12z run. I took a further look at the region in which TD 12 developed, looking at all storms that formed in the vicinity of 7.4N-11.4N/21.3W-31.3W since 1950. 13/19 (68%) of storms grew into hurricanes. 11/13 (85%) of the hurricanes were major hurricanes. 9/13 (69%) of the hurricanes reached Category 4 or 5 with 4/13 (31%) reaching Category 5. 6/19 (32%) of the storms made U.S. landfall and all 6 storms were hurricanes. Hence, of the storms that grew to hurricane status, 46% made U.S. landfall. 6 hurricanes recurved, 3 tropical storms recurved, and 3 tropical storms fizzled out. 1 hurricane made Canadian landfall. In contrast, less than 14% of tropical cyclones that formed east of 30W made U.S. landfall. Overall, odds of TD 12's (future Katia) making U.S. landfall are greater than the climatological norm for Cape Verde storms. If the satellite guidance is right, TD 12 is close to tropical storm status. My guess is that it will become TS Katia at the 5 am advisory somewhere in the vicinity of 31W. Afterward, based on a blend of the computer guidance and historic statistics for hurricanes that formed in the region in which TD 12 originated, TD 12 should grow into a hurricane by the time it reaches an area in the 39.5W-44.5W vicinity. Development into a hurricane at the slower part of the range (farther west) does not necessarily mean that the storm wouldn't grow into a Category 4 or 5 storm. Cleo (Cat. 5), Donna (Cat. 5), Frederic (Cat.4), and Ivan (Cat. 5) all reached hurricane status 12° or more West than when they became tropical storms. Don, thanks for taking the time to post this information. Feel free to contribute more in the tropical threads Link to comment Share on other sites More sharing options...
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