Amped Posted September 4, 2011 Share Posted September 4, 2011 NAM looks like the euro from several days ago. Would be fascinating to see two llc's split apart like that. Yo can see it statrting to elongate a little to the east. Also concerning is that the NAM is further south than 18z. We'll see it by tomorrow morning if it's going to happen. Link to comment Share on other sites More sharing options...
janetjanet998 Posted September 4, 2011 Share Posted September 4, 2011 it did jog WSW since 7pm .1 S and .2W BULLETIN TROPICAL STORM LEE ADVISORY NUMBER 10 NWS NATIONAL HURRICANE CENTER MIAMI FL AL132011 1000 PM CDT SAT SEP 03 2011 ...LEE STILL MEANDERING NEAR THE COAST OF SOUTHERN LOUISIANA... SUMMARY OF 1000 PM CDT...0300 UTC...INFORMATION ----------------------------------------------- LOCATION...29.4N 92.6W ABOUT 85 MI...140 KM WSW OF MORGAN CITY LOUISIANA ABOUT 65 MI...105 KM SSW OF LAFAYETTE LOUISIANA MAXIMUM SUSTAINED WINDS...50 MPH...85 KM/H PRESENT MOVEMENT...NNW OR 335 DEGREES AT 2 MPH...4 KM/H MINIMUM CENTRAL PRESSURE...988 MB...29.18 INCHES Link to comment Share on other sites More sharing options...
Ed Lizard Posted September 4, 2011 Share Posted September 4, 2011 Lee may be bringing nearly TS sustained winds to GLS, but 10 pm CDT warnings don't look to have changed as far as Sabine Pass being the Western end. Link to comment Share on other sites More sharing options...
janetjanet998 Posted September 4, 2011 Share Posted September 4, 2011 TROPICAL STORM LEE DISCUSSION NUMBER 10 NWS NATIONAL HURRICANE CENTER MIAMI FL AL132011 1000 PM CDT SAT SEP 03 2011 NATIONAL WEATHER SERVICE RADAR DATA AND SURFACE OBSERVATIONS INDICATE THAT THE CENTER OF LEE HAS BEEN MEANDERING NEAR THE SOUTHERN COAST OF LOUISIANA THIS EVENING. AN OIL PLATFORM LOCATED ABOUT 20 MILES WEST OF MARSH ISLAND HAS BEEN REPORTING A PRESSURE OF AROUND 988 MB MOST OF THE EVENING. THE WINDS AT THAT SITE WERE VARIABLE FOR SEVERAL HOURS...BUT RECENTLY HAVE SHIFTED TO THE SOUTHEAST AROUND 15-20 KT INDICATING THAT THE CENTER OF LEE REMAINS OFFSHORE. THE HIGHEST SUSTAINED WIND OBSERVATIONS DURING THE PAST FEW HOURS ARE 40-44 KT AT SEVERAL ELEVATED RIGS OFF THE COAST OF SOUTHWEST LOUISIANA. BASED ON THESE OBSERVATIONS...THE INITIAL INTENSITY IS SET AT 45 KT...WHICH COULD BE A LITTLE GENEROUS. LEE IS EXPECTED TO WEAKEN AS IT MOVES INLAND DURING THE NEXT DAY OR SO. HOWEVER...SINCE A LARGE PORTION OF THE CIRCULATION WILL REMAIN OVER WATER...LEE WILL LIKELY REMAIN A TROPICAL STORM FOR ANOTHER 24 TO 36 HOURS. LEE IS FORECAST TO DRIFT NORTHWARD DURING THE NEXT DAY OR SO AS A SHORTWAVE TROUGH MOVES INTO THE NORTH-CENTRAL UNITED STATES. AFTER THAT TIME...THE CYCLONE IS EXPECTED TO INTERACT WITH A COLD FRONT THAT SHOULD TURN LEE EASTWARD...THEN NORTHEASTWARD WITHIN 24 TO 36 HOURS. BOTH THE GFS AND ECMWF MODELS SUGGEST LEE WILL BECOME AN EXTRATROPICAL CYCLONE IN 2-3 DAYS...A SOMEWHAT UNUSUAL OCCURRENCE IN THIS AREA AT THIS TIME OF YEAR. THE GLOBAL MODELS AND THE OFFICIAL FORECAST ALSO NOW INDICATE DISSIPATION OVER THE SOUTHERN APPALACHIANS IN 4-5 DAYS. THE OFFICIAL FORECAST HAS BEEN SHIFTED WESTWARD THROUGH 24 HOURS DUE TO THE MORE WESTWARD INITIAL POSITION...BUT THE REMAINDER OF THE TRACK IS ESSENTIALLY AN UPDATE OF THE PREVIOUS FORECAST. SINCE HEAVY RAINS AND STRONG WINDS EXTEND VERY FAR FROM THE CENTER IT IS IMPORTANT NOT TO FOCUS ON THE EXACT FORECAST TRACK. Link to comment Share on other sites More sharing options...
mike2010 Posted September 4, 2011 Share Posted September 4, 2011 Looks like their still not budgin.. maybe to protect their butts, they'll classify the secondary track (on the NAM) as Lee eventually.. Link to comment Share on other sites More sharing options...
wxsmwhrms Posted September 4, 2011 Share Posted September 4, 2011 I just do not see any way that the NAM could be close to right. There is no way that all of the models that are robust and have high verification scores could be that wrong - plus, there really isn't any meteorological reason to expect it to be right. Having said that, it could drift just offshore and perhaps the center could remain just offshore. Convection is developing near the center with cooling tops - it will be interesting to watch. One other thing to mention is that mid level dry air has really surged into the area just E and SE of the center, and as this evolves over the next 12-24 hours, this could definitely result in an enhanced tornado risk, particularly over SE LA and southern MS. Link to comment Share on other sites More sharing options...
Cheeznado Posted September 4, 2011 Share Posted September 4, 2011 Agree, NAM is just horrific- new GFS, WSI RPM, RGEM all have the slow east drift, none of this south movement garbage. It is totally safe to throw the NAM out completely. I wonder if the "improved" NAM is better? I do not know where to see it now that NCEP changed web sites..... Link to comment Share on other sites More sharing options...
wxsmwhrms Posted September 4, 2011 Share Posted September 4, 2011 Lee may be bringing nearly TS sustained winds to GLS, but 10 pm CDT warnings don't look to have changed as far as Sabine Pass being the Western end. Buoy 42035 (just SE of GLS Bay) is very close as well. 36 mph sustained gusting to 45 mph. Link to comment Share on other sites More sharing options...
wxsmwhrms Posted September 4, 2011 Share Posted September 4, 2011 New GFS still has the center of Lee sitting along the coast just E of Vermilion Bay at 12Z Mon. Looks a little too far north in the very near term tonight based on the observational data. Link to comment Share on other sites More sharing options...
dan88 Posted September 4, 2011 Share Posted September 4, 2011 GFS looks to be west of the 12z/18z runs, and is in particular slower moving it out. It brings it inland in the short term, then has is drift southward from 24-36 hours, getting it's feet wet at 36 hours. It starts to move out from there, staying close to the coast through 42 hours to the coast (just East of New Orleans at that time) and Southwest of previous runs. Link to comment Share on other sites More sharing options...
Logan11 Posted September 4, 2011 Share Posted September 4, 2011 I find the new NCEP models website to be so annoying. You have to keep resetting the page to shift from each parameter ...e.g 500 mb to 1000-500 to 850 mb etc.... The old simple chart page allowed you to just click on each so easily if you just wanted to do a fast look. I'm sure the new page allows you to do more, but why could they not have kept the other format on a separate link also.... Agree, NAM is just horrific- new GFS, WSI RPM, RGEM all have the slow east drift, none of this south movement garbage. It is totally safe to throw the NAM out completely. I wonder if the "improved" NAM is better? I do not know where to see it now that NCEP changed web sites..... Link to comment Share on other sites More sharing options...
Logan11 Posted September 4, 2011 Share Posted September 4, 2011 It's got to get out of there by Monday sometime or the trough misses it.... then nothing to kick it east anymore. Doesn't mean the NAM is correct in having it southeast of Brownsville. LOL New GFS still has the center of Lee sitting along the coast just E of Vermilion Bay at 12Z Mon. Looks a little too far north in the very near term tonight based on the observational data. Link to comment Share on other sites More sharing options...
wxsmwhrms Posted September 4, 2011 Share Posted September 4, 2011 GFS looks to be west of the 12z/18z runs, and is in particular slower moving it out. It brings it inland in the short term, then has is drift southward from 24-36 hours, getting it's feet wet at 36 hours. It starts to move out from there, staying close to the coast through 42 hours to the coast (just East of New Orleans at that time) and Southwest of previous runs. Agreed, looks to be trending toward the ECMWF (surprise). Link to comment Share on other sites More sharing options...
Chicago Storm Posted September 4, 2011 Share Posted September 4, 2011 I wonder if the "improved" NAM is better? I do not know where to see it now that NCEP changed web sites..... It supports the OP NAM. http://www.nco.ncep.noaa.gov/pmb/nwpara/analysis/namer/nam/00/model_s.shtml Link to comment Share on other sites More sharing options...
Hoosier Posted September 4, 2011 Share Posted September 4, 2011 It supports the OP NAM. http://www.nco.ncep.noaa.gov/pmb/nwpara/analysis/namer/nam/00/model_s.shtml This will be the coup of the year if the NAM pulls this off. Hard to go with it given that it's an extreme outlier. It'd be one thing if it was showing this wacky solution in its outer periods but it starts deviating significantly rather early. Link to comment Share on other sites More sharing options...
Amped Posted September 4, 2011 Share Posted September 4, 2011 This will be the coup of the year if the NAM pulls this off. Hard to go with it given that it's an extreme outlier. It'd be one thing if it was showing this wacky solution in its outer periods but it starts deviating significantly rather early. ETA agrees, SW motion starts between 0z and 3z tomorrow. Link to comment Share on other sites More sharing options...
DAWGNKITTEN Posted September 4, 2011 Share Posted September 4, 2011 Just wondering that if more of the dry air gets entrained or pulled into Lee, would that mean an early demise? Not that I want it, NE GA needs the rain like everywhere else, but looking at the loops it just seems like it's getting more and more dry air pulled into it. Link to comment Share on other sites More sharing options...
Hoosier Posted September 4, 2011 Share Posted September 4, 2011 It would be a coup for the NAM but I'm not sure it can be discounted given that the system is well within range and not at the edges of its areal coverage. Agreed...much easier to dismiss without thinking twice if it were 84 hours out. Link to comment Share on other sites More sharing options...
phil882 Posted September 4, 2011 Share Posted September 4, 2011 This will be the coup of the year if the NAM pulls this off. Hard to go with it given that it's an extreme outlier. It'd be one thing if it was showing this wacky solution in its outer periods but it starts deviating significantly rather early. If you guys need any more examples on why the NAM should never be used as a tropical model, the 00z run should be your answer. It just has no idea how to handle tropical features as it drops Lee down due south along a shear axis as the mid-level trough to the north swings through. No only is this solution a strong outlier, but it also does not make any physical sense. The trough should extend a weakness towards the system, and the typical response should be for it to be picked up to the northeast after a period of slow movement. The NAM instead over-emphasizes the low level vorticity to the east of Lee to the point that it becomes stronger than Lee itself, which causes binary interaction between the two features with Lee forced southward and the area of low level vorticity to the east picked up to the north. This goes along with the typical bias of the NAM overdeveloping every single little bit of vorticity because of improper convective parameterizations made in the tropics. It has a zero percent chance of verifying. Link to comment Share on other sites More sharing options...
earthlight Posted September 4, 2011 Share Posted September 4, 2011 SPC-WRF at least partially in the NAM camp with the center back over water at 30 hrs and then drifting east afterwards..the NAM seems to want to keep a more south motion compared to the SPC-WRF. http://www.emc.ncep.noaa.gov/mmb/mpyle/cent4km/conus/00/ Link to comment Share on other sites More sharing options...
dan88 Posted September 4, 2011 Share Posted September 4, 2011 GFS Ensemble mean is into the gulf past 60 hours, though with the pressures it is probably becoming increasingly divergent with individual members (most likely a left behind camp and a follow the OP camp) Link to comment Share on other sites More sharing options...
earthlight Posted September 4, 2011 Share Posted September 4, 2011 Pretty large distance spread for a 48 hour forecast, but you can see that a good amount of 21z SREF members (the first 15 ARW/NMM/RSM members) are much more in-line with a GFS or GFS Ens type evolution when compared to the 00z NAM or ETA. Not surprisingly the final 6 SREF members (ETA members) have a few isolated solutions similar to the NCEP NAM and ETA. http://www.meteo.psu.edu/~gadomski/SREF21PRSSC_21z/f48.gif Link to comment Share on other sites More sharing options...
phil882 Posted September 4, 2011 Share Posted September 4, 2011 Now I want it to verify just because you said this. I'm always a fan of crazy solutions, and the weenie inside of me wants nothing more than to see it verify and defy all our expectations, but just a glance at the upper level winds over what is suppose to be an intensifying Lee in the Gulf of Mexico frankly doesn't make any sense with the system seemingly developing right over an upper level trough which then magically turns into an area of diverging winds at 48 hours due to convective feedback. Its just all sorts of wrong. Link to comment Share on other sites More sharing options...
dan88 Posted September 4, 2011 Share Posted September 4, 2011 Looking at the individual GFS ensemble members, turns out there isn't all that much divergence after all. During the next 24 hours they all pretty much complete a loop leaving them in the gulf (initial NW motion then S, SE, E), and afterwards they go south of Louisiana and end up near Florida while steadily weakening. Link to comment Share on other sites More sharing options...
phil882 Posted September 4, 2011 Share Posted September 4, 2011 Looks like the eastward drift has commenced! Link to comment Share on other sites More sharing options...
Sunny and Warm Posted September 4, 2011 Share Posted September 4, 2011 Looks like the eastward drift has commenced! That's a pretty significant movement in the last hour or so. Appears to be finally making its eventual move. The models should gain a much better grasp of speed and direction now that it is being picked up by the trough. Can we put the NAM solution to rest now?? Link to comment Share on other sites More sharing options...
kpantz Posted September 4, 2011 Share Posted September 4, 2011 That's a pretty significant movement in the last hour or so. Appears to be finally making its eventual move. The models should gain a much better grasp of speed and direction now that it is being picked up by the trough. Can we put the NAM solution to rest now?? Well, by that loop, it seems we can certainly put the break in precip to rest. Look at that conveyor of heavy precip making its way onshore! Link to comment Share on other sites More sharing options...
DaculaWeather Posted September 4, 2011 Share Posted September 4, 2011 Well, by that loop, it seems we can certainly put the break in precip to rest. Look at that conveyor of heavy precip making its way onshore! Moving NE at 3 mph now. Down to 990mb. Make you GRLevel3 loop of choice from below! Link to comment Share on other sites More sharing options...
NavarreDon Posted September 4, 2011 Share Posted September 4, 2011 A question for you guys. Found this in the GSP AFD. Is this why the NAM is being "wacky"? CONDITIONS WILL START GOING DOWNHILL LATER THIS AFTERNOON. FIRST OFF...THE 00Z NAM SOLUTION WAS THROWN ON THE SCRAP HEAP AS INITIALIZATION ERRORS HAVE EVIDENTLY TRICKED IT INTO A WACKY SOLUTION WHERE T.S. LEE MOVES SOUTH OUT OVER THE WRN GULF. THUS... THE NEW FCST IS LARGELY BASED ON THE 00Z GFS AND 21Z SREF WHICH ARE MUCH MORE IN LINE WITH THE OFFICIAL NHC TRACK OF LEE. THAT BEING SAID...THE MAIN ISSUE WITH THE FCST IS THE DEVELOPMENT OF SHOWERS THIS AFTERNOON IN THE GRADUALLY STRENGTHENING AND MOISTENING S TO SE LOW LEVEL UPSLOPE FLOW...THEN THE ARRIVAL OF THE PRECIP BANDS ASSOCIATED WITH THE TROPICAL SYSTEM. THE GFS MAINTAINS CONTINUITY WITH PREVIOUS THINKING THAT A DIGGING UPPER TROF OVER THE NRN PLAINS AND MIDWEST WOULD GRADUALLY TAP INTO THE MOISTURE ASSOCIATED WITH LEE AND PULL IT NE OVER NE GEORGIA AND THE WRN CAROLINAS. IF WE BLEND THE NEW GFS AND THE 21Z SREF...THE MOISTURE TRANSPORT BEGINS IN EARNEST AFTER 00Z...AT WHICH TIME THE PRECIP SHOULD BE SPREADING SW TO NE ACROSS THE FCST AREA. SO...AFTER A MOSTLY QUIET MORNING AND EARLY AFTERNOON...THE PRECIP CHANCES RAMP UP FROM THE SW. WILL BRING THE POP UP INTO THE LIKELY CATEGORY LATE IN THE DAY UP THE SAVANNAH RIVER VALLEY AND NC MTNS AND HOLD OFF WITH ANYTHING MORE THAN ISOLATED ACROSS THE WRN PIEDMONT OF NC. THINGS CONTINUE TO DETERIORATE TO THE POINT WHERE A CATEGORICAL POP IS WARRANTED OVER THE ENTIRE FCST AREA BY SUNRISE MONDAY. PRECIP AMOUNTS WILL BE FAIRLY LIGHT INITIALLY. ANTECEDENT MOISTURE CONDITIONS AND STREAM FLOWS ARE SUCH THAT NO FLOODING PROBLEMS ARE ANTICIPATED UNTIL AFTER 12Z MONDAY. PREFER TO LET THE DAY SHIFT HAVE ONE MORE MODEL CYCLE... HOPEFULLY TO GET THE NAM BACK ON BOARD...BEFORE WE ISSUE A FLOOD WATCH FOR ALL OR PART OF THE FCST AREA. Link to comment Share on other sites More sharing options...
phil882 Posted September 4, 2011 Share Posted September 4, 2011 A question for you guys. Found this in the GSP AFD. Is this why the NAM is being "wacky"? More or less... combine a poor initialization with poor handling of convective feedback in the tropics, and it will try to randomly generate vorticity in places where it simply doesn't exist. In this case bogus vorticity to the east of Lee caused a binary interaction that caused Lee to move south while the bogus vorticity merged with the shortwave moving down from the midwest. By the time the interaction is over, Lee is too far south to be picked up by the trough, so this is why it continues to meander in the Gulf. Link to comment Share on other sites More sharing options...
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