1900hurricane

The typical JTWC biases are actually to be too low when a storm is strengthening or near peak intensity and then constrain the storm too high once it has begun weakening. The 2015 Typhoon Season was actually stripped of about 20*10^4 kt^2 between the operational and final best track data largely because of over-constraining a weakening storm. However, in this case I'd say JTWC's intensity estimate was pretty good. Keep in mind that in order to make a real time intensity estimate (in this case, at 18Z), only the data up to that point is available to be used, so in this case, the data mainly used came from between 12Z and 18Z (images below are from 1650Z).

From the latest HGX discussion:

Yep, that's what I think too. While I won't completely dismiss the 883 mb theory, I also think it is unlikely.

It might be a faulty report. The island was still in the eye at 18Z. Alternatively, I've seen some speculation that the 9 should be replaced with an 8.

Wow, JTWC actually went up to 165 kt/887 mb for 18Z.

Yeah, this is really something right now.

Not sure I fully buy into JTWC's 00Z intensity estimate of 160 kt. They're putting a lot of weight on SATCON for that estimate, which a notable deviation of standard policy for them. It could be correct for all I know, but the Dvorak Technique is the one with the proven track record. I know next to nothing about SATCON's verification.

Good morning to Super Typhoon Meranti.

Meranti went berserk and is now at 155 kt. Rai and Malakas are now also named in the South China Sea and near Guam, respectively.

It has been a somewhat slow Western Pacific Typhoon Season so far this year. The season started late in July, only four or five (depending on your choice in agency) typhoons have been observed so far, and ACE still remains a fair bit below 100*10^4 kt^2. Things may be changing though, especially with La Nina struggling to develop. At the time of this original post, Tropical Storm Meranti has just developed, and it may go on to be a very powerful typhoon. WV loop above will continue to update and stay current.

The Pacific jet showing up in medium range guidance sure is nice looking. As others have alluded to across various media, this could help make things rather active later on in June.

Looks like today's 12Z GFS and ECMWF runs highlight two different return flow scenarios. This run of the ECMWF looks considerably more robust with its modeled warm sector when compared to this particular GFS run. The 570 dam thickness of the former lies across Texas while the latter depicts it still well offshore in the Gulf. Lots of variability still. Sent from my iPhone using Tapatalk

Maybe one last chance for 2015?

I'll be honest and say I haven't really looked much at anything other than the standard height plots up to this point, but I can see how that could be an issue. Having the current system shear out and leave some junk behind for a few days certainly doesn't help things at the surface with return flow. I'll still be watching it though, and if the models don't shift anything around with the timing, I'm actually probably good to go Wednesday if things look good at that point. *EDIT: Just looked at the 12Z ECMWF CAPE for Wednesday. Ick, I can see what you mean...

So, the last few ECMWF runs have looked interesting about 6 days out.

I can't say I've really looked at this with great detail, but the way things have been playing out this year does somewhat remind me of 1957. Both this year and 1957 can be described as El Nino springs with the southern plains transitioning from a very bad drought to flooding due to craploads of rain.

Random question, but does anyone know why the SPC has been consistent in putting "Potential Too Low" over the past few days? Especially today, it's thrown me off a little.

As am I. Even at the tail end of fantasyland for most of the operational models, the change is already starting to be picked up on. It might be time for me to start looking at my schedule and seeing what I might need to do to free up a day in the future.

Last couple of ECMWF runs have been trying to bring a huge piece of energy down in the west at the end of the forecast cycle. That might be something to watch coming up and could also be the harbinger of the oft-mentioned pattern change.

Eight or so days out looks fun. ECMWF has been really consistent showing a strong trough ejecting into the plains despite the range.

Pretty good WPC Extended forecast discussion this morning talking about pattern change and the emergence of the Subtropical Jet.

Looks like a pretty pronounced split flow regime will likely establish itself for the first half of December, particularly for the second week. That week, medium-range guidance is placing a ridge over the northern part of the CONUS and into Canada on top of a trough in the Southwest. Looks like a pretty warm pattern with the potential for some good rain across the southern plains, although the European guidance is much less amplified with the southern stream. Sent from my iPhone using Tapatalk

Yep, I've been keeping an eye on it as well. I missed andyhb's post with the convective outlook in the Texas thread, but I figure I'll post it over here if just for posterity's sake. Predictability Too Low >> Probability Too Low any day of the year. ZCZC SPCSWOD48 ALL ACUS48 KWNS 171000 SPC AC 171000 DAY 4-8 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0400 AM CST MON NOV 17 2014 VALID 201200Z - 251200Z ...DISCUSSION... MODEL CONSENSUS IS THAT UPPER PATTERN WILL BEGIN TO DEAMPLIFY BY THURSDAY /DAY 4/ AND TRANSITION TO A MORE PROGRESSIVE REGIME WITH SEVERAL LOWER-LATITUDE IMPULSES EXPECTED TO MOVE THROUGH THE SRN THIRD OF THE COUNTRY. AN INITIAL LOW-AMPLITUDE SHORTWAVE TROUGH SHOULD MOVE THROUGH THE SRN PLAINS AND LOWER MS VALLEY THURSDAY...BUT IT CURRENTLY APPEARS MOISTURE RETURN WILL REMAIN SOMEWHAT LIMITED FOR AN ENHANCED SEVERE THREAT. FRIDAY /DAY 5/ COLD FRONT IS EXPECTED TO MOVE SWD TOWARD THE COAST AS SHORTWAVE RIDGING BUILDS OVER THE SRN PLAINS. SATURDAY /DAY 6/ MODELS HAVE TRENDED TOWARD SIMILAR SOLUTIONS WITH SPEED AND AMPLITUDE OF A MORE SUBSTANTIAL SHORTWAVE TROUGH THAT WILL MOVE INTO THE SRN PLAINS SATURDAY AND CONTINUE INTO THE MS VALLEY LATER SATURDAY NIGHT. GIVEN THE ANTECEDENT FRONT IS NOT EXPECTED TO PENETRATE THE GULF...MORE SUBSTANTIAL MOISTURE RETURN AND INSTABILITY SHOULD OCCUR IN ADVANCE OF THIS FEATURE SUPPORTING POTENTIAL FOR A MORE ROBUST SEVERE THREAT FROM TX INTO A PORTION OF THE LOWER MS VALLEY. AN ENHANCED SEVERE RISK AREA WILL LIKELY BE INTRODUCED ON THE NEXT 4-8 UPDATE FOR A PORTION OF THIS REGION IF MODEL ENSEMBLES CONTINUE TO DEMONSTRATE CONSISTENCY. FOR DAYS 7-8 SOME SEVERE THREAT WILL PROBABLY DEVELOP THROUGH SRN PORTIONS OF THE GULF COAST STATES AND INTO THE CAROLINAS. ..DIAL.. 11/17/2014

Looking ahead some, the next trough should start carving itself out across the central part of the country this weekend and going into next week. Of particular interest to me is the initial shortwave disturbance currently progged to eject into the southern plains Saturday. Even though the airmass across the southern plains and lower Mississippi Valley is going to need some major modification between now and then, guidance seems to think enough time will elapse to offer up some surface instability in the warm sector of the developing storm system. With adequate surface instability and wintertime dynamics, it looks like we might have our first real chance at some severe weather in quite a while.

I almost hate to mention it with so much uncertainty almost a week out, but the recent ECMWF solution shows some similarity to the system from November 1992. I highly doubt something near that magnitude will occur, but it certainly has intrigue. It'll be interesting to see how the solutions evolve over the next several days.