At first I was going to say she is crazy, you have to wait for a few runs to see, but there were actually several runs that showed something when she posted that. The easy answer, the GFS has backed off some. While it is long range, there were a few runs that showed something and even still do to a lesser extent. I'm not sure about other models though. I did a quick look at some, but maybe they too backed off. Looking at the timing of her tweet, she was looking at the GFS for the 12Z run on the 21st. (and/or the previous few runs) For that specific run, one site had a low at around 997mb, a moderate tropical storm perhaps. That image is here. I am looking at this site: http://mag.ncep.noaa.gov/ On another site that attempts to get the lowest pressure, it had 996mb while still in the middle of the Gulf and that is as far as it goes. That image is here. From this site: http://www.emc.ncep.noaa.gov/gmb/tpm/emchurr/tcgen/ The prior run, 6Z on the 21st had this on one site with about 1004mb, perhaps a tropical storm, but then the other site had around 997mb in this image. That far out, the resolution is not as good, so trying to get the pressure is probably much more difficult and perhaps a reason for the difference. Pressures on an image in a global model often do not represent the lowest pressure. Global models do not resolve the lowest pressure as good in these images, especially in the longer range. If you look at a loop, stuff gets kind of larger all of a sudden. You usually seem to get an isobar well away from the low pressure center and the lowest might be much lower in strong storms. However, the pressure seems to be under the "L" in the images on the one site, so I assume that is the low pressure it resolved, though it may still be high. I was looking at the "10m_wnd_precip" imagery which has a pressure under the "L". Some other images do not and only have the pressure of an isobar well away from the center. I also just took a look back at one other run, 0Z on the 21st, and it too had something. 995mb in the central Gulf, that image here. The tracks on that site only go out 240 hours (10 days) which is why the lines just stop. On the other site they go out to 384 hours (16 days). All three of those runs, 0Z, 6Z and 12Z on one image: http://www.emc.ncep.noaa.gov/gmb/tpm/emchurr/tcgen/tcgif/track.gfso.2013062112.tc_atl_ll.4cyc.png So, some consistency, although perhaps just one model. The two subsequent runs, 18Z on 6/21 and 0Z on 6/22 do not have a low any more, though they both do carry moisture that seems to be associated with the same disturbance that the prior two runs picked up on more vigorously. As for the origin. Take a look at the Tropical Weather Discussion at the NHC every 6 hours if you want to track some tropical waves. (http://www.nhc.noaa.gov/text/refresh/MIATWDAT+shtml/) Looking at satellite imagery for the basin: http://www.ssd.noaa.gov/imagery/tatl.html And GFS data from the Model Analysis and Guidance site, I can't quite tell which tropical wave the GFS might be picking up on. It does look like, in some runs, it might be one of the two waves that is currently in the mid Atlantic. The NHC on that discussion page posts a link to the current analysis. The current image as of posting this is here because 0Z is the latest, but later it will be the 06Z image then 12Z and then 18Z. I think, maybe, the GFS is picking up on the impulse of one of those waves. At first I thought the first one on some of the earlier runs and then the second one on a later run, but I am not sure. The area comes from just off South America around Panama before it really starts in most of these runs. But since there is something out there, I guess the GFS could possibly be on to something, but whether it is something developed, a downpour or nothing at all, remains to be seen. No reason to cancel any plans yet! ------------------------------- ------------------------------- O/T And interestingly, we have a little not officially an invest blob just off the coast of the Carolinas. Near 0% chance, but it even has its own invest floater: http://www.ssd.noaa.gov/PS/TROP/floaters/IN1/IN1_floater.html 2AM EDT on 6/22: "TROPICAL WEATHER OUTLOOK NWS NATIONAL HURRICANE CENTER MIAMI FL 200 AM EDT SAT JUN 22 2013 FOR THE NORTH ATLANTIC...CARIBBEAN SEA AND THE GULF OF MEXICO... 1. SHOWER ACTIVITY ASSOCIATED WITH A WEAK LOW PRESSURE AREA ABOUT 60 MILES EAST-SOUTHEAST OF MYRTLE BEACH SOUTH CAROLINA SHOWS SOME SIGNS OF ORGANIZATION. HOWEVER...SURFACE OBSERVATIONS INDICATE THAT PRESSURE ARE HIGH AND WINDS ARE LIGHT IN THIS AREA. UPPER-LEVEL WINDS ARE NOT CONDUCIVE...AND NO SIGNIFICANT DEVELOPMENT IS EXPECTED BEFORE THE LOW MOVES INLAND OVER SOUTH AND NORTH CAROLINA LATER TODAY. THIS SYSTEM HAS A LOW CHANCE...NEAR 0 PERCENT...OF BECOMING A TROPICAL CYCLONE DURING THE NEXT 48 HOURS. ELSEWHERE...TROPICAL CYCLONE FORMATION IS NOT EXPECTED DURING THE NEXT 48 HOURS. $$ FORECASTER BEVEN" From: http://www.nhc.noaa.gov/gtwo_atl.shtml Again, not what we are talking about, but the NHC put a near 0% yellow circle up at 2am and that is kind of cool. |