1745 1 NOV 2012… STARDATE 201211.01
I am not as comfortable in forecasting a big East Coast storm as other for NOV 6-7-8 . Most of the forecasters yesterday who were talking about potential for East Coast storm were focused on the event happening November 6 -7. That struck me as being too soon because the pattern over both Western Canada and southeastern Canada was NOT very favorable for the East Coast storm to develop … though there is better chance for an east coast storm for NOV 7-8
Basically there are two pieces of energy which we have to watch for next week. These two pieces of energy in the jet stream– which in the weather business is refer to as SHORT WAVE — could met and if they do …. IF…. then the potential increases for significant East Coast autumn storm.
The southern piece of energy or the southern shortwave is going to move drop south from Nebraska and Kansas into Arkansas and Louisiana on November 6. The northern piece of energy is coming in from Western Canada and will be located over Manitoba. In order to get the big East Coast storm this northern piece of energy over Manitoba has to drop south eastward through the Ohio Valley and merge or phase with the southern piece of energy coming up from Louisiana and the gulf coast.
YESTERDAY … model most of the model data was clearly showing that the Ridge in the jet stream would NOT be amplified rnough … which meant that be Manitoba Energy would NOT drop southeast in phase or merge with the system coming out of Louisiana . Instead the Northern Energy over Manitoba Canada would track due east across the northern Great Lakes. The result? No big east coast storm yes
Today most of the model data is depicting Western North America significantly different. The models which are showing the big East Coast storm all have a stronger Ridge in the jet stream over the West Coast. This causes the energy in the northern portion of the jet stream over Manitoba Canada… To dive southeast word and phase/ merge with the system coming out of the Gulf of Mexico. This results in a much more significant East Coast storm.
My concern however before I go all in here is that the west coast of North America is being depicted this afternoon a extremely differently than what we are seeing yesterday… And for that matter significantly different from what the model data was showing earlier this Thursday Morning.
WHAT COULD GO WRONG?
The ONLY way to get this big East Coast storm to occur…. and develop as the models on Wednesday afternoon are depicting it… is for the energy over Manitoba Canada to phase or merge with the energy coming out of the southern jet stream and the Gulf coast.
And the ONLY way for that to happen ….is for the Ridge on the West coast to stay strong. It is this particular aspect of forecast I am worried about. There is an awful lot of energy coming into the Gulf of Alaska and the Pacific Northwest…. and I am worried that this energy may come and faster or differently than the models this afternoon are depicting .
IF…. that happens … THEN there will NOT be a MAJOR East Coast storm on November 7 or 8. There will be something along the coast but it would slide mostly to the east. Perhaps later in the week ….I will feel more confident about what’s going on over western North America the right now I have some skepticism which has to be “solved” before I go all in on a potential significant East Coast storm November 7 – 8
2300 31 OCT 2012
One of my favorite all times sayings is this one... bad forecasters are like bad generals. They always fight the last war. When I give weather talks and presentations I often use that quote.
Another one which I use even more in fact it’s my e-mail signature is this one… When everyone is thinking the same someone isn’t thinking... George S Patton.That is a really big thing for me.
As we move past the remains of sandy …we see strong signals coming from SOME sources that these lessons are not really being taken to heart and learned. There are several sources which are talking about potential for significant coastal storm for the Middle Atlantic and New England coasts on election day November 6.
At this point in time I strongly disagree that forecast with about every single fiber in my being that I can muster. I think it’s also somewhat ironic that some of the forecast services — accu weather for example– which it downplayed the threat of sandy for several days…. are now the ones which are banging the drum for the next upcoming threat.
This sort of phenomenon happens a lot in the mass communication feel whether it’s politics …or war …or economics or …weather forecasting. That after being caught by a unforeseen event of immense impact — what is called a black swan event— the next several events which come along get over hyped or overplayed.
For example if you recall the massive Derecho that moved through the Ohio Valley and into the Middle Atlantic states on June 29. A lot of forecasts were very late in detecting the severity of this system and some will only given a few hours notice (that was not the case here at WXRISK). However the point is that after that event pass through the next several thunderstorm or thunderstorm clusters which formed were immediately compare to the June 29 Derecho. It took about a week before a lot of TV forecasters and the weather channel finally realize that not every single thunderstorm cluster is going to become a historic record shattering Derecho.
We are experiencing the same sort of thing with potential for this next event. Let me be clear about what I things going to happen on November 6. There may be a brief interval of moderate or light rain across portions of the East Coast on the morning of the NOV 6. But light to er moderate rain that lasts a few hours is not in any way a coastal storm. Those are two entirely different animals and it may be y hype to gain the attention of more viewers and subscribers to assert that the November 6 event is going to be a serious coastal storm.
Essentially the uncertainty has to do with the development of Low pressure on a stalled cold front over Tennessee and North Carolina this coming weekend. All of the various weather models are developing this wave of low pressure on the front but some of the models are developing the Low fairly close to the coast into a coastal storm . Other weather models are developing a system much further off the coast …. So the only thing the East Coast would see would be a period of rain .
This first image shows the last four runs of the operational or regular GFS model. The top left map refers to the 0z wed GFS … the top right 6z GFS … the Bottom Left map the 12z GFS and the bottom right map the 18z GFS. But I think is significant is that the two model runs of the GFS which have a full set of model soundings– the 0z and 12z GFS have the weakest overall threat and development from the low pressure area on the southeast
Clearly the GFS model is the most bullish on this potential event for November 6. The key here is that the GFS model develops Upper Low over Ohio which helps keep the surface Low fairly close to the coast and allows it to develop into a more significant system.
However the other models do not agree with this scenario. Remember that the atmosphere a pattern is what determines how the coastal event is going to develop not the weather models. The fact that the GFS may show a coastal storm developing does not mean is going to develop.
This next image shows the 0z runs of the European model from early Wednesday morning. The key here is that the model shows a pretty strong piece of energy — called a short wave– moving through Central Canada on the Middle Map and into Eastern Ontario north of the Great Lakes on the Right side map. This feature I have highlighted with a red line . It should be noted that the GFS model has is feature much weaker if at all. This is important because the arrival of this feature over central and Eastern Canada means that the system trying to develop over Tennessee North Carolina will be kicked off the coast. The European model develops this weak Low over Tennessee and North Carolina but it does so well out to sea.
The 12z European model shows very much the same sort of thing. In fact the model is even more emphatic that any sort of Low pressure area which develops off the Carolina Coast will not develop into a little way out to sea. On this image the map of the left hand side which is valid for the morning of November 5 shows a disturbance over the Canadian Rockies which reaches Manitoba and Western Ontario Canada November 6. It is the arrival of this feature which does not allow the weak Low over TN / NC to develop at all and instead slides off the coast.
The early Wednesday morning Canadian model case a compromise between the GFS and the European…. but still is way think is way too aggressive with a coastal development.
The Wednesday afternoon British model is pretty bullish with a velvet this feature with a stronger low over North Carolina and southeastern Virginia on November 5 and a correspondingly more developed coastal low on November 6 up by Cape Cod and Boston. Notice here also however that the British model has a much weaker system upstream— recall that feature which I refer two before as a kicker? On the British model it is not there so the system over the southeastern states gets a much better chance to develop.
And finally if you look at the overall important hemispheric patterns such as the NAO and the AO … That they are weakly negative NOV 1-4 but by the time we reach November 6 they have reached neutral conditions. The reason why these two features are important –for those of you who are not weather knowledgeable– is that it is very difficult to get a significant coastal Low to form if BOTH the AO and the NAO are running neutral.
SUMMARY…. The pattern is all wrong for significant East Coastal Low foreman close enough to become significant or major event on November 5-6-7. In addition there is probably a lot of energy coming in from Western Canada which will prevent any development of the weak Low over North Carolina from developing rapidly . At this Point I am strongly against the idea of a significant coastal Low during the NOV 5-6-7. SOME rain yes. But that’s not the same thing as a coastal storm or nor’easter.
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