There is alot of truth to the title of this post. In reference to the December 19-21st time frame ..guidance could not be further from clarity.
European computer model at 12 Z yesterday in the range of about 72-96 hours out buried I 95 as well as areas to the N and W of there. It showed anywhere from 6 inches to over 2 feet of snow.
Early this morning at 1 AM when the 00z ECM came out it shifted east by a good 500 miles. In all my years of following this model i have never seen such a drastic shift under 72 hrs.
Enter the GFS. While the ECM originally picked up on this threat the GFS was showing a flat pattern. Then the GFS switched gears and showed several runs essentially burying the same regions as the ECM at 12 Z buried yesterday. However…ECM during this time switched gears to missing well out to sea. So essentially they have traded places.
Now the past few runs of the GFS have been slowly trending N and W but not to the extent of what the ECM at 12 yesterday showed!
What makes matters worse is the Ensemble means of the GFS are slowly trending more west and then ensemble means of the ECM are more west then the op. However, the icing on the cake is not just the surface depictions on the models changing but we are also talking drastic changes to the upper levels or H5 500 mb levels every 6 hrs.
So..we could toss our hands up in the air..throw a few darts at a dart board or be blindfolded and place a pin on a weather board… or we could try and figure out what is going on.
Everything at this point is low confidence.
Tonight’s guidance indicated a new area of low pressure coming out of the GOM essentially at the same time that are system is trying to organize and deepen. This piece of energy was not on previous runs. It could very well be convective feedback but then it would be as though every model is suffering from convective feedback. However..it is this extra piece of energy if you will that is more or less robbing the main show of its moisture and flattening the heights along the east coast there by making the flow flatter so the players do not phase and create a SECS or MECS but a near by miss.
First thing we begin to notice is that this point and time the NE is being dominated by a large area of low pressure. This can be confirmed by looking at a recent surface map from HPC
If that huge area of low pressure does not begin to lift out of the picture or move westwards ..this chance will more then likely slide off to the south and east because of the currents you see above that are just streaming west to east.
However..a 2nd thing we have been watching is that the southern stream shortwave has been stronger and deeper then what the modeling has been showing.
Finally a third thing we have been watching is the radar and there is a decent amount of moisture currently building thru the South Central US and some coming out of the GOM.
So, with the models in extreme chaotic states and constantly changing at H5 and the surface..and what appears to be the models underestimating the strength of the southern Stream S/W..ensemble means coming slowly west..NAM & GFS moving slowly west…we have decided to keep the level 1 in place at this point and time.
Current thinking is that since the means are coming west or in the case of the ECM further west then the OP..and not 100% certain that the dual low structure is valid..we feel if that dual structure was not there…that the heights along the coast would have been higher and this storm system would have been right along the coast.
Tough pattern, alot of players on the field & it may just come down to good ole fashion nowcasting and the day before the storm on the models. Keep and eye on pressure falls, satellite & radar and steering currents.
Nothing has changed from the images posted several days ago.
Stay tuned for more information on the Nightmare On Weather Avenue!
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