March 10-12th Update –Flooding Concerns Remain High

Let me start this off with saying that Real Wx Services feels that flooding is still going to be an issue with this upcoming event…despite what the 00Z GFS says…

With the high amplitude ridge off the east coast in place this would act as a roadblock or at the very least a mechanism in place to slow the forward progression of the system and its associated fronts. Due to the progressive nature of the GFS it does not have enough moisture associated with it and it fails to develop a low further to the south like the rest of the guidance from 00z. Again, at the time of this writing..the 00z ECM is not available..

So lets look at the guidance tonight for the next system..

GGEM

As you can see from the images above the GGEM brings an abundant amount of moisture to the region once again which would cause concerns for flooding with saturated ground from 2 + inches of rain from the most current system..In addition falling on top of snowfall that places also have been recieving after the initial rains.

While the precipitation maps for the UKMET are not available beyond 72 hrs one can tell by at least the progression of the UKMET it would be slower then the 00z GFS which we will see below..

As you can see on the GFS even without 120 hrs in here..by 108 hrs the system is basically long gone and well into the Northeast..

By 120 hrs the system is completely gone with the exception of Maine.

00z NAM while in its long range we feel is closer to the rest of the guidance then the GFS as it seems to have a slower approach with the system and also develops that secondary low pressure at 84 hrs out.

Just in is the ECM at 96 hrs it also develops the secondary wave of low pressure and even though it is still progressive it to has slowed down compared to its prior runs.

Now what is interesting is the GFS ensemble means QPF shows the reason for the concern for flooding..

While the operational is much lower then what the above shows. Also when looking at the spaghetti plots of the GFS you will see a large amount of them still showing the potential for a cut off low.

So at the present time we feel that the GFS operational is an outlier model tonight compared to the rest of the guidance and the ECM slowing down the progression is a good indicator that the GFS is also to progressive.

To make matters even worse for the GFS and the way it is handling this system is too look at the most progressive model there is when it comes to forecasting the weather and seeing that model being slower then the GFS..

00z NOGAPS

That very factor alone should testify volumes to the GFS being to fast with the system.

So the potential for flooding remains quite high and a high impact precipitation event appears likely once again. To pinpoint where exactly at this time range is not possible but parts of the region will pick up another 2-3 inches of rain out of this system.

Stay tuned for further updates on this next potential flooding event!