Real Weather Services Alert #2 Repeat or Not is the Question?

Date:2/01/10

Time: 4 PM

Review of the 12 Z Guidance

12 Z GFS  takes the low to a 991 well off the coast of Hatteras

12 Z ECM has come north has a 996 East of Hatteras

12 Z  GFS ensemble means has a 993 off of hatteras but closer to the coast then the op

12 Z ECM ensemble means is NW of the operational ECM

12 Z GGEM has a 985 east of the Delmarva Region

12 Z GGEM means have a 994 east of the delmarva region

The above is a simplified version of the 12 Z model suite. ECM operational brings about .25-.50 to the NY /PA border and about .35 into NYC .. .50-.75 into KPHL ...and about 1.00-1.25 into SNJ.

12 Z GGEM ensembles show about a 1.00 + from east central PA Southwest and also southeast wards.

So what does this all mean at this point and time? 

GGEM has been staying relatively consistent with this event. ECM has trended north with this event. It is the opinion of Real Weather Services that the ECM at this point and time is trending towards the GGEM and what it has been suggesting for its past few runs.

At this point and time the GFS model is considered the outlier model and also is an outlier to its own ensemble means. 

Real Weather Services at this time recognizes the potential for a snowstorm to effect portions of the mid atlantic into the Northeast from VA to Southern New England. 

Real Weather Services feels at this point and time that the potential exists for a significant snowfall in this region.

Differences between this storm and last event is the PV is weaker and not as far south as the last event. This means the confluence across the region is not as strong as the last event so would not keep this as far south.

Blocking is also in place with this storm over Greenland and this suggests a more Northward track. 

At this point and time a track that follows the western edge of the Gulf stream seems most likely. To show the expected track from Real Weather Services see the image above.

This storm should deepen quite rapidly once it hits the waters off of Hatteras and then move NE up the eastern seaboard along that western edge of the Gulf Stream. 

Real Weather Services feels that this storm has the potential to drop 6 plus inches of snow across the region highlighted.

Real Weather services also feels that there is  a potential for a phase to occur which would cause the storm to deepen and become stronger and wrap in more QPF..However..the CAVEAT to this is it would bring mixing issues along the I-95 corridor. 

Stay tuned for further updates...