Sunday, March 3, 2013

Midweek Storm Close Enough to Watch

A large ocean storm will develop mid week but it will be difficult for the storm to affect SNE.  While I cannot rule out light snow for Cape Cod and coastal Southern MA/RI/CT the vast majority of the region will be spared.  

Current Conditions/Short Range Forecast
A stubborn Upper Level Low continues to spin offshore.  The result is clouds and a few light snow showers
941 am NWS Boston radar
The low can be seen on sat and in the upper level charts
12z NAM 500 mb vort from 8 am 
The latest WV
NOAA Water Vapor Sat 915 am
Two weak upper level features are converging in SNE and the result is the light snow.  Temperatures are currently 
9 am 2 m Temps (image weatherbell)
Temperatures today will top in the mid to upper 30's with low 40's possible near the coast
EPS 2 m Max temps Sunday Afternoon (image weatherbell)
Overnight lows will be in the low to mid 20's.  Monday will be much like today although I do not think the snow showers will be an issue tomorrow.  However it will still be mostly cloudy as the ULL struggles to get out of here.  Eventually, by Wednesday the low will kick itself out.  And just off the NC/VA coast we have this
12z NAM 500 mb Vorticity Wednesday 7 PM
Pretty much all of the support is out to sea for this.  Why?  Well a there is a massive atmospheric block.  It is too strong for a New England storm.  The storm track is suppressed to the south.  Look at the current temperatures in the Southeast
2 m temps 9 am (image weatherbell)
When one sees cold like that in Florida its a tall tail sign that the NAO/AO are extremely negative.
Weatherbell AO/NAO time-series
The forecast
GFS NAO forecast (image weatherbell)
With a negative anomaly like that it will be hard to get snow into New England. The negative anomaly is also why we have been unable to kick out the ULL.  So here is what we are looking at Wednesday and Thursday
HPC Day 3 Wednesday 7 am
Thursday
HPC Day 4 Thursday 7 am
The high pressure is in a good spot for inland snows.  It will important to fine tune this as the event comes closer.  A 50 mile jog to the north would bring accumulating precipitation into SNE.  Here is the HPC 5 day precipitation totals
HPC 5 day precipitation totals
Have a good Sunday, we'll talk tomorrow and see if there are any northward trends.












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