Thursday, June 27, 2013

Flash Flood Watch Issued Today & Friday

A anomalous low pressure system will cut up through the Appalachians keeping most of New England in a wet pattern.  While some of the storms are bound to be hit or miss the air mass is very tropical and the ground is saturated.  Therefore the National Weather Service in Taunton has issued a Flash Flood Watch for all of Southern New England (except Cape and Islands)

NWS Boston (top) and NWS Portland (bot) Hazards
A stationary boundary to the north will help usher multiple storms into New England.  Surface low pressure is developing in the Ohio Valley.  
WPC surface analysis 5 am
At the upper levels the low has not "cut off" as of yet but that will happen later today/tonight.  As of this morning a shortwave was pressing through the Ohio Valley
06z NAM hires 500 mb heights 8 am Thur (image weatherbell)
Here is the amount of moisture available in the air.  We call this Precipitable Water, or PWATS
SPC 10z PWAT Mesoanalysis
A batch of 2 inch PWATS is just offshore and moving NE.  This will be the main threat with any embedded thunderstorms along with frequent lightning.  Winds and hail appear to be a marginal at best threat today in Southern New England.  The Storm Prediction Center (SPC) likes a severe threat in the Mid Atlantic
SPC Day 1 Thunderstorm Outlook
Depending on how much sun light can break through portions of Southwest New England may be in on the severe weather action.  By tonight the front will be sagging south towards the MA/NH/VT border and perhaps to Worcester.  At the same time the low pressure system will be moving through PA and NE into NY state
WPC surface forecast 8 PM 
Tomorrow morning the rain will be heavy an intense.  Here is a snapshot at the potential PWATS at 10 am
06z NAM hires PWAT 10 am Fri (image weatherbell)
With a surface chart like this
WPC surface forecast 8 am Fri
One will expect inches of rain in the Northeast tomorrow.  The WPC is forecasting between 2-3 inches of rain through Sunday morning
WPC Day 1-3 total precipitation
Temperatures
Current temperatures (5 am)
5 am 2 m temps (image weatherbell)
A mild and muggy start in Southern New England.  The cold front is draped through Eastern NH and ME.  Today Southern New England warms while Northern New England does not
06z NAM hires 2 m temps 4 PM (image weatherbell)
With temps in the low to mid 80s in the CT River Valley it will be interesting to watch storms firing in the high grounds of the Berkshires. Tonight the boundary will push to the MA/CT border and perhaps even to Hartford.  Temps will be in the 50's on the North side, upper 60's on the south side
06z NAM hires 2 m temps 6 am (image weatherbell)
Finally high temperatures rise into the 70's tomorrow
06z NAM hires 2 m temp 3 PM Fri (image weatherbell)
All for now, talk to you tomorrow












 

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