Friday, May 31, 2013

Sizzling Friday

Most areas topped out in the upper 80's yesterday although isolated pockets reached 90.  Today the majority of the region will reach 90.  A few pop up showers/thunderstorms are possible, but odds are very low.  My best bet is NW CT and the Berkshires.  There is no relief on Saturday as temperatures region wide will be near 90.  Sunday a front begins to approach from the west but will not quite reach New England until Monday.

It is a warm start this morning.  Here are the temperatures as of 4 am
4 am 2 m temperatures (Image weatherbell)
The surface analysis 
330 am WPC surface analysis
At the 500 mb level we have a strong upper level low pressure center over the Dakota's and a sharp ride in the east.  That sets up 90 degree weather in New England an a strong thunderstorm threat in the heartland.
06z NAM 500 mb heights 2 PM
This is as of 2 PM.  Here is the SPC thunderstorm outlook for the day
SPC Day 1 Thunderstorm Outlook
This pattern is not great for the folks in Oklahoma, but that is one of the hazards of living in that region of the country.  The green indicates any type of thunderstorm is possible.  Back in New England today will be the hottest day of 2013 (so far)
06z NAM hires 2 m temps 3 pm (image weatherbell)
Dew points will be running in the mid 60's.  Today will be humid and hot but not overly oppressive.  That said the Massachusetts Environmental Protection Department has issued an Air Quality Alert for ground level ozone so if you are sensitive to slightly unhealthy air today is a day to stay inside in an air cooled building
NWS Boston homepage, Air Quality Alert
Tonight low temperatures drop only into the upper 60's.  Some urban areas may not drop below 70.  Tomorrow morning a warm boundary will exist in the Northern portion of New England but high pressure will still be in control along the east coast.
WPC Surface Forecast 8 am Sat
There will be a slight chance of a shower/thunderstorm
SPC day 2 thunderstorm outlook
Temperatures are only slightly cooler than today
06z NAM hires 2 m temps 2 pm Sat (image weatherbell)
Temperatures Saturday night will fall to the mid 60's.  On Sunday a large high pressure area will push the cold front in the midwest east towards the Atlantic.  Here is the forecast surface chart Sunday morning
WPC surface forecast Sun 8 am (image weatherbell)
That cold front is pushing into a very warm and humid air mass.  Needless to say Severe Weather is possible if not likely on Sunday in NY, PA, WV and even pushing into Western MA/CT and Northern New England later Sunday/Monday morning
SPC Day 3 outlook
Temperatures Sunday
06z NAM hires 2 m temp Sun 2 pm (image weatherbell)
Western New England may be looking at an overnight severe weather outbreak.  Eastern New England will be under the gun (potentially) Monday morning with a surface set up like this
WPC surface analysis Monday AM
Here is the latest EURO for Monday morning
00z EURO precip Monday 2 PM
This front will bring relief from the heat.  I'll watch it, have a good Friday.

Thursday, May 30, 2013

Hot and Humid Thursday

Temperatures near 90 and dew points in the mid 60's will give the region its first true summer air mass.  Thunderstorms last night announced the arrival of this air mass which is somewhat unusual as the majority of the time strong thunderstorms signal relief to heat.  Take a look at the radar image I saved from last night
NWS Boston Radar 904 PM
The storm dropped between 0.5 and 1.5 inches of rain 
NWS Boston Radar Storm Total 5/29/13
Wind damage was also common across Western MA
SPC preliminary storm reports 5/29/13
The boundary has lifted North through New England as the upper level shortwave has passed.  Here is the surface chart
WPC surface analysis 630 am
Temperatures as of 5 am were in the low 60's across Southern New England
2 m temps 5 am (image weatherbell)
Temperatures will be in the 70's by 9 am and low 80's by lunch.  Some will hit 90 this afternoon, others will be close.  With dew points in the 60's it will feel like 90 regardless
06z NAM hires 2 m temps 4 pm (image weatherbell)
Ridging is present at the 500 mb level
06z NAM 500 mb heights 2 pm (image weatherbell)
A pop up shower or thunderstorm will be possible today.  There isn't a true trigger for thunderstorms like a front or a trough but with an air mass like this it will not be impossible to see something fire.  We can repeat this forecast Friday and Saturday.  Sunday looks dry but will have to monitor the speed of an incoming cold front Sunday/Monday.  Have a good day stay hydrated.

Wednesday, May 29, 2013

Severe Threat Continues- UPDATE 717 PM

The Storm Prediction Center in Norman, Oklahoma has issued a severe thunderstorm watch for Northeast CT, SW NH, and all of MA from Worcester County West.  
Severe Thunderstorm Watch 246 (SPC)
A strong line of thunderstorms is moving through upstate New York.  Many locations are under severe thunderstorms warnings and several are under tornado warnings.
NWS Albany Radar 711 PM
Tornado warnings are in red, severe thunderstorm warnings in yellow.  This is a dangerous line of thunderstorms that should hold together as they march into Western and Central MA, and NE CT.  
There is still energy available in SW New England
The energy is forecast to stay in place and a nasty batch of thunderstorms may strengthen as it enters Western MA.  This will have the potential to knock downs trees and power lines with wind gusts up to 75 as the storm hits.  As it reaches Worcester County it should begin to weaken but will still pack a punch.  I expect it to enter MA by 8 PM.  It should reach central MA by 9 or 930.  Here is the high resolution short range HRRR model between 8-9 tonight
21z HRRR Simulated Radar
You should take in anything that may blow away.  


As of this writing no severe weather watches have been issued for New England.  I do believe this will change but I will be out this afternoon.  Here is a quick update

The sun is working into the SW corner of New England.  It extends all the way to Worcester and Providence
NOAA GOES_East Visible Sat 145 PM
The radar is quiet for now as most of the precipitation has dissipated or moved offshore
NWS Northeast Regional Radar 228 PM
Afternoon short range models continue to indicate a the potential for a squall line this evening.  Squall lines often produce dangerous lightning and damaging winds followed by heavy rain.
16z HRRR simulated radar 6 pm (ESRL)
Surface based available energy is low at the moment, but with the sun shining destabilization should increase in New England through the afternoon.  Western MA and CT will see storms fire first around 4-5 PM.  Central MA and RI will be okay until at least 6 PM.  There is a small chance a rogue super-cell could outrace the main line before hand so keep an eye to the sky.  Remember, lightning travels the path of least resistance.  If you hear thunder you can be struck by lightning.

Rain to Clear, Severe Thunderstorms Possible Later

A warm front is moving northeast toward New England and ahead of this boundary moderate rainfall is falling in portions of Southern New England.  This afternoon the boundary lifts into Northern New England and if enough sun breaks out then severe thunderstorms will break out.  A ridge is building in the east so temperatures will be on the rise for the next several days.

Observations/Short Range Forecast
A decaying band of showers is located in Eastern MA and Northern RI
NWS Boston radar 602 am
This complex will be offshore by 8 am.  Temperatures this morning
2 m temps 5 am (image weatherbell)
Most areas are in the mid to upper 50's.  By 8 am the warm front is on the doorstep of SW CT
WPC Surface forecast 8 am
At noon all of Southern New England is into the 70's
06z NAM hires 2 m temps 12 pm (image weatherbell)
Dew points will also be on the increase, first in CT then into MA and Northern RI.  At noon dew points are in the low to mid 60's.  The dew points will continue to increase as the warm front surges north.  At 2 PM
WPC Surface Analysis 2 pm
A wave of low pressure in Canada with an associated surface trough will act as the "trigger" this afternoon to fire these thunderstorms.  Several factors will need to come into play.  The sun has to shine or else convection will be limited.  Temperatures at 5 PM
06z NAM hires 2 m temp 5 PM (image weatherbell)
An hour later here are the dew points.   Many are in the upper 60's or low 70's
06z NAM hires 2 m dew points 6 PM (image weatherbell)
Severe Weather Threat
As of 2 am, the Storm Prediction Center has much of Central/Western MA, Northern RI, and all of CT in a slight risk for severe storms
SPC Day 1 Outlook
The main threat with any thunderstorms will be damaging wind.  A "severe" wind is one in excess of 58 mph.  
There is a 15% chance of a severe wind occurring within 25 miles of any given point in the yellow below
SPC Day 1 Severe Wind Outlook
Although not as likely, severe hail will be possible as well.  Severe hail is at least an inch in diameter 
SPC Day 1 Severe Hail Outlook
Finally if a few super cell thunderstorms indeed develop, there is a low chance for a tornado in Eastern NY state and Western/Central Southern New England
SPC Day 1 Tornado Outlook
The threat for thunderstorms appears to be between 4-8 PM tonight.  Any thunderstorms will have frequent lightning and heavy downpours.
WPC Day 1 Precipitation Outlook

Tonight lows drop into the mid 60's so it will be a mild night.  Summer sends its first true wave into New England tomorrow.  Most see high temps in the upper 80's/low 90's.  Friday looks to be even warmer, low to mid 90's.  Have a good one, I will be out this afternoon but will try to update as needed.

Tuesday, May 28, 2013

Dry Tuesday, Warm Up for End of Week

After a pleasant and dry Tuesday a warm front will lift through Southern New England tonight and Wednesday.  There will be a threat of showers and thunderstorms tonight and the potential for some severe weather tomorrow.  By Thursday high temperatures will be soaring into the upper 80's/low 90's and these temperatures will last through the weekend.

Observations/Short Term Forecast
It is a chilly start this morning with temperatures in the mid 40's
4 am 2 m temps (image weatherbell)
High pressure is in control in New England.  This will depart the east coast this afternoon
WPC surface analysis 330 am
A shortwave at the 500 mb level and a building ridge will force the warm front to the northeast today.  Already there is heavy precipitation along the warm front
NWS Northeast Regional Radar 548 am
That will keep temperatures down in the NY/PA area this afternoon
06z NAM hires 2 m temp 3 pm (image weatherbell)
Clouds will be increasing in New England this afternoon as the system approaches.  It seems like some of this will hold together tonight and there could be a rumble of thunder especially in W MA/CT.  Temperatures will only fall to the mid 50's tonight.  It will be warmer in urban areas. Here is the thunderstorm outlook for Wednesday
SPC day 2 thunderstorm outlook
Green represents general thunderstorm formation possible, yellow means an increased chance of severe thunderstorms.  Here is the 500 mb pattern tomorrow around 11 am. A noticeable wave will be moving over the top of the ridge
06z NAM 500 mb heights 11 am Wed (image weatherbell)
Tomorrow night the surface analysis will look like this
WPC surface forecast Wed 8 PM
Temperatures will be in the mid to upper 70's.  In Western New England there is a good chance of severe weather.  In Eastern New England we will need a lot of sun to help destabilize the atmosphere
06z NAM hires 2 m temp Wed 2 pm (image weatherbell)
Dew points will be in the mid to upper 60's tomorrow
06z NAM hires 2 m dew points Wed 5 pm (image weatherbell)

On Thursday the ridge will build into the east.  A trough digs into the Plains which is looking like a classic tornado outbreak for those folks.
06z NAM 500 mb heights Thurs 11 am (image weatherbell)
Here are temperatures Thursday afternoon
06z NAM hires 2 m temp Thur 2 pm (image weatherbell)
By Friday these temps will climb in near 90.  The weekend looks warm and dry but a cold front will be approaching early next week.  So to recap

Tuesday High 75, increasing PM clouds, light winds SW 5-10 mph.  Temps drop to mid 50's overnight with showers and isolated thunder

Wednesday High 76, severe weather possible in Western MA/CT.  Scattered showers and thunderstorms for the rest of the region.  Dew points in the upper 60's.  Overnight lows in the 60's

Thursday High 87, dry and summer like.  West wind 10-15 mph

Friday High 90.  Dry, hot, humid.  Southwest Wind 8-12 mph

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