5 Years Later- The Joplin Tornado

For the second time (and not the last) I am recapping a devastating tornado from 2011.  The first was the April 27, 2011 super tornado outbreak that killed 327.  That outbreak featured over 200 tornadoes.  On May 22, 2016 a single tornado killed 158 people and injured over 1000.  This made the Joplin, MO tornado the deadliest one in modern times (since 1950- a tornado in 1925 claimed over 600 lives).  

Joplin, MO tornado damage (image Wikipedia)

Sunday May 22, 2011 began with a moderate threat of severe weather in the Mississippi River Valley.  Many tornadoes formed but they were of course over shadowed by the Joplin event.  Here is the SPC risk and actual reports

SPC 5/22/11 severe weather outlook with actual reports

So how did such an event occur?  Let's start at the lower levels of the atmosphere and work our way up.

WPC Surface Analysis 5/22/2011 5 PM EST 

What we have here is a surface high pressure system along the Gulf of Mexico and a low pressure system in the upper plains.  The clockwise flow around the high was sending very warm moist air northward into the Mississippi River Valley/Midwest.  The counter clockwise flow around the low was sending cool dry continental air into the plain.   A little higher up in the atmosphere (~2500 ft) we can see the wind direction much better

SPC analysis 925 mb heights, temps, winds 8 PM 5/22/11

If you look closely you can see a wind shift or convergence zone near the OK/MO/KS border.  This created a favorable atmosphere for storm growth.  If we go further in the atmosphere to 18000 ft we find this

SPC analysis 500 mb heights, temps, winds 5/22/11 8 PM

Notice the wind direction is all southwesterly.  So we have winds turning with height.  This helped give the Joplin tornado tremendous rotation.  As a result at 547 PM local time the radar over Joplin looked like this

NWS Springfield radar 547 PM CDT 5/22/11

There was so much damage the radar picked up a debris signature.  Meteorologists watched in horror knowing that this wasn't a corn field it had just traveled over- it was a city with 50,000 people.  In all damage was estimated to be nearly $3 billion.

NWS Springfield, MO stats on tornado

The city is recovering but it takes a long time to heal from something as devastating as this.  We have a few anniversaries in New England coming up, one of which is on par with Joplin.

-Zack Green 

Summer? Oh There You Are!

Although temperatures were cooler on Sunday than most of would like most of Southern New England stayed dry.  We stay dry during the daylight hours today as well.  The stationary low to our south will begin to move offshore and out to sea tonight.  As it begins to move there will be an increased chance of showers and thunderstorms.  The threat begins in Western New England later this afternoon/evening and moves east overnight.  This continues Tuesday.  By Wednesday temperatures should soar into the mid 80's.  The long weekend is looking warm.

General Overview

The surface chart shows our storm in the Mid Atlantic and a frontal system in the Midwest

WPC surface analysis 8 AM

High pressure is deflecting the clouds away from Southern New England at the moment.  Here is the visible satellite loop

NOAA GOES_East visible satellite loop

High temperatures this afternoon will reach the mid 70's. In the CT River Valley highs will approach 80 but this is also where thunderstorms could erupt this afternoon.  Heavy rain and lightning will be the primary threats.  Clouds will increase as we approach evening elsewhere.  All in all it will be mild tonight with lows dropping only to the mid 50's.  By tomorrow morning the stalled low will be near New England.  You can see it here on the mid atmosphere chart

12z NAM 500 mb vort, heights 2 AM Tuesday (image NCEP)

  This upper low will bring with it an unstable air mass and chances of precipitation.  The day is not a washout but there will be scattered showers and isolated thunderstorms.  Here is the 8 AM surface forecast

WPC Surface forecast 8 AM Tuesday

One high resolution model is showing showers/thunderstorms in South Central MA around noon time.

12z NAM Hires Simulated radar 12 PM Tue (image Weatherbell)

The good news is the upper low moves away Tuesday night.  High pressure off the Mid Atlantic coast will bring southwesterly flow into the region.  

WPC Surface forecast Wednesday 8 AM 

High temperature forecast on Wednesday

NWS NDFD maximum temp forecast Wednesday (image Weatherbell)

I expect Thursday to be similar although Western New England will have to watch for some showers.  A warm front will try to lift into the region Thursday night/Friday.  Temperatures will be in the mid to upper 70's on Friday due to some cloud cover and morning showers.  

Now I know many people want to know the forecast for this weekend.  I believe it will be warm with temperatures in the 80's.  I'll have to watch out for showers/thunderstorms but I feel the weekend as a whole will be terrific.  I'll keep an eye on the showers/thunderstorms for tomorrow and this weekend.

-Zack Green

Pleasant Weather Friday Evening and Saturday

High pressure is in control this afternoon.  Temperatures are mild and conditions are dry.  Low pressure will slowly track northeast across the Southern states and will emerge off the Mid Atlantic coast Saturday afternoon but not before a decent Saturday.  Conditions deteriorate Saturday night as a spring Nor'Easter passes south of New England.  Steady rain will be confined to the overnight hours and the heaviest will be closer to the South Coast.  Northeast winds on Sunday will make for a dreary day.

Temperatures as of 1 PM are in the mid 70's inland and near 70 at the coast.

RTMA 2 m temps 1 PM (image Weatherbell)

 The surface chart shows high pressure in the northeast and a developing low near the Gulf Coast

WPC Surface Analysis 11 am 

The low will deepen overnight.  There is a lot of moisture associated with the disturbance right now.  Some signals indicate rain by 5 PM tomorrow night while others keep the rain out of the region until after 8 PM.  Let's compromise and say rain showers begin around 630 tomorrow.  I'll evaluate the radar trends tomorrow.  High temperatures are in the low 70's in Central/West but closer to 75 in E/NE MA. 

NWS NDFD Maximum Temps Saturday (Image Weatherbell)

Skies remain sunny until noon time when clouds will steadily increase.  Here is the 8 PM surface forecast tomorrow

WPC Surface forecast 8 PM Sat

We get stuck in a bit of dreary weather pattern after this.  Highs on Sunday will stay in the 50's with occasional showers.  I'll keep an eye on the timing tomorrow.

-Zack Green

Showers, Thunderstorms likely Thursday PM

A upper level disturbance will move over New England tomorrow afternoon.  Cold temperatures in the upper atmosphere will combine with a warm surface to produce numerous showers and thunderstorms.  The thunderstorms will be capable of gusty winds and small hail.  High pressure will build in again Friday before we begin a transition to cooler/wet Saturday PM.

Overnight a few sprinkles will fall in Southern New England.  Temperatures stay in the mid to upper 40's.

NWS NDFD Minimum Temps Wednesday Night (image Weatherbell)

Here is the upper air (~18k ft) at 8 PM.  Notice the depression around the Great Lakes.  This is the upper level trough that will move over New England tomorrow.

18z NAM 500 mb vort 8 PM Wed (image NCEP)

Here is the same chart valid 5 PM tomorrow.  The trough is directly over New England.

18z NAM 500 mb vort Thursday 5 PM (image NCEP)

So why would this cause thunderstorms in the absence of a cold front?  Here are the temperatures at 500 mb.

18z NAM 500 mb heights, temps Thursday 5 PM (Image College of Dupage Weather Center)

Now it won't be hot by any means tomorrow but temperatures should get to the low 70's which is close to if not a few degrees warmer than average.  None the less this large difference in surface temperature and upper air temperature will allow for air parcels to become unstable tomorrow afternoon.

NWS NDFD 2 m max temp Thursday (image Weatherbell)

Showers and thunderstorms develop around 1-2 PM in VT, NH and W MA.  This moves into Worcester county around 4 PM.  By 5 PM high resolution weather models show a lot of activity in NH and C MA.

18z NAM simulated radar Thursday 5 PM (image credit College of Dupage Weather Center)

The activity moves towards Boston by 8 PM but it will weaken.  Thursday night is fairly nice as temperatures will drop to about 50.  Friday is very nice as high pressure sits over the region.  Expect temperatures in the mid 70's.  Saturday AM looks pretty good as of now but all eyes are on a system to our south for Saturday PM into Sunday.

More details on the weekend tomorrow.  I'll keep an eye on the radar/sky tomorrow.

-Zack Green

Reader Question- What's up with the Weather Changes?

Saturday was certainly the pick of the weekend.  Although it is not raining today temperatures are much colder this afternoon compared to yesterday.

Temperature comparison 

This prompted a question from a faithful reader of the blog.  He asks "What causes temp drops/increases on a day to day basis?  How is it that much colder today than yesterday?"

The simple answer to this question is a wind shift.  Here is the surface chart from yesterday afternoon.

WPC 18z Surface Analysis Saturday 2 PM

Remember that air flows clockwise around high pressure and counter clockwise around low pressure.  The front that brought rain showers Friday night didn't really have a significant air mass change as high pressure was not driving it like the second front.  Instead a surface low developed on the front and helped pull warm southern air into New England.  Now let's take a look at the 11 AM analysis today.

WPC 15 z Surface Analysis 11 AM Sunday

High pressure has taken control in the central US so the air source is from Canada, not the Southern US.  The wind this afternoon is combination of the incoming high and departing low in Northern New England.  Another way to look at this is at the upper levels where the steering of surface systems largely occurs.

2 PM Saturday

Saturday 18z NAM 500 mb vort Sat 2 PM (image NCEP)

Sunday 2 PM

Sun 12z NAM 500 mb vort Sun 2 PM (image NCEP)

It is generally the same story.  Saturday southerly flow with a source in the Atlantic/Gulf to Sunday north/westerly flow with a source in Canada.

Now those watching the Red Sox today see the sun peaking out from time to time.  The reason for all these clouds is very cold air in the mid levels of the atmosphere.  This cause the sun to warm the surface (it is Mid-May after all) and air parcels begin to rise.  The parcels rapidly cool with height so they condense into cloud droplets.  Think a cold drink on a hot day.  A dew will develop on outside of the container.  This is why some showers are possible this afternoon.

18z HRRR simulated radar 5 PM (image Weatherbell)

The rule this spring has been slow moving weather systems.  The same is true for this system as high pressure slowly works east.  Temperatures tonight will drop into the 30's but there are no frost/freeze headlines in Southern New England thanks to windy conditions overnight and a dry air mass.   The weather Monday is similar to today but probably more sun.  Temperatures right around 60.  We get back into the mild weather by the end of the week.

More on this week's weather tomorrow.

-Zack Green

Sunny Skies Give Way to Showers Friday PM

A few people actually complained that it was "too hot" yesterday.  Any suggestions on what to do with these people?  They will be complaining again today as it will be slightly warmer than Wednesday.  Enjoy it as a frontal system will move across New England tomorrow and Saturday bring rain/thunder and eventually cooler temperatures..

Here is a summary of yesterday's high temperatures around the region with my forecast highs for today

Max T Wednesday, forecast for Thur

Downtown Boston. Cambridge etc will be much warmer than the airport where the official temperatures are recorded.  The River Valleys (Merrimack, Connecticut, Blackstone) will all be a bit warmer than some of the surrounding areas.  High pressure is directly over New England

WPC 8 AM Surface Analysis

Low temperatures tonight will be around 50 with increasing clouds.  A warm front will first move through tomorrow morning with some rain showers.  A trailing cold front will then move through Western New England firing off showers and thunderstorms.

WPC projected surface analysis 8 AM Friday 

Temperatures will stay in the 70's tomorrow albeit with overcast conditions.  Rain moves into Central and Eastern MA Friday around 5 PM.  Afternoon sporting events should be good to go but junior leagues playing Friday night may be in trouble.  I'm not anticipating a lot of thunderstorms but I think there will be isolated severe storms in New York, Western CT and MA.

Saturday will be similar.  Saturday morning sports/golf/hikes will be good to go.  It will not be until later Saturday afternoon that showers and thunderstorms develop.  Temperatures reach the low to mid 70's.    Here is the Saturday AM projected surface chart.

WPC surface analysis Saturday AM 

With a bit more sunshine the atmosphere may become unstable enough to support severe weather.  Right now the Storm Prediction Center has a marginal threat mainly for the Mid Atlantic.  I think this ends up further east into Western New England.  As of now I think we end up with rain in Central MA but I don't think the thunderstorms can survive.   Rain is gone Saturday evening but temperatures crash behind the cold front.

SPC Day 3 Severe Weather Outlook

Sunday is partly cloudy with temperatures in the mid to upper 50's.  We may be looking at another frost Sunday night.

On This Day in History
A major flood occurred on this day in 2006.  I posted a bit on 2006 in a previous post here in which I discussed some of the similarities between last week's pattern and the May 2006 pattern.   This happened on Mother's Day.  The flooding wasn't as bad as the October 2005 flooding in the Blackstone Valley but it was severe in Northeast MA and Southern NH. where 6-12" of rain fell.

NWS Boston May 12, 2006 flooding

The Merrimack River in Lowell, the Spickett River in Methuen among others recorded Top 5 river crests.

NWS Radar Loop 5/12/06 2-3 PM 

Moisture from the Atlantic streamed inland and deposit rounds of rain on New England.

More on the thunderstorms tomorrow.

-Zack Green

Daily Weather Briefing May 10, 2016

High pressure is dominating the weather in the northeast.  Gone are the brisk winds from Monday and the cold of this morning.  This afternoon will be bright and mild.  Here is the national surface chart

WPC Surface Analysis 11 AM

Local temperatures in the Blackstone Valley as of 1230 PM were in the low to mid 60's.  These will rise this afternoon and approach 70.

NWS Enhanced Data Display temps, wind direction 1230 PM

Temperatures are a bit warmer in the Merrimack Valley and similar everywhere else with the exception of the coast/Cape which are still in the 50's.  Tonight is not as cold as last night so I am not anticipating any Frost/Freeze headlines.   In general temperatures will hover around 40.  Wednesday and Thursday are near carbon copies of one another with temperatures in the low to mid 70's and mostly sunny skies.

National Outlook
The severe weather threat moves east and south today.  The SPC severe weather outlook

SPC Day 1 Severe Weather Outlook 

Yesterday some significant tornadoes tore through the Plains and Mississippi River Valley.  Here is the severe weather report chart combined with the Storm Prediction Center (SPC) outlook for yesterday

SPC Severe Reports 5-9-16 with 9 AM severe outlook

Unfortunately 2 people were killed and a lot of homes were damaged and destroyed.  National Weather Service (NWS) teams are still surveying the damage but I would imagine some of these storms were EF-3/EF-4.  Although it is a killer this photo is a beauty.

KFOR NBC Oklahoma Digital Team blog 

On This Day in Weather History
Up to 20" of snow fell in Southern New England beginning on May 9 and ending early morning May 10 in 1977.   Up to 13" fell in Worcester and for the only time in recorded history (1870's in Boston) a snow depth was recorded in May at Logan Airport.  The NWS put together this nice graphic from the storm.

NWS Boston May 9-10, 1977 recap

The snow did not stick around long.  The mid May sun is similar to the early August sun.  This is an event more extreme than the Halloween snow of 2011.  I'm sure quite a few of you remember this event well.  You know that upper air pattern is not all that dissimilar from last week's pattern.  I guess just dissimilar enough!

NOAA NCEP Reanalysis May 9, 1977 8 PM

-Zack Green