Showing posts with label 2022 spring outlook. Show all posts
Showing posts with label 2022 spring outlook. Show all posts

Sunday, March 20, 2022

2022 Northeast Spring Outlook Part 2

 

If you haven’t read part one of this outlook you can find it here.

 

There is no doubt that long-range forecasting is difficult, but meteorological spring is a few weeks behind us and astronomical spring comes Sunday at 11:33 AM, after doing a lot of research involving model data, teleconnection and other atmospheric signals as well as looking at some analog years, here's how the end of March into June should generally go.

 

Looking back at the temperature and precipitation anomalies from winter 2021-2022

December 2021 temperature departure

 


December 2021 percent of normal precipitation

 





January 2022 temperature departure

 


January 2022 percent of normal precipitation

 





February 2022 temperature departure

 


February 2022 percent of normal precipitation

 







The teleconnections:

The El Nino Southern Osculation (ENSO):

ENSO has a major influence on the atmospheric patterns and the complex exchange between the ocean and the atmosphere. An El Nino phase is characterized by warmer-than-average sea surface temperatures over the equatorial Pacific Ocean and La Nina is characterized by cooler-than-average sea surface temperatures over the equatorial Pacific Ocean. A neutral ENSO means conditions are considered average, with no influence from El Nino or La Nina. We are currently in a 2nd year of La Nina.    

La Nina conditions continue in the equatorial part of the Pacific Ocean which then weakened from their peak to near neutral status during the spring and summer of this year.

Below-average sea surface temperatures (SSTs) strengthened during February 2022 across the central and east-central tropical Pacific

The weekly ENSO region departures updated March 14th.

Nino 1+2 -0.5°C

Nino 3 -0.8°C

Nino 3.4 -1.0°C

Nino 4 -0.7°C



Earlier this winter the La Nina was stronger in the eastern equatorial Pacific, but in spite of the models saying back in early winter that La Nina would be neutral by April into May. The La Nina while past its peak it has strengthened in the central and western equatorial Pacific while weakening in the eastern tropical Pacific, giving the look of a La Nina Modoki (central based).  The trade winds remain stronger than average in the western Pacific. As long as these trades remain strong it will keep delaying the La Nina retreat.  Negative

Below-average temperatures have expanded near the surface and at depth near 150°W

The critical ENSO region is 3.4. But looking at the ENSO region data, we can clearly see the La Nina has shifted west into the central Pacific.



Looking at the Subsurface data from the Global Tropical Moored Bouy Array Office we can clearly see the water is cooling.



In part 1 of this outlook, I touched on how we could see La Nina extend into winter or even beyond. The Australian Models now indicate a return to neutral ENSO levels—neither La Nina nor El Nino late in the late in the autumn. The IRI/CPC plume has changed from what it was showing back in February, and lengthening the La Nina.    When we look at the CFSv2 Nino 3.4 forecast, we can see it supports the idea of La Nina lasting through this Summer and perhaps into 2023. The European Model is also showing the La Nina lasting longer than it originally thought. Even if La Nina weakens, it will continue to influence global weather and climate. This of course would have a big impact on the 2022 Atlantic hurricane season.

 

We have a negative Pacific Decadal Oscillation (PDO) off the Alaskan Coast in the Northwest Pacific

 

The PDO pattern favors colder temperatures across northwestern North America and milder temperatures across southeastern North America.

 

The Arctic Oscillation (AO) is currently positive and is predicted to remain neutral to positive through late-March with mixed to mostly negative height anomalies across the Arctic especially the North Atlantic side of the Arctic and mixed height anomalies across the mid-latitudes. The North Atlantic Oscillation (NAO) is also positive and is predicted to remain positive as height anomalies are predicted to remain negative across Greenland the next two weeks.

 

The Polar Vortex (PV):

On the picture under we now have the seasonal common zonal wind pace for the Polar Vortex at 10mb degree. The black line is the long-term common, and the blue line is the polar vortex power within the 2021/22cold season. We are able to see that for many of the chilly season, the polar vortex was stronger than regular.

When we look at the PV is already somewhat disrupted.  We can see there is polar stratospheric warming going on spread across the North American side of the Arctic with ridging centered near Alaska.

When we look at the Northern Hemisphere 500 mb from Tropical Tidbits,

In the first image we can see two areas exhibiting a strong Rossby wave improvement, releasing lots of power up into the stratosphere.

 


In the second image, we can see two area of chilly air separated by two strong ridges. One of the cores of colder air is over Siberia the other is over eastern North America.  These colder pockets will lengthen as we move toward into April.

 


This all shows up the best in the third image that is a 3D construction forecast. The Polar Vortex is clearly separated on all however the lowest ranges. Cores are absolutely indifferent and shedding power.



Over the winter we had several Sudden Stratospheric Warmings that lead to weak PV disruptions, The current one is more of a classic PV disruption. So, this will likely be the largest and last PV disruption of the year.

This supports the idea I’ve been talking about on my social media weather pages for a while. And how we’re not quite done with coolish weather and possible shots of winter weather. This would indicate that there is a good likelihood of high latitude Greenland blocking that sets up that would help bring in a colder and/or stormier weather across the Eastern US.

 

March:

After an extremely mild December into early January, we’ve seen most of January into early March with average to below normal temperatures.  Winter was relatively short but a roller-coaster winter, with wild swings in temperatures.  As we get into Spring the pattern looks to fairly remain an extension of the winter pattern.

As is typical of March we’ve seen some wild swings in temperatures. The pattern is hinting at the idea of a trough setting up over the East for the last week of March, this will allow for generally below average temperatures to return as we close out March. March is typically fairly wet, and this March shouldn’t be an exception.

April:

I expect to see the trough to basically stick around for the first part of March. With the trough April should start out with cooler than average temperatures. Once we approach mid-April, we should see the pattern quickly change to a prolong spring with generally warmer than average temperatures.

It’s not uncommon to see snow in the end of March into April. With the pattern remaining active there could be snow chances during that time, this will be especially true for New York State and northern and central New England; I don’t think New York State nor New England will see any more major snowstorms, minor accumulating events of a few inches will be possible. While I can’t rule out higher elevation snow in Pennsylvania and the Middle Atlantic, I think your snow chances are fairly low.  

As far as rain, I think this April is going to see generally average to below average rainfall over a large part of the Northeast and Middle Atlantic.

 

Here is a look at the forecasted average 500 mb geopotential heights (dam; contours) and geopotential height anomalies (m; shading) across the Northern Hemisphere for April 2022. The forecasts are from the 00Z 14 March 2022 CFS.

 


May:

Looks to be generally quite warm, I also see the theme from April continuing with generally dryer than average conditions setting up across the region.

 

March, April and May overall:

I expect this to be a warm overall spring, with temperatures averaging 1 to 2 degrees above average.

We're expecting a changeable pattern into mid-April with a couple of “colder” spells, then we believe the overall pattern turns milder from mid-April on through spring and we average 1 to 2 degrees warmer than normal.

I think average spring rainfall across the Northeast and Middle Atlantic is going to generally be average to slightly below average.

 

Spring Flood Potential:

We have a lack of deep snowpack across the region. So, this will severely curtail Spring snow melt and runoff.  As a result, I don’t see a major flood issue across the Northeast and Mid-Atlantic, due to winter time conditions.

 


Drought outlook:

As I said this Spring looks to see average to slightly below average rainfall.

Drought conditions have been slow to improve over the last few months in New England. Looking at the drought monitor map we can see a large part of New England as well as southeastern and southern Pennsylvania into Maryland, Delaware and New Jersey are experiencing abnormal dryness and moderate drought conditions.  So, I think the drought conditions will slowly worsen during this Spring; then the drought conditions will become even worse as we head into the dryer summer months.

 


Severe Weather:

Spring generally means that warmer temperatures are returning. But with warmer temperatures, the severe weather season also returns to the United States. Severe weather will be slow to ramp up this Spring. but now is the time for you and your family to prepare for what may be a busier than normal season.

Typically, during La Nina, the Spring tornado season in the United States tends to be very active.

Below we have a very interesting image from NOAA Climate. It shows a frequency of hailstorms and tornado events during the spring season in the United States, compared between El Nino and La Nina years.

 


We can see that in a La Nina spring season, there is a substantially higher frequency of hailstorms and tornado events compared to an El Nino. The highest frequency is found in the southern and southeastern parts of the United States.

So, I expect to see an active severe season here in the Northeast and Middle Atlantic Region.

 

Atlantic Hurricane Season:

As I said above, over the past few weeks, La Nina has grown stronger.  Those cooling waters in the equatorial Pacific will have a direct impact on the Atlantic Hurricane Season.  

Hurricanes need Sea Surface Temperatures (SST) to be more than 80°F for up to 165 feet below the ocean’s surface, The warmer the water, the warmer the water the more energy available to fuel the hurricane, and the stronger it becomes. They also need high relative humidity values from the surface to the mid-levels of the atmosphere.  They also need low wind shear, wind shear is very disruptive for hurricanes, and tropical storm formation.

La Nina's most pronounced impact in the Atlantic basin is decreasing the amount of this disruptive wind shear.  Lower wind shear increases the potential for increased number of hurricanes that develop and allows stronger hurricanes to form.  

As I said, our current La Nina could very well, persist through September. If this happens it would only be the third time since 1950 that La Nina was present for three consecutive hurricane seasons.

When we look at the Atlantic SSTs, it shows warmer Atlantic Ocean waters, that will likely continue into summer.

So based on how this current La Nina is looking to evolve, we will likely see more hurricanes than average during this upcoming hurricane season.  The last two hurricane seasons were very active. Based on the current setup, my very early call is for 16-24 Atlantic Tropical Cyclones for 2022.

 

Wednesday, February 23, 2022

2022 Northeast spring outlook part one

 

It is that time of year for the spring flood outlook.

This is the first of two scheduled outlooks for the Northeast and Middle Atlantic region.

Meteorological spring runs from March 1 through the end of May.

October was very warm, whereas November was cold with shots of snow. This pattern carried into the winter.

Winter 2021-2022:

Temperatures were significantly above average across the region through the month of December. Generally, the regional temperatures ranked among the top-five Decembers since records began in 1895. December was also generally a drier-than-average month for the Northeast.

 January started off unseasonably mild. January ended up being cold and snowy and for parts of the region it was one of the snowiest Januarys on record. January was much colder than the 1991-2020 thirty-year average. But while January 2022 was a cold month, generally temperatures are not getting as cold as they once did 30-40 years ago.

So far February has been volatile. With the temperature pendulum making wide swings back and forth.  Based on how I think the pattern will evolve, February will likely end up slightly below average as far as overall temperatures.

The overall pattern this winter has seen a mostly positive North Atlantic Oscillation (NAO) and arctic oscillation (AO). In the Pacific La Nina conditions in the equatorial Pacific. Madden-Julian Oscillation (MJO) is in Phase 3 this is a cold phase for February.  The MJO went into the cold phase in December before retreating into the null phase, where it had no real influence, but pattern remembered the earlier influence leading to the cold January. The Eastern Pacific Oscillation and Western Pacific Oscillation have been the dominate teleconnections this winter. They are the major reasons we’ve seen the back-and-forth temperature pattern every 4 to 6 weeks.   Western and northern parts of the region and the Middle Atlantic including the I-95 corridor with the exception of Philadelphia have seen near average to above average snowfall to date. While a large part of eastern Pennsylvania southeast New York State including the NYS Capital District into western and central New England have seen below average to well below average snowfall to date. The reason for the snowfall disparity is due to the timing of the elements and storm tracks.

Spring 2022 thoughts:

The Climate Prediction Center (CPC) just released their latest 3-month climate outlook for the United States.

Temperature forecast March-May: Climate Prediction Center

 


The CPC is showing above average temperatures for the Northeast and Middle Atlantic region.

 

Precipitation forecast March-May: Climate Prediction Center

 


The CPC is showing above average precipitation for western New York State and western Pennsylvania, with near average for the rest of the Northeast and Middle Atlantic region.

 

La Nina:

 


The 2021-2022 La Nina has been classified as a weak La Nina with sea surface temperatures only slightly below normal. The La Nina in 2020-2021 was a moderate event. As is typical of weak La Nina’s this one made for a chaotic rollercoaster ride this winter. During a weak La Nina the region has a slightly better chance for above normal snowfall and slightly above normal temperatures over the entire winter season.

Temperatures were significantly above average across the region through the month of December. Generally, the regional temperatures ranked among the top-five Decembers since records began in 1895. December was also generally a drier-than-average month for the Northeast.

 January started off unseasonably mild. January ended up being cold and snowy and for parts of the region it was one of the snowiest Januarys on record. January was much colder than the 1991-2020 thirty-year average. But January 2022 was an illustration that even in a cold winter month these days, it's on average not getting as cold as it once did.

In a La Nina wintertime pattern, the polar jet stream tends to dip farther south across the continental United States. Resulting a better chance for cold and snow across northern parts of the region. But the jet stream position does vary. La Nina is expected to stick around for at least a little while longer, with the transition back to neutral conditions most likely not taking place until early this Summer. One thing we have to keep in mind, is that the Great Lakes also have a lot of influence on the Region.  

As I said above, we’re in a 2nd year La Nina. There are some signs that show the possibility for a return to La Nina conditions for next Fall into Winter 2022-2023.  That could allow for another active Atlantic hurricane season, The Atlantic hurricane season does not officially start until June 1, but a storm could form before the official season gets underway. There is also a chance for above average tornado activity this year.  

Sudden Stratospheric Warming Event:

Here is a look at the stratospheric temperature forecast from NOAA. It shows the sudden stratospheric warming event unfolding and bringing the Great Lakes and East plenty of cold air as we head into March.

 


 


Madden-Julian Oscillation (MJO):

The MJO phase diagram illustrates the progression of the MJO through different phases, which generally coincide with locations along the equator around the globe. RMM1 and RMM2 are mathematical methods that combine cloud amount and winds at upper and lower levels of the atmosphere to provide a measure of the strength and location of the MJO. When the index is within the center circle the MJO is considered weak, meaning it has little to no influence.  







From here the MJO looks to go into Phase 4, this is a cold phase for March. The American GFS model takes the MJO into phase 5 and maybe phase 6. But the European ECMWF, Japanese JMA, United Kingdom UKMET and most of the others keep in phase 3 or 4 than move it into the center circle (Null). So I don’t think the GFS has a good handle on the pattern.  This time of year, phases 3,4, and 5 are cold phases for March and April. As we saw in the end of December, the atmospheric pattern could end up remembering the earlier MJO input. If this does happen March would be colder than average overall.

  

The other Pacific Teleconnections:

 

The Pacific has been in the driver’s seat this winter. It has overridden the Atlantic Oscillation and North Atlantic Oscillation this winter. There are several reasons for that, not the least of which is warming global temperatures.

The EPO:

 




The WPO:

 




The Eastern Pacific Oscillation and Western Pacific Oscillation have been the dominate teleconnections this winter. These are going to take a sharp dive into the negative phase.  That is a strong signal for a cold March. 

The AO:

 




The NAO:

 




The AO and NAO have been overall positive so far this winter. As I said, the EPO and WPO have been overriding the AO and NAO. But the AO and NAO are looking to go negative; with all these teleconnections cooperating with each other March into April could be very cold indeed.  

 

All of this means that March into April will surely be colder than average overall.  With the cold will come snow opportunities, how those chances work out and for who, will depend on the exact storm tracks. But historically March is more than capable of delivering major snowstorms. So we will see.

 

The spring flood risk:

First taking a look back at how much precipitation fell across the region before the ground froze. The map from the Northeast Regional Climate Center (NRCC) shows the accumulated precipitation (in) departure based on the 20th century average. The map shows that Central into Eastern New York State saw slightly above average precipitation for Oct through December, with most of the rest of the region seeing around average to slightly below, while Maryland, Delaware and the Middle Atlantic region saw below average precipitation.



 


The maps from NRCC shows that much of the region saw below average precipitations for January.  

 




The maps from WeatherBELL Analytics showing data from the Climate Prediction Center show how much of the region is below average for precipitation over the few months.







The recent milder temperatures across the region have resulting in snow loss

The map from the National Operational Hydrologic Remote Sensing Center shows across most of northern New York State and northern New England along with the higher terrain in Central New England have a snowpack with 4 to near 14 inches of water equivalent.  


 

As a result of all of this any spring flooding will be due to spring precipitation, rather than from fall and winter conditions. It also means we will have a possible drought issue this Spring.

Any spring flooding will be due to spring precipitation than from fall and winter conditions.

 Conclusion:

While Spring 2022 will likely see overall temperatures average to slightly warmer than average. I think the CPC is overdoing the overall warmth.  March going into April is looking to be cold. The 2nd half of April and May will likely see spring warmth. But I don’t see Spring having well above average temperatures overall.

For the rest of winter, I think the pattern will remain active. So, we will be seeing more snow/mix and rain.  But I think the amount of precipitation that makes it into the ground is going to be average to below average.  So later in the Spring going into Summer could see drought conditions become a problem.

 

That’s the end of part one. I will be releasing part two during the first part of March. Part two will go into more detail on temperature and precipitation patterns.