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June 2019 General Discussions & Observations Thread


Rtd208
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Quite the discussion from Mt.Holly ref late weekend/next week.

.LONG TERM /SUNDAY THROUGH FRIDAY/... 
  So it continues. A stormy period looks to be taking shape Sunday  
  through Friday. The Mid-Atlantic continues to be sandwiched in  
  between the mid-level high to our south and the mid-level low to our  
  north. In between, a somewhat zonal flow this week with a handful of  
  fast moving perturbations.   
   
  Latest model runs have consistently shown a front approaching the  
  Mid-Atlantic Sunday and Monday before stalling it near or in the  
  area for the rest of the week. The forecast problem comes down to  
  timing the best chances for convection in this regime, which is tied  
  to low-amplitude (and likely convectively-generated/maintained)  
  perturbations moving eastward in the quasi-zonal mid/upper flow  
  across the eastern U.S. throughout this period. Unfortunately, this  
  is of low predictability, with models once again exhibiting  
  variations run to run and model to model. Thus, the approach for the  
  medium-range forecast remains the same: higher-than-climatology PoPs  
  for most of the period and near to slightly above average  
  temperatures. In general, the updated forecast is quite close to  
  continuity. 
   
  The main changes are with the Sunday/Monday forecast, where models  
  are showing slow convergence on the convective evolution. The  
  aforementioned cold front will be approaching the lower Great Lakes  
  east-northeast to northern/central New England on Sunday, with  
  several weak perturbations moving west-to-east near the boundary.  
  Convection should readily develop along/downstream of the front by  
  afternoon, mainly to our north/west but probably also in our CWA as  
  well. The 00z GFS is depicting a stronger vort max approaching the  
  northern Mid-Atlantic during the evening, with a round of  
  strong/widespread convection in our area by this time. The 00z ECMWF  
  is fairly similar, which provided enough confidence to raise PoPs to  
  high-chance and even likely in northern portions of the CWA Sunday  
  afternoon/night. Precipitation will wane late Sunday night as  
  nocturnal stabilization takes over and the strongest large-scale  
  lift moves to our east.  
   
  The CAPE/shear parameter space would be sufficient for severe storms  
  Sunday afternoon/evening, and I am rather concerned the GFS is  
  underdoing instability in the pre-frontal warm sector given  
  increasingly warm/moist conditions. Moreover, BUFKIT  
  soundings/hodographs suggest a substantial amount of low-level  
  shear/helicity may exist. Will need to watch Sunday afternoon/night  
  closely for the severe-weather threat in the coming days. 
   
  After perhaps a brief reprieve late Sunday night into Monday  
  morning, chances of strong convection return Monday afternoon. Both  
  the 00z GFS and ECMWF depict another strong perturbation moving  
  through the northern Mid-Atlantic during the afternoon/evening. Once  
  again, the CAPE/shear parameter space is favorable for severe  
  storms, though shear may be somewhat weaker than the previous day.  
  However, the pre-frontal warm sector may be more unstable (using  
  model sounding comparisons Sunday versus Monday). Complications from  
  antecedent convection will exist (increasing the uncertainty in the  
  forecast by this point), not to mention the model volatility already  
  in place with the perturbations responsible for the larger-scale  
  lift associated with the convection. Nevertheless, I am becoming  
  quite concerned with the severe threat both of these days, and hydro  
  issues will be an increasing concern as well given the multiple  
  rounds of storms that may affect the area. 
   
  Speaking of, the forecast does not look much better Tuesday onward.  
  Models show little southward progress of the front and more low- 
  amplitude perturbations affecting the region the rest of the week.  
  Variability in timing/track of these vorticity maxima is quite high  
  during this period, but the pattern is certainly suggestive of a  
  stormy period...with hydrologic concerns only increasing if such a  
  pattern were to verify. 
   
  && 

Upton:

.LONG TERM /SUNDAY THROUGH FRIDAY/...
The main story of the long term will be with a frontal boundary that
approaches on Sunday and then likely stalls over the Tri-State on
Monday. This front may linger near the region through the rest of
the week. Confidence in the exact location of the front remains
uncertain later in the week, with the best consensus of model data
indicating the front remains near the region.

The 12z ensemble means continue to show an upper level low over
southeast Canada on Sunday becoming mostly locked in place through
the middle of next week. This is due to a blocking pattern at higher
latitudes. Ridging sets up over the western Atlantic through the
week. The surface frontal boundary will become nearly stationary
near the region next week between the upper low to the north and
western Atlantic ridging.

Chances for showers and thunderstorms increase Sunday afternoon and
evening as the front nears. Shortwave energy appears weak so have
capped PoPs off at 50 percent. A little better defined shortwave and
frontal wave is progged to move through late Monday afternoon and
Monday night. Have increased PoPs to likely based on some better
support aloft (shortwave energy) as well as some continuity among
the models with the frontal wave. With the front near the region on
Tuesday, the chance for showers and possible storms continues.
Guidance over the last several runs has hinted that the front may
try to sink south on Wednesday. Have not completely gone dry yet as
this may be too aggressive. Unsettled weather may continue for the
end of the week. A more well defined shortwave is currently
indicated by the GFS/ECMWF/CMC to act on the front to bring
precipitation late Thursday into Friday.

While the long term looks unsettled, there will be periods of dry
conditions and periods of precipitation. The exact timing remains
uncertain.

Temperatures through the long term will average near to slightly
above normal.

&&

 

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10 hours ago, AfewUniversesBelowNormal said:

Nice shift to a N. Pacific ridge the next few days.. close to Alaska though, let's see if NYC can stay cool. 

Lets see if this translates to SE ridging on subsequent guidance runs.

test8.gif

 

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Under bright sunshine and scattered clouds, temperatures rebounded into the 70s today. Readings will likely reach or exceed 80° across much of the Middle Atlantic region and into southern New England tomorrow.

The ENSO Region 1+2 anomaly was -0.4°C and the Region 3.4 anomaly was +0.9°C for the week centered around June 5. For the past six weeks, the ENSO Region 1+2 anomaly has averaged +0.08°C and the ENSO Region 3.4 anomaly has averaged +0.80°C. Conditions consistent with El Niño appear likely to persist through at least late June in Region 3.4.

The SOI was -0.28 today.

Today, the preliminary Arctic Oscillation (AO) figure was -0.841. The ongoing blocking will likely continue through mid-month and then could slowly fade. At the same time, blocking is consistent with warmth on the East Coast during the middle and latter part of summer. Hence, should blocking generally persist, the prospects of a warm or perhaps very warm second half of summer could increase.

With respect to the current month, there were 13 cases where the AO averaged -0.75 or below during the first half of June. The mean temperature for the second half of June usually fell within 1° of normal in the northern Middle Atlantic region. In addition, since 1950, there was only a single year that saw the AO average -1.000 or below in May and -0.500 or below in June (as appears likely in 2019): 1993. 1993 featured much above normal readings in the East during the late summer (August 15-September 15 period) and predominantly cooler than normal readings across the western third of the nation during much of the summer.

On June 13, the MJO was in Phase 3 at an amplitude of 0.917 (RMM). The June 12-adjusted amplitude was 0.716.

Since 1974, 7 years saw the MJO in Phases 1 or 2 at an amplitude of 2.000 or above during the May 27-June 5 period. The mean temperature for those cases during the June 1-15 period in New York City was 68.2°, which was about a degree below the mean temperature for the entire period. Thus, the MJO signal may reinforce the idea of a somewhat cooler than normal to near normal first half of June indicated from the recent warming of ENSO Region 1+2. Through June 14, the mean temperature in NYC is 68.4°. Based on the latest guidance, the implied mean temperature for the first half of June is about 68.6° (0.7° below normal).

The second half of June, particularly after June 20th could feature warmer conditions relative to normal than what is likely through mid-month. However, exceptional warmth currently appears unlikely. This period could feature above to possibly much above normal precipitation in the Middle Atlantic and southern New England areas. There are some hints on the guidance that the end of June and start of July could feature drier conditions.

The implied probability of a warmer than normal June in and around New York City remains near 55%.

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3 hours ago, SACRUS said:

Lets see if this translates to SE ridging on subsequent guidance runs.

test8.gif

 

The higher heights around Greenland are starting to relax in the long term, which should make it easier to allow ridging in the East. However, the same low heights are lingering near Newfoundland. Why this pattern couldn't happen 5 months ago...

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Next 8 days averaging 73degs., or 1deg. AN.

Month to date is  -0.7[68.4].     Should be Near Normal,  0.0[70.0], by the 23rd.

EURO Weeklies like June 28 through holiday weekend for some AN.     More BN overall for next 6 weeks.

Just having ridgeing will not give AN w/o good surface wind direction, however.   But be ready for at least one 90* reading with this setup.

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The biggest heat remains to our south through at least the next 10 days. The 50/50 low and cold pool continues to keep the SE Ridge in check. Notice how those features remain in place after the -NAO begins to relax.

 

11EFE625-3785-42A2-863D-63D2D0BBD74C.thumb.png.d1e3eed8d4e8460048b01ee04160b793.png

C0EB2D94-610C-4F3F-AA70-A253DE24127F.thumb.png.3323d7a35a9a097e3acd20f0da3d9d7a.png

5AEB4AD7-7104-449D-9CA2-041F809816CF.thumb.gif.12c7cb1858a5d32648e2b05f5dcfb83d.gif

 

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48 minutes ago, bluewave said:

The biggest heat remains to our south through at least the next 10 days. The 50/50 low and cold pool continues to keep the SE Ridge in check. Notice how those features remain in place after the -NAO begins to relax.

 

11EFE625-3785-42A2-863D-63D2D0BBD74C.thumb.png.d1e3eed8d4e8460048b01ee04160b793.png

C0EB2D94-610C-4F3F-AA70-A253DE24127F.thumb.png.3323d7a35a9a097e3acd20f0da3d9d7a.png

5AEB4AD7-7104-449D-9CA2-041F809816CF.thumb.gif.12c7cb1858a5d32648e2b05f5dcfb83d.gif

 

So, not to get into any climate change debates or anything, but there is MASSIVE ice melt from Greenland coming early this year. Would the melting ice have anything to do with the cool waters off of the NE coast and our weather being cooler than normal?

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41 minutes ago, TriPol said:

So, not to get into any climate change debates or anything, but there is MASSIVE ice melt from Greenland coming early this year. Would the melting ice have anything to do with the cool waters off of the NE coast and our weather being cooler than normal?

That cold pool is related to the AMOC, NAO, and Greenland long term melting. It emerged following the record 2012 melt season. But it shifts its location each year where the predominant North Atlantic vortex sets up. This year it has been lingering near the position of the 50/50 low. So the SE Ridge has been getting suppressed. Last year the cold pool and vortex was  further north with a record WAR/SE Ridge  pattern for us.

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30 minutes ago, Rtd208 said:

I actually would have thought the dew point and humidity would have started to rise by now but it has stayed pretty low this afternoon making for a nice day.

Current temp 84/DP 53/RH 32%

Was thinking the same thing. Strong SW wind all day and dews still in the 40s. 81, DP 44 here.. It's probably an unpopular opinion but I find it a little too dry to me. Esp for allergy and asthma purposes.  Doesnt have to be 70s but I'd like to reach a point where dews stay basically 50+ for the season. 

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I recall many posters on another board expected us to have a "torch" March, April and May after last winter's debacle. That never materialized and we may even finish June below normal pending on the outcome for the second half of this month.

I would not bank on a warmer-than-normal summer for us. This current spring reminds me a lot about what transpired in 2009 - and we all know what happened with that summer.

Can anyone share the statistic for the latest date of a 90-degree day at Central Park in any given summer? It would be appreciated.

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27 minutes ago, Hailstorm said:

I recall many posters on another board expected us to have a "torch" March, April and May after last winter's debacle. That never materialized and we may even finish June below normal pending on the outcome for the second half of this month.

I would not bank on a warmer-than-normal summer for us. This current spring reminds me a lot about what transpired in 2009 - and we all know what happened with that summer.

Can anyone share the statistic for the latest date of a 90-degree day at Central Park in any given summer? It would be appreciated.

I would say it was 2009 when Central Park didn't hit 90 in the summer until mid August or something. Then I remembered it hit 90 for a few days that April so that wouldn't exactly crack the top 10

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The 18z GFS looks very wet over the next several days. The 18z NAM catching on a bit as well. The upcoming week should have several bouts of heavy rain/severe weather. We could see some showers and maybe storms move thru overnight before things really start to ramp up tomorrow and continue thru most if not all of the upcoming week.

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