May 2018 Discussions & Observations Thread

[doncat]

30 minutes ago, Cfa said:

Climbed into the 70’s not once, not twice, but three times today. I’m guessing that was the sea breeze boundary moving back and forth.

 

Same thing here...looks like a trace you would have if clouds were moving in and out, but skies were clear...I've noticed this before with onshore winds...

[dWave]

2 hours ago, Cfa said:

Climbed into the 70’s not once, not twice, but three times today. I’m guessing that was the sea breeze boundary moving back and forth.

 

I went from upper 70s early afternoon to upper 60s then back to mid 70s by late afternoon. Like a sea breeze just fell apart over me.

[Rtd208]

Slight risk for severe just west of the city.

 

 

[Rtd208]

Another good write up by Mt.Holly for today's severe potential and the severe/heavy rain potential over the next several days. Upton's write up not as detailed so won't bother posting.

.NEAR TERM /UNTIL 6 PM THIS EVENING/... 
  As of 3 AM, very weak surface ridging trying to develop over the  
  area with low pressure located well off the coast. The low level  
  flow has had an onshore component and this has resulted in a marine  
  layer with coastal fog once again this morning, especially along the  
  NJ coast where a Dense Fog Advisory remains in effect until 9  
  AM. Otherwise, a fairly quiet morning across the area.  
   
  Heading into the day Thursday, weak surface ridge quickly gives way  
  to a SW flow ahead of an approaching frontal system so expect fog to  
  mix out by mid morning. The main concern will then shift to  
  shower/thunderstorm potential with approaching front. At this point,  
  expect an initial area of some showers with possible embedded thunder  
  to move through mid to late morning as activity currently over Ohio  
  moving into western PA moves east and weakens with time. Don`t  
  expect this to produce any severe weather. Beyond this time there  
  should be a break before additional showers and storms re-develop  
  along an approaching pre-frontal trough and move through the area  
  west to east during the latter part of the afternoon. Forecast  
  models generally indicate 500-1000+ J/kg of ML CAPE over the  
  area by this time with the exact amounts depending on how much  
  sun breaks out between the two rounds of precip. In addition,  
  mid level flow looks to be around 40+ knots in the 700-500 mb  
  layer with 30+ knots near the top of the boundary layer. This,  
  along with a relatively dry layer in the mid levels suggests  
  damaging winds may be able to be brought down to the surface in  
  any storms...especially along and N/W of the I-95 corridor. In  
  fact, the Storm Prediction Center has upgraded most of our  
  forecast areas except the coast to a Slight Risk for severe  
  storms. Again, biggest threat looks to be damaging winds though  
  large hail also a possibility in any stronger updrafts. Highs  
  today will generally be in the 70s to around 80  
  degrees...coolest along the coast and over the southern Poconos. 
   
  &&  
   
  .LONG TERM /FRIDAY THROUGH WEDNESDAY/... 
  Main concern for the long-term forecast remains the evolution of a  
  meandering front across the northern Mid-Atlantic this weekend into  
  next week, with several rounds of convection potentially affecting  
  the area. 
   
  On Friday, the cold front will have progressed through much of the  
  CWA, with dry and somewhat cooler conditions expected. Used a  
  consensus blend of bias-corrected statistical guidance, which has  
  performed well in recent days. Not expecting significantly cooler  
  temperatures, as there will likely be ample sun and some warming via  
  downsloping. 
   
  Forecast becomes tricky starting Friday night, as weak midlevel  
  perturbations begin to progress eastward via quasi-zonal midlevel  
  flow. In advance of the first vort max, the cold front should begin  
  to return northward as pressure falls occur downstream. How far  
  north the front advances is somewhat uncertain, with models already  
  exhibiting some discrepancies by this point. Thinking is that the  
  front`s retreat northward is probably overdone (typical model bias),  
  with the 00Z ECMWF favored given its relative consistency with this  
  first event over the past several days. The heaviest precipitation  
  looks to be north and west of the area, but areas north of I-78 may  
  see some decent amounts by Saturday morning. The NAM and NAM Nest,  
  notably, bring a swath of 1+ inch rains in this area, but the  
  GFS/CMC are much farther north (New York). The ECMWF is slightly  
  farther south than the GFS/CMC, but not much, so kept QPF generally  
  a half inch or below in this area for now. Confidence in this  
  portion of the event is on the low side. 
   
  The second round of precipitation may come as early as Saturday  
  afternoon and evening, as combination of diabatic heating and  
  enhanced convergence around the lingering front may initiate  
  convection. There are reasonably strong hints of this in all of the  
  operational models, with subtle depictions of vorticity maxima  
  continuing through the region during this time. CAPE-shear parameter  
  space is suggestive of an environment favorable for some strong to  
  severe storms, though antecedent precipitation and lingering effects  
  on destabilization do not have me sold on the potential yet.  
  Nevertheless, the potential is there, with organizing processes  
  associated with the front likely to generate some increasingly  
  widespread showers/storms by Saturday night (with potentially  
  locally heavy rainfall). Aside from the somewhat dry GFS, the  
  NAM/CMC/ECMWF all depict 0.5-2 inch rainfall totals by Sunday  
  morning in much of the area (including the QPF from Friday  
  night/Saturday morning). My forecast is on the conservative side  
  (given the uncertainty in frontal placement, along with the drier  
  looking GFS), but with the potential for multiple rounds of  
  convection affecting the area by this point, I am a little concerned  
  about potential impacts by this point. 
   
  Sunday looks wet, with all models depicting more convection  
  affecting the area as the front begins to sag southward. Instability  
  looks to be more marginal by this point, with widespread  
  clouds/precipitation ultimately hindering development of more  
  substantial CAPE. Nevertheless, plentiful moisture will be available  
  (PWs 1.25-1.75 inches), and the frontal progression southward will  
  be slow. Heavy rainfall potential continues to be a concern through  
  this time, though the axis of maximum QPF becomes more uncertain.  
  The GFS looks most aggressive in the southward progression of the  
  front, which continues to look like an outlier. Nevertheless,  
  convective/mesoscale processes (poorly modeled in general) will  
  ultimately dictate the front`s evolution. So a broad-brush of chance  
  to likely PoPs looks prudent for most of the area at this time.  
  Trend has been for much lower temperatures Sunday compared to  
  Saturday, which makes sense given the anticipated  
  clouds/precipitation coverage. 
   
  There does seem to be a precip lull in most of the model output for  
  Monday and Monday night, so kept a relative minimum in PoPs for the  
  area during this time. The front may progress far enough southward  
  to keep the best chances out of the CWA. This also coincides with  
  trough passage to the north Sunday night, with upstream synoptic- 
  scale descent likely hindering much precipitation coverage during  
  this period. However, did keep mentionable PoPs given remaining  
  uncertainty and the front`s continued proximity to the area. 
   
  However, there are indications that precipitation chances will  
  increase again for much of the rest of the week (at least at times)  
  as more perturbations pass the area in the quasi-zonal midlevel  
  flow. Furthermore, an upper-level low in the Southeast is expected  
  to drift northward east of the Appalachians Tuesday through  
  Thursday. A lengthy southerly (moist) fetch will develop and extend  
  into the northern Mid-Atlantic, and the lingering boundary along  
  with a reinforcing cold front and attendant vort max mid-to-late  
  week will provide ample lift for widespread showers/storms. It is  
  during this period that flood potential will likely increase  
  markedly. Stay tuned. 
   
  && 

[CIK62]

Next 8 days averaging  66degs., or 3degs. AN.

Month to date is   +10.2.   Should be  +6.5 by 18th.

[bluewave]

Looks like the warmest part of the mid-May warm up will be focused to our south over the Mid-Atlantic region. The MJO isn't forecast to make into the warmer phases again for this month. So it's possible that the 94 high at Newark on May 3rd stands for the month. If this is the case, then it would be the earliest May monthly maximum temperature at Newark since 2001. That year peaked at 94 degrees on May 4th.

 

[MJO812]

55 now

[allgame830]

What are the thoughts on probability of a storm later today... have 2 softballs game 730 and 830 this evening?? 

How is this compared to last Thursday storms we had coming through? 

[Brian5671]

1 minute ago, allgame830 said:

What are the thoughts on probability of a storm later today... have 2 softballs game 730 and 830 this evening?? 

How is this compared to last Thursday storms we had coming through? 

here's the 3K nam-looks like the action is west at 8pm and isolated.

[allgame830]

7 minutes ago, Brian5671 said:

here's the 3K nam-looks like the action is west at 8pm and isolated.

Oh great so looks like if any activity comes through it will be later on in th evening which would be good!!

[Brian5671]

GFS has quite the temp gradient for Sat

[AfewUniversesBelowNormal]

1 hour ago, Brian5671 said:

GFS has quite the temp gradient for Sat

I would expect the ridge to build more north. This is the pattern since February, and fwiw I think the model is taking -AO to much into consideration because it's building from south to north, not north to south like usual. 

[Stormlover74]

EWR sitting at 63, was supposed to make it to the mid 70s

[Rtd208]

Current temp is 73 here.

[jm1220]

3 hours ago, AfewUniversesBelowNormal said:

I would expect the ridge to build more north. This is the pattern since February, and fwiw I think the model is taking -AO to much into consideration because it's building from south to north, not north to south like usual. 

With the upper air low and troughing developing north and east of us, most of us might be on the cooler side over the next week. That’s a recipe for onshore flow and backdoor fronts. 

[SnoSki14]

57 minutes ago, jm1220 said:

With the upper air low and troughing developing north and east of us, most of us might be on the cooler side over the next week. That’s a recipe for onshore flow and backdoor fronts. 

I don't see that at all, gfs currently shows another round of record heat after Monday.

[Sophisticated Skeptic]

Pea size hail covering the ground right now!

severe storm

[Sophisticated Skeptic]

Poconos

[mattinpa]

37 minutes ago, SnoSki14 said:

I don't see that at all, gfs currently shows another round of record heat after Monday.

I see some warmth for a few days but forecasters do not seem convinced of record heat yet.

[dWave]

Decent t storms now. Not much wind but lots of lightning 

[Cfa]

Lightning visible from Suffolk.

[ict1523]

Lots of lightning, cloud to ground strikes, some loud thunder also. Not much else. Not bad.

[Juliancolton]

Some handheld lightning this evening. Double rainbow was just a bit off the left side of the frame.

[Rtd208]

Picked up 0.17" of rain for the day.

[CIK62]

Next 8 days up to an average of 68degs., or about 5degs., AN.

Month to date is   +9.0.   Should still be in record territory of +7.2 by the 19th.

[bluewave]

Models continuing with the impressive May backdoor pattern over the next week to 10 days. Some brief 80's warmth tries to sneak in around the middle of next week. Plenty of Canadian high pressure keeping an easterly component to our winds on numerous days.

 

 

 

[uncle W]

there have been a few Mays with some cold days after mid month during developing el nino years...1963 had the latest 39 temp...1976 the latest 38 temp...1972 had a late cool spell...2002 had a significant cool spell...

[donsutherland1]

11 hours ago, Juliancolton said:

Some handheld lightning this evening. Double rainbow was just a bit off the left side of the frame.

Very beautiful.

[jm1220]

4 hours ago, bluewave said:

Models continuing with the impressive May backdoor pattern over the next week to 10 days. Some brief 80's warmth tries to sneak in around the middle of next week. Plenty of Canadian high pressure keeping an easterly component to our winds on numerous days.

 

 

 

Hopefully the backdoor can be held off but for many of us that’s a classic signal for cooler conditions on the easterly winds such highs generate. In times where we can get westerly flow I agree it can get well into the 70s or 80s. 

[psv88]

2 hours ago, jm1220 said:

Hopefully the backdoor can be held off but for many of us that’s a classic signal for cooler conditions on the easterly winds such highs generate. In times where we can get westerly flow I agree it can get well into the 70s or 80s. 

Temps have consistently beat guidance this spring, up to 71 now, forecast was 66. I expect that to continue moving forward