E PA/NJ/DE Spring 2026 Obs/Discussion

[The Iceman]

1 hour ago, Violentweatherfan said:

So SEPA can anticipate at least some wicked thunderstorms right?

Ehhh overnight runs shifted the threat more towards Lehigh valley and Lancaster for our area. Some of the meso’s now are bringing a lot of crapvection throughout the day and the QLCS breaks up and weakens as it approaches SE PA with zero instability. Mid Atlantic/DC area looks primed for a tornado outbreak though. It’s going to come down if the QLCS line can hold together or not for us. That change and slightly later timing though has made this less exciting than yesterday for se pa imo

[The Iceman]

See SEPA is totally screwed severe wise if the HRRR is right, this crap at 18z tomorrow basically ruins the entire threat, dc into central pa though look under the gun 

 

[ChescoWx]

Today should be the calm before the storm. We see temperatures close to normal today in the lower 50's before rain arrives this evening. We have a chance to actually move to above normal precipitation for the year with between 1" to 1.75" of rain possible across the area. There will be a severe weather threat tomorrow especially with a strong cold frontal passage tomorrow evening. We could see temperatures fall by over 25 degrees over just a couple hours after highs well into 60's. Rain will possibly mix with or change to some brief snow before ending by Tuesday morning. We will see well below normal temperatures both Tuesday and Wednesday before we return to slightly below normal temperatures for the rest of the work week.

[LVblizzard]

A lot of the mesos fail to advance the most favorable severe parameters past Berks/Lebanon counties tomorrow. This doesn’t diminish the wind threat much but the chance for supercells could be confined to central PA.

[Mikeymac5306]

I could be wrong but if memory serves me right with these severe storms in March we (Philly forum) wind up with a more wind driven event than severe lighting and tornados and such.  West of us could be an issue but the daytime heating is gone, and we get the leftovers especially east of 95. 

[enpawx_observer]

Going to be interesting to see the evolution of this SPC outlook. HRRR and NAM both seem like the cool off a good bit as soon as the line enters Eastern Berks, Western Montco/Chesco. NAM also has been hinting at a later arrival time for the Philly burbs which might tamp down the storms a bit.

[LVLion77]

Perhaps I am wrong, but based on experience I tend to be highly skeptical of these forecasts when there is an easterly flow off the very cold Atlantic ocean. That is a stable air flow in March. The forecasts stubbornly have rain tonight. It likely will not happen until the flow is southerly (later in the am.) Hopefully the action heats in the afternoon, but I have a hard time believing we have anything beyond mist until then.

[Albedoman]

37 minutes ago, LVLion77 said:

Perhaps I am wrong, but based on experience I tend to be highly skeptical of these forecasts when there is an easterly flow off the very cold Atlantic ocean. That is a stable air flow in March. The forecasts stubbornly have rain tonight. It likely will not happen until the flow is southerly (later in the am.) Hopefully the action heats in the afternoon, but I have a hard time believing we have anything beyond mist until then.

Yes I agree,  the clody maritime SE fetch is going to destroy the instability factor east of the Blue Mts. No sunshine = no severe weather. The race is on if the sun comes out before the storms hit our area.  I see a duration of light to moderate rain until late in the afternoon as the best bet.  Rumbles of thunder and heavier downpours tomorrow evening with squallywinds at frontal passage . Anyone west of York/Lancaster, watchout.  Tornado watches west of Berks county a good bet

[LVLion77]

Yes I agree,  the clody maritime SE fetch is going to destroy the instability factor east of the Blue Mts. No sunshine = no severe weather. The race is on if the sun comes out before the storms hit our area.  I see a duration of light to moderate rain until late in the afternoon as the best bet.  Rumbles of thunder and heavier downpours tomorrow evening with squallywinds at frontal passage . Anyone west of York/Lancaster, watchout.  Tornado watches west of Berks county a good bet

I wish the flow would turn more sw earlier in the day to remove the maritime layer. Until then drizzle or light showers at best. Hope I am wrong and look like a fool.

[MGorse]

1 hour ago, Albedoman said:

Yes I agree,  the clody maritime SE fetch is going to destroy the instability factor east of the Blue Mts. No sunshine = no severe weather. The race is on if the sun comes out before the storms hit our area.  I see a duration of light to moderate rain until late in the afternoon as the best bet.  Rumbles of thunder and heavier downpours tomorrow evening with squallywinds at frontal passage . Anyone west of York/Lancaster, watchout.  Tornado watches west of Berks county a good bet

Except that southeast flow will increase the low-level rotation. In addition, this is a very dynamic system so not as much instability is needed for damaging storms. I do agree that the greatest severe risk is to our west and southwest. It will be very interesting to see how this plays out. 

[WxUnit]

12 minutes ago, MGorse said:

Except that southeast flow will increase the low-level rotation. In addition, this is a very dynamic system so not as much instability is needed for damaging storms. I do agree that the greatest severe risk is to our west and southwest. It will be very interesting to see how this plays out. 

This is exactly what I think. The low level jet is so strong with this event I and think the general region is bound to see some very strong winds mixing down to the surface with storms. I also think we can't rule out the earlier supercell threat, which some models are hinting at in southeast PA.

[Albedoman]

4 hours ago, MGorse said:

Except that southeast flow will increase the low-level rotation. In addition, this is a very dynamic system so not as much instability is needed for damaging storms. I do agree that the greatest severe risk is to our west and southwest. It will be very interesting to see how this plays out. 

 I agree mIke. Anything from the midwest  deep LP storm means business. Let see how much those southerly winds increase tomorrow afternoon.

[Mikeymac5306]

Are we having a repeat of last Thursday where we get a little white rain on the back end of this?  

[enpawx_observer]

60/60, overcast.

[ChescoWx]

We have picked up 0.43" of rain so far here in East Nantmeal since midnight. We could see upwards of another inch of rain by late tonight. Today will be unseasonably warm followed by unseasonably cold tomorrow through Thursday. A wind advisory is in effect for wind gusts as high as 40 mph through tonight. A strong cold front will cross the area from west to east around the 9pm tonight. Temperatures will drop close to 20 degrees over an hour or so. Rain could briefly turn to sleet and then snow before ending. Temperatures return to near normal by next weekend.

[The Iceman]

I would be surprised if we see widespread severe now. The stuff from last night is beginning to re intensify and is likely going to come into our area early this afternoon but there just isn't going to be instability in place. The best dynamics are in place after that but this afternoon stuff is going to sap all the instability and moisture. Maybe some gusty winds still with the front passing through but it continues to look less and less interesting here. Will still be a significant temp drop at least. 

[Mikeymac5306]

Tornado watches up for DC/Baltimore with warnings to the west of DC. If it holds its gonna make it into Lancaster early afternoon. 

[Birds~69]

62F

[mattinpa]

Tornado watch until 7 for the whole region 

[Hurricane Agnes]

Tornado Watch lofted (pretty big expanse now that they added us to the MA folks) - 

Quote

TORNADO WATCH OUTLINE UPDATE FOR WT 68
NWS STORM PREDICTION CENTER NORMAN OK
1130 AM EDT MON MAR 16 2026

TORNADO WATCH 68 IS IN EFFECT UNTIL 700 PM EDT FOR THE
 FOLLOWING LOCATIONS

PAC001-011-017-025-029-037-041-043-045-055-067-071-075-077-087-
089-091-093-095-097-099-101-107-109-119-133-162300-
/O.NEW.KWNS.TO.A.0068.260316T1530Z-260316T2300Z/

PA
.    PENNSYLVANIA COUNTIES INCLUDED ARE

ADAMS                BERKS               BUCKS
CARBON               CHESTER             COLUMBIA
CUMBERLAND           DAUPHIN             DELAWARE
FRANKLIN             JUNIATA             LANCASTER
LEBANON              LEHIGH              MIFFLIN
MONROE               MONTGOMERY          MONTOUR
NORTHAMPTON          NORTHUMBERLAND      PERRY
PHILADELPHIA         SCHUYLKILL          SNYDER
UNION                YORK
$$

Currently 63 with dp 62.  Have 0.61" in the bucket from the earlier round of rain.

[The Iceman]

60% of 2 or more tornado's, 30% EF 2 or stronger. 80% wind probs.

[LVblizzard]

55 minutes ago, The Iceman said:

I would be surprised if we see widespread severe now. The stuff from last night is beginning to re intensify and is likely going to come into our area early this afternoon but there just isn't going to be instability in place. The best dynamics are in place after that but this afternoon stuff is going to sap all the instability and moisture. Maybe some gusty winds still with the front passing through but it continues to look less and less interesting here. Will still be a significant temp drop at least. 

The afternoon stuff looks like it’ll be the main show at this point. The line along the cold front will be some gusty winds and nothing more.