purduewx80

The developing -NAO largely explains the suppression. It's digging more to the south due to the depth/magnitude of the trough currently approaching the East Coast (again related to the anomalous ridge developing over Greenland).

18Z Euro even farther south, suggesting parts of the Chicago metro are in play for 4-6".

It's a shame lapse rates aren't better. The warm front will probably get hung up before the triple point/coastal low passes through in the evening, but I still think there will be ample forcing/instability for elevated storms region-wide. Some of the hi-res today is showing multiple rounds of convection tomorrow.

should be an interesting day in at least parts of the region. there is enough elevated instability for thunderstorms in the city, but it's not yet clear if we get any surface-based CAPE nearby. some models are picking up on a more phased look at 500mb friday - that would certainly do it w/ the dynamics at play and a redeveloping coastal low passing across the city or long island. sounds pretty much like a continuation of our winter pattern.

Probably into at least eastern Nassau; there have been some rando lightning strikes outside of those heavier bands too...two of which have occurred ~20 miles SE of JFK.

should be a few storms in suffolk co today. numerous lightning strikes just s of the forks now.

New April record for OKX, beating the prior by 0.05": WAL down on the Delmarva also set their April record at 1.77".

Deep layered southerly flow out of the tropics should easily produce mid-60s+ dew points, similar to Sunday PM. The ECMWF shows a peak of 69F at DCA Friday afternoon.

this is the cold front. the pre-dawn round wiped out the best instability, but there is a vort max w/ the upper trough accompanying the front, so the little bit of heating we had this morning allowed it to pop some showers. thunder risks will end up being a bit higher in southern new england where there will be a longer period of heating, resulting in over 500 j/kg of cape.

Looks like another round of heavy showers and embedded thunderstorms w/ the cold front later this morning. There is also good support from a 500 vort max. Forecast soundings support several hours of 50 MPH gusts across the city late this afternoon into the early evening as colder air returns to the area.

thunderstorm in bk

thunder and a downpour in bed-stuy. that inversion is pretty shallow.

Yep, count on cold air winning out this time of year if there is ever a question it may occur. We're probably looking at a morning high and falling PM temps ahead of the PM squall.

Models waffling on whether or not we stay in the warm sector Tuesday. Quite a bit of evidence a backdoor cold front ruins the party for most of the city while NJ could see another day in the 70s.

Sounds humid and stormy.

unlikely w/ this event. the shear/instability combo isn't quite right.

Lapse rates look great around here Monday, but dry air and lack of convergence may prevent much in the way of convection after the AM warm air advection ceases. The focus will likely end up being farther south in the Mid-Atlantic in VA and the Carolinas. Tuesday is showing some greater potential for thunderstorms on some of the guidance, including the 06Z ECMWF, FV3 and 12Z NAM + RGEM as the upper trough and stronger cold front approach during the afternoon. Their timing would bring the front through late afternoon as temps warm back up into the 70s.

The uber dry antecedent air mass helped, too, and is being fed directly from the offshore high. Some of the fcst soundings did suggest wet bulb temps would fall below freezing a few hours again before heavier rain moves in with WAA this evening.

can verify, got pinged in the face to/from the haircut over the past hour.

Wind direction from the SW-W in the afternoon definitely favors over-achieving; however, most of the guidance is showing thick cirrus associated with the jetstream throughout the day.

-PLRA here in Long Island City now.

Usually at this range, I find blending frontal timing between these two pieces of guidance is best. Euro too slow/GFS too fast 9x out of 10. the 12Z Euro was a good 6h quicker with the front than the 00z run, now showing a morning high and falling PM temps Sunday.

There may be some decaying squally showers late Friday afternoon/early evening on LI. Lapse rates become quite steep as the potent upper low and cold pool transition into the area. It's well timed with max heating over the mountains, so I think there could be a few thunderstorms with small hail just W/NW of the city Friday afternoon as the true cold front comes through.

Totally agree. Whatever low the Canadian members are trying to blow up farther S/E will probably be more of a triple point that will erupt later - once the 3rd piece of energy dives in and closes off.

Can already see a surface reflection offshore the Carolinas this morning. Most guidance brings this inland overnight, but it will be important to watch whether or not convection can keep it tied to the Gulf Stream tonight. If that occurs (big IF), then areas outside of the higher terrain may have a chance to flip to snow since the surface low would track farther offshore than the overnight consensus indicates.