weathermedic

Looks like a few storms beginning to pop on radar over Sussex County and near Allentown PA

Mesoscale Discussion 2185 NWS Storm Prediction Center Norman OK 0213 PM CDT Tue Sep 01 2026 Areas affected...portions of the Mid-Atlantic Concerning...Severe potential...Watch likely Valid 011913Z - 012115Z Probability of Watch Issuance...80 percent SUMMARY...Thunderstorm development is anticipated within the next 1-2 hours across portions of the Mid-Atlantic region. Given a favorable convective environment, storms will likely intensify and pose a severe wind/hail threat through early evening. Watch issuance is likely by 21z (5 PM EDT) as thunderstorms begin to mature. DISCUSSION...Latest GOES day cloud phase imagery depicts towering cumulus on the north/northeastern fringe of a low-level thermal ridge (roughly outlined by the 90 F isotherm) where modest warm advection is promoting ascent. Some lingering inhibition is noted in satellite imagery, but this should continue to erode over the next couple of hours as the diurnal heating maximum approaches. Latest guidance generally depicts deep convective initiation by 20-21 UTC within this regime and potentially along a diffuse frontal boundary draped from southern NY into northern PA. Regional VWPs continue to sample mid-level flow on the order of 35 knots, which is supporting similar effective bulk shear values given somewhat weak near-surface winds. Based on these observations and recent forecast soundings, hodograph elongation appears sufficient for organized convection, including the potential for a few supercells. While discrete modes persist, large hail (potentially up to 1.75 inches) will be possible. A brief tornado may also be possible - particularly across northern NJ/far southern NY near a weak surface trough where low-level veering may be adequate for a localized tornado threat. With time, clustering should promote some degree of upscale growth with an increasing severe wind threat, especially with southward extent into southern NJ and DE where guidance has been consistently showing a signal for clustered/linear storm modes. Given the favorable convective environment, watch issuance will likely be needed as convection begins to intensify.

Nice write up about the severe weather potential around here from OKX AFD this morning: The main focus of concern will come this afternoon into early this evening. A warm front will lift north of the area this morning, but only for a brief time. Strengthening high pressure across eastern Canada into New England will send the front back to the southwest as a backdoor cold front late this afternoon into this evening. Winds will back around to the east behind it. While there is some uncertainty as to how much the airmass will destabilize in the warm sector today, HREF mean SBCAPE values are still 1000-2000 J/KG across the marginal and slight risk areas. Greatest instability will be north and west of the NYC metro. Additionally, there is 40-50kt of deep-layer shear and decent directional shear 0-3km. SPC has included part of the area in a low probability for tornadoes (less than 5 percent). However, mid-level lapse rates are marginal around 6C. The flood threat remains low with the area under a marginal risk of excessive rainfall. This is for an isolated flash flood threat. While the airmass is loaded with moisture, PW values around 2 inches, there is decent storm motion in the westerly flow aloft. Training does not seem likely in this event. SPC HREF probabilities are greater than 50 percent for an 1" in 3 hours, but less than 10 percent for 3" in 3 hours. Much of the strong to severe convection should drop south and west of the area around or shortly after 00Z (8 PM). .KEY MESSAGE 2... An easterly flow will result in a much more stable airmass across the area on Wednesday. The frontal boundary is expected to stay south and west of the region before starting to move back in Wednesday night into Thursday as a warm front. SPC has the western half of the area in a marginal risk for severe weather, mainly due to some uncertainty with how far south and west the front gets. Right now, expecting mainly scattered showers for the western half of the forecast area. Greater coverage of showers and thunderstorms is expected Wednesday night into Thursday morning with the warm front lifting across the area. The airmass will then warm up and destabilize Thursday in the warm sector with another chance of strong to severe convection with the cold front late Thursday afternoon/evening. SPC has western portions of the area under a marginal/slight risk and WPC has the entire area under a marginal risk of excessive rainfall. Details should fall better into line in the next 24h.

House fire on the southern end of Hylan Blvd on Staten Island reportedly from a lightning strike a short time ago

.70 here from this morning’s rain.

1.47 inches here in Sheepshead Bay

From OKX AFD: While still low confidence, given high shear and little instability, severe thunderstorms for northeast NJ, NYC and western Long Island can not be completely ruled out. This would be mainly an isolated damaging wind gust threat, but given decent low level curvature in model soundings an isolated tornado is also possible.

89/74 currently at my station so dews still very uncomfortable

Some impressive 40k+ cloud tops with some of these storms

91/78 HI 107

83/77...yuck

Up to 4.0 inches at my station

3.18 so far at my station

Already at a 74 dewpoint at my station now.

Up to 9.4 for the month at my station.

.85 total at my station

.05 here so far

Looks like showers popping up SW to NE from Breezy Point to Valley Stream

Severe thunderstorm warning for Bronx and Queens just issued until 5pm. 60 mph winds possible.

Echo tops with some of the storms in NJ are over 30,000 feet. Not very common around these parts. The one just north of Morristown is showing 37,000 ft.

Tornado watch through 9pm for a large part of the area including NYC

Mesoscale Discussion 1690 NWS Storm Prediction Center Norman OK 1223 PM CDT Tue Jul 21 2026 Areas affected...portions of the Mid-Atlantic into the Northeast Concerning...Severe potential...Watch likely Valid 211723Z - 211930Z Probability of Watch Issuance...80 percent SUMMARY...Increasing storm coverage is expected through the afternoon and will necessitate a watch. DISCUSSION...Recent composite radar indicates increasing shower and thunderstorm coverage across eastern Pennsylvania on the leading edge of mid 70s dewpoints as they advect northward. Most of this activity is moving away from the greater moisture/instability, but continued northward destabilization is anticipated. In addition, broken cloud cover across southeast Pennsylvania and New Jersey will result in greater instability within this zone. The leading edge of a 50 knot mid-level jet (centered around 5-6km) has been sampled by the CCX VWP within the last half an hour. As this overspreads the warm sector, shear will be in place for storm organization, including supercells. Damaging winds will be the primary threat, but some large hail and a few tornadoes will also be possible. The greatest threat will be across southeast Pennsylvania and New Jersey, where the greater instability is in place. However, as the warm front lifts northeastward, the threat could extend into southeast New York and Connecticut this afternoon. ..Bentley/Mosier.. 07/21/2026 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...BOX...OKX...ALY...PHI...BGM...CTP...LWX... LAT...LON 39187437 38877495 39457648 39867689 41097690 42277653 42657593 42727456 42487358 42037309 41257279 40597287 40417378 39187437 MOST PROBABLE PEAK TORNADO INTENSITY...85-110 MPH MOST PROBABLE PEAK WIND GUST...55-70 MPH MOST PROBABLE PEAK HAIL SIZE...1.00-1.75 IN

Good technical discussion from the AM OKX AFD: .DISCUSSION... .KEY MESSAGE 1... An upper level trough digs down into the Great Lakes Saturday and swings across eastern Canada and the northeast US Saturday night. Ahead of this feature, shortwave energy will pass across the area this afternoon as a warm front lifts north of the area into the afternoon. A pre-frontal trough will follow late in the afternoon with the main cold front moving across the area this evening with the potential of another line of showers/storms. Severe thunderstorms and potential flash flooding are the main concerns this afternoon and evening. It is important to note the exact location of the severe and flooding hazards may not become clear until a few hours before the onset due to the aforementioned uncertainties. PWATs are progged to reach between 2 and 2.25 inches, which is well above the observed 90th percentile per OKX RAOB climo. Freezing levels look to range from 13-15 kft with deep warm cloud layers, supporting efficient warm rain processes. These ingredients support the potential for heavy downpours in any convection this afternoon and evening. There is still some uncertainty with the amount destabilization today, especially with lingering smoke this morning and potentially apart of the afternoon (see key message 2 for more details on the smoke). The passage of the shortwave should allow the smoke to move away from the area in the afternoon. The greatest instability may set up just to our southwest, especially as the shortwave moves across the area. There should still be at least 1000-1500 J/kg of MUCAPE, but surface based CAPE could be limited this afternoon, unless greater destabilization occurs further north. The mid level flow is also fast enough to keep the convection moving across the area, which may limit the flooding potential. The latest HREF has a small area of 30 percent chance of greater than 3 inches in 3 hours just south of of our NE NJ and NYC metro zones. This is close to our flood watch and most susceptible areas for flash flooding, so no changes were made to the flood watch. Peak hourly rainfall rates of 1.5-2"/hour are possible. Isolated instances of flash flooding in some urban areas across the I-95 in S CT and potentially western LI are possible, but not enough confidence for an expansion of the watch at this time. WPC has maintained the slight risk for excessive rainfall. SPC has expanded the enhanced risk into much of the Lower Hudson Valley, NE NJ, and NYC metro with a slight risk remaining elsewhere. As noted above, there is uncertainty with the amount of destabilization due to smoke and potential of a round of convection as early as late morning and early-mid afternoon. The 00z HREF is indicated a mean SBCAPE of around 1000 J/kg across NE NJ into the NYC metro, but an ensemble maximum of upwards of 2000-3000 J/kg this afternoon for these areas. Elsewhere, the mean is around 500 J/kg with an ensemble max of 1500-2000 J/kg. The max surface CAPE values are possible if the smoke clears sooner and if the first round of convection is weak or moves out quicker. Bulk shear around 40 kt continues to be progged and there is low level directional shear/curvature in the wind profiles. The main threat from any severe storms will be damaging wind gusts. There is also a risk of a tornado, especially if the warm front lingers nearby, which would enhance low level helicity and shear. If we are able to get clearing and the first wave does not leave behind subsidence, then the potential line of storms with the cold front/pre-frontal trough could also contain a few severe thunderstorms. The cold front moves through the area around midnight, bringing an end to the threat of showers and thunderstorms. .KEY MESSAGE 2... Smoke is beginning to filter back into the area from the south early this morning as high pressure has moved offshore. HRRR, RAP, and RRFS smoke fields all show areas of smoke lingering across the area this morning and potentially into a portion of the afternoon. The smoke should begin to clear out and move to the east as a shortwave and showers/storms move across the area. There will be reduced air quality and visibilities into at least the early afternoon. NYDEP, NJDEP, and CTDEEP all have air quality alerts in effect until midnight.

The sun is literally a red ball in the sky