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The above hopefully encapsulates the likelihood of two upcoming significant east coast storms. Changes will occur from the some of the attached supporting graphics but we're in line for more significant weather and I'm sort of concerned about flood potential. This time maybe wet snowfall NYC.? Please consider limiting NYC snow enthusiasm with the stats attached from Don, at least until we get Jan 4-5 (if snow is still in the possibilities). It is hoped the Bluewave produced lack of 2" snowfall at CP can be put to bed, but it's possible that next Sundays probable wintry event will shift a little more inland with rain dominating along the coast. The event for the 10th could be brief snow or ice to heavy rain and snow melt, presuming we accumulate anywhere close to the attached 00z/31 EPS prob of 4" axis. Wind damage graphic via the EPS for the 10th... expectations are more of an e-ne wind (nor'easter we hope) for the 7th with gust potential 40-50 MPH along the coast and maybe minor coastal flooding (tide cycles are LOW for this storm). The event around the 10th "may" have stronger winds gusts vicinity 60MPH along the coast and a better chance of coastal flooding (tide cycles 10" higher to start). Power outages possible but impossible to predict without 24 hour confidence on wind gusts/qpf amounts/ptype/temp if and when it snows. This thread was started since I think there is general interest in snow, also flood potential for this weather interested forum. I may comment once/day but it's all yours. OBS for the 6th-7th will go in here. For whatever occurs the 10th...may have to separate out the OBS in a supplemental thread late 9th, but that's 10 days away and at least a portion of these ensemble expectations may be less than out looked through the 00z/31 cycle and therefore less impact and more routine. No guarantees here but definitely worth monitoring. Edited title 1156AM-Jan 6 to include obs and tags added obs and sleet. Edited title 645 AM Jan 8 iso include OBS for Jan 9-10 and removed the ? behind damaging wind.

Please follow National Weather Service warnings/statements. Starting from another 10 degree morning in NYC, a rapidly changing weather scenario will cause some power outages, accidents (despite a Holiday weekend) and slippery travel for a time in a fairly large portion of the forum, in part due to at least 42 consecutive hours of freezing temperatures on non snow covered ground, and beginning near sundown when the impact of solar insolation lessens. Exactly who gets how much of what is being determined by member observations with model and forecast contributions enhancing, but not hyping interest. Coastal flood threat as per OKX. Usually we like at least 12 hours of gale force onshore flow to build the water levels, but with the astronomically higher tide cycle, 980s MB pressure at Monday morning high tide, an inch of rain in the 6 hours up to high tide emptying from rivers-streams, there should be enough surge and incoming wave action to cause coastal flooding. Working a bit against the flooding NYC southward along the NJ shore is the onslaught of wind abating and turning southerly near the time of high tide. Certainly the early part of the morning high tide cycle looms larger. If you're in a tidal inundation area, follow NWS statements. I'd park my car with parking laws in mind where it can't get flooded. Wind damage: several 12z/16 HRRRX graphics are appended. Please use the legend. Midnight to 6AM is best chance for damaging wind , to occur in a 3hour period ranging from near 2A NYC to near 5A e LI. Gusts to 60 kt possible e LI with gusts 45 kt possible NYC metro airports. I could be too conservative. Have cell phones charged and be prepared for no internet early Monday. Many of our members, even to western LI will be reporting a bit of snow or sleet late today (some are from Ocean Effect already). mPing will be helpful especially for us inland folks just north of I78 where an hour or 2 error in the precip phase change from snow to sleet/freezing rain or rain can mean an inch or two of snow. The 12z HRRR, HRRRX, and 3K NAM seem to support slightly more snow than maybe some are anticipating. Whether that occurs is unknown. No matter, if you have heart problems and live north of I80, you may want some assistance removing slush laden with maybe 3/4" of rain (glop). And of course have your resources to clear it by 6PM Monday when temperatures falling below freezing start the solidifying process. {The HRRRX amounts may be too large by 2", so it is a slower to change model with 1/4-1/2" everywhere up through I84 by 06z, so that could bias the amounts high there. edited in at 1036AM} ICE: I think parts of the I84 corridor including Sussex County NJ may have pockets of damaging ice near 4AM Monday when the ice combined with wind gusts 45 MPH in the ridges could be enough to knock out some power. Monday afternoon-evening: The trough aloft passage and influx of colder air should wring out areas of 0.1-1" snowfall in the steep moist lapse rates associated with the cold pool aloft, including NYC-LI.

Active Pacific pattern assisting downstream northeast USA blocking of two large 500MB trough passages next week. This should result in at least one Nor'easter and possibly a classic fall severe weather event if a 985MB low moves northward through central PA. Max isolated rainfall potential of ~7" somewhere in the NYC subforum (interior) would lead to isolated Flash Flooding but the dry October of generally less than 1/2" so far in NYC 'should' limit the flash flood threat. There has been more rain I84 northward so the flood threat may eventually be targeting the interior NYS/CT portion of our forum. The general non-astronomically high tide cycles should at least partially limit the potential for moderate coastal flooding. Of greater concern appears to be softening of the ground by next weeks rains and the probability for a period of 45-55MPH wind gusts on fully leaved wet tree branches in parts of the area, which would lead to a power outage problem. At this Friday October 22 608AM issuance time, it's far too early to focus on the details. The headlines of this topic will adjust a bit as we move through the weekend, including tags. For now have left SVR and FF out of the tags. 430P/Saturday the 23rd added the FF Tag. 7P/Sunday the 24th increased general rainfall to a range of 2.5-8" up from 1.5-4".

The gusty east winds of 45-60 MPH along the NJ and Li coasts early tonight will ease from south to north by sunrise Saturday as the bands of heavy showers and embedded thunderstorms sweep north through the NYC subforum with generally 3/4-2" amounts. Depending on amounts ne NJ might end up with flooding overnight, while streams and rivers that were receding start rising again during the night through Saturday. There should be a lull in the showery weather Saturday morning-midday, but drizzle may occur in some areas. Another burst of showery rains, should develop across the subforum mid Saturday afternoon, except maybe missing to the east of PA. This is associated with low pressure and the approaching sharp but weakening 500MB trough heading east-northeast through the mid Atlantic states. There are questions on how much rain can occur with this second system, the HRRR and 3KNAM tending to be furthest west. It's possible thunder will occur with system as well as instability approaches 0C during the evening.

This first event is slated mainly for Monday night-early Tuesday night but with a pulse of showers, some heavy occurring overnight Sunday night and potential for bands of high wind and or heavy rain remaining in the NYC subforum into early Wednesday, depending on the departure of the eventual nor'easter. Max gust for e LI may get close to 70 MPH with wind damage 'potential' of 50 MPH gusts s of I84 in CT into far se NYS through ne NJ. Fully leaved tree branches with potential for sodden ground uproots Tuesday due to heavy rainfall and the gusts should result in pockets of power outages from simply broken branches. If it looks extensive, we will update the topic title. Max rainfall seems to be targeting CT/se NYS/NYC metro-ne NJ but proximity of max inflow-moisture transport still showing modeling variability for the primary target. In any case... it appears likely that along and north of I78 there will be periodic showers overnight with new rainfall by sunrise ranging from a few hundredths to possibly 1". After a break Monday, bands of heavy showers should be developing north and northwest into the area Monday evening and slow their northwest to west progress Tuesday before turning southward later Tuesday night. By 8AM Wed, isolated 6" rains may have occurred with a general 1.5-3" in the subforum. FF potential while initially limited by recent dryness, the rainfall rates and amounts in banding will eventually determine where any FF potential will be realized-it's just too early to determine, as of this 720PM Sunday writing. Please follow all future NWS warnings/statements. Let's see what the OBS herein tell us about the modeling by Tuesday night. Edited title rainfall up from 1.5-4 iso 6, to 2-5, iso 8. Edited title at 1025A/26 to like 40-60KT gust focused on CT-LI.

SPC 854A upgrade -slight expansion D1 attached. ...Northeast... Scattered to locally numerous thunderstorms are expected to develop from late morning through the afternoon along/ahead of the cold front -- first in northern/western portions of the region, then spreading/expanding eastward. Sporadic damaging winds and isolated severe gusts/hail are possible. While magnitude of damaging gusts should be mostly subsevere to marginally severe, given the lack of both greater moisture/buoyancy and low-level flow, the expected dense coverage of convection may result in enough events to justify a 15%/categorical upgrade to wind probabilities at this time. Convection will be supported by a combination of weak MLCINH, diurnal heating, modest but adequate low-level moisture, boundary- layer convergence near the front and low, and large-scale lift aloft ahead of the shortwave trough. Moist advection should increase surface dew points over most of this area to the upper 50s and low 60s F. This will contribute to MLCAPE mainly in the 300-800 J/kg range. Strong mid/upper (anvil-level) winds will aid in organization, though low-level flow will remain too weak to enlarge hodographs appreciably. Well-mixed sub cloud layers will aid in localized strong-severe gust potential, until evening stabilization of the boundary layer removes enough low-level CAPE/lapse rates to weaken convection substantially with proximity to the Mid-Atlantic Coast and western New England.

The tag features the damaging wind in the dry air, especially mid-late Friday afternoon at the warmest time of the day. The severe tag is low risk (Marginal part of the area as per SPC D2 outlook). There should be bands of heavy showers, isolated embedded thunderstorms, moving east northeast across the area between 5A-2P, but the inverted or isothermal sounding should limit transfer of gusts during the morning. However, he last possible line along the cold front midday-early Friday afternoon might allow for isolated SVR as the sounding becomes more unstable to the surface? Please add Friday guidance and reports for Friday's event to this thread, keeping OBS and NOWcast embedded within this thread as well.

Thursday will be a regional severe wx outbreak. @CheeselandSkies I think SPC was waiting for American guidance to come toward the ECMWF. It was stubbornly slow this time. Regardless of how we got here, we are at hatched ENH Day 3 now. First thing I noticed with 12Z guidance is that 500/200 mb winds are forecast WSW. Some of the sloppy South days those winds are SSW. From the SW is plenty of turning. From the WSW as forecast offers robust turning with height. No strange 700 mb winds, smooth forecast hodographs. LLJ is still forecast S or SSW, correct for South severe, even on the squirrelly GFS runs. Winds of course strengthen with height too. Warm sector looks a little bigger than last week defined by northward extent of the synoptic warm front. That does not necessarily mean intense severe weather farther north. That'll depend on the outflow boundary situated south of the warm front, and influenced by midday rain. Undisturbed warm sector soundings should have a little EML and lots of instability. Background pattern is there for a severe weather outbreak. Mesoscale details remain up in the air as usual Day 3, including the size of the region impacted.

OBS and NOWCAST as this storm unfolds. Power outages may limit some of our participants from adding data. Be prepared for losing the internet, even if you own a generator.

Topic Edit 508AM: Added HIGH IMPACT and the time back in to the topic and extended 4 hours. Strongest winds in NJ/ne PA/se NYS roughly 10PM-4A, NYC/se NYS 1A-6A, LI/CT 2A-to possibly as late as 9A/25 e tip of LI. Minimum wind gust on LI 55 MPH with max 75MPH, NYC-se NYS minimum wind 50 MPH isolated max 70 MPH. Please follow NWS on all warnings/statements. I'll leave it yourselves to add graphics etc as need be. I'll begin an OBS-NOWCAST thread by 6A. Have not looked at soundings but everything else discussed in yesterdays 518AM topic edit below including HSLC SVR's continues. We may reach within 2F of the record 66F-2015 max temp for Christmas Day at CP. Flooding of some of the larger rivers, if it is to occur, may be delayed 24 hours or more after after the rain quits Christmas morning, Max rainfall axis in our forum looks to me to be CT, isolated 4", not including snowmelt runoff. If anything is missed, please let me know. Thank you. Topic Edit 518AM Wednesday 12/23: No significant changes. The prime threat period might by 2 hours too fast but not enough evidence to change the primary initialization period of weather related issues. My assessment tells me to prepare, without science, for many many thousands without power starting 9PM to midnight Christmas Eve evening, and then across se NYS, LI, CT, MA beginning midnight to 6AM Christmas morning. Gusts NYC airports should be 45-55kt, with potential for isolated 65KT LI/CT/MA. I expect SVR's for the HSLC lines of heavy showers to help focus the primary short-fuse threats. Lower chance of any damage northeast PA but ridges there will be most vulnerable there to ~ 55 MPH gusts. There is limited science on power outage wind damage with leaved trees, without, softer unfrozen ground versus frozen but I don't have this information nor any private services predictive algorithms. I still think that wind damage will prevail as the most important aspect of this storm, but please follow NWS flood watches, warnings as issued, due to the combined snowmelt and new widespread NYC subforum rainfall of 1-2", with isolated 4" potential inland-most of this in a 9 hour period during Thursday night, Any snow on the backside is exceedingly minor on the I84 high terrain. There actually might be a little better chance for a slight coating of snow Christmas night with the weakening trough aloft passage. --- Topic edit at 526AM Tuesday the 22nd: Changed the title to WILL be accompanied by damaging wind LI, and restricted the period of accumulative snow to the interior. I think the wind damage potential is the largest threat from this rapidly deepening 980s surface low moving northward up the front into NYS predawn Christmas. SVR's possible (in my mind likely, even if no lightning) for High Shear Low Cape (HSLC) heavy showers.The Richardson (R)#/wind profile combo on the NAM and even GFS tells me 45kt+ gusts all the major airports in NYC sometime between 10P/24 and 5A/25 . This is further supported by multiple models 80KT+ 850MB winds over LI, in some cases around 90-95kt. From my looking at R# and wind grab, this has the most favorable potential in my past 3 months of examining to realize downward transfer 50-65KT from the lowest 25 to 50 MB of the boundary layer. Whether an isothermal sounding in the lowest part of the boundary layer, or even a slightly inverted sounding can diminish-mute the potential, I don't know. What I do think, is that a lot of folks could wake up with lights out Christmas morning across LI, and possibly NJ/CT. Flooding potential to me looks the same as it did yesterday-previous days, all a matter of qpf, snowmelt combo to prompt a few rivers into minor or eventually moderate flood stage, even as temps plummet from 60ish near midnight Christmas morning, to near freezing by ~ Noon Friday. Please follow NWS closely on flood potential-they have more tools than I. Snowfall, accumulation less than 1 inch probably restricted in our forum counties only I84 high terrain northwestward. I'll copy this to the last page of this topic and add a couple of wind profiles there. The future posts will look at FOUS BL winds, which I think will exceed 34kt at LGA and BOS around 06z and 12z/25 respectively. IF not, then I'm a little too severe on my wind expectations. Also, I'll be adding shorter term wind gust potential graphics, especially Wednesday onward. (corrected many typos 826A) --- Below from the origination date of Friday evening the 18th. This topic is started primarily because of the recent operational model cycles at one time or another offering a more than ordinary 12-18 hour period of weather here near Christmas, on top of melting snow. Always uncertainty. Uncertainties abound, including how far inland can a couple of hours of 60 degree temperatures penetrate to melt the snowpack, and will there be any hazardous snow accumulation closer than the hilly western and northern suburbs? Add to that, is there an inversion thats prevent excessive low level winds from reaching the ground.? Snowpack will be melting a bit the next few days,, til a sudden brief surge of 60 degree warmth Thursday evening or very early Friday morning, associated with a strong cold front. That front is embedded within a high amplitude trough. It's slowed by a strong 1030-35MB high anchored near the Maritimes, and there is potential for northward moving low pressure along the front, as it traverses across the NYC forum. Max rainfall should be concentrated just inland (se or sse surface wind) and combined with remaining snow, may? be enough to promote some small stream flooding? Flooding will be dependent on how much snow melts on the 24th/early 25th combining with around 1" to possibly 2" of rain, prior to the sharp cool down to near freezing by midday the 25th. Current 12/18 river response models to multiple ensembles are not alarmed at this point so I don't want to make this look worse than it will be. Of greater concern is the ECMWF cyclic offering of 60+ MPH gusts to LI (50 inland) which may cause some damage. Recent experience with the storm of the 16th-17th suggests to me, that we will need at least 60 MPH gusts to see significant damage along the coasts and ridges. It's possible - IF the 850MB southerly jet can exceed 75 knots, preferably 85 knots. The 18z/18 GFS has 80 knots for e LI and the 12z/18 EC has near 100 knots for all of LI. IF the ECMWF were to verify, it would be lights out for many and not a pleasant Christmas morning. Timing of the event probably sometime at night (6P/24-6A/25 EST) Snow: Backside snow doesn't often accumulate significantly with temperatures falling rapidly from the 60s to near freezing. Thinking best chance I84 corridor high terrain sometime Friday morning the 25th. Graphics: 1) 12z/18 EC 850 wind. EC surface gusts, GEFS chance of 60 MPH wind gusts early Christmas and finally, the WPC qpf forecast from ~18z/18. 608P/18

Good Wednesday morning everyone, I've followed a recent example on the New England forum and offer this topic as a start over at 1PM with obs-nowcasts. The tags included hopefully cover the gamut of potential amounts. If we are certain about daily records being exceeded please add and ditto if we get top 20 at any xmacis climate site. Thank you all for contributing to the excitement-anticipation of a pretty good nor'easter.

Edit topic: 525A Wednesday 12/16: No change in thinking including uncertainties along I95. I just cannot shake the basics: S+ axis is usually 90 miles left of the 850 low and the northern half of the 700MB low and the deformation zone near 500 MB with contribution from the nose of the 850MB 50-65 kt easterly jet (moisture transport). This favors I84 and banding casts northwest to a central PA - east central NY area (roughly IPT-ALB) where 20-25" seem probable within 60 miles of that axis - at least in the high terrain, but must consider mountain shadow lesser amounts in the leeward valleys. There a multiple models showing that axis. In our forum, I think most everyone will see a period of sleet near or after midnight and that the bulk of the snow occurs in a 6-10 hour period prior ~ midnight, but that there will be a tail of moderate to heavy snow toward dawn with still 1-4" after sunrise Thursday on top of whatever occurs before sunrise---the heavier 4" potential ne PA, extreme nw NJ, se NYS and CT {where 5" may occur in 2-3 hours after sunrise Thursday}. Drifts to 4 feet possible ne PA, se NYS and northern CT where 18" accumulates since winds will gust 30-40 Mph at times overnight. NYC CP still 6-10" in my mind but shakey and may be too high because of only 10-1 snow ratios at best, sleet and possibly rain compacting as well as temps near 33F at times during the night. The power outage concerns continue near I95 with 45-50 MPH gusts (9P-6A). Coastal flooding - please see NWS offices for minor or moderate near the time of high tide Thursday morning. Finally, even if it rains or is above freezing w LI and Monmouth/northern Ocean County NJ tonight--- there could be sudden icing near sunrise Thursday when the wind switches from northeast to north and drops temps 5-10F in an hour, and iceing the residue and make travel very hazardous again in leftover new snowfall. Otherwise temps in the I84 corridor ~20-25F throughout the event. Will add some graphics by 6AM on wherever the last page of the thread. NOT a top 20 for NYC...best chance is MPO-POU axis in our forum. This is my last topic update for this event. Edit Topic: 445 AM Tuesday 12/15: NO change in thinking. Except for the outlier south GFS/GEFS, all systems appear go for a major snowstorm as outlined below in the 6AM Monday topic update. Will detail in the latest page by 545AM. 00z/15 EC/NAM/RGEM/UKMET/GGEM/UKMET operationals on board! There will be multiple (~12 graphics of supporting model documentation-most probabilistic and 2 day top 20 snowfalls in the available period of record). --- Edit Topic headline at 6AM Monday 12/14/20. Please monitor NWS Watch-Warnings for this storm and associated statements and still uncertainty on where highest impact. There is/was some overall slight southward shift in the guidance in the past 24 hours and so my uncertainty for the forum is northern CT-Catskills, and LI/I95 southeastward. WPC still has 1.5"+ qpf just s of I80-LI and 3/4" into northern CT. If you have travel plans Wednesday into Thursday I95 northwestward from VA through WV, PA, NJ, NYS and southern New England it's probably a good idea to consider changes, based on your NWS or other favorite media outlet forecasts. I think this will be a top 20 snow storm for a few parts of our NYC subforum (basically ~ 1 foot will prompt that review) but unsure where. For now between I95 to I84. Anticipating (not guaranteed) widespread closures or delays for all transportation systems I95 corridor northwestward Wednesday evening into Thursday morning,. For those who have access and wish to do so, you can calculate an experimental storm index to get an idea of what is probably coming. I don't want to presume more than Major yet (crippling is the next step up). Here is some information. https://www.ncdc.noaa.gov/snow-and-ice/rsi/?nesis Still variability in northward extent of heavy 1 foot snow ranging from the NAM Adirondacks to the GFS-RGEM I80-LI. UKMET is still quite far north. Ensembled r/s line looks to remain mostly south of I80-LI but awfully close, close enough to think sleet, rain or freezing rain mixes in for a time after the initial Wednesday evening thump for LI and s of I80. EPS continues almost unyielding on the widespread 8-18" snowstorm (isolated 2 feet possible in the banding somewhere north of I80-LI). Major power outages possible wherever the 6" of 32-33F wet snow accumulates along with wind gusts of 40-50 MPH. If this were to occur, it would most likely develop between 9 PM and midnight Wednesday evening per consistent modeling of snow onslaught and wind gusts increasing past 30 MPH. Am targeting LI south coast and NJ coast but this will require 6" wet snow (32-33f). Isolated wind gusts above 50 MPH possible on those coasts. Snowfall rates of 1-3"/hr possible in northward transiting bands Wednesday-evening/ night. Where these tend to park on the northern extent of the storm, will probably be the 2 feet of snow, especially with ratios drier than 10 to 1 (maybe 13 to 1). NWS has the multi model ratio blend tool and BUFKIT can assist for those who have that tool. There could be closing bands of moderate snowfall Thursday morning after sunrise into early afternoon as the comma head tends to fold southeastward behind the eastnortheastward departing storm. Clearing the first few inches of snow around 8-10PM Wednesday will make it easier to remove the additional snow Thursday morning. Where it's wet-caution for those with heart conditions., This strong easterly surface gradient (northeast wind) between the cold 1035MB high over Quebec and and the probable 995-1000MB low near Cape May early Thursday will produce minor to moderate coastal flooding, for the Thursday morning high tide cycle. Follow NWS statements. No graphics update with this topic edit. --- Edit Topic time at 506AM Sunday... otherwise an 18-24 hour nor'easter coming with the uncertainties continuing as previously listed below. HIGH impact late Wednesday afternoon into Thursday morning with many cancellations probable of whatever activities in this Pandemic. It's 5-6 days away but taking my cue from our participants, have separated Wednesday-Thursday (16-17) from the prior 5 day (14-18) topic. Modeling is showing the potential for a 6"+ snowfall for a large part of the NYC forum area, somewhere between the I95 corridor and I90. There is model uncertainty regarding the intensity of the upper air and surface systems but enough information in the models to monitor this storm for possible high impact in parts of the NYC subforum. Some potential exists for nearly a foot of snow in a small portion of the forum area, IF everything comes together correctly... but it's too early to be sure and it's best not to focus on the higher amounts yet. Banding in the DGZ could make for as much snow along and north of I84 as may occur closer to the storm center in NNJ where the snow could be a lot wetter. Usually it takes -3 to -5C at 850MB this early in the season with wind off the 40's SST, for snow not to change to rain. So LI and the NJ coast are presently in the modeled greatest uncertainty region whether it's mostly rain or snow. Astronomically high tides Wednesday and Thursday mornings seem destined to allow some coastal flooding within 2 hours of high tide, but this is going to be driven by storm intensity and wind direction. Just too early have a good handle on flood potential but I would think minor at a minimum. Not posting a topic for late Friday-Saturday Dec 18-19 as that storm could easily pass to our south. Just good enough to know that appears to be a highly unusual week, potentially, for the NYC forum to have up 3 different snow events of varying magnitude in a 6 day period. Added this afternoons NWS ensemble driven D6 chance of more than 3" of snow, which has increased considerably over the past 24 hours. I also added the GEFS probability of half a foot of snow or more... use the legend color (greens-yellows edging past 65%) for your area of interest. The Dec snowfall's in NYC since 2010, 2nd column from the right. and The daily almanac for NYC CP-Wednesday Dec 16...the 5.3 " is the daily snowfall record. Small chance of daily record snowfall??

Please see SPC, NWS discussions, any statements, and our own members. Leftover PWAT, relatively strong 500MB (30kt) wind field, modeled CAPE, lightning density, SPC HREF and WPC D1 QPF all suggest pretty decent convection this afternoon dying out by late evening. Combination of convection (expecting several 1.5 to as much as 3" amounts today) and past weeks rains, should more easily permit isolated flash flood. Wind damage, mostly associated with wind and maybe a couple of uproots because of somewhat softer ground. Hail not mentioned but I dont think primary in this leftover tropical environment. Eastern LI seems less likely for SVR/FF this event.

It's a bit early, but while Tuesday may be a subdued day compared to this afternoon in NJ, it appears Wednesday afternoon-evening should be our big convective event of the Mon/6th-Thu/9th time frame, similar or a bit less compared to what occurred today near PHL. KI/CAPE/PWAT slow movers in a fairly steamy uncapped environment developed on the remnant warm front/sea breeze boundaries and subsequent outflows, should promote thunderstorms-"potential"prolific rain producers in part of NNJ/se NYS, spilling east-southeast over Long Island (heaviest for LI probably NYC vicinity, but unknown). Since we saw probable 5-7" rainfall in isolated locations of Morris County NJ and down near PHI on Monday the 6th, it won't surprise if similar isolated 5"+ rainfall occurs in the NYC forum Wednesday. My main concern: do we get enough heating (temp upper 80s)? Potential for short fuse warnings flash flooding and maybe severe wind. Will reassess Tuesday morning, possibly updating this topic. I'm not thinking about the Friday (low chance FAY? per NHC 2PM/6 5D TWO 40%)-weekend cold front events, understanding in part that the Friday event may need to drop into the tropical portion of the forum? (if it becomes named).

SPC D1 prompts this topic. Have a little concern that todays strongest storms (2-3" rain producers/damaging wind) will be concentrated down in central or s NJ, but some spots in our NY metro from NYC westward should see isolated SVR late today. Think eastern LI is out of it today. However, with the large CAPE axis just s of us, cannot rule out a cluster of drenching thunderstorms forming-developing eastward later tonight and eventually making it to eastern LI. This latter is with considerable uncertainty.

Good Friday morning July 3, 2020. This mornings SPC marginal risk, OKX near term discussion covers the basics (both review more data than I). Additionally I like to use SPC HREF which from my daily review WPC uses frequently for its day1 QPF. Have made this a larger window for thunderstorms/heavy rainers due to some of modeling lingering through ~06z, which I think is possible (not strictly heating related convection). Believe most of the big storms are in the 5-10P window associated with 850 MB vorticity-trough passing southward into our area. Regarding Severe: "probably" isolated but power outages from lightning could be somewhat more extensive than the damaging wind gusts due to PWAT briefly near 2" this eve. Can see isolated rainfall 3.5" somewhere in the area... best chance I think is se NYS or NNJ...from 2-3 bands of heavy showers/storms this afternoon, otherwise WPC D1 qpf looks reasonable. Will post as time permits later today/this eve and summarize with final LSR/Rainfall maps sometime around 6A Saturday.

I guess today will be bigger in Ny metro than yesterday? Figured I'd start this if you want to use and keep the rest of the reports off yesterdays disappointment topic. Will start with the first posted LSR. Will replace these LSR maps as time permits and events dictate. See SPC D1 and local NWS offices/friends etc for any comments.

Severe weather outbreak looking more and more possible across portions of the lower Mississippi Valley and deep south tomorrow and tomorrow night. This evening the culprit low is located across western Kansas with a warm front stretching along the Kansas border and into northern Missouri. The dryline is located from west of KICT down through western Oklahoma and Texas … roughly along a line from Altus, OK to Sweetwater, Texas and then southwest from there. The cold front is lagging behind in far western Kansas and eastern New Mexico. A fairly large moist warm sector has developed thanks to an extended period of southerly winds off the Gulf. Dew points in the 50s extend almost up to the Missouri/Iowa line ahead of dryline/cold front and will generate instability on the order of around 750j/kg despite clouds and lack of strong radiational heating of the boundary layer. As forcing increase aloft and steeper lapse rates move in, atmosphere will likely pop along/ahead of the dryline as it punches into eastern Texas. Models hinting at two potential dryline bulges north and south of Austin, Texas. This will have to monitored for possible initiation areas as the morning/afternoon progresses. Low level storm relative winds on the order of 20-40 knts and upper/mid level storm relative winds parallel to dry line/initiation axis will promote uniform gust front lifting and upscale growth into a squall line/QLCS structures with damaging winds being the primary threat. Convection will move East with the evening and overnight hours. As it does, shear will increase across Arkansas, Louisiana, Western Tennessee, and Mississippi and hodographs are expected to become open and elongated. Thus, the tornado threat will likely increase as we approach dark and persist into the overnight … especially if more QLCS type structures can be maintained though the time period. Couple this with low LCLs under 500 meters and there could be a strong tornado somewhere tomorrow night … again if semi-discrete QLCS structures persist. Folks across southern Arkansas, northern Louisiana, and western Mississippi definitely need to monitor this situation closely.