wdrag

While this remnant TC moisture plume is probably hard to discern and am sure most if not all are reluctant to ascribe the coming Sunday-early Monday shower event to Nora's RH, I will. The initial burst is Sunday morning and how much elevated convection remains as it crosses the area is debatable but have to think there will be some showers in the associated instability burst (850 MB sw speed max crossing PA-NYS). 500 MB winds are not favorable for a large event here. There could be another burst of showers in the leftover moisture late Sunday or Monday morning. All totaled, as per WPC, probably less than 1/4". Should be a non player in leftover receding waters of Post Trop IDA.

We'll need some sort of organized program. Either that or we can conference 2 -4 folks somehow. Am not a super specialist on technical but can get it done. Not til after 3P.

Have placed my final review in the original IDA thread and answered a question on how to access some pretty good predictive data that I think WPC relies upon, maybe more so than specific ensembles for the first 48 hours.

Check this out from the 12z cycle yesterday, available by 1530z when less than 0.10" had occurred NYC while I was near 0.9" in extreme nw NJ. https://www.spc.noaa.gov/exper/href/?model=href&product=snowfall_024h_mean&sector=conus Change the date and cycle. Change the area of interest down from CONUS to NORTHEAST. Then go to precip and review 24 hour MEAN at the three 24 hour intervals provided. Then click MAX and check for the same time. I do the same for snow. Also, can look at hourly mean ptype/amount, ditto wind (found under FIRE). It's a tool...imperfect but I and believe WPC think it's the best available, for now. EC has a lot of fans but is inadequate when it comes to convective release (secondary imo to the NCEP GFS). ANY questions: write me. I could conduct a ZOOM on how to use all these tools in predictive sense, but all who participate must have pretty good internet.

CoCoRaHS data as of 9A, and some reports possibly delayed where no power. The red is the max wsw-ene axis near I95 which favors SPC HREF and GFS modeled axis as best forecast, along with EPS GEFS swath primary 2+ rainfall. The 10"s were possible. Added Radar-sensor combined. Appears to be 1/2-1" too low for yesterday. Also added yesterdays 12z/1 SPC HREF showing general 5" swath just nw of NYC but also look at the max for same time period showing the spotting of 10-15" across NNJ to s CT. CLICK MAPS for greater clarity of each. Finally some perspective: These amounts have occurred in the recent decade and will again, but over the identical areas as yesterday--- possibly not, but close. We can go back to the historic tropical data base into the mid 1950s when I was a kid floating toy boats down the rain swollen streets in Newton NJ in 1955 (Connie-Diane in an 8 day period of early August). Yesterdays problem was in part antecedent conditions but I think mostly, that 80% of the rain fell in less than 3 hours. NO URBAN SYSTEM can handle that unless budget allocations change and there is too much else to care for. Finally: misuse of data is too much drama. For instance: Unprecedented use of the term Flood EMERGENCY. NWS implemented that I think it was 2017-18. Not a very long period of record. I also think the same on recurrence interval. We simply don't have reliable data. Tentatively: I will log this as a moderate event on the edges BUT major where 8"+ and deaths which is near and just north of I95 corridor. The MAJOR 8+ was much more extensive than I had capability of confidently predicting including over NYC. (Not much flooding here in Wantage Sussex County NJ despite 4+". Have a few road closure due to wind related downed branches) The TOR added spice but this was mainly a heavy rain event with gusty winds 40-60 MPH causing the uproots, branch breakage-power outages.

Hope folks are checking the SPC HREF, which WPC follows closely for its D1-2. VERY VERY good.

Will update this wrap-up post around 10A with more data. Prelim: CoCoRaHS data as of 720A, and reports possibly delayed where no power. The red is the max wsw-ene axis near I95 which favors SPC HREF and GFS modeled axis as best forecast, along with ENS. The 10"s were possible. Will detail the data when i can later on today, by which time you'll have many NWS lists. Added Radar-sensor combined. Appears to be 1/2-1" too low for yesterday. Also added yesterdays 12z/1 SPC HREF showing general 5" swath just nw of NYC but also look at the max for same time period showing the spotting of 10-15" across NNJ to s CT. Finally some perspective: These amounts have occurred in the recent decade and will again, but over the identical areas as yesterday--- possibly not, but close. We can go back to the historic tropical data base into the mid 1950s when I was a kid floating paper boats down the rain swollen streets in Newton NJ in 1955 (Connie-Diane in an 8 day period of early August). Yesterdays problem was in part antecedent conditions but I think mostly that 80% of the rain fell in less than 3 hours. NO URBAN SYSTEM can handle that unless budget allocations change and there is too much else to care for. Finally: misuse of data is too much drama. For instance: Unprecedented use of the term Flood EMERGENCY. NWS implemented that I think it was 2017-18. Not a very long period of record. Tentatively: I'll review further but I will log this as a moderate event except major where 8"+ and deaths. The MAJOR 8+ was much more extensive than I had capability of confidently predicting as well as over NYC. (Not much flooding here in Wantage despite 4+".) The TOR added spice but this was mainly a heavy rain event with gusty winds 40-60 MPH causing the uproots, branch breakage-power outages. Added NYS Mesonet just after initial post.

Prelim: CoCoRaHS data as of 720A, and reports possibly delayed where no power. The red is the max wsw-ene axis near I95 which favors SPC HREF and GFS modeled axis as best forecast, along with ENS. The 10"s were possible. Will detail the data when i can later on today, by which time you'll have many NWS lists. Added Radar-sensor combined. Appears to be 1/2-1" too low for yesterday. Also added yesterdays 12z/1 SPC HREF showing general 5" swath just nw of NYC but also look at the max for same time period showing the spotting of 10-15" across NNJ to s CT. Finally some perspective: These amounts have occurred in the recent decade and will again, but over the identical areas as yesterday--- possibly not, but close. We can go back to the historic tropical data base into the mid 1950s when I was a kid floating paper boats down the rain swollen streets in Newton NJ in 1955 (Connie-Diane in an 8 day period of early August). Yesterdays problem was in part antecedent conditions but I think mostly that 80% of the rain fell in less than 3 hours. NO URBAN SYSTEM can handle that unless budget allocations change and there is too much else to care for. Finally: misuse of data is too much drama. For instance: Unprecedented use of the term Flood EMERGENCY. NWS implemented that I think it was 2017-18. Not a very long period of record. Tentatively: I'll review further but I will log this as a moderate event except major where 8"+ and deaths. The MAJOR 8+ was much more extensive than I had capability of confidently predicting as well as over NYC. (Not much flooding here in Wantage despite 4+".) The TOR added spice but this was mainly a heavy rain event with gusty winds 40-60 MPH causing the uproots, branch breakage-power outages. Added NYS Mesonet just after initial post.

September second dawns with NYC having been doused with ~7.2" of rain from the remnants of IDA, resulting in death and major flooding in the NYC metro area. September normal rainfall is about 4.31". The target is 10" for September, which is possible and would be a first time in the 150+ year history (POR back to 1869) of CP record keeping. AND, iffff we get to 10", can the 3 month total in 2021, exceed the 3 month ASO 2011 total of 34.43"? There may be opportunity, dependent on the latter half of December steering flow. Have not checked other 3 consecutive month totals for CP in the database, so there may be an even larger value somewhere in there.

No comment: Please see NWS issuances on those stage details. I'm just going back as I can to find the IRENE-LEE storm totals for now.

Nora remnants - minor but coming. Added PW axis seen in Rockies aligning east and shooting to the mid Atlantic States by Sunday. Amounts small and may only be scattered but showers are coming Sunday the 5th. If the timing delayed from Sunday morning to Sunday afternoon and the modeled CAPE increased, we'd be looking at a pretty decent band of convection but for now, ensembles are under 0.2 inches.

Wantage NJ 4 św 4.69" finał for the period of 415AM/ Sept 1 through maybe 1AM/Sept 2. MAX G 30 MPH 809P/1.

that 3" in 1 hour must be anew record and puts NYC well over 4.3" now for the storm.

Wantage NJ 4.16... think we'll kind of level off here near 5" worst of rain has occurred.

Rainfall from mesonet sites... Seems like I78 ish to I80 and NYC taking over as big #'s with a secondary group in PA.

METAR: KTEB [Teterboro Arpt] METAR: KTEB 020117Z 02017G38KT 1/2SM +TSRA FG SCT006 OVC010 18/17 A2955 RMK AO2 PK WND 30051/0059 WSHFT 0059 LTG DSNT S P0173 T01780172 RVRNO 51 KT at Teterboro just before 9P.

NYC CP as of about 908P 2.13 out so today. Note wind directions below. Unsure if wind eqmt out or a GW? or just a convergent zone. KNYC 020106Z AUTO 1/4SM +RA FG BKN008 OVC013 19/18 A2956 RMK AO2 PK WND 26033/0058 P0043 T01890178 $KNYC 020059Z AUTO 26015G33KT 240V310 1SM +RA BR BKN008 OVC013 21/19 A2959 RMK AO2 PK WND 26033/0058 PRESRR P0004 T02060194 $KNYC 020051Z AUTO 08012G23KT 2SM RA BR BKN006 OVC013 21/20 A2949 RMK AO2 PK WND 05035/2356 VIS 1 1/2V3 CIG 005V009 PRESFR SLP977 P0055 T02060200 $

PO going up in NJ.

I think it is happening... we get a piece of NORA RH and a band of showers on Sunday or Monday. I haven't forgotten. The monthly contribution will be a pittance compared to Sept 1 rainfall... and not as many people as hoped to enjoy Labor Day will notice since we'll be cleaning up from this mess...flood waters/trees. I haven't forgotten NORA. My first goal tomorrow morning is to CoCORAHS the amounts and radar analysis as well and be done with IDA remnant. Then figure out the rest of the month... if thats possible.

From Mt Holly... the official unofficial sensor amounts through the 8PM ob, past 24 hours in NJ/PA.

Follow HRRR. You and I are basically done around midnight-2A. I am thankful it is soon to lessen here. 3.54" climbing.

NYC CP 1.44" as of 812PM. G34 kt there too. 3.43" Wantage NJ so we're on the lower side with the max axis developing se of Wantage. Not often that you see virtually all the I95 corridor under FFW's. 815P.

Rainfall thru 815PM... note the 5's in NJ.

NYC CP as of 745P 1.07 for the day.