wdrag

Last week it looked to me that Tuesday-Aug 11 might be a svr day but models have slowed and changed so that seems to be off the boards. Instead a 4 day heat wave (Sun-Wed) may be getting started this afternoon in parts of the non marine influenced NYForum coastal plain. Nothing outrageous but warmer than normal for sure. Also...noticed some for the global modeling has virtually no rain for the western 1/3 of the country (Rockies west to Pac Coast) the next 10 days. Suggest parts of the east will have more than normal QPF... wet begets wet (sometimes) in a generally stable trough ridge pattern. 9A/9

Final eval: no 4+ our area and SPC HREF potential 10+ wrong for our area. Max our area, that I could quickly find. Rutgers climate site Cream Ridge 2.84. Weatherunderground Cream Ridge 3.53 and nearby Jacobstown just across the Burlington County border 3.19. I saw one posted 6+ inch report in PHL CWA, in se PA Chester County. (941AM -Added CoCoRAHS visual of 24 hour rainfall ending roughly 8AM Saturday and not inclusive of the pre 8AM Friday rain.) 755A/8

89 MPH at 705PM in Upper Deerfield Township (a Rutgers University climate site). Cumberland County...has to be some damage. I see number of damage reports in far southwest NJ. (not our forum but 89mph is notably higher than more typical severe gusts of 55-70 MPH)

Have to be careful with some of these reports. I saw 1 report from wx underground at 6+ inches near PHL... checked the station and found it had started at 3" as a baseline. Power outages maybe compromising some of the data. In any case, I'll try and check some of this data later tonight--- if I can wake up at 1130PM. So far for our area, am looking at this as routine showers/thunderstorms with a + QPF axis near I195 but it isn't over. Diurnally it should calm down during the night but with the trough aloft coming through and remaining moist low levels, we might get a cluster or two of heavy showers/iso thunderstorms overnight. Prospects for severe in our forum area overnight look very limited-and not expecting any but I could see another inch or 1.5" of rain in a few spots of NJ overnight? I am pretty certain the radar is underestimating storm total precip... have checked MARFC multi sensor ending 7P. Looks about 1" shy of reality. Here it is. (820P/7)

Agreed... though one positive for the early Euro on Isaias... it sensed a struggle from start up to ~FL...in other words it was so weak it kind of knew conditions were not very good. That's my take away when models disagree, especially longer range=caution. That's one reason was very broad in the NYC forum topic starter outlook. Didn't want to overplay the hand.

Cream Ridge and Jacobstown NJ... in or extremely close to our NYC forum (Monmouth and very northern Burlington County) 3.19 and 2.93 respectively since 6AM. Respect the rainfall rates in what I think may be a hybrid SHARS situation... subtle. Note also a possible connector-training event may???? be developing JFK-ABE. I think radar is underestimating the yield on this. 918A/7

So far, quiet in this topic. Not over, though modeling is tempered and probably a not occurring 4" but still time. 714A/7

I want to close with a few pieces of information, including graphics for Isaias-tropical connection. Borrowed this written piece from Ramblin Red post on tropical forum: Good article on the effects of the storm from the Wash Post. https://www.washingtonpost.com/weather/2020/08/05/isaias-power-outages/?hpid=hp_national1-8-12_cwgisaias-3pm%3Ahomepage%2Fstory-ans 78 mph: The wind gust clocked one mile southwest of Battery Park City in Manhattan and in Farmingdale, on Long Island. Numerous gusts reached around 70 mph in the New York City boroughs, including at JFK and La Guardia airports, both located in Queens. Oak Island, N.C.: 87 mph Cape May, N.J.: 75 mph Ocean City, Md.: 74 mph McClellanville, S.C.: 78 mph Dewey Beach, Del.: 68 mph Assateague, Va.: 68 mph Wallops Island, Va.: 68 mph Atlantic City, N.J.: 66 mph Norfolk: 61 mph Virginia Beach: 59 mph Richmond: 51 mph 146 mph: The wind gust measured at the top of Mount Washington, N.H., the highest on record there in the month of August. 115: The number of tornado warnings the National Weather Service issued over the storm’s duration. 33: The number of tornado reports associated with Isaias that the National Weather Service Storm Prediction Center received Monday and Tuesday. Nine inches: The rainfall in Sotterley, Md., in St. Mary’s County, less than 60 miles southeast of Washington. Widespread rainfall totals along Isaias’s path reached three to six inches, with localized amounts between six and nine inches. Some of the heaviest rain fell from eastern Virginia through Washington’s eastern suburbs in Maryland into eastern Pennsylvania and southern New York. ------------- First image: Leftover power outages 48 hours after Isaias passed. Rainfall, departure from norm and percent departure from normal Aug 1-5 (ending 12z/5). Guidance was on the right track...just a bit too far east of the reality. No classic PRE occurred because no surface high north of us and not enough separation between the hybrid PRE late Monday-early Tuesday and Isaias. Finally, a little more detail in the last image with the NWS MARFC radar-platform integration of rainfall (7- near 10" in brown) Not much more I can add. I think 70 MPH gust event was pretty good for our coastal areas and that the HRRRX wind gust predictor while maybe 10 kt high at 24 hours was very accurate within 12 hours. 829P/6

Think we're starting to see the first storms. Rainfall rate 3-5"/hr Wellsvile PA near Harrisburg.. over 1" there with radar indicating 1.5". Lets see how this develops northeastward overnight. WXWUNDERGROUND station verifying radar. 813P

LOW chance of exceeding 4" but this is worthy of awareness, I think. Have reviewed most of the typically used 12z/6 modeling, and WPC/SPC guidance. The scenario is a weak wsw flow aloft at 700 mb, over a very moist (near 15C dew point) 850MB vorticity rich wind shift across NJ (sse-sw) with 500mb vorticity maxima passing newd within an approaching 500mb trough that doesn't swing its broad axis through our NYC forum until about 12z Saturday. Dewpoints are already generally in the mid 60s with PWAT 1.6-1.8",-not overly wet, but with slow movers, plenty to allow for potentially excessive rainfall. How it all works is not clear and odds are that more than 4" of rain won't occur but have seen 12z/6 SPC HREF MAX precip guidance nears 10" in 1 spot of east central NJ and spotty 10+ s of LI. Best axis: unsure but for now along or s of I80 through LI or southward down to near I-195 (Ocean Mercer) counties. It should light up late tonight in central or northern NJ into LI and continues into forenoon Friday,. (Could be one or 2 isolated wet microburst SEVERE's?). For nw NJ, if there is very little tonight then I could see isolated svr thunderstorms in ne PA drift into nw NJ and se NYS late in the afternoon or evening and then continue to LI as showers Friday night. Low prob of occurrence. SPC has no risk and wind fields are generally a little too light. 627P/6

Hi... have regained a bit of situational awareness after being without internet for a day. Possibility of isolated 4" rainfall parts of LI/NNJ by Noon Saturday, from several episodes of heavy showers/thunderstorms. No topic at this time due to uncertainty of 4+, and FFG not alarmingly low. Will rereview late today. Iso embedded severe possible as well in one of those episodes. Favorable RRQ of the UL jet, PWAT near 1.8" north of a front with waves of weak pressure falls leading the more notable episodes east-northeast across the southern part of our NYC forum area. Ocean County seems to be at greatest risk for iso FF/SVR. WPC D1-2 has the overall picture of general amounts. Sunday should be a rain free day for our NYC forum. One or two episodes of thunderstorms expected Monday-Tuesday, with Tuesday's having a small chance of severe PWAT, CAPE and KI are up - though late in the season and wind flow aloft not remarkable. Still something to recheck in future cycles. This post does not look beyond Tuesday with any confidence. 605A/6

Wantage NJ 3.12" Max G 43 MPH 348P/4 in the westerly wrap around. I wouldn't call it a true sting. Nor did we have a true PRE (no High to the north for good sfc convergence) and Isaias too fast behind the overnight-early morning qpf. I think the fact that trees were leaved, and a bit of ground softening contributed to what will be a long duration cleanup. (see officials for duration but cant see how this will be less than a few days for some rural areas). Frankford Township7MI away had 3.35" Wantage-this section was without power from 430P/4-630P/5 - this evening. I here a part of Sparta may not get power til Saturday? I may add a little more early Thursday and get reacquainted with the upcoming pattern then. 756P/5

Wantage NJ 2,86" still power but over 990,000 without power in NJ or around 1/4 of the NJ residential population.

Lst's see if the west wind puffs to 45 kt at 4 or 5P.

2.5" total in Wantage so far, all since midnight.

Several 17z/4 METAR sites NYC area to MMU rocking at 50+ knots. Added at 112P as are some wxflow sites on LI...

783,000 without power in NJ. equates to about almost 2 milion people, or about 20% of the state population. 107P/4

Quickly: a post of svr wx reports since midnight. TORS in red, bunch of flood reports and wind reports. Pretty serious impact up here in NJ/LI/CT and e PA. 1.84" in Wantage NJ at 101P/4

My mistake: hurried multi tasking. Those weather underground are ONLY since midnight!!!!! You'll see some massive amounts near PHL when this all said and done...my """guess""" 10" since last evening.

over 15% of the state of NJ population without power...650,000+

Here's some more rainfall for you since 1201AM this Tuesday morning! Wantage now 1.50" Worried about tree branches breaking. Wunderground for nw NJ and down near ABE-TTN. Thinking and thank that the modeling is doing well... too far east on track the past 5 days but consensus tracks said we had a problem. Will try and provide some brief overview images Wed morning. Credit to all the researchers and use of computers-stats. 245P/4

Thank you... i saw the 95 kt but didn't take the time to look back at detail. Has to be massive problem near that station. Would like to know.

Yes... but LI-yours is to come now. If you get to 65-68 kt in a few places.. i consider that a hit on 24 hours notice. Let's see what happens. In the meantime... there will be maybe a 1 hour lull when the wind shifts from south to sw, then blasts for 30 minutes out of the west 45-55kt, before the wind abruptly drops off. Used the experience of platforms in DE.

Many reports 50-60 kt coastal plain of NJ and Atlantic Coastal DE. At least one station not reporting anymore in DE BAY. Perth Amboy near 50 kt now. NJ power outages up to at least 274,000 customers (more than half a million people without power). 1.16 Wantage at 1205P/4

Give this til 130P. If nothing, then don't giver up on back side G 45-50kt for an hr around 4P. HRRRX modeling has been good at 24 hrs and very good inside 12 hours.