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bluewave

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  1. bluewave
    I am wondering if it would take a scientific journal article on the cooling of NYC summer high temperatures? We have shown on this forum how there has been a cooling since around 1990. Perhaps a well publicized scientific paper on how the quality of weather observations in our biggest city has been compromised would get the attention need for improvement.
  2. bluewave
    They found the effect was greater on daily maximum temperatures than the minimums. Variability in daytime air temperature within the urban landscape averaged 3.5 °C (range, 1.1–5.7 °C). Temperature decreased nonlinearly with increasing canopy cover, with the greatest cooling when canopy cover exceeded 40%. The magnitude of daytime cooling also increased with spatial scale and was greatest at the size of a typical city block (60–90 m). Daytime air temperature increased linearly with increasing impervious cover, but the magnitude of warming was less than the cooling associated with increased canopy cover. Variation in nighttime air temperature averaged 2.1 °C (range, 1.2–3.0 °C), and temperature increased with impervious surface. Effects of canopy were limited at night; thus, reduction of impervious surfaces remains critical for reducing nighttime urban heat. Results suggest strategies for managing urban land-cover patterns to enhance resilience of cities to climate warming.
  3. bluewave
    Yeah, that is probably the case. Recent studies have shown how much lower the temperatures are under an urban tree canopy. The older Central Park observations weren’t located under the canopy like they are now. So it’s no surprise that NYC had more 90° and 100° days back then. This recent study found significant temperature differences between open and forested parts of parks. The differences in Central Park summer high temperatures before 1990 and after seem to match their study. The paper in the link goes into more detail than the news article. The 1990 date is around the time that the canopy began to cover the observation site. https://www.ncel.net/2019/09/01/canopy-tree-cover-can-drastically-reduce-heat-island-effect/ Results: Researchers found an urban tree canopy of at least 40% results in the most cooling – as much as four to five degrees Celsius (seven to nine degrees Fahrenheit). Anything less than 40% canopy cover results in very small amounts of cooling. Since this threshold was previously unknown, researchers hope this will guide strategies for increasing tree cover. Trees are often planted in wealthier neighborhoods. Therefore, distributing planting to be more equitable can help to not only lower temperatures but also bring mental and physical health benefits to the community. Resources: Read the full study through PNAS.
  4. bluewave
    This is probably our first mid-July backdoor pattern with such a strong ridge. In the past, these near record heights were associated with around 100° heat. So all the clouds, onshore flow, and rain are keeping temperatures significantly lower.
  5. bluewave
    The regional signal from the models was very strong for a high end flash flooding event. But pinpointing the exact location is always going to be a challenge before the convection forms. NYC was able to add a 2nd hourly rainfall record in under a week. So the most extreme portion of the event occurred near the southern edge of the outlook zone issued earlier in the day by the WPC. https://www.wpc.ncep.noaa.gov/metwatch/metwatch_mpd_multi.php?md=519&yr=2021
  6. bluewave
    It may be easier to do this at the airport since the ASOS units are placed on open grassy strips away from the paved surfaces. In the downtown parts of the city, it may be harder to find grassy areas away from buildings or pavement. So you can see how our only really compromised site is Central Park since it sits underneath trees.
  7. bluewave
    Newark is accurate.This summer is an over the top heat pattern. So DCA to Philly is running cooler than points further north. Notice how Corona, Queens reached 103° like Newark at the end of June. The Caldwell station to the NW also has 20 days that reached 90° this year so far. Summer 2021 highs so far Boston…….100° Hartford…..99° LGA…….….100° Corona……103° Newark…..103° Philly……….97° DCA………..95° Time Series Summary for CALDWELL ESSEX COUNTY AP, NJ - Jan through Dec Click column heading to sort ascending, click again to sort descending. Year Number of Days Max Temperature >= 90 Missing Count 2021 20 172 Time Series Summary for NEWARK LIBERTY INTL AP, NJ - Jan through Dec Click column heading to sort ascending, click again to sort descending. Year Number of Days Max Temperature >= 90 Missing Count 2021 20 172
  8. bluewave
  9. bluewave
    Newark is in line with the reporting stations west of NYC that are running a little above normal MTD.
  10. bluewave
    Newark is accurate.This summer is an over the top heat pattern. So DCA to Philly is running cooler than points further north. Summer 2021 highs so far Boston…….100° Hartford…..99° LGA…….….100° Corona……103° Newark…..103° Philly……….97° DCA………..95°
  11. bluewave
  12. bluewave
    Flash Flood Statement National Weather Service Mount Holly NJ 514 PM EDT Mon Jul 12 2021 NJC005-PAC017-101-130100- /O.CON.KPHI.FF.W.0014.000000T0000Z-210713T0100Z/ /00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/ Burlington NJ-Bucks PA-Philadelphia PA- 514 PM EDT Mon Jul 12 2021 ...FLASH FLOOD EMERGENCY FOR BENSALEM, BRISTOL, FLORENCE AND VICINITY... ...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 9 PM EDT THIS EVENING FOR NORTHWESTERN BURLINGTON, SOUTHEASTERN BUCKS, AND NORTHEASTERN PHILADELPHIA COUNTIES... At 514 PM EDT, Doppler radar indicated thunderstorms producing heavy rain across the warned area. Between 4 and 7 inches of rain have fallen. Additional rainfall amounts of 1 to 3 inches are possible in the warned area. Flash flooding is already occurring. This is a FLASH FLOOD EMERGENCY for Bensalem, Bristol, Florence and vicinity. This is a PARTICULARLY DANGEROUS SITUATION. SEEK HIGHER GROUND NOW! HAZARD...Life threatening flash flooding caused by thunderstorms. SOURCE...Radar. IMPACT...This is a PARTICULARLY DANGEROUS SITUATION. SEEK HIGHER GROUND NOW! Life threatening flash flooding of low water crossings, small creeks and streams, urban areas, highways, streets, and underpasses. Some locations that will experience flash flooding include... Philadelphia, Bensalem, Willingboro, Florence, Burlington, Bristol, Riverside, Palmyra, Bordentown, Beverly, and Tullytown. This includes the following highways... New Jersey Turnpike between exits 6 and 7A. Pennsylvania Turnpike between mile markers 350 and 359. Interstate 95 in Pennsylvania between mile markers 27 and 40. Interstate 295 in New Jersey between mile markers 48 and 57. PRECAUTIONARY/PREPAREDNESS ACTIONS... Move to higher ground now! This is an extremely dangerous and life-threatening situation. Do not attempt to travel unless you are fleeing an area subject to flooding or under an evacuation order. &&
  13. bluewave
    Very unusual to get such a low a mid-July extent with a strong reverse dipole.This used to be a cold regime that was great for sea ice retention. But the NSIDC noted how its been warmer than expected for a strong low pressure pattern. https://nsidc.org/arcticseaicenews/ Unusually strong low pressure (up to 10 hPa below average) near the North Pole dominated the average atmospheric circulation pattern for June Air temperatures near strong low pressure areas over the Arctic Ocean have historically been associated with relatively cool conditions. However, June temperatures in the vicinity of the low-pressure pattern were near the long-term average.
  14. bluewave
    http://www.nysmesonet.org/weather/meteogram#network=nysm&stid=manh The Manhattan mesonet picked up 0.98 in just 15 minutes.
  15. bluewave
    Newark set its wettest July record last year. Time Series Summary for NEWARK LIBERTY INTL AP, NJ - Month of Jul Click column heading to sort ascending, click again to sort descending. Rank Year Total Precipitation Missing Count 1 2020 11.22 0 2 1988 9.98 0 3 1984 8.65 0 4 2004 8.39 0 5 1996 8.27 0 6 1975 8.02 0 7 1938 7.96 0 8 1961 7.95 0 9 1967 7.53 0 10 1969 7.11 0
  16. bluewave
    Pretty impressive so far.
  17. bluewave
    Parts of the area are almost to 10.00” on the month so far. Locust Valley 0.3 E Lat: 40.8813 Lon: -73.5813 * indicates Multi-Day Accumulation Report Station NY-NS-32 Date Precip in. 07/01/2021 0.52 07/02/2021 1.26 07/03/2021 1.67 07/04/2021 -- 07/05/2021 -- 07/06/2021 -- 07/07/2021 0.22 07/08/2021 -- 07/09/2021 5.81 07/10/2021 0.37 07/11/2021 -- Totals : 9.85 in.
  18. bluewave
    The HREF did a good job on rainfall amounts with Elsa and the moisture streaming north the day before. So more flash flooding potential on top of already saturated ground. Parts of the area will make a run on their wettest July records.
  19. bluewave
  20. bluewave
    Tuesday looks like it may be the first time that we had a 597 dm backdoor pattern in July. The forecast 597 dm height is among the highest on record for July. In the past, this has been associated with record heat instead of a cooler easterly flow.
  21. bluewave
    Updated for the 6.18 max at Locust Valley, NY NY-NS-32 Locust Valley 0.3 E Lat: 40.8813 Lon: -73.5813 Date Precip in. 07/09/2021 5.81 07/10/2021 0.37 Totals : 6.18 in.
  22. bluewave
    The next record WAR pattern this week will have more clouds, convection, and onshore flow than the previous ones. So the high temperature potential will be lower. But the mid to upper 70s Miami dew points will make it feel warmer than the actual temperatures.
  23. bluewave
    Several stations just had their wettest first 9 days of July on record. So it’s no surprise that July is off to a cooler start. Seems like the only way to keep our summer temperatures down these days is to have a deluge. EWR….+0.6…..4.75 NYC…..-2.1……6.79 LGA……-2.0…..4.74 JFK……-1.1…….3.72 BDR…….-2.1…..7.63 ISP………-1.3.…4.58
  24. bluewave
    Nearly 10.00” since June 30-July 1 near the North Shore. NY-NS-32 Locust Valley 0.3 E Lat: 40.8813 Lon: -73.5813 * indicates Multi-Day Accumulation Report Station NY-NS-32 Date Precip in. 07/01/2021 0.52 07/02/2021 1.26 07/03/2021 1.67 07/04/2021 -- 07/05/2021 -- 07/06/2021 -- 07/07/2021 0.22 07/08/2021 -- 07/09/2021 5.81 Totals : 9.48 in.
  25. bluewave
    The July 1-9 record rainfall could be signaling that the all-time June high of 103° at Newark will be the warmest of the summer. This was earliest in the season that we had a tropical storm or hurricane following a 100° day by a very wide margin. The usual pattern in the past was to have the 100° heat in July or August with the tropical system in August or September. This seasonal cycle getting moved up to late June and early July is unprecedented since at least 1944. Newark closest 100° dates followed by a tropical storm or hurricane 8-5-44….102°………9-15-44……Great Atlantic Hurricane 7-31-54…103°……...8-31-54……Hurricane Carol….10-15-54….Hurricane Hazel 8-2-55….100°……….8-13-55……TS Connie…..8-17-55….TS Diane 7-21-91...102°……….8-19-91……Hurricane Bob 7-5-99….103°…….…9-16-99…..TS Floyd 7-22-11…108°……….8-28-11……Hurricane Irene 7-18-12…104°……….10-29-12…Hurricane Sandy 6-30-21…103°………7-9-21……..TS Elsa
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