bluewave

Next several days look warm and dry with highs making another run on 70° today.Then it appears that the high over the region providing the dry and warm conditions will shift east by Friday. So more of a backdoor onshore flow developing. Main question is where the front will stall out. That will determine where the best rainfall potential sets up. Dry and warm N to NW flow next several days High moves east by Friday allowing more onshore flow with a backdoor nearby

Yeah, JFK can have some of the warmest area temperatures on dry offshore flow days. JFK and EWR both made it to 70°. Our area was far enough SW of the storm east of New England. Looks like the blocking ridge should keep most rain west of the area this week. Then it appears that the ridge eventually weakens by the weekend allowing better rain chances.

The warm spots may make a run on 70° today as these dry and windy downslope days often beat guidance. KEWR GFS MOS GUIDANCE 4/05/2021 0000 UTC DT /APR 5 /APR 6 /APR 7 / HR 06 09 12 15 18 21 00 03 06 09 12 15 18 21 00 03 06 09 12 18 00 X/N 68 44 66 46 67 TMP 50 47 49 58 64 67 61 55 49 46 50 57 62 64 60 55 50 48 51 64 61 DPT 27 27 28 27 26 25 27 29 29 28 29 25 22 23 26 30 32 33 35 34 37 CLD CL CL FW FW FW CL SC BK CL CL CL CL FW FW FW FW CL CL FW SC BK WDR 31 27 31 32 31 30 30 31 31 28 31 32 31 32 32 33 30 36 35 34 11 WSP 07 07 13 15 17 18 16 12 06 05 08 11 13 10 09 04 03 02 04 06 06

It’s one of the quirks of our warming climate. The average first 80° day has moved one month earlier up at Newark from April 28th in 1970 to March 31st in 2021. But the average first 90° day has remained nearly unchanged from May 19th in 1970 to May 21st in 2020. So record early 90°+ heat like April 2002 remains rare. The fall is reversed. Later last 90° day while the last 80° day is mostly unchanged.

The south based blocking has been the real deal since early December. We can see how it has resulted in a drier pattern for New England. We’ll probably have to wait for it to weaken a bit to get more significant rain chances again here. But the rains eventually end up arriving even if they get pushed back a little from earlier forecasts.

Looks like we are headed for a pattern when the warmest days top out in the 60s. Some days that get more onshore flow and clouds may only make it to the 50s. The blocking has corrected further south in the most recent model runs. So the lows get forced by well to our south. The NW to NE flow prevents us from making a run on 80s like late March for a while. Our next chance at any significant rains will have to wait for the block to weaken a bit. Funny how we are seeing a spring version of the winter south based blocking pattern. KEWR GFSX MOS GUIDANCE 4/04/2021 0000 UTC FHR 24| 36 48| 60 72| 84 96|108 120|132 144|156 168|180 192 SUN 04| MON 05| TUE 06| WED 07| THU 08| FRI 09| SAT 10| SUN 11 CLIMO X/N 61| 43 67| 43 66| 44 65| 48 61| 47 59| 46 56| 42 59 40 59 New run blocking pressing further south Old run more low pressure near the Northeast

Tough to keep the 60s away for long this time of year. KEWR GFSX MOS GUIDANCE 4/03/2021 1200 UTC FHR 24 36| 48 60| 72 84| 96 108|120 132|144 156|168 180|192 SUN 04| MON 05| TUE 06| WED 07| THU 08| FRI 09| SAT 10|SUN CLIMO N/X 38 59| 41 66| 43 62| 46 63| 47 64| 47 59| 46 63| 48 40 59

Yeah, the low humidity season usually peaks in March and April here. Things should gradually moisten back up going into next week. Then it looks like our next chance of significant rain again in about a week. We saw this in March when we went from very dry to wet again. The main take away is that dry patterns don’t have much staying power in our new wetter climate. https://mesonet.agron.iastate.edu/plotting/auto/?_wait=no&q=157&network=NJ_ASOS&station=EWR&year=2020&var=min_rh&dir=below&thres=20&dpi=100&_fmt=png

Looks like another low dewpoint and low relative humidity special today. Dewpoints are forecast to drop to near 0 with temperatures getting back above 50°. We make a run on 60° tomorrow and get back into the 60s on Monday. So it’s tough to maintain the record cold of the last few days very long. KEWR GFS MOS GUIDANCE 4/03/2021 0600 UTC DT /APR 3 /APR 4 /APR 5 / HR 12 15 18 21 00 03 06 09 12 15 18 21 00 03 06 09 12 15 18 00 06 X/N 55 38 58 40 65 TMP 36 44 52 55 51 46 42 40 44 49 55 56 53 48 44 42 46 56 62 58 50 DPT 9 3 3 5 11 17 21 25 29 31 31 29 29 30 29 28 29 28 27 30 32

This is only the 3rd April since 1990 with a NYC high temperature below 40°. The other 2 years were 2003 and 1995. It was also the first -14 daily temperature departure in NYC since November 18th. Time Series Summary for NY CITY CENTRAL PARK, NY - Month of Apr Click column heading to sort ascending, click again to sort descending. Year Lowest Max Temperature Missing Count 2021 39 28 2020 46 0 2019 45 0 2018 43 0 2017 48 0 2016 43 0 2015 43 0 2014 47 0 2013 43 0 2012 52 0 2011 44 0 2010 52 0 2009 48 0 2008 50 0 2007 41 0 2006 47 0 2005 50 0 2004 43 0 2003 37 0 2002 45 0 2001 43 0 2000 43 0 1999 46 0 1998 48 0 1997 42 0 1996 40 0 1995 39 0 1994 53 0 1993 41 0 1992 45 0 1991 46 0 1990 46 0

Outside of the unusual cold today and tomorrow, I don’t think anyone is forecasting dreary and cold for the whole month. The models have the blocking shifting from Greenland back to Canada over the next few weeks. So we trade in Greenland blocking for more +PNA blocking as the month progresses. We could easily get 60s like the models show coming up. Highs to our north will probably mean plenty of NW to NE flow. Maybe a low will eventually try to cut off underneath leading to several days of more easterly flow and rains. Northeastern New Jersey... Newark, NJ Ptcldy Sunny Mocldy Sunny Sunny Ptcldy Ptcldy /42 29/55 39/62 42/65 42/66 46/66 49/65 /00 00/00 10/10 10/00 00/10 20/20 20/30

Record cold today at LGA and EWR only a week after the record 80s heat last Friday.

This made the top 5 for greatest spring 7day temperature drops. https://mesonet.agron.iastate.edu/plotting/auto/?_wait=no&q=169&network=NJ_ASOS&zstation=EWR&hours=162&month=spring&dir=cool&dpi=100&_fmt=png

Updated for March 2021. 3....2021...LGA.....9...JFK....10.....BDR....8

I believe this is the fastest NYC freeze chance after a spring (MAM) 80°day since 1978. Data for NY CITY CENTRAL PARK, NY Click column heading to sort ascending, click again to sort descending. Date Max Temperature Min Temperature 2021-03-26 82 52 2021-03-27 69 50 2021-03-28 60 48 2021-03-29 55 45 2021-03-30 61 42 2021-03-31 67 50 2021-04-01 M M Data for NY CITY CENTRAL PARK, NY Click column heading to sort ascending, click again to sort descending. Date Max Temperature Min Temperature 1978-04-01 82 47 1978-04-02 61 37 1978-04-03 40 31

These cool downs and blockier intervals following an early 80°+ day have become common in recent years. So the early April freeze coming up following the 80s last week isn’t a surprise. The first 80° at Newark has moved up nearly one month since the 1970s. The average back then was 4-23 and 3-30 since 2011. But the last freeze date has only moved up 4 days over the same period from 4-7 in the 70s to 4-3 since 2010. First/Last Summary for NEWARK LIBERTY INTL AP, NJ Each section contains date and year of occurrence, value on that date. Click column heading to sort ascending, click again to sort descending. Year First Value Last Value Difference Minimum 03-29 (1977) 09-16 (1971) 127 Mean 04-23 10-05 165 Maximum 05-19 (1975) 11-01 (1974) 204 1970 05-02 (1970) 80 10-08 (1970) 80 158 1971 05-11 (1971) 82 09-16 (1971) 85 127 1972 04-19 (1972) 87 09-27 (1972) 85 160 1973 04-19 (1973) 80 10-05 (1973) 82 168 1974 04-22 (1974) 81 11-01 (1974) 81 192 1975 05-19 (1975) 81 10-15 (1975) 84 148 1976 04-16 (1976) 82 09-20 (1976) 82 156 1977 03-29 (1977) 80 09-19 (1977) 84 173 1978 04-01 (1978) 82 10-23 (1978) 82 204 1979 04-23 (1979) 80 10-23 (1979) 80 182 1980 05-03 (1980) 83 09-23 (1980) 85 142 First/Last Summary for NEWARK LIBERTY INTL AP, NJ Each section contains date and year of occurrence, value on that date. Click column heading to sort ascending, click again to sort descending. Year First Value Last Value Difference Minimum 02-21 (2018) 09-28 (2014) 167 Mean 03-29 10-08 192 Maximum 04-18 (2015) 10-21 (2017) 231 2011 03-18 (2011) 80 10-10 (2011) 85 205 2012 04-15 (2012) 80 10-05 (2012) 81 172 2013 04-09 (2013) 85 10-07 (2013) 80 180 2014 04-13 (2014) 83 09-28 (2014) 87 167 2015 04-18 (2015) 82 10-09 (2015) 81 173 2016 03-09 (2016) 82 10-19 (2016) 87 223 2017 04-10 (2017) 82 10-21 (2017) 81 193 2018 02-21 (2018) 80 10-11 (2018) 81 231 2019 04-08 (2019) 80 10-07 (2019) 80 181 2020 03-20 (2020) 80 09-28 (2020) 81 191 2021 03-26 (2021) 84 - - - Frost/Freeze Summary for NEWARK LIBERTY INTL AP, NJ Each section contains date and year of occurrence, value on that date. Click column heading to sort ascending, click again to sort descending. Year Last Value First Value Season Length Minimum 03-21 (1973) 10-19 (1976) 189 Mean 04-07 11-06 213 Maximum 04-17 (1980) 11-29 (1979) 235 1970 04-11 (1970) 32 11-23 (1970) 26 225 1971 03-26 (1971) 31 11-08 (1971) 32 226 1972 04-09 (1972) 29 10-20 (1972) 31 193 1973 03-21 (1973) 32 11-10 (1973) 31 233 1974 04-10 (1974) 31 10-19 (1974) 31 191 1975 04-13 (1975) 32 10-30 (1975) 32 199 1976 04-12 (1976) 27 10-19 (1976) 30 189 1977 04-09 (1977) 26 11-12 (1977) 32 216 1978 04-03 (1978) 31 11-25 (1978) 32 235 1979 04-08 (1979) 31 11-29 (1979) 32 234 1980 04-17 (1980) 30 11-03 (1980) 30 199 Frost/Freeze Summary for NEWARK LIBERTY INTL AP, NJ Each section contains date and year of occurrence, value on that date. Click column heading to sort ascending, click again to sort descending. Year Last Value First Value Season Length Minimum 03-24 (2017) 10-19 (2015) 196 Mean 04-03 11-08 217 Maximum 04-17 (2020) 11-28 (2016) 244 2010 03-27 (2010) 28 11-27 (2010) 32 244 2011 03-29 (2011) 32 10-31 (2011) 32 215 2012 03-27 (2012) 30 11-06 (2012) 27 223 2013 04-04 (2013) 31 11-04 (2013) 32 213 2014 04-16 (2014) 31 11-08 (2014) 32 205 2015 03-29 (2015) 25 10-19 (2015) 31 203 2016 04-10 (2016) 31 11-28 (2016) 32 231 2017 03-24 (2017) 31 11-10 (2017) 25 230 2018 04-11 (2018) 32 11-10 (2018) 32 212 2019 04-01 (2019) 32 11-08 (2019) 29 220 2020 04-17 (2020) 32 10-31 (2020) 32 196

This is the first two consecutive Marches in NYC that were this warm. The current 45.4° is the 14th warmest March average temperature for NYC. Last March was the 7th warmest. Time Series Summary for NY CITY CENTRAL PARK, NY - Month of Mar Click column heading to sort ascending, click again to sort descending. Rank Year Mean Avg Temperature Missing Count 1 1945 51.1 0 2 2012 50.9 0 3 1946 49.8 0 4 2016 48.9 0 5 1921 48.4 0 6 2010 48.2 0 - 1903 48.2 0 7 2020 48.0 0 8 2000 47.2 0 9 1979 46.9 0 10 1977 46.7 0 11 1973 46.4 0 12 1898 46.1 0 13 1985 45.8 0 14 2021 45.4 1

This has to be the most perfect February to March temperature reversal across the US on record.

This is one of those rare times that an October minimum temperature departure was lower than the whole DJF winter. 10-31 had a -14 low temperature departure in NYC. The winter lowest temperature departure was -13 on 1-29. Almanac for NY CITY CENTRAL PARK, NY October 31, 2020 Daily Data Observed Normal Record Highest Record Lowest Max Temperature 46 59 81 in 1946 41 in 1869 Min Temperature 32 46 62 in 1961 29 in 1925 Almanac for NY CITY CENTRAL PARK, NY January 29, 2021 Daily Data Observed Normal Record Highest Record Lowest Max Temperature 25 39 69 in 2002 13 in 1977 Min Temperature 14 27 50 in 2002 -0 in 1873

It was a 2 part event. Morning warm front followed by evening cold front. Most impressive rains here were with the morning warm front.

This was the first time that portions of Long Island like Islip had 1.00”+ of rain since Christmas. 2021-03-28 57 47 52.0 9.1 13 0 1.05 2020-12-25 59 32 45.5 12.5 19 0 1.05

Staten Island Mesonet gusting to 54 mph. Wind: W at 21 mph Gust: 54 mph

MCGUIRE AFB,NJ (WRI) ASOS reports gust of 61 knots (70.2 mph) from WSW @ 2335Z -- KWRI 282335Z 25030G61KT 220V280 10SM SQ VCTS FEW065 FEW090 21/15 A2952 RMK LTG DSNT W PRESRR SLP996 53005

The warm front just came through MMU. 17:17 66.2 58.6 5.8 SW 29.27 29.47 Mist 3.00 600 OK 16:45 62.6 57.2 0.0 N 29.28 29.48 Mist 1.25 200 OK 15:45 60.8 56.5 0.0 N 29.30 29.50 Mist 0.75 200 O

It’s interesting how warm Novembers and Marches go together. November was the warmest on record in NYC. So it’s no surprise that March is running well above average. Monthly Mean Avg Temperature for NY CITY CENTRAL PARK, NY Click column heading to sort ascending, click again to sort descending. Year Nov Dec Jan Feb Mar Mar Departure 2020-2021 53.0 39.2 34.8 34.2 44.7 +2.9 2015-2016 52.8 50.8 34.5 37.7 48.9 +6.4 2001-2002 52.7 44.1 39.9 40.6 44.1 +1.6 1979-1980 52.5 41.1 33.7 31.4 41.2 -1.3 1948-1949 52.4 38.3 38.6 38.6 42.8 +0.3 1975-1976 52.3 35.8 27.3 39.9 44.4 +1.9 2011-2012 51.9 43.3 37.3 40.9 50.9 +8.4 2006-2007 51.9 43.6 37.5 28.3 42.2 -0.3 1994-1995 51.9 42.2 37.5 31.6 45.0 +2.5 1931-1932 51.9 40.9 43.2 36.1 37.3 -5.2 1902-1903 51.4 32.4 30.5 33.5 48.2 +5.7 2009-2010 51.1 35.9 32.5 33.1 48.2 +5.7 1999-2000 50.8 39.9 31.3 37.3 47.2 +4.7