donsutherland1

Morning thoughts... It will be mostly sunny and warm. High temperatures will likely reach the upper 60s and lower 70s in most of the region. Likely high temperatures around the region include: New York City (Central Park): 70° Newark: 71° Philadelphia: 71° Tomorrow will be partly cloudy and still mild. It could turn somewhat cooler during the latter part of the week and weekend. Temperatures could then be confined mainly to the upper 50s with some lower 60s.

On this date in 1982, a blizzard brought widespread heavy snow to New York City into New England. This time around, springlike warmth prevailed. As a result of today's warmth, Central Park now has a monthly anomaly of 0.5° above normal. New York City finished winter 2020-21 with 38.6" snow. That was New York City's 39th highest seasonal figure on record. Over the past 30 winters, New York City has averaged 30.3" of snow. Newark's final snowfall figure of 45.7" ranked 14th highest. Over the past 30 winters, Newark has averaged 32.4" of snow. Philadelphia's final snowfall amount of 23.9" ranked as that city's 49th highest figure on record. Over the past 30 winters, Philadelphia has averaged 23.4" of snow. In the northern Middle Atlantic and southern New England areas, temperatures will likely top out in the 60s through Thursday. Some areas could again reach 70°. Afterward, it will become somewhat cooler. Then, temperatures could be confined mainly to the 50s in much of the region. Based on the latest guidance, no significant precipitation is likely into the weekend. Up north, excessive warmth will develop in northeastern Canada where some record high temperatures will be possible from tomorrow through Saturday. The ENSO Region 1+2 anomaly was -1.1°C and the Region 3.4 anomaly was -0.5°C for the week centered around March 31. For the past six weeks, the ENSO Region 1+2 anomaly has averaged -0.25°C and the ENSO Region 3.4 anomaly has averaged -0.63°C. La Niña conditions will likely give way to neutral-cool ENSO conditions as the spring progresses. The SOI was -0.58 today. The preliminary Arctic Oscillation (AO) figure was +0.301 today. On April 4 the MJO was in Phase 5 at an amplitude of 1.419 (RMM). The April 3-adjusted amplitude was 1.562 (RMM).

Central Park got to 32. The 47-degree figure was an error and has since been corrected.

Morning thoughts... It will be mostly sunny and warm. High temperatures will likely reach the upper 60s and lower 70s in most of the region. Likely high temperatures around the region include: New York City (Central Park): 69° Newark: 70° Philadelphia: 71° Tomorrow will be partly sunny and continued warm. The latter part of the week will turn somewhat cooler with readings mainly in the upper 50s and some lower 60s.

Today saw temperatures rise into the upper 60s and even the lower 70s in some parts of the region. Tomorrow will be a similar day. Meanwhile, excessive warmth will shift into northeastern Canada where some record high temperatures will be possible from Wednesday through Saturday. In the northern Middle Atlantic and southern New England areas, temperatures will likely top out in the 60s through Thursday. Afterward, it will become somewhat cooler. Then, temperatures could be confined mainly to the 50s in much of the region. Based on the latest guidance, no significant precipitation is likely into the weekend. Historic experience following a warm to very warm March suggests a probability that is skewed toward a warmer than normal April. That warmer scenario remains the base case despite the current strong cold shot. The ENSO Region 1+2 anomaly was -1.1°C and the Region 3.4 anomaly was -0.5°C for the week centered around March 31. For the past six weeks, the ENSO Region 1+2 anomaly has averaged -0.25°C and the ENSO Region 3.4 anomaly has averaged -0.63°C. La Niña conditions will likely give way to neutral-cool ENSO conditions as the spring progresses. The SOI was +12.76 today. The preliminary Arctic Oscillation (AO) figure was +0.454 today. On April 3 the MJO was in Phase 5 at an amplitude of 1.501 (RMM). The April 2-adjusted amplitude was 1.477 (RMM).

Central Park picked up 0.8”.

Morning thoughts... It will be mostly sunny and warm. High temperatures will likely reach the middle and upper 60s in most of the region. Likely high temperatures around the region include: New York City (Central Park): 67° Newark: 68° Philadelphia: 69° Tomorrow will be mostly sunny and continued warm.

Clouds gave way to sunshine and the temperature rose into the 60s in much of the region this afternoon. Tomorrow will be fair and continued mild. Meanwhile, near record and record warm temperatures prevailed from the Southwest to the Northern Plains. Daily record high temperatures included: Bismarck: 83° (old record: 82°, 1921) Casper: 74° (tied record set in 1943) Cheyenne: 75° (old record: 72°, 1889) Colorado Springs, CO: 79° (old record: 77°, 1959 and 1967) Denver: 80° (old record: 76°, 1959 and 1967) Huron, SD: 83° (tied record set in 1929) La Crosse, WI: 80° (tied record set in 1910 and tied in 1929) Las Vegas: 91° (tied record set in 1943 and tied in 1959 and 1961) Phoenix: 98° (tied record set in 1961) Rochester, MN: 80° (old record: 77°, 1929 and 1942) Tucson: 96° (old record: 94°, 1943) Phoenix has had 29 days since 1896 when the temperature fell below 40° in April. The last such date occurred on April 11, 1979 when the mercury fell to 39°. Phoenix has never had an April freeze. At Tucson, there have been 18 days on which the temperature fell to or below freezing in April since 1895. The last such date was April 4, 1945 when the temperature dipped to a monthly record low of 27°. Tomorrow will be another very warm day from the Southwest to the Northern Plains States. Afterward, the excessive warmth will shift into northeastern Canada where some record high temperatures will be possible from Wednesday through Saturday. In the northern Middle Atlantic and southern New England areas, temperatures will likely top out in the 60s through Thursday. Afterward, it will become somewhat cooler. Then, temperatures could be confined mainly to the 50s in much of the region. Based on the latest guidance, no significant precipitation is likely into the weekend. Historic experience following a warm to very warm March suggests a probability that is skewed toward a warmer than normal April. That warmer scenario remains the base case despite the current strong cold shot. The ENSO Region 1+2 anomaly was -0.9°C and the Region 3.4 anomaly was -0.6°C for the week centered around March 24. For the past six weeks, the ENSO Region 1+2 anomaly has averaged -0.15°C and the ENSO Region 3.4 anomaly has averaged -0.67°C. La Niña conditions will likely give way to neutral-cool ENSO conditions as the spring progresses. The SOI was +4.47 today. The preliminary Arctic Oscillation (AO) figure was +0.454 today. On April 2 the MJO was in Phase 5 at an amplitude of 1.477 (RMM). The April 1-adjusted amplitude was 1.397 (RMM).

A day later. JFK’s latest measurable snowfall occurred on April 19, 1983.

The latest freeze at Charleston occurred on April 20, 1983 when the temperature fell to 31°.

The record is 5 consecutive days. The record was set from April 2 through April 6, 1881.

Morning thoughts... Early morning clouds will give way to sunshine. The afternoon will be mostly sunny and mild. High temperatures will likely reach the lower and middle 60s in most of the region. Likely high temperatures around the region include: New York City (Central Park): 63° Newark: 64° Philadelphia: 67° Tomorrow will be mostly sunny and mild. Out West, there is a chance that the temperature could make a run at 100° at Phoenix for the first time this year today. Should the temperature reach the century mark, that would be the 3rd earliest such temperature on record for Phoenix.

The region started with readings at or below freezing for a second consecutive day. However, the strengthening April sun boosted temperatures into the 50s in much of the region during the afternoon. Elsewhere, daily record low temperatures were set or tied. Daily records included: Allentown: 20° (tied record set in 1954) Charleston, SC: 31° (old record: 33°, 1962) Charlotte: 26° (old record: 28°, 1972) Columbia, SC: 28° (tied record set 1992) Jacksonville: 36° (old record: 39°, 1962) Savannah: 32° (old record: 33°, 1966) Sherbrooke, QC: 9° (old record: 28°, 2008) Wilmington, NC: 30° (old record: 31°, 1992) Meanwhile, in the Southwest, Phoenix reached a record-tying high temperature of 97° today. That warming trend will tomorrow into early next week. Temperatures will likely return to the 60s in parts of the Middle Atlantic region tomorrow and then in much of the region on Monday. Historic experience following a warm to very warm March suggests a probability that is skewed toward a warmer than normal April. That warmer scenario remains the base case despite the current strong cold shot. The ENSO Region 1+2 anomaly was -0.9°C and the Region 3.4 anomaly was -0.6°C for the week centered around March 24. For the past six weeks, the ENSO Region 1+2 anomaly has averaged -0.15°C and the ENSO Region 3.4 anomaly has averaged -0.67°C. La Niña conditions will likely give way to neutral-cool ENSO conditions as the spring progresses. The SOI was -0.46 today. The preliminary Arctic Oscillation (AO) figure was +0.533 today. On April 1 the MJO was in Phase 5 at an amplitude of 1.398 (RMM). The March 31-adjusted amplitude was 1.297 (RMM).

Under an almost cloudless sky, the temperature rose into the lower 50s following the second consecutive morning with freezing temperatures. Some photos from the New York Botanical Garden:

It is increasingly uncommon. The last time it happened was April 9, 2003. Since 1950, there have been only 9 such dates: April 8, 1956 April 4, 1975 April 7, 1982 April 9, 1982 April 5, 1995 April 7, 2003 April 8, 2003 April 9, 2003 April 2, 2021

Morning thoughts... Across the region, temperatures again started at or below freezing. At Allentown, the low temperature of 20° tied the daily record set in 1954. Saranac Lake reported a near record low of just 2°. The cold start will give way to a warmer afternoon. Today will be mostly sunny and milder. High temperatures will likely reach the lower and middle 50s in most of the region. Likely high temperatures around the region include: New York City (Central Park): 54° Newark: 55° Philadelphia: 55° The warming trend will continue through the weekend. Out West, there is a chance that the temperature could make a run at 100° at Phoenix for the first time this year tomorrow. Should the temperature reach the century mark, that would be the 3rd earliest such temperature on record for Phoenix.

Basically, air flows toward the area of low pressure. As that happens, air rises leading to condensation and then precipitation. Here’s a more detailed summary: https://scied.ucar.edu/learning-zone/how-weather-works/highs-and-lows-air-pressure

Earlier today, many parts of the region saw their coldest April temperatures in nearly five years. Low temperatures included: Albany: 24° Allentown: 24° Atlantic City: 30° Baltimore: 30° Binghamton: 17° (old record: 19°, 2003) Boston: 29° Bridgeport: 29° Harrisburg: 29° Hartford: 27° Islip: 31° New York City-JFK: 29° New York City-LGA: 29° (old record: 32°, 2018) New York City-NYC: 28° (coldest April temperature since April 5, 2016) Newark: 28° (tied record set in 1964; coldest April temperature since April 6, 2016) Philadelphia: 29° (coldest April temperature since April 11, 2018) Providence: 31° Poughkeepsie: 27° Scranton: 23° Trenton: 27° Washington, DC: 31° (first April freeze since April 10, 2016) Wilmington, DE: 29° Worcester: 24° Today was also the first April day since April 8, 1997 when the temperature fell below 30° in both New York City and Philadelphia on the same date. Since 1980, such days have only occurred in 1982, 1985, 1995, and 1997. The mean highest temperature during the April 16-30 period for such cases was 80° in New York City and 81° in Philadelphia. 1997 had the lowest maximum temperature during the second half of April with 73° figures in both cities. 1985 had the highest such temperatures with a high of 88° in New York City and 90° in Philadelphia. New York City had a daily high temperature of just 39°. The last time New York City had an April maximum temperature below 40° was April 9, 2003 when the temperature topped out at 39°. After another frosty night, tomorrow will see temperatures warm into the upper 40s and lower 50s during the afternoon. That warming trend will continue this weekend and into early next week. Temperatures will likely return to the 60s in the northern Middle Atlantic region by Sunday or Monday. Historic experience following a warm to very warm March suggests a probability that is skewed toward a warmer than normal April. That warmer scenario remains the base case despite the current strong cold shot. One thing to watch for would be a possible further decline in the AO during the second half of April. Since 1950, there were 28 cases where the AO averaged between -0.999 and -0.001 during the April 1-15 period, as appears possible in April 2021 based on the most recent guidance. In the subset of cases where the AO average was even lower during the second half of April, the mean temperature during that time was 57.0°. 60% of those cases saw a mean temperature of 56.0° or above during April 16-30. In contrast, the subset that saw the AO rise from the April 1-15 average saw the temperature average 54.7°. 78% of those cases had a mean temperature of less than 56.0°. The ENSO Region 1+2 anomaly was -0.9°C and the Region 3.4 anomaly was -0.6°C for the week centered around March 24. For the past six weeks, the ENSO Region 1+2 anomaly has averaged -0.15°C and the ENSO Region 3.4 anomaly has averaged -0.67°C. La Niña conditions will likely give way to neutral-cool ENSO conditions as the spring progresses. The SOI was -9.59 today. The preliminary Arctic Oscillation (AO) figure was +0.787 today. On March 31 the MJO was in Phase 4 at an amplitude of 1.298 (RMM). The March 30-adjusted amplitude was 1.434 (RMM).

Atlanta’s geography is conducive to allowing cold shots to move into the area without the kind of moderation that sometimes occurs in the New York City area.

With a low temperature of 31°, Washington, DC experienced its first April freeze since April 10, 2016 when the temperature also fell to 31°.

Morning thoughts... Low temperatures in New York City, Newark, and Philadelphia were 28°, 28°, and 29° respectively. For Central Park, that as the coldest April temperature since April 5, 2016 when the temperature fell to 26°. For Newark, it was the coldest April temperature since April 6, 2016 when the temperature was 27°. For Philadelphia, it was the coldest April temperature since April 11, 2018 when the mercury dipped to 29°. At Binghamton, the temperature fell to 17°. That broke the daily record of 19°, which was set in 2003. Today will be variably cloudy and unseasonably cold. A stray rain or snow shower cannot be ruled out during the afternoon, especially north and west of New York City. High temperatures will likely reach the upper 30s and lower 40s in most of the region. Likely high temperatures around the region include: New York City (Central Park): 41° Newark: 43° Philadelphia: 45° Tomorrow will start off with unseasonably cold temperatures, but a warmer afternoon is likely. The warming trend will continue through the weekend.

As a strong cold front moved eastward, Binghamton picked up 2.7" snow. That broke the daily record of 1.4", which was set in 1991. It also raised that city's seasonal snowfall to 102.9", which ranks as 17th highest. At 8 pm, readings in and around Newark and New York City were in the lower and middle 40s. Colder air continued to press into the region. Overnight, New York City's Central Park will likely see its first April freeze since April 9, 2018. Both the MOS and NBM are in good agreement about such a freeze. In an area extending from the Gulf States to the Southeast, some near record and record low temperatures are possible tomorrow morning. Tomorrow will be partly to mostly cloudy and unseasonably cold. The temperature will struggle to reach the lower 40s. Moderation will occur during the weekend. Temperatures will likely return to the 60s in the northern Middle Atlantic region by Sunday or Monday. Historic experience following a warm to very warm March suggests a probability that is skewed toward a warmer than normal April. That warmer scenario remains the base case. The ENSO Region 1+2 anomaly was -0.9°C and the Region 3.4 anomaly was -0.6°C for the week centered around March 24. For the past six weeks, the ENSO Region 1+2 anomaly has averaged -0.15°C and the ENSO Region 3.4 anomaly has averaged -0.67°C. La Niña conditions will likely give way to neutral-cool ENSO conditions as the spring progresses. The SOI was -4.83 today. The preliminary Arctic Oscillation (AO) figure was +1.015 today. On March 31 the MJO was in Phase 4 at an amplitude of 1.301 (RMM). The March 30-adjusted amplitude was 1.434 (RMM).

Morning thoughts... Light rain will end this morning. The clouds will gradually give break during the afternoon. It will become breezy. Temperatures will likely reach the upper 40s and lower 50s across much of the region this afternoon before falling toward evening. Likely high temperatures include: New York City (Central Park): 50° Newark: 52° Philadelphia: 52° Tomorrow will be partly sunny, blustery and unseasonably cold. 30-Day Verification: New York City (Central Park): Average daily forecast: 53.7° Average temperature: 54.2° Average error: 2.1° Newark: Average daily forecast: 55.0° Average temperature: 55.3° Average error: 2.3° Philadelphia: Average daily forecast: 57.3° Average temperature: 57.2° Average error: 1.9°

March 2021 finished with a mean temperature of 45.8° in New York City. That was 3.3° above normal and ranked March 2021 as the 13th warmest March on record. A brief shot of much cooler air is now on its way. As a strong cold front advances eastward and a storm moves northward along the front, there will be periods of rain overnight. Across central and upstate New York and parts of Quebec, the rain will change to accumulating snow. There a moderate to significant accumulation is possible. Following the frontal passage, April will start out on the cold side. Despite a return of sunshine tomorrow, it will be blustery and cold with highs struggling to get out of the 40s. On Friday morning, New York City's Central Park could see its first April freeze since April 9, 2018. In an area extending from the Gulf States to the Southeast, some near record and record low temperatures are possible that morning. Moderation will occur during the weekend. Temperatures will likely return to the 60s in the northern Middle Atlantic region. Historic experience following a warm to very warm March suggests a probability that is skewed toward a warmer than normal April. That warmer scenario remains the base case. The ENSO Region 1+2 anomaly was -0.9°C and the Region 3.4 anomaly was -0.6°C for the week centered around March 24. For the past six weeks, the ENSO Region 1+2 anomaly has averaged -0.15°C and the ENSO Region 3.4 anomaly has averaged -0.67°C. La Niña conditions will likely give way to neutral-cool ENSO conditions as the spring progresses. The SOI was -6.75 today. The preliminary Arctic Oscillation (AO) figure was +1.512 today. On March 29 the MJO was in Phase 4 at an amplitude of 1.397 (RMM). The March 28-adjusted amplitude was 1.685 (RMM).

DCA _ NYC _ BOS __ ORD _ ATL _ IAH ___ DEN _ PHX _ SEA 1.4 1.7 1.6 3.6 0.2 0.3 2.7 1.0 -0.8