April 5, 2012: Chilly Pattern Continues

Between April 6-13, this blog is going on vacation. Brief updates will be posted on occasions, especially when stormy weather is possible. The next full update will be posted on Sunday, April 14.


-------------------------------------------------------------

Forecast Highlights:


- Colder pattern continues; near-below average temps next week
- Mostly dry conditions continue, some light rain next week
- Breezy winds expected this weekend, early week
- Temperatures may warm up by end of next week/next weekend


-------------------------------------------------------------

As yet another chilly air mass moved into the area, temperatures today were colder than those of yesterday. High temperatures reached the mid 50s in northwestern areas inland, upper 50s to lower 60s in the immediate NYC area, and the mid to upper 50s in Long Island and southern CT. Since the big March warm spell, a cooler pattern developed across the region, with temperatures dropping down to near average levels, ending up below average on some occasions. While there is uncertainty with exactly how long the pattern lasts, it will continue to be in place through at least most of next week.


Tomorrow's Outlook:


Tomorrow will bring mainly sunny skies across the area with light NW winds expected. Temperatures will be similar to those of today, reaching the mid to possibly upper 50s inland, upper 50s to lower 60s in the immediate NYC area, and mid to upper 50s in Long Island and southern CT.


Weekend Outlook: Slightly Warmer


Mainly sunny skies will continue through the weekend as well, with temperatures slightly warming up but still remaining close to the average. Highs are expected to reach the mid 50s to lower 60s across the area on Saturday, with widespread lower to mid 60s on Sunday. Breezy winds are expected for both days with gusts up to 30, locally 35-40 mph, possible.


Next Week: Chilly Pattern Continues


A weak low pressure currently in the southern US will move east and offshore this weekend, as many of this winter's storms have done. Unlike the rest of these storms, however, the storm will be blocked from moving northeast, and will strengthen while retrograding towards Maine, moving from east to west through Nova Scotia and New England before stalling over the region. This is the result of a weak blocking pattern that has developed with more ridging near Greenland; this type of pattern, should it have taken place during the winter, would have easily been supportive of sustained cold and snow, but by the time the stubborn and long lasting warm pattern observed in the winter fell apart, doing so in mid March, it was already too late for winter to return to the NYC area. As a result of this, a trough will once again lock itself over the region for most of next week, with chilly temperatures expected to continue, ending up near to below average, with a few light rain possibilities.

Partly to mostly cloudy skies are expected on Monday as the low pressure moves into southeastern Canada, with a stronger west/WSW expected for the area; gusts have the potential to reach and/or exceed 40 mph across parts of, if not most of the area. Temperatures will be similar to those of Sunday, reaching the lower to mid 60s for most places north/west of NYC and the mid 50s to lower 60s in Long Island/southern CT. Some showers are possible on Monday night as light precipitation moves through, with Tuesday bringing partly to mostly cloudy skies and highs reaching the lower to mid 50s inland and the mid to upper 50s across the rest of the area. Breezy winds are expected again on Tuesday but with less wind compared to Monday.

There is some more uncertainty for the middle of next week as the GFS keeps the area dry while the ECM has more rain and keeps the trough amplified through next week. At this time, I am leaning closer to the drier GFS, with the ECM possibly overdoing the amplification of the trough, with some light rain possible again on Wednesday, although no significant rain is expected at any time next week; most of the time frame is likely to be dry for the area. Temperatures will depend on the rain probability and the exact location of the low pressure to the north, although temperatures are still expected to stay in the 50s across the area.


Longer Range / Rest of April Outlook: Uncertainty increases beyond the middle of next week due to the time range, although despite signs of the blocking weakening, the chilly pattern is not expected to reverse to a warm one. The warm pattern that has brought persistently significant positive temperature departures across the region has likely ended with the warm spell in mid March; troughs have become more frequent in the region, warm spells in the central US struggle to reach the region, and ridging is showing up more often near Greenland. While a warmer second half of the month is expected compared to the first half of the month, temperatures are still expected to remain relatively close to average, leaning towards warmer than average. There could still be some warm days, but given the pattern they would more likely be in the form of 1-2 day warm surges as opposed to prolonged warm spells. Overall, April is expected to end up only slightly warmer than average across the area, as opposed to the last few months which were much warmer than average, especially March which was the 2nd warmest March on record. The warmest departures will remain in the central US. April is also expected to feature below average precipitation.


As mentioned in the start of the post, this will be the last full update until April 14. Until then, occasional brief updates will be posted, including updates on the forecast for next week as well as the longer range.