Mar 27, 2012: Winter Attempts Last Comeback

Forecast Highlights:


- Warmth briefly returns; 68-72 degrees in NYC on Weds.
- Pattern transitions to a slightly colder, wetter one
- Cold rain in NYC, New England snow possible this weekend
- Rain likely returns next week


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Blog Notices:
- Daily updates will resume starting today in the 5-Day Forecast page.
- The Severe Weather page will also be updated daily, highlighting any strong thunderstorm risk across the region.

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Yesterday's Observations:
Monday, March 26

As I was unable to post an update yesterday, I added a review of yesterday's observations into tonight's discussion. Mostly to partly sunny skies were observed across the area as a cold front moved through; temperatures peaked in the morning hours for most of the area before dropping steadily by the afternoon as a much colder air mass quickly came through. High temperatures peaked in the lower to mid 50s across the area,  with the warmest temperatures near southern CT and Long Island. Windy conditions were observed as well, with most of the area observing 35-45 mph gusts.



Today's Observations:
Tuesday, March 27

With a strong yet short lasting trough in place, today brought chilly high temperatures but cold overnight lows, dropping into the mid 20s to lower 30s across the area, a noticeable change from just a week ago when temperatures reached the 70s across most of the area. Highs were colder than average as well, reaching the lower 50s across most of the area, with a couple of places failing to reach the 50 degree mark. Mainly sunny skies were observed today with weaker winds compared to those of yesterday.

A warmer air mass will briefly move through the region tomorrow, resulting in much warmer temperatures along with a risk of isolated thunderstorms in the afternoon and evening, although it may not rain in the entire area. With a slightly colder pattern in place, however, temperatures will quickly cool back down into the 50s again through the end of the week and into the weekend with a possible storm on Saturday and/or Sunday, followed by another brief warm up potential towards the middle of next week.


Tomorrow's Outlook:


*Isolated Severe Weather Risk (10%) - More information in Severe Wx page*

A low pressure will move through the region tomorrow, tracking not too far north of the area. Although temperatures will remain chilly tomorrow morning, with the storm tracking to the north the area will enter the warm sector for at least a couple of hours. A rise in temperatures is expected towards the mid afternoon hours, with highs taking place towards the evening with temperatures reaching the mid to upper 60s from NYC and further north/west, possibly getting into the lower 70s west of NYC, and the mid 50s to lower 60s in Long Island and southern CT. Depending on the possible rain in the middle of the afternoon, should the line of storms discussed in more details below end up stronger and more widespread, temperatures would end up slightly colder than those mentioned above.

With the approaching low pressure, two lines of rain and thunderstorms could move through the area. The first possibility of rain is around 2-4 PM, when a line of locally heavy thunderstorms will approach the area. Parts of the area may stay mainly dry, although most of the area is likely to see at the very least some rain, even if it's light, with locally heavy thunderstorms possible. Once temperatures warm up in the late afternoon and evening, another weaker line of thunderstorms is possible around 7-9 PM, focusing around the immediate NYC area. Overall, most of the area is still expected to end up with up to 1/4 inch of rain, with some areas possibly failing to see more than a drizzle.


Thursday - Next Week: Chilly, Winter Attempts To Return


The type of pattern typically required to produce snow in the winter, involving at least some ridging near Greenland with cold air displaced near the region, has failed to set up for any prolonged period of time this season. Now that winter is over, the pattern is gradually becoming more winter-like, with a couple of snow potentials in New England expected over the next 2 weeks along with cooler temperatures returning into NYC again. Thursday and Friday will be dry with highs cooling back down into the lower to mid 50s across most of the area, possibly reaching the upper 50s near NYC on Thursday.

By Saturday, the next low pressure will approach the region. Currently, the GFS model is the weakest with this development, while the rest of the models show a stronger storm with more rain. Although the blocking may suppress the storm, at this time I sided with the majority of the models, with rain likely to fall on Saturday, although it is still not certain that it does rain, especially should the GFS, the current outlier, verify with a much weaker low pressure. With the suppression, it appears at this time that this storm should track at least near or south of NYC; while it is not cold enough for snow to fall in NYC, the location on the storm on some models, such as the NAM and ECM, actually favors accumulating snow over parts of southern New England away from the coast.

The forecast for Saturday does not have a high confidence level yet with these differences, although it does appear that should it rain, it would be a cold rain, with high temperatures in the 40s to possibly the low 50s at most, with snow possible in interior parts of New England. For tonight's 5-Day Forecast, I put a likely mention of rain, not a certain forecast, with highs in the upper 40s to lower 50s, although this will likely change with tomorrow's update depending on any developments regarding the intensity and placement of the low pressure. Stay tuned for more information on the weekend outlook.

Going into next week, most models show another brief warm up around the early-mid week with another low pressure moving through the region by the middle of next week. While the mid week storm has a warmer look to it, and is expected to bring more rain into the area, it is possible that colder temperatures may once again return behind the storm into the end of next week. More information will be posted on the long range as details become clearer.