Mar 3, 2011: Rain For Sunday, Next Thursday

A strong cold air mass moved into the region last night, bringing clear skies and cold temperatures. Even though low temperatures were wmer than predicted especially in interior areas, only reaching the mid 10s inland, high temperatures were cold, peaking in the lower to mid 30s across the area.

Warmer weather will return as soon as tomorrow, with high temperatures back into the 40s, steadily warming up until Saturday and Sunday, when temperatures should peak in the lower to mid 50s across the area and even a few upper 50s cannot be ruled out. Along with these warmer temperatures, however, will come stormy conditions, as a storm moving towards the region will produce heavy rain from Sunday afternoon into the overnight hours, and even some snow is possible in the interior parts of the area as the storm ends. This storm is not the last of the heavy rain threats, as yet another storm in the medium range is expected to bring more rain to the area on Thursday and Friday next week.


Tomorrow's Outlook:

After moderately cold overnight temperatures, which will reach the mid 10s inland, high temperatures tomorrow will be warmer than today, peaking in the upper 30s to lower 40s across the area, and a few mid 40s are possible from NYC and further south/west. A southeast wind is expected.

Cloud cover will increase tonight, becoming mostly cloudy by the late morning hours. Overnight, a little precipitation may reach the area west of NYC, and with temperatures cold enough, this will support the potential for a light wintry mix north and west of NYC. Any precipitation that does fall, however, should be light with little to no accumulations expected.


Saturday - Monday: Cloudy, Becoming Wet, Ending As Snow?

As the storm will begin to slowly enter Pennsylvania on Saturday, mainly cloudy skies are expected throughout the day with the potential for a few isolated showers, especially in the western parts of the area. High temperatures will peak in the mid to upper 40s for most of the area, however some lower 50s are expected in the immediate NYC area, with mid 50s possible southwest of NYC.

Overnight lows will be steady in the lower to mid 40s north of NYC and in the mid to potentially upper 40s for NYC and further south/southwest. There is uncertainty with the high temperatures on Sunday, which depend on the location and timing of the storm, however they are likely to peak in the upper 40s to mid 50s across the area, and if the slower/warmer scenario verifies, places southwest of NYC may be able to reach the upper 50s or even the 60 degree mark.

The storm will be slow to move into the area, however it will be full of moisture, with precipitable water values over 1 inch. As we have seen many times this winter and unfortunately seeing again, we are three days away from the storm and there is still a large spread with the models, ranging from the NAM which still has the heavy rain west of the area by Monday morning when most models already have dry conditions, to the GFS which is going with light rain amounts between 1/2 and 1 inch, to the ECMWF which has snow for the interior parts of the area as the storm ends. Right now the ECMWF's solution does not have much support, and showed up as a different scenario in its previous run, so while back end snow is possible with this storm especially for interior areas, I would rather see other models support this idea before using it for my forecast.

For now, the smaller details in the forecast such as the exact timing of precipitation are generally low-moderate confidence, however looking at the overall picture, there will be heavy rain sometime between Sunday afternoon to Monday morning, which has the potential to bring a widespread 1 to 2 inches across the area. Depending on tomorrow's models and trends, I may issue a Rain Watch for the area. Stay tuned for more information on this storm and how it may affect the area.


Longer Range: Drying Up, Then More Rain Late Next Week

Behind this storm, colder conditions will briefly return for Monday into Tuesday, which will not be as cold as today's temperatures but will still be below the average temperatures for this time of the year. There is uncertainty with the exact temperatures next week with several different solutions showing up, however the next storm will approach on Thursday and is also expected to track west of the area. While there could be cold air damming in the start of the storm, the main part of the storm does appear to be rain once again. Stay tuned for more information on the longer range.