July 20, 2012: Drier, Warmer Weekend Coming Up

Forecast Highlights:

- Drier/Warmer Weekend Follows Chilly Rain
- More Storms Early Next Week
- Upcoming Pattern Favors Less Heat


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Today's Observations:

As a wave of low pressure developed over the Mid Atlantic region along a stalled cold front, cloudy skies and widespread showers spread across the region resulting in an unusually chilly July day, with highs only in the lower to mid 60s across most of the area during the day, slightly above 65 in some areas, which was significantly colder compared to just two days ago when temperatures soared above 100 degrees in the immediate NYC area. The usual high/low temperature times were the opposite of the usual; actual high temperatures were observed around 12-5 AM, peaking in the upper 60s to lower 70s before dropping into the 60s by the morning hours. Meanwhile, low temperatures were observed for most either late at night or during the middle of the day.

The main highlight of the day was the rain event, as it ended up unfolding differently than the expectations. The model guidance never had a solid handle on the event from the start, leaving some room for error, especially with the axis of heavy rain which remained uncertain through the short range, as the model guidance generally pointed to the heaviest rain staying west and south of NYC with some models showing it north of NYC but not too far north. Locally heavy rain did end up in southern/central NJ and parts of western NJ, but the axis of heavier rain was well north of the expectation, ending up as far north as the Connecticut/Massachusetts border. Some model runs didn't even had rain making it that far north. There were hints of a further north axis of heavier rain with yesterday's radar when the steadier rain was further north than modeled. The rain also came in earlier than some models showed, as the ECM/GFS were moderately slow with bringing the rain in while the NAM was too slow, with the rain only starting in the morning for most. The rain was supposed to last throughout the day today and into parts of the overnight hours. Instead, the rain already started in the middle of the overnight hours and ended west of NYC as early as 3 PM. In the early afternoon hours. Rain totals ended up close to the expectation, however, with totals locally above 1 inch.


Weekend Outlook: Drier, Warmer


Clouds will stick around in parts of the region on Saturday, although clearing is expected for other parts including the area, with partly sunny skies expected for Saturday along with temperatures warming up into the upper 70s to lower 80s for most of the area, a bit cooler in eastern areas and warmer in the immediate NYC area. Partly cloudy skies are also expected for Sunday with highs in the lower to mid 80s across most of the area with upper 70s to lower 80s further east. Parts of the immediate NYC area may pass 85 degrees.


Next Week: Warmer, More Storms


Temperatures on Monday are likely to be similar to those of Sunday, in the lower to mid 80s, with partly to mostly cloudy skies and scattered thunderstorms. The next cold front will move through the area on Tuesday with additional scattered thunderstorms possible along with highs in the mid 80s to lower 90s across the area, with the warmest temperatures in the immediate NYC area and the coolest temperatures further east. At this time, there does not appear to be a widespread risk of severe storms. Following the cold front, temperatures will cool down into the lower to mid 80s for highs on Wednesday and perhaps Thursday. By the late week into next weekend, temperatures are likely to warm up a bit, but the upcoming pattern, although still not a persistently chilly one in the region, favors less heat in the region compared to the first 20 days of the month, with less frequent 90s. Some models show the next risk of rain to be around Friday and/or the weekend, although this far out there is still some room for changes.