May 25, 2011 Brief Update

Note: The next full update will be posted late on Thursday, May 26. This post was slightly revised early on May 26.

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Thursday - Saturday: Warmest Temperatures So Far

As a warm air mass moves into the area, with 850 mb temperatures reaching the 18-20c range, tomorrow and Friday will bring the warmest temperatures of the year so far. Thursday will still bring an onshore wind, keeping Long Island and southern Connecticut with cooler temperatures in the 70s, but from NYC and further west, high temperatures will reach the lower to mid 80s, with a few upper 80s expected in parts of the immediate NYC area. Partly cloudy skies are expected with no rain.

On Friday, the warmest temperatures will take place, when NYC and further west will reach the upper 80s, with even a few lower 90s possible from NE NJ into Newark and further south. Humid conditions are expected as well, with dew points in the mid 60s in the immediate NYC area. A severe weather outbreak will take place in Pennsylvania and New York State, and while the area will be under supportive parameters, most of the precipitation will stay to the west of the area. A few scattered showers and thunderstorms cannot be ruled out west of NYC, especially near NW NJ where some storms may be severe, but the best risk of severe thunderstorms is to the west of the area.

The weakening cold front will reach the area by Saturday, producing scattered showers and thunderstorms, potentially strong, but the severe weather risk will decrease. High temperatures will remain warm from NYC and further west, reaching the lower to mid 80s.

Next Week: Heat Wave Potential Update

Today's models continued to show signs of a heat wave for next week. An official heat wave is defined as 3 or more consecutive days of 90+ degrees, and for the NYC area, the Monday-Wednesday time frame will be close to a heat wave, if not one. Sunday will begin to slightly warm up, with temperatures reaching the lower to mid 80s away from the coast. Memorial Day will be much warmer, when 850 mb temperatures near, if not slightly over 20c are expected. Combined with mostly sunny skies and a southwest wind, this will result in high temperatures reaching the lower to mid 90s from NYC and further west.

Some models are showing a weak cold front barely dropping into the area on Tuesday before lifting north again. At this time, I do not expect temperatures to cool down by much, if at all. I am expecting warmth to continue with temperatures similar to those on Monday but slightly cooler, reaching upper 80s to lower 90s from NYC and further west. Tuesday's temperatures are still slightly uncertain and are subject to change. As a cold front approaches on Wednesday, temperatures may be slightly warmer before the front moves through, bringing a severe weather risk.

There is some slight uncertainty with the exact temperatures, but locations in the NYC area from NYC and further west are expected to see 90 or more degrees at least once in this 3-day period. Temperatures could get as hot as the mid 90s in the immediate NYC area, and while at this time, upper 90s are not expected in the area, such temperatures are likely to be found further south, towards Washington DC and Virginia. Should the warmer case scenario, with temperatures over 90 degrees each day, this may end up as the area's first heat wave of the year.

Stay tuned for more information on Thursday night regarding Friday's heat/storms and the warm spell for early next week.