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our first nudge towards autumn comes thursday through friday


earthlight

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I still don't think the official ob station is getting below 50, but I may eat crow on this one. The one thing that's a bit bothersome is that models are kind of slowing the clearing a bit. Interior areas will have more time to radiate. But I do agree with the thoughts on the winds---they won't be calm--but they won't be howling either. Interestingly, most guidance picks up the NW winds again Friday afternoon and they become more gusty.

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I still don't think the official ob station is getting below 50, but I may eat crow on this one. The one thing that's a bit bothersome is that models are kind of slowing the clearing a bit. Interior areas will have more time to radiate. But I do agree with the thoughts on the winds---they won't be calm--but they won't be howling either. Interestingly, most guidance picks up the NW winds again Friday afternoon and they become more gusty.

Winds are pretty strong.

With wind forecasts I always look at marine weather.

For the western LI sound:

Today...SW winds 5 to 10 kt...becoming W early this afternoon... Then becoming NW 15 to 20 kt with gusts up to 30 kt late. Seas 1 ft or less...then 2 to 3 ft this afternoon. A slight chance of showers with isolated tstms late this morning. Showers likely with isolated tstms this afternoon.

Tonight...NW winds 15 to 20 kt with gusts up to 30 kt. Seas 2 to 3 ft. Showers likely in the evening.

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I agree. The High won't be overhead so the winds will doubtfully go calm and most likely be above 10mph throughout the night with the ensuing CAA. This allows for more uniform temps across the board, and if the suburbs are getting into the 40s, NYC will not have a problem doing so as well into the upper 40s. I would even reason that tonight will be cooler than Friday night, IN THE CITY; By then the winds will be calm with the high crossing over, for more ideal radiational cooling (which the city does not do so well this time of year), suburbs are a different story, but tonight I'd have to go with the greater possibility of 40s in NYC.

Need to be a bit careful about the timing of the CAA though.. If you look, much of the major CAA is actually through by this evening. Thickness values and 850 mb temps level off during much of the night. The more forceful CAA takes place over northern New England. Per Upton's latest discussion, they see NYC metro having lower 50's tonight:

SHOWERS TAPER OFF FROM W TO E TONIGHT AS STRONG CANADIAN HIGH PRES

BUILDS OVER THE GREAT LAKES. WINDS GRADUALLY DIMINISH TONIGHT

ALTHOUGH SHOULD REMAIN STRONG ENOUGH TO INHIBIT RADIATIONAL

COOLING CONDITIONS. NONE-THE-LESS TEMPS WILL BE 10-15 DEGREES COOLER

THAN NORMAL DROPPING INTO THE 40S ACROSS MUCH OF THE TRI-STATE

AREA. COULD SEE SOME UPPER 30S IN EXTREME NW ZONES AND LOWER 50S

IN THE NYC METRO AREA.

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Tonight should be several degrees cooler than tomorrow night in the city. Sfc high pressure will be almost directly overhead tomorrow night, which is more ideal for suburbia, but less conducive to cooling in NYC proper. Generally you like to see a light/moderate N wind for maximum cooling in the park (even the stronger northerly winds tend to chill the city pretty good). Tonight looks like we'll have decent north winds, so plenty of advection from nern suburbs. With that said, I don't think 850's are cold enough to support mid 40s in the city (they're cold enough to support 40-45 in NNJ, locallized 30s), but my best guess right now is they do fall under 50F by a little, 48-49F should do it.

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I still don't think the official ob station is getting below 50, but I may eat crow on this one. The one thing that's a bit bothersome is that models are kind of slowing the clearing a bit. Interior areas will have more time to radiate. But I do agree with the thoughts on the winds---they won't be calm--but they won't be howling either. Interestingly, most guidance picks up the NW winds again Friday afternoon and they become more gusty.

if someone is going to radiate, it will end up being a list minute deal for sure.. the gradient really doesn't let up until close to 12Z.. tomorrow night.. definitely a different story.. High is centered close to us so we should have much more disparity in low temp ranges on Friday night.

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Need to be a bit careful about the timing of the CAA though.. If you look, much of the major CAA is actually through by this evening. Thickness values and 850 mb temps level off during much of the night. The more forceful CAA takes place over northern New England. Per Upton's latest discussion, they see NYC metro having lower 50's tonight:

this is correct and you can see the 10m winds in response are less than 10 kts at 06z. that's not too bad for radiating at all with clear skies being advertised on the cloud cover maps after 06z as well.

http://www.meteo.psu.edu/~gadomski/ETAPA_12z/f21.gif

but notice how the winds increase again tomorrow afternoon...not atypical at all to the morning after a big cold frontal passage and nw flow

http://www.meteo.psu.edu/~gadomski/ETAPA_12z/f27.gif

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Tauntan severely underestimated the surge of warm air before the frontal passage. Their zone forecast for Boston has temps holding steady in the low 70's. They just spiked 5 degrees in the last hour and are sitting at 81.. it'll be even more of a shell shock for them as they had a chance to warm up a bit before the front comes through.

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GFS MOS takes it right to 50 Friday am.

http://www.nws.noaa....mav.pl?sta=KNYC

I don't know about the NYC area, but I can tell you that Albany GFS MOS has been busting 5 degrees too low all week. I am playing in an Albany forecasting contest and GFS MOS is one of the opponents and it has been missing the mark on night time lows.. That might not be the case in NYC though. I really haven't checked.. but just sayin'

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I don't know about the NYC area, but I can tell you that Albany GFS MOS has been busting 5 degrees too low all week. I am playing in an Albany forecasting contest and GFS MOS is one of the opponents and it has been missing the mark on night time lows.. That might not be the case in NYC though. I really haven't checked.. but just sayin'

Yeah,we'll have to see how it performs with a strong cold frontal passage.It's very close to the NAM 2m T's.

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Tauntan severely underestimated the surge of warm air before the frontal passage. Their zone forecast for Boston has temps holding steady in the low 70's. They just spiked 5 degrees in the last hour and are sitting at 81.. it'll be even more of a shell shock for them as they had a chance to warm up a bit before the front comes through.

Shirley, NY has also hit 80 degrees Fahrenheit.

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