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OBS-NOWCAST Significant rain event of Sunday Feb 28-Monday March 1 with a burst of wind driven polar chilled flurries Monday night


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Monday morning March 1 625AM Update: Good to see the sleet obs yesterday in our distant nw suburbs. 
 
Below restates what is obviously modeled and discussed in prior days updates: I moved the timing up an hour and changed the title to add OBS-NOWCAST as well.  Will have summary maps of rain, any snowfall, and possibly wind gusts 45+ in tomorrow's (Tuesday) 10AM wrapup-review. 
 
Tonight 7PM/1 -3AM/2. Turning sharply colder with bands of flurries and snow showers causing a few areas of hazardous travel as temps fall from near freezing at 7PM to between 5 and 15 above by dawn Tuesday I84, and near 20 NYC, along with gusty northwest winds 35-45 MPH and wind chill down just below zero. Most areas only flurries, but a half inch of snow is possible a few locations ne PA, extreme nw NJ and especially se NYS, CT and maybe even e LI. A wind advisory is posted with NYC wind chill close to zero at sunrise Tuesday.
 
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650A Sunday/28:  Ttile dropped snow from the snow to rain scenario. Significant 21 hour rainfall (1/2" I84 to 3/4-1.5" NJ/LI) this afternoon into Monday mid morning with snowmelt but not enough for a problem. Could see the need for something water related a part of urban ne NJ by Monday morning? Dense fog possible tonight with mild moist air over chilly ground. I think there will be spotty icing highest peaks of the Poconos/Catskills/Litchfield Hills this afternoon-tonight but no significant treated road problem. Small chance that rain ends as wet snow forenoon Monday I84 high terrain with little or no impact, if it does end as snow.  

Monday evening from roughly 8P -4A Tuesday, flurries likely to near NYC with a band or two of snow squalls CT/NYS/ne PA and possibly extreme nw NJ that could coat roads with a hazardous 1/2" accumulation in 30 minutes, along with gusty northwest winds to near 45 MPH, a few minutes of reduced visibility under 1/2mile and icy roads due to temps plummeting from near freezing at 8PM to the teens by dawn Tuesday (20-22F NYC?) and wind chill near zero CT/NYS/PA.  We'll see if the models back off but from what i can tell, the early GFS op (V15) has been onto this from many days ago, much more so than any other model. NYC either no snow or a Trace of flurries.  Some of the modeling suggests a band of squalls crosses from CT through e LI later Monday night. 

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655A Saturday/27:  Coming to the end of this thread... that may end with a noticeable bang.  Definitely a significant rainfall (1/2"or more) Sunday into Monday morning with snowmelt but not enough for a problem. Dense fog possible Sunday night with mild moist air over chilly ground. Chance that rain ends as wet snow forenoon Monday I84 high terrain with minuscule impact.  However,  Monday evening from roughly 8P -4A Tuesday, flurries likely to near NYC with a band or two of snow squalls CT/NYS/ne PA and possibly extreme nw NJ that could coat roads with a hazardous 1/2-1" accumulation in an hours time, along with gusty northwest winds to near 45 MPH, a few minutes of reduced visibility under 1/2mile and icy roads due to temps plummeting from near freezing at 8PM to the teens by dawn Tuesday (20-22F NYC?) and wind chill near zero CT/NYS/PA.  We'll see if the models back off but from what i can tell, the early GFS op (V15) has been onto this from many days ago, much more so than any other model. Bluewave detailed elsewhere in the March thread. 

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Good Friday morning everyone, Feb 26: Focus is mainly the I84 corridor. The Adirondacks are reserved for the last pgh.
1201AM-10AM Saturday (27th). A 1-4 hour period of showery wet snow-sleet will probably occur from the Baltimore area northward across the I-84 corridor early Saturday. There even could be spotty freezing rain? Minor-short duration impact, at worst, reserved primarily higher terrain where an inch or 2 is possible in the Poconos. Elsewhere for the I84 corridor, inclusive of nw NJ, expect a Trace-3/4"; Baltimore-Phildelphia urban centers a Trace. A quick change to rain occurs shortly after onset, except that change to rain in the Poconos and northwest hills of CT may not occur til ~ 10AM Saturday. Melting all surfaces once the change to rain has occurred. Most may not notice the snow if sleeping.
Late Sunday the 28th-Monday March 1: I84 corridor. Uncertain but probably not a significant problem. Complex rain (spotty ice) possibly end as snow event. Any icy weather Sunday evening the 28th is reserved for the Poconos. Precipitation may end briefly as snow the rest of I84 corridor Monday morning March 1? So far, models say proceed with normal life with significant wintry weather unlikely.
Monday night March 1 I-84 corridor---near midnight: A strong cold frontal passage may be accompanied by a dusting to 1/2" of snow. If this occurs, the sudden drop in temps with the snowfall would make it slippery.
March 3-6: Uncertain modeling continues to suggest a wintry event that may include several inches of hazardous snow for the I84 corridor northward? Some models have no storm, so nothing to be sure of.
Adirondacks: Please follow local forecasts: snow showers or flurries this morning. A period of snow Saturday changes to rain. A period of rain or ice is possible Sunday. Then, a refreshing of accumulative snow late Monday followed by a polar plunge Monday evening. March 3-6--- uncertain but seems like a period of snow in there somewhere.
The second week of March, especially after the 7th... looks rather mild. 615A/26

 

Friday 517PM/26 update: 

517PM Friday: seems to be getting slightly more interesting for ice and snow distant nw-ne suburbs.  

First: GFS v15 looks like, (barring a complete fade within 4 days) the winner regarding  the intensity of this cold shot Monday night.  

Second: Unclear to me whether it warms much above freezing high terrain near I84 Sunday and I can see smidge of ice there. 

Third: Chance of dense snow eating fog late Sunday?

Fourth: Modeling from both the GFS V15 and 16 has started showing more minor snow shower/flurry action Monday, on the backside of Sundays rain (and dense fog by night?).  And 18z/26 GFS modeling is moving flurries down to near LI sound later Monday night with the strong polar cold front that looks like it may have gusts near 45 MPH drilling sharply colder temps into NYC.  Will revisit Sunday morning.

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Friday 638AM update:  Am still not convinced that this event will be insignificant but it's heading to a possibly wrongs-wasted thread.  We do know it's going to rain and potentially pretty hard for a time on Sunday with precipitation lingering into Monday morning.  Evolution has not yet permitted cold enough air to return, allowing for precip to change to snow Monday.  Of concern to all who favor the GFSv16 implementation, is the still far different modeling between the V16 and the current operational V15.  V15 in my opinion seems to have a pretty good chance of prevailing with it's polar cold frontal passage Monday night, flurries or snow showers possible down to NYC with plunging temps well down into the 20s in NYC (maybe ~22?).
 
Meanwhile late Sunday the 28th-Monday March 1: I84 corridor. Uncertain but probably not a significant problem. Complex rain (spotty ice) possibly end as snow event. Any icy weather Sunday evening the 28th is reserved for the Poconos. Precipitation may end briefly as snow the rest of I84 corridor Monday morning March 1? So far, models say proceed with normal life with significant wintry weather unlikely.
 
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Thursday morning  (25) 659AM update:   Modeling and WPC is coming up on qpf for Sunday and there may be lingering Monday morning at the least.  I have not crossed this thread off as a bust for the I84 corridor.   No excuses.  I still think it's on the boards and what I do think I know is that decent qpf is coming the 28th. 

Late Sunday the 28th-Monday March 1: I84 corridor. Uncertain but probably not a significant problem. A complex rain (spotty ice) possibly change to snow event. Any wintry weather Sunday evening the 28th is reserved for the Poconos. It could spread across the rest of I84 corridor by Monday morning March 1, but for now models say proceed with normal life.  As you know, GFS modeling is drifting away from its excessive cold outbreak Monday night and leaves the door open for a little more than meets the eye (so far). I might be completely wrong for this period, regarding a wintry event occurrence but the door for me, is not yet closed. 
 
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Wednesday  morning 655 AM update:  Title remains unchanged.  May need to add a bit of ice for the interior in future reviews.  Multiple model ensemble reviews of the 00z/24 cycle and 06z/24 GFS and V16 op reviews. 

Late Sunday the 28th-Monday March 1: I84 corridor. Still uncertain. A complex potential significant rain to snow event. Any wintry weather Sunday evening the 28th is reserved for the Poconos. It could spread across the rest of I84 corridor by Monday morning March 1 with significant hazardous high terrain accumulations of several inches I84 itself northward, while much less impact in the valleys below 700 feet elevation (Hartford, Poughkeepsie, Scranton). A shot of notably cold air follows Monday night (but not the GFS op ferocity which doesn't have much support).  This for me is the 00z/24 consensus from NAEFS and 06/24 V16.  Definitely not buying the GFS powerful cold shot preempting an event. I could be wrong but I see enough cold air seeping into the backside of whatever comes out of the Ohio Valley to make for a snow risk. It could even snow down to LI/I78 at the tail end (low chance for now, but a window that needs to remain open).  It's complex and details remain tbd. It's possible I've read too much into this thread??  Considerations include WPC continues rather dry and very little wintry weather risk. 

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624A/23 - Tuesday: Incorporates modeling of ensembles through 00z/23, and op models through 06z/23. Maintain patience. A significant event is probably coming including some snow for I84 and possibly  to NYC's immediate n/w suburbs. EPS/GEFS trending a fairly significant decline in AO/NAO first couple of days in March (think this an EPS concession to the GEFS, as i recall). GEFS has significant snow for the Virginias on the 2nd.  That is a sign something is coming, with latitude axis of snowfall in doubt. I favor further north, per NAEFS.  Also, the 06z/23 GFS op not given any weight in my thinking since its prediction for the NYC 1000-500MB thickness 06z/2 is 240 m less than the V16. (504 op vs V16 528 for NYC).  Sensitivity between northern southern stream interactions is probably messing up solutions and so uncertainty. It either snows a bit late 28, or what i think is more likely is some snow late March 1-morning 2.  EC wants to snow the 3rd.  Therefore, no change in thread. 

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646A/22: May extend the title to 3P March 2 in the updated post tomorrow morning, otherwise, despite some dry modeling, I think we're on track for a significant event, some of it wintry, especially I84 corridor. Details TBD but it looks to me like a warmer wet prelim event late 28-early March 1, then some cooling and a change to snow from north to south late March 1 or early March 2. If its the standard CFP with low north of our forum, then no snow LI, but if it's two waves of low pressure, then the fun of the challenging forecast.  I can definitely see 4" of snow in the northwest part of the forum for this complicated event. Not saying 4" will happen but definitely potential. 

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550A/21: No change to thread (for me). Model variability. By and large looks too warm for more than 1" of snow/sleet NYC-LI-s of I78, if any at all. Modeling does have an option for heavy qpf, snow/sleet/freezing rain to rain, end as snow especially I84 corridor.  Not saying that will happen, but I think that option is realistic instead of the all warm-wet Great Lakes inside runner scenario. It's complicated and if necessary in a day or two may need to change the primary end date to March 2, as optioned in the initial thread. Also, for now no flood threat due to snowmelt/qpf, if that warm heavy qpf option comes to pass as the primary reality.  That flood threat insert for me, has to wait 3 more days before throwing in the towel on my primary concern for wintry elements. Finally, that closed low option continues (06z/21 V15 ballistic, V16 not).  Will monitor successive GEFS 6 hour member cycles as seen on http://www.meteo.psu.edu/~fxg1/ENSHGTAVGNH_0z/ensloopmref.html

Any questions and I can guide us thru this. Just use your cursor to slide over the hours from L to R and not only monitor the mean, but the spaghetti, which for me is crucial to understanding future model options. 

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330P/20: 12z/20 EPS GEFS diverge with the Canadian GEPS favoring too warm for snow I80 south but that can change in 9 days.  What does seem apparent is that there will be strong WAA into the top of the ridge, which can allow snow at warmer than expected 1000-500MB thicknesses due to marginal column temp for phase change to rain.  Also, there have been some GEFS members trying to close off a low over the forum (too little-too late  & too far north?).  While that type of deepening is not predominant now, it seems worthy of monitoring daily trends.  One of my concerns is that LR modeling in the 6-10 day range has yielded colder results recently, than what we would have thought beyond D5. 12z/20 modeling also indicates a healthy qpf event of 1/2 to possibly 1".  

This event is focused on the 28th-1st, but not impossible to see it begin late 27 or end on Mar 2. . 

Only 1 graphic for a couple of days. 

Screen Shot 2021-02-20 at 3.23.04 PM.png

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550A/21: No change to thread (for me). Model variability. By and large looks too warm for more than 1" of snow/sleet NYC-LI-s of I78, if any at all. Modeling does have an option for heavy qpf, snow/sleet/freezing rain to rain, end as snow especially I84 corridor.  Not saying that will happen, but I think that option is realistic instead of the all warm-wet Great Lakes inside runner scenario. It's complicated and if necessary in a day or two may need to change the primary end date to March 2, as optioned in the initial thread. Also, for now no flood threat due to snowmelt/qpf, if that warm heavy qpf option comes to pass as the primary reality.  That flood threat insert for me, has to wait 3 more days before throwing in the towel on my primary concern for wintry elements. Finally, that closed low option continues (06z/21 V15 ballistic, V16 not).  Will monitor successive GEFS 6 hour member cycles as seen on http://www.meteo.psu.edu/~fxg1/ENSHGTAVGNH_0z/ensloopmref.html

Any questions and I can guide us thru this. Just use your cursor to slide over the hours from L to R and not only monitor the mean, but the spaghetti, which for me is crucial to understanding future model options. 

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As of general 12z/22 modeling: doesn't look as promising for snow on the 28th, daytime 1st. The night of the 1st or on the 2nd, it's possible I84?  There are some changes occurring in the modeling with the southern trough dragging a bit.  Will revaluate more fully tomorrow morning.  Atmosphere needs to figure out what it wants to do. Definitely not cashing in. 

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624A/23 - Tuesday: Incorporates modeling of ensembles through 00z/23, and op models through 06z/23. Maintain patience. A significant event is probably coming including some snow for I84 and possibly  to NYC's immediate n/w suburbs. EPS/GEFS trending a fairly significant decline in AO/NAO first couple of days in March (think this an EPS concession to the GEFS, as i recall). GEFS has significant snow for the Virginias on the 2nd.  That is a sign something is coming, with latitude axis of snowfall in doubt. I favor further north, per NAEFS.  Also, the 06z/23 GFS op not given any weight in my thinking since its prediction for the NYC 1000-500MB thickness 06z/2 is 240 m less than the V16. (504 op vs V16 528 for NYC).  Sensitivity between northern southern stream interactions is probably messing up solutions and so uncertainty. It either snows a bit late 28, or what i think is more likely is some snow late March 1-morning 2.  EC wants to snow the 3rd.  Therefore, no change in thread. 

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Wednesday  morning 655AM update:  Title remains unchanged.  May need to add a bit of ice for the interior in future reviews.  Multiple model ensemble reviews of the 00z/24 cycle and 06z/24 GFS and V16 op reviews. 

Late Sunday the 28th-Monday March 1: I84 corridor. Still uncertain. A complex potential significant rain to snow event. Any wintry weather Sunday evening the 28th is reserved for the Poconos. It could spread across the rest of I84 corridor by Monday morning March 1 with significant hazardous high terrain accumulations of several inches I84 itself northward, while much less impact in the valleys below 700 feet elevation (Hartford, Poughkeepsie, Scranton). A shot of notably cold air follows Monday night (but not the GFS op ferocity which doesn't have much support).  This for me is the 00z/24 consensus from NAEFS and 06/24 V16.  Definitely not buying the GFS powerful cold shot preempting an event. I could be wrong but I see enough cold air seeping into the backside of whatever comes out of the Ohio Valley to make for a snow risk. It could even snow down to LI/I78 at the tail end (low chance for now, but a window that needs to remain open).  It's complex and details remain tbd. It's possible I've read too much into this thread??  Considerations include WPC continues rather dry and very little wintry weather risk. 

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Thursday morning  (25) 659AM update:   Modeling and WPC is coming up on qpf for Sunday and there may be lingering Monday morning at the least.  I have not crossed this thread off as a bust for the I84 corridor.   No excuses.  I still think it's on the boards and what I do think I know is that decent qpf is coming the 28th. 

Late Sunday the 28th-Monday March 1: I84 corridor. Uncertain but probably not a significant problem. A complex rain (spotty ice) possibly change to snow event. Any wintry weather Sunday evening the 28th is reserved for the Poconos. It could spread across the rest of I84 corridor by Monday morning March 1, but for now models say proceed with normal life.  As you know, GFS modeling is drifting away from its excessive cold outbreak Monday night and leaves the door open for a little more than meets the eye (so far). I might be completely wrong for this period, regarding a wintry event occurrence but the door for me, is not yet closed. 
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Friday 638AM update:  Am still not convinced that this event will be insignificant but it's heading to a possibly wrongs-wasted thread.  We do know it's going to rain and potentially pretty hard for a time on Sunday with precipitation lingering into Monday morning.  Evolution has not yet permitted cold enough air to return, allowing for precip to change to snow Monday.  Of concern to all who favor the GFSv16 implementation, is the still far different modeling between the V16 and the current operational V15.  V15 in my opinion seems to have a pretty good chance of prevailing with it's polar cold frontal passage Monday night, flurries or snow showers possible down to NYC with plunging temps well down into the 20s in NYC (maybe ~22?).

Meanwhile late Sunday the 28th-Monday March 1: I84 corridor. Uncertain but probably not a significant problem. Complex rain (spotty ice) possibly end as snow event. Any icy weather Sunday evening the 28th is reserved for the Poconos. Precipitation may end briefly as snow the rest of I84 corridor Monday morning March 1? So far, models say proceed with normal life with significant wintry weather unlikely.

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517PM Friday: seems to be getting slightly more interesting for ice and snow distant nw-ne suburbs.  

First: GFS v15 looks like, (barring a complete fade within 4 days) the winner regarding  the intensity of this cold shot Monday night.  

Second: Unclear to me whether it warms much above freezing high terrain near I84 Sunday and I can see smidge of ice there. 

Third: Chance of dense snow eating fog late Sunday?

Fourth: Modeling from both the GFS V15 and 16 has started showing more minor snow shower/flurry action Monday, on the backside of Sundays rain (and dense fog by night?).  And 18z/26 GFS modeling is moving flurries down to near LI sound later Monday night with the strong polar cold front that looks like it may have gusts near 45 MPH drilling sharply colder temps into NYC.  Will revisit Sunday morning.

 

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655A Saturday/27:  Coming to the end of this thread... that may end with a noticeable bang.  Definitely a significant rainfall (1/2"or more) Sunday into Monday morning with snowmelt but not enough for a problem. Dense fog possible Sunday night with mild moist air over chilly ground. Chance that rain ends as wet snow forenoon Monday I84 high terrain with minuscule impact.  However,  Monday evening from roughly 8P -4A Tuesday, flurries likely to near NYC with a band or two of snow squalls CT/NYS/ne PA and possibly extreme nw NJ that could coat roads with a hazardous 1/2-1" accumulation in an hours time, along with gusty northwest winds to near 45 MPH, a few minutes of reduced visibility under 1/2mile and icy roads due to temps plummeting from near freezing at 8PM to the teens by dawn Tuesday (20-22F NYC?) and wind chill near zero CT/NYS/PA.  We'll see if the models back off but from what i can tell, the early GFS op (V15) has been onto this from many days ago, much more so than any other model. Bluewave detailed elsewhere in the March thread. 

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650A Sunday/28:  Ttile dropped snow from the snow to rain scenario. Significant 21 hour rainfall (1/2" I84 to 3/4-1.5" NJ/LI) this afternoon into Monday mid morning with snowmelt but not enough for a problem. Could see the need for something water related a part of urban ne NJ by Monday morning? Dense fog possible tonight with mild moist air over chilly ground. I think there will be spotty icing highest peaks of the Poconos/Catskills/Litchfield Hills this afternoon-tonight but no significant treated road problem. Small chance that rain ends as wet snow forenoon Monday I84 high terrain with little or no impact, if it does end as snow.  

Monday evening from roughly 8P -4A Tuesday, flurries likely to near NYC with a band or two of snow squalls CT/NYS/ne PA and possibly extreme nw NJ that could coat roads with a hazardous 1/2" accumulation in 30 minutes, along with gusty northwest winds to near 45 MPH, a few minutes of reduced visibility under 1/2mile and icy roads due to temps plummeting from near freezing at 8PM to the teens by dawn Tuesday (20-22F NYC?) and wind chill near zero CT/NYS/PA.  We'll see if the models back off but from what i can tell, the early GFS op (V15) has been onto this from many days ago, much more so than any other model. NYC either no snow or a Trace of flurries.  Some of the modeling suggests a band of squalls crosses from CT through e LI later Monday night. 

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Monday morning March 1 625AM Update: Good to see the sleet obs yesterday in our distant nw suburbs. 
 
Below restates what is obviously modeled and discussed in prior days updates: I moved the timing up an hour and changed the title to add OBS-NOWCAST as well.  Will have summary maps of rain, any snowfall, and possibly wind gusts 45+ in tomorrow's (Tuesday) 10AM wrapup-review. 
 
Tonight 7PM/1 -3AM/2. Turning sharply colder with bands of flurries and snow showers causing a few areas of hazardous travel as temps fall from near freezing at 7PM to between 5 and 15 above by dawn Tuesday I84, and near 20 NYC, along with gusty northwest winds 35-45 MPH and wind chill down just below zero. Most areas only flurries, but a half inch of snow is possible a few locations ne PA, extreme nw NJ and especially se NYS, CT and maybe even e LI. A wind advisory is posted with NYC wind chill close to zero at sunrise Tuesday.
 
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First wind gusts I've seen 40kt or greater nearby to our northwest, in the previous hour ending around 4PM. 

 

KALB: Albany, Albany Intl Arpt, United States [44kt, 23m/s]

KBFD: Bradford, Bradford Regional Airport, PA, United States [40kt, 21m/s]

KELZ: Wellsville, Wellsville Municipal Airport, NY, United States [40kt, 21m/s]

KPSF: Pittsfield, Pittsfield Municipal Airport, MA, United States [41kt, 21m/s]

KSWF: Newburgh / Stewart, NY, United States [40kt, 21m/s]

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We popped 40* for a little bit this afternoon but then the wind came up and it dropped right back down. It's really windy out there now, garbage is blowing out of melting snowbanks and blowing all over Rt 6. The roads are super wet in a lot of places as the snow is melting back, when that freezes later it's gonna be sketchy!

38/25/W10G18/Partly cloudy

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