Monday, March 27, 2017

Monday Weekly Weather Summary: Seasonal Week With Severe Weather in Plains

Good morning. Its pretty remarkable how there can be so much transition in one month, but thats what March is all about. We went from an all out winter to an all out spring pattern in a matter of weeks. Sure we could still see the occasional spring snow up in New England but overall thats a wrap.


This week will feature temperatures in the mid 50's with rain today tomorrow and Friday.

The current weather system should clear out area by this afternoon leaving overcast conditions...

Notice the snow over mid to northern Maine. 

Tomorrow, more rain approaches by the mid morning as a low pressure system passes to our west...


Things then clear out for Wednesday and Thursday with sunny skies and highs in the 50's.

The big weather story this week however will be the severe weather in the southern plains. Very warm moist air from the Gulf of Mexico will collide with cooler air approaching from the west due to an upper level trough. This should cause some super cell thunderstorms and potentially tornadoes Wednesday afternoon. You can see model projections below showing the storm popping up especially in TX..


We will keep a close eye on this over the next 24 hrs. 

That is all for now. Thanks for reading. 




Monday, March 20, 2017

Monday: One More Shot of Winter Air This Week

Welcome to the 1st day of Spring! The season is under transition and we will see a lot of back and forth this week to that point. Things will start off more on the seasonable side today and Tuesday with temperatures in the upper 40's to low 50's  with mostly sunny skies.

Winter then gives us another jab however as an arctic air mass arrives Wednesday...



This arctic shot will only bring temperatures into the mid to upper 30's for highs Wednesday and Thursday with lows in the teens. It will feel more like mid-February again not late March.

Warm air however returns on Friday and Saturday with temperatures building back into the 60's by Saturday!

Things then get interesting Saturday night into Sunday as rain moves into the area with potential snow to the north...


I am watching this very closely especially for ski areas. This can be one of the last hurrah's for them. The reason the models are showing snow to the north with this system is due to a high pressure system building in on top of the low pressure from the north. Situations like this usually do produce some snow for New England, especially the ski areas. Further to the south it is highly unlikely anyone sees the frozen stuff.

Thats all for now, thanks for reading. 




Saturday, March 18, 2017

Major Shifts Last Night: Limited Impacts

*Note- I accidentally deleted last night's post. Any comments I can not see or respond to from that time.*


Good morning. Well, that was interesting. Every major model has backed off on anything impactful for today. Just some light snow for spots. We knew how tricky this system was to begin with, but I will say I am suprised with the degree things shifted. Talk about curve balls.

At this time looks like up to an inch maybe locally twi can fall in higher elevations of pa into NNJ. From there, the only consistency I can find is extreme eastern Mass/the Cape seeing accumulating snow. This will have to be watched in real time. 

Systems like this will always be hard to predict. Their features are small scale in nature which means a pin prick of a change in whats modeld has drastic changes in fhe forecast. Who knows maybe there will be a few suprises later today.

Friday, March 17, 2017

Friday Morning: A Closer Look at Tomorrow's Snow Threat

Summary:


  • Light snow moves in tomorrow morning
    • It will be rain to start for areas around I-78 south
  • A heavier band of snow develops Sat afternoon-Night
    • The exact placement of this is very difficult to nail down due to nature of storm system
  • The higher totals on my map are at elevations over 700ft 

Good morning. I have tweaked my map from yesterday regarding tomorrow's snow event. It is extremely difficult to nail down the accumulations with this one due to the fact they will be associated with something called an inverted trough. In simple terms an inverted trough means there will be a narrorw band of heavier snowfall in a localized area. It is almost impossible to the models to nail down the exact location in situations like this.

In any event here is my map. Again, the top range of the totals are for high elevations above 700ft. It is important to remember that. This is a light event for most. 



Light snow moves into the area tomorrow morning. For areas more south of my zones the initial precipitation can be rain. Notice I have marked that the higher end of totals are at higher elevations. That is an important point for this event as temperatures will be marginally cold for snow Saturday. 

Heavier snow should develop on Saturday afternoon into the night as a coastal low takes over. This is where that inverted trough is supposed to develop to produce the heaviest band. At this time it looks like NNJ into Southeastern New England has the best chance of getting in on that band. There will be localized heavy amounts (5"+) depending on who is in the best spot.

Looking at the models, light snow moves in tomorrow morning as a warm front associated with the approaching low moves moisture into the area...


Notice the rain and snow in NJ to my point above. This initial batch should not cause much in terms of accumulations except for higher elevations. 

A costal low then takes over on Saturday night...



This is where the heavier snowfall should develop in my highlighted zones. You can see the next frame of this progression below...


Notice how this model doesn't have much snow up in SE New England. Other models do however...



Again, that heavier band of snow you see above (darker blue) is caused by the inverted trough. You an see an inverted trough on an upper air map by a kink in the height lines...



Where ever this sets up gets the most snow. I can guarantee you one thing with this system, some will be disappointed.

More later. 

Thursday, March 16, 2017

No Post Tonight, Tomorrow AM Update

No changes to thoughts from this morning. Will evaluate updates to the Saturday into possibly Sunday morning snow threat for my highlighted area in the morning. 

Thursday Morning: More Snow on Tap Saturday

Thats right, that pesky little disturbance I mentioned yesterday looks like it want to produce on Saturday. 

The disturbance moves into our region early Saturday morning from the north...

This should cause snow to fall from I-78 north into New England. As this disturbances intensifies, low pressure looks to develop off the coast Saturday afternoon...


This is the tricky part, the exact placement of the heavy band of precip/snow is going to be tough to nail. We have evidence of something called an inverted trough that can develop. These are known for producing a narrow band of heavy snowfall. The model above shows it developing of NNJ into SE NE later on Saturday afternoon. However, other models vary with its placement.

My first estimate of what this system can produce is below....


I will update this map tomorrow morning as necessary.  It may be March, but the weather pattern we are in is more like early February. The weather will always surprise you. 

More later tonight, be sure to check in. 

Wednesday, March 15, 2017

Wednesday Morning: The Aftermath

Good morning. Our storm is now over, and we can evaluate what happened and why. It is no secret that the snowfall amounts did not live up to expectations around the I-95 but lets take a look at final outcome...

Vs my final forecast...



VS my initial impact map made Friday...



You can see my error was not to bring the 4-8 (light blue zone) further north. In reality it should have be touching the red zone. The red zone overall actually made out well. I reported 16" at  my location  in NW NJ and areas further north and west did see up to a 2 feet and locally more.  We discussed the risk in my video discussions of the I-95 but I was surprised how quickly that warm air moved in yesterday morning.

The crazy thing is (not to make excuses) every major model had all snow for I-95 except for the NAM. Hard to just ride one model into the sunset when making a forecast. However, the one red flag was the temperature profile of the upper atmosphere. Even tho most models had all snow, the margin was so thin that any slight adjustment would bring just enough warm air into the mix to cause sleet.  Thats exactly what happened. Our storm center formed about 30 miles more west than expected and well the rest is history. Places near I-95 were literally right on the edge the whole time which is why snow and sleet kept interchanging.

So moving on, today is cold and blustery (will feel like Feb) with blowing snow and snow showers moving through later..


This is due to the upper level low associated with yesterdays storm moving through...



The colder than normal air will be around at least the next 5 day. This weekend we have to watch the shot for some light to maybe moderate snow as a storm system dives down from the NW. If this system redevelops on the coast we could have an issue but thats not my forecast at this time. New England would be the focus anyway.

Thanks for all the interactions yesterday.