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Long Range Forecast Looks Stormy  11/20/2018 3PM

TELE-CONNECTIONS POINT TO A POTENTIAL STORMY PATTERN AHEAD


long range blocking

Weather models overnight continue the trend of the last week as we are now seeing long range blocking developing in  the North Atlantic. The North Atlantic Oscillation is going to be negative to at times strongly negative through the next 2 weeks. We saw this last March for almost 4 weeks which resulted in 4 powerful noreasters. Nothing is exactly the same but the presence of blocking would favor storm systems tracking to our south and east. It also will mean colder than average temperatures in the Eastern US. The signal to watch with this is the Pacific North America index which is forecast to be strongly almost off the wall positive this weekend and peaking early next week. The combination of these two indices point to storminess in the East.  Saturday night into Sunday morning we could see some rain as the cold air pulls out and a weak system moves through. There shouldn’t be much with this and the cold air will be long gone by the time that precipitation gets here.

long range blocking

The upper air for next Sunday illustrates the blocking and how it impacts the jet stream. Higher pressures build in the northern latitudes and lower pressures are to the south. Short wave troughs are forced to move all along against their natural tendency to want to move northeast into Canada and instead are forced to more more to the east.

long range blocking

Watch the map sequence above where the primary low moves out of Missour and heads toward the Eastern Great Lakes. The block forces the energy to the coast and a low develops in Virginia and completely takes over. The GFS has a very amplified look and develops a major rain and wind event for next Monday. The other models have similar ideas but they have a less developed low and hold on to the primary low much longer. This may or may not be correct but it does mean some rain for Monday and it could be substantial if the more amped GFS is correct. One thing we know for sure is that in spite of all the arctic air coming Thursday and Friday it will be long gone before this system arrives.

long range blocking

The blocking pattern has staying power and it is still there as we go out further in time. This will probably create opportunities for more storminess into the first week of December. Cold air is not an issue on Monday but it could become an issue later next week as the cold flow from Canada increases as a surface high builds in Southeastern Canada and attempts to hold in. Since we have already seen an early snowstorm, it will probably be wise to keep an open mind as this pattern develops.

 

THANKSGIVING ARCTIC COLD RECORD LOWS POSSIBLE THURSDAY & FRIDAY

TEMPERATURES REBOUND QUICKLY OVER THE WEEKEND

RAIN SATURDAY NIGHT INTO SUNDAY

thanksgiving arctic cold

This morning we are seeing showers moving away to the northeast as a frontal boundary buckles and a wave of low pressure begins to move to off the coast of Southern New England. Temperatures are in the 40s this morning and we will likely sit in the upper 40s and lower 50s today, depending on whether we get any breaks of sunshine developing this afternoon which is certainly possible. Going forward we can certainly say that there will be no weather related travel problems going into Wednesday which is the peak travel day before the Thanksgiving holiday. Weather in most of the United States looks relatively quiet.

Watching the satellite and radar loops this morning we see the showers thinning out on the western flank and they should be gone off the local radars shortly. We see some breaks in the cloud cover on the satellite loop to the west which bodes well for some breaks of sunshine developing this afternoon.

We don’t see any important changes in the outlook over the next 2 days. Bitter cold arctic air (for this time of year) is going to start arriving on Wednesday. Look for winds to increase as the day wears on and temperatures that will likely hover in the upper 30s and lower 40s and then gradually begin to drop later in the day. There could be a passing snow shower or two as the arctic front goes by. Then it’s down to teens to near 20 Thursday morning.

thanksgiving arctic cold

The big issue for the Macy’s Thanksgiving Day Parade is the wind for the big balloons. Winds will gust to 30 mph or more Thursday morning so this could be an issue. Also if you are going to the parade be prepared to endure temperatures in the low 20s and wind chills in the single digits. At least we will have sunshine and I suspect if you are home the kitchen will be the warmest room in the house.

thanksgiving arctic cold

Temperatures will drop into the teens and single digits at night and then start moderating back to the upper 30s and lower 40s on Friday with plenty of sunshine. The weekend will bring higher temperatures into the 40s Saturday and into the 40s on Sunday as a warm front approaches and low pressure develops to the south of us. Some showers are likely Saturday night into Sunday morning. There will be no cold air around for any frozen precipitation.

NEW YORK CITY AND VICINITY SNOW

https://www.weather.gov/images/okx/winter/StormTotalSnowWeb.png

 

NEW JERSEY & PARTS OF NE PA


https://www.weather.gov/images/phi/winter/StormTotalSnowWeb1.png

SOUTHERN AND SOUTHEAST NEW ENGLAND

http://https://www.weather.gov/images/box/winter/StormTotalSnowWeb1.png

NORTHERN NEW ENGLAND

https://www.weather.gov/images/car/wxmaps/CAR_Snow.png

WESTERN NEW ENGLAND
https://www.weather.gov/images/btv/winter/StormTotalSnowWeb.png

MIDDLE AND UPPER HUDSON VALLEY

https://www.weather.gov/images/aly/winter/StormTotalSnowWeb1.png

CENTRAL NEW YORK & NE PA

https://www.weather.gov/images/bgm/winter/StormTotalSnowWeb1.png

 

EASTERN SATELLITE

storm free

REGIONAL RADAR

storm free

LOCAL RADAR NEW YORK CITY

storm free

LOCAL RADAR PHILADELPHIA

storm free

 

MANY THANKS TO TROPICAL TIDBITS FOR THE USE OF MAPS

Please note that with regards to any tropical storms or hurricanes, should a storm be threatening, please consult your local National Weather Service office or your local government officials about what action you should be taking to protect life and property.