High pressure will be building into the area from Kentucky as we head into the weekend.  Very little cloud cover expected with temps during the day around 50 and overnight low temps in the low 30s.  The wind will average west/northwest around 10-15 mph.  Boaters should be able to get out and enjoy the water with all advisories cancelled by the weekend.

With the very dry air in place this weekend, yards and playgrounds should begin to dry out nicely before more rain and showers arrive Monday afternoon.

Meteorologist Jon Cash

Another shot of cold air from Canada will begin to invade the area early next week.  At the same time shots of moisture will attempt to move in from the west or the southwest.  The key to the forecast later next week is where that moisture comes from.  If it comes from the southwest it will make it here and attempt to mix with the cold air from the north.  If it comes more from the west the moisture will be limited and most likely evaporate before making it across the mountains.

The upshot is there is more cold and possibly stormy weather on the way for late February and early March.  Stay tuned!

Meteorologist Jon Cash

So far in 2010 we have officially received 8.3 inches of snow at the Norfolk Airport.  Inland and northern spots have had more.  To put this into perspective, the average snowfall for the season is around 7 inches.  Why does it seem so abnormal with the snow around this year?  Simple!  We have been in a snow drought for the past 5 years.  Winter after winter has passed with nothing more than a trace here and a trace there.  This year has been different but not that abnormal.

In the past 130 years more than 30-40 seasons have seen more than ten to fifteen inches of snow at the Norfolk Airport.  So in perspective…this season has been nothing more than slightly above normal.

Meteorologist Jon Cash

The jet stream will be moving in a “zonal” pattern for the next five days leading to dry weather.  A zonal jet stream moves from west to east across the United States of America.  This does not allow moisture to come out way from the Gulf of Mexico or the Atlantic Ocean…hence the dry forecast.

The pattern for next week is a bit fuzzy right now so it’s certainly too early to say the snowstorms are over with.  Stay tuned…it can snow around here anytime in March!

Meteorologist Jon Cash

A large upper level low will push through northern Virginia tonight.  This places our area on the warmer and weaker side of this low pressure system.  This means rain showers will overspread the area late today and this evening.

The temps in the clouds (around 5000 feet) will be below freezing so the prec. will actually fall as snow but will melt before hitting the surface.  With this storm so far north the amount of rain that does fall will be under a quarter or even a tenth of an inch.  Colder air will rush into the area just as the showers end.

Snow is expected in northern and western Virginia with an inch or two in D.C. and one to three inches in the Valley.

Meteorologist Jon Cash

For the past four days the computer models have been misjudging the location of an area of low pressure that has been moving from Southern California through the deep south and into the Gulf of Mexico.  Each new run of the models brings it a tad bit more north increasing our shot of snow again for Saturday.

The key to the movement of this low (located near the Florida Panhandle) is the movement and strength of some upper level energy (vorticity max or trough) that is dropping down from the Dakotas.   This is the “kick” that will move the surface low which in turn will affect how much snow we get.

Because the models have handled this so poorly in the past couple of days, the current forecast snow amounts could quickly change as the location and strength of the low becomes clearer.  Amounts could be adjusted up or down depending on the “kicker” vorticity max dropping down toward the southeast coast.

At this point the numbers look like this.

2-4″ Outer Banks…highest amounts south

1-3″ in Carolina…highest amounts east

A dusting to an inch in the metro…highest amounts near the border and coast.

Stay tuned!

Meteorologist Jon Cash

The pattern is set.  Get ready for more wintry weather the next couple of weeks.  The southern jet stream continues to be very active with systems crashing into Southern California and moving through the deep south and either pushing just south of us or heading straight into the area.  This provides the moisture for the heavy rain and heavy snows we have seen this winter.  The northern part (polar) of the jet stream is rising deep into western Canada (causing a snow drought for the Olympic Games) and then heads south from Canada into the deep south and southeast.  This is why it has been so cold lately.

This cold, wet, stormy pattern is not rare in the Mid-Atlantic area for a week or two…but it is unheard of for an entire season.  While Hampton Roads has been spared the worst of the snow…I would be surprised if we did not see at least 3-5 more chances of snow this month.  Simply put…it will keep happening until this pattern changes…

Meteorologist Jon Cash

Bands of heavy snow showers have left the metro area covered in anywhere from a dusting to two inches of  the white stuff.  With the snow heavier than expected (creating evaporative cooling)…the temps have dropped more than forecast leaving many roads either slick or snow-covered.  Extra caution needed today…especially during the morning hours.

The upper level low moving across the state will bring another chance of snow flurries and snow showers later this afternoon and evening but this should not be as heavy as what we experienced this morning.

Meteorologist Jon Cash

Bands of heavy snow showers have left the metro area covered in anywhere from a dusting to two inches of  the white stuff.  With the snow heavier than expected (creating evaporative cooling)…the temps have dropped more than forecast leaving many roads either slick or snow-covered.  Extra caution needed today…especially during the morning hours.

The upper level low moving across the state will bring another chance of snow flurries and snow showers later this afternoon and evening but this should not be as heavy as what we experienced this morning.

Meteorologist Jon Cash

An unusually strong upper level low pressure system in the jet stream level (around 20,000 feet) is the key to how much snow you get in your city.  The rule of thumb is rather simple for meteorologists.  The accumulating snow occurs along and north of the upper level low vorticity max.  This system is easily seen on current satellite images and is better seen on what we call “water vapor” loops.

The forecast is for this low to drop down from southwest VA toward Raleigh and then across Northeastern N.C. to a location near Knotts Island late today.  So draw a line from those locations northward and that’s where the snow will fall and stick.  The second rule to remember is the heaviest snows usually occur 40-100 miles north of the upper low track.  So I am expecting 1-3″ on the southside, 2-4 inches on the peninsula, 3-7 inches middle peninsula, northern neck and the northern part of the Eastern Shore.  Carolina will receive lesser amounts with little or none on the Outer Banks.

If the track of that low shifts even a bit…that can alter snowfall amounts and drastically impact travel for the better or worse depending on your location.  At this point it would be safe if everybody was home by 10-11am on the peninsula and 11am-12pm on the southside.

Meteorologist Jon Cash