Saturday, October 31, 2009

Forecast This Evening

6 PM: Isolated showers, especially west of I-95 (30%)...70°
9 PM: Widely scattered showers (40%)...66°
12 AM: Scattered showers (50%)...63°

Rain will become likely later tonight after midnight and could be heavy at times. Showers should persist into the first half of Sunday and then slowly taper in the afternoon and evening.

Friday, October 30, 2009

Weekend Rain Potential

A strong storm system is headed toward Virginia this weekend, after causing an early season winter storm in the Rockies and High Plains since Tuesday. Rain should begin moving into the Commonwealth Saturday night and overspread the state into Sunday morning. Here are the projected rain totals Friday into early Sunday as a result of this system:

Virginia could see around an inch of rainfall accumulation.

This system will be cutting it close for the Trick-or-Treaters, but it appears that only a few light showers will be possible in Central Virginia Saturday and into early evening. If you live closer to I-81, though, rain chances will occur earlier. After 9 p.m., rain chances start to go up all along I-95 as the line of rain associated with the upper wave begins sweeping through the state. Richmond's best rain chances will occur from Midnight into Sunday morning. Here is the Richmond Saturday Evening Planner:
Halloween Forecast
Sunset 6:12 p.m.
Mostly Cloudy & Mild
5 p.m.: 76 degrees 20% rain
7 p.m.: 69 degrees 30% rain
9 p.m.: 63 degrees 50% rain
11 p.m.: 61 degrees 50% rain

Thursday, October 29, 2009

First Major Snowstorm Of Season


(Photo: KCNC, Heather Michelotti, Greenwood Village, CO, Oct. 28, 2009)
The first major snowstorm of the season has been plowing through the Rockies and parts of the northern Plains this week, dumping more than three feet of snow in parts of Colorado and two feet in Wyoming. This is a bit early in the season to be getting this much snow. Case in point: Cheyenne, WY. Because of this storm and previous snowfall earlier in the month, Cheyenne, WY has now recorded its snowiest October on record. The previous record-holding October was more than a hundred years ago in 1906, when 23.1" of snow fell. This month, more than two feet have fallen, and it's still snowing there Thursday morning. Also, I-80 between Laramie and Cheyenne, WY was shut down Wednesday into today because of the snow and traffic accidents occuring in the hazardous weather.

Here are some of the snow totals so far:
Pinecliffe, CO 39"
Nederland, CO 30"
Evergreen, CO 28"
Lander, WY 25"
Boulder, CO 17"
Deadwood, SD 12"
Denver, CO 12"
Chadron, NE 10"
Cheyenne, WY 9"

It's still snowing this morning in the Denver area, and you can watch live cameras from our CBS sister station KCNC.

The storm system responsible for the snow will continue to track slowly to the east, bringing us a chance for rain late Saturday night into Sunday. At this time, it looks like Trick-or-Treat time should be dry!

REMINDER: Daylight Saving Time ends Sunday morning at 2 a.m., so be sure to "Fall Back" those clocks Saturday night before you go to bed!

Wednesday, October 28, 2009

Rain Totals

From the two rounds of rain this week, here are some of the totals (with most of the rain falling overnight last night):
Newland 3.0"
Coatesville 2.1"
Danville 1.8"
Richmond 1.7"
Lynchburg 1.7"
Charlottesville 1.6"
Farmville 1.5"
Reedville 1.4"
Fredericksburg 1.0"
Staunton 1.0"
Wakefield 0.7"
Petersburg 0.5"
South Hill 0.5"
Williamsburg 0.4"
Emporia 0.3"
Norfolk 0.2"
The upper-level disturbance and low responsible for our rain Tuesday and early Wednesday is rapidly exiting through the Northeast this morning. Our next storm system is currently overspreading snow through much of the Rockies and into the northern Plains. A foot or more of snow accumulation is possible by tomorrow.
Winter Storm Warnings and Watches have been expanded into the Dakotas as a result of this strong, early season snowstorm.

Tuesday, October 27, 2009

Widespread Rain Likely Tonight

Two systems are making weather headlines today, one in the East, and another in the West:
The first system in the East is the result of an upper-trough. As this system swings through the Eastern U.S. Tuesday and Wednesday, widespread rain will overspread the Commonwealth tonight into the first half of Wednesday after producing heavy rain in Texas and Louisiana Monday. The heaviest rain for us will likely fall around the Wednesday morning commute. Totals will be around an inch for many places in Central Virginia, with some higher totals possible. Here is the expected output from this upper system in the Eastern U.S.
The precipitation you see in the Plains and West is a result of the next upper system currently entering the Rockies. This storm system will bring more snow to the Mountain West, and another round of rain for the Plains. Check out the Winter Advisories/Watches/Warnings in Utah, Colorado, Wyoming, Idaho, Montana, and western Nebraska:
You can watch the snow as it falls in Colorado on their live traffic cams here. Also notice the Wind Advisories/Warnings from California to Arizona as this system brings gale-force winds. This potent storm will track northeast the rest of this week, passing through the Great Lakes Friday into Saturday. This is the storm that will sweep a cold front through Virginia Halloween and bring a slight chance for some rain. At this time, it appears any showers that do affect Virginia will exit the area Saturday evening. We'll be providing updates for the Trick-or-Treaters as we get closer to Saturday.

Monday, October 26, 2009

Hurricane Home Stretch

The World Series is upon us, and the match is now set (Yankees-Phillies, folks). With World Series time, I think about Halloween, cool-to-cold nights, and the end of the Atlantic Hurricane Season. We have about a month left of hurricane season (it officially ends November 30), and here's what typically happens during the last month of the season:
Not much activity, right? This map above shows the prevailing track of any storms that do form in November, and also indicates that the probability (compared to the height of the season) is less likely. Here's what September's climatology looks like, so you get the perspective:
So far this 2009 season, we've had eight named storms in the Atlantic Basin, two of which became hurricanes (Bill and Fred, both major hurricanes). An "average" season has about 10 named storms, with six becoming hurricanes, and 2-3 of those becoming major (Category 3 or stronger) hurricanes. So you can see by the math, that this season has been a little below average for total storms, but still produced two major hurricanes. There's still one month left before we close the book on this year's hurricane season, but this is typically when tropical activity starts winding down.
So why the below-average season? There is some research linking El Nino-La Nina with tropical activity. During a La Nina year, Atlantic cyclone development may be more likely, while during an El Nino year (like this year), less likely. The reverse happens for the Pacific Basin. So this year, often when it appeared that a system might organize in the Atlantic enough to strengthen to hurricane status, wind shear would disrupt the organization process. Could El Nino be to blame? It's certainly possible.

Sunday, October 25, 2009

Less Humid!

I'm sure you noticed it right away when you stepped out the door today - the humidity has dropped significantly over the past 24 hours. Meteorologists use the dew point to gauge the amount of moisture in the air. Yesterday the dew points were in the upper 60s, which is typical for a summer day. Today dew points have dropped into the upper 30s...almost half of yesterday!

Saturday, October 24, 2009

Severe Thunderstorms Possible Today

Scattered rain showers linger across the area this morning. These are ahead of a front that will pass the area later this afternoon. The atmosphere should become even more unstable during that time, especially if we see any sunshine.


Wind shear also looks very strong. This means that we will have the threat for fast-moving thunderstorms capable of damaging winds and possibly an isolated tornado. This will occur anywhere from 3 to 9 PM and includes most of central and eastern Virginia.


We are watching this closely and will have more updates soon!

Friday, October 23, 2009

The Latest On Saturday Storm Potential

After looking at the latest data, there will still be some strong "lift" in the upper atmosphere. In addition, the jet stream will provide plenty of shear.


In addition, the cold front will pass the area in the late afternoon.


Morning showers should briefly reduce the instability, however, the atmosphere should recharge by the afternoon. If this scenario pans out tomorrow, we could see some severe thunderstorms in the area. We will have more updates in the next 24 hours.

Update On Severe Potential

The atmosphere still looks marginally unstable heading into Saturday afternoon, however, there will be strong "lift" in the atmosphere to create a few thunderstorms. Right now it looks like the best chances for severe storms will be in our area and especially farther north. This is still a developing situation, so we will have more updates soon.


Thursday, October 22, 2009

Severe Thunderstorms Saturday?

A few thunderstorms will be possible on Saturday as a cold front passes the area. The front will be along I-81 during the late afternoon.


Jet stream winds will provide strong speed shear (winds increasing with height).


And there should be enough instability in the atmosphere to support thunderstorm development.


One limiting factor on Saturday will be cloud cover, which will reduce instability. In addition, there could be too much shear, which would inhibit thunderstorm development.

This is something we are watching closely and will have more updates in the next couple days.

Tuesday, October 20, 2009

Meteor Shower Wednesday Morning


(Composite Image: Chris Peterson, Guffey, Colorado, Oct. 21, 2008)
The Orionids Meteor Shower will peak in the pre-dawn hours of Wednesday morning, October 21. This meteor shower is caused annually when the Earth passes through debris from Halley's Comet on its orbit around the Sun. The past several years have produced a good show, with up to 60 meteors visible to the naked eye per hour. All you have to do is go outside in the few hours before Dawn, and patiently keep your eyes trained to the Southeastern sky.

(Image: NASA)
You should see several dozen bright, long streaks of light per hour, originating from in-between the Orion and Gemini constellations.
Several factors are making this year's show a good one, including the nearly-New Moon completely absent from the pre-dawn sky and clear skies expected over Central Virginia Wednesday morning. Also, the meteors will be beautifully surrounded by some of the brightest stars and planets in our night sky right now, including Venus, Mars, Sirius, and the constellations Orion, Gemini, and Taurus. So why have the last several years produced such good meteor showers? NASA scientist Dr. Tony Phillips explains:

"According to Japanese meteor scientists Mikiya Sato and Jun-ichi Watanabe, 2006 marked Earth's first encounter with some very old debris. 'We have found that the [elevated activity of 2006] was caused by dust trails ejected from 1P/Halley in 1266 BC, 1198 BC, and 911 BC,' they wrote in the August 2007 edition of Publications of the Astronomical Society of Japan. In their paper "Origin of the 2006 Orionid Outburst," Sato and Watanabe used a computer to model the structure and evolution of Halley's many debris streams stretching back in time as far as 3400 years. The debris that hit Earth in 2006 was among the oldest they studied and was rich in large fireball-producing meteoroids."

So all these factors should make for an excellent Orionids viewing Wednesday morning. Don't worry, it won't be in the 30's in Central Virginia like it has been the past couple mornings! The morning low Wednesday in Richmond should be around 47 degrees. So take advantage of our ideal viewing conditions and check out some several-thousand-year-old debris smacking into the Earth's atmosphere.

Monday, October 19, 2009

Frost Advisory in Effect Tonight


High pressure will result in clear skies and light winds tonight, promoting widespread frost development by Tuesday morning. Full sunshine will allow temperatures to quickly warm into the 40s by 9 AM, with 70s expected by afternoon.

Monday Morning Coldest Of Fall So Far

This Monday morning at Richmond International Airport, the temperature dropped to 37 degrees around sunrise, which is the first time this Fall season we have officially dipped into the 30's in Richmond. Widespread Frost Advisories and Freeze Warnings were in effect this morning for the entire Southeast U.S.
Surface high pressure is in place across the Southeast, and with clear skies again tomorrow morning, I expect a similar setup for freeze and frost in the region.

When Do We "Fall Back?"


Over this weekend, a lot of people were asking me, "Hey, when do we change our clocks back?" Soon! In fact, after your kids finally wind down after the sugar rush of trick-or-treat Halloween candy, and before you finally collapse after keeping an eye on them, turn that clock back. Daylight Saving Time ends Sunday, November 1st at 2 a.m., the morning after Halloween. So make sure you aren't spooked the following morning by the time change! Remember, we "Spring Forward, and Fall Back."

Sunday, October 18, 2009

Here Comes The Sun!

After a long stretch of cloudy and cool weather, it will feel nice to see the sun tomorrow! Here is a look back at high temperatures for the past five days. Each day was significantly lower than the average high for this time of year.

Frost Advisory To The West


TONIGHT/MONDAY
The core of an arctic air mass will settle into the area tonight. Lows will drop into the upper 30s for most areas. It will be even colder west of I-95 where a frost advisory is in effect from 3 to 9 AM (Richmond and Petersburg not included in the advisory). We will finally see the sun tomorrow – enjoy it!

FRIDAY/SATURDAY
Data is still very consistent with our next storm system. A few showers could develop ahead of the front on Friday, however, these will be widely scattered. A better chance for rain will arrive Friday night and into early Saturday as the front passes overhead. We could even see an isolated thunderstorm embedded within these showers.

Saturday, October 17, 2009

Weather Update

TONIGHT/SUNDAY
Drizzle and light rain will stay mainly north of I-64 overnight and into tomorrow morning. However, I can’t completely rule out a stray shower or some mist for communities farther south. An isolated shower will be possible for tomorrow afternoon as the core of the storm system passes overhead. Winds will also strengthen from the north 10 to 20 mph.

Friday, October 16, 2009

Extended Winter Outlook: CPC

Yesterday we talked about the late Fall-early Winter outlook for temperature and precipitation. Today, we'll look at the extended Winter outlook, also issued by the Climate Prediction Center (CPC).

(Images: NOAA)

As explained previously, these outlooks are primarily based on the El Nino-Southern Oscillation trend, which is currently in El Nino. These long-range Winter outlooks, which cover the Winter months (December into March), are related to the North American weather trends that tend to result from the equatorial Pacific waters being warmer-than-average. The warmer waters alter the tropical rain patterns, with a domino effect into the jet stream pattern over the Pacific into North America. When the jetstream shifts, that also shifts the track low-pressure systems take, making some regions drier than average, while others can expect a wetter Winter than average. With the jet hugging the southern parts of the U.S., this should bring more precipitation to that region. It will also result in cooler conditions for the Southeast into the Mid-Atlantic. This long-range outlook coincides with the three-month outlook we talked about yesterday, supporting the expected continuation of the El Nino trend. For Virginia, this could mean a wetter, cooler Winter, which would thus mean the potential for more winter weather events (translated: kids, that means maybe more snow days!). Look for Chief Meteorologist Zach Daniel's Snow Outlook to be released in early December.

Thursday, October 15, 2009

Double Dip of Record Cold Highs

The high temperature for Thursday of 54 degrees set a new record for the coldest low, or what is called a record low maximum. The old record low maximum was 56 set in 1939. It's very likely that tomorrow's high will set another record, making it back-to-back record-setting days. The record low maximum for tomorrow is 54 set in 1940, and we are forecasting a high of just 49. Those 70s next week can't get here too soon.

Late Fall-Early Winter Outlook

Today, the Climate Prediction Center issued its long-range forecast for November through January, based primarily on the El Nino-Southern Oscillation trend.
Here's the Temperature Trend, where blue shades indicate cooler-than-average temperatures, and the orange shades warmer-than-average:


And the Precipitation Trend, where green shades indicate wetter-than-average conditions expected, and the tan shades indicate drier-than-average conditions:


The equatorial Pacific west of South America has been in El Nino conditions (meaning warmer-than-average ocean surface temperatures) for months now, and looks like it will continue through the North American winter months as well. This has meant in previous El Nino Winters that the Southeast tends to be a little cooler-than-average. Here is an example of a strong El Nino event occurring during Winter (January-March):


So based on this information, it appears that the Commonwealth can expect a cooler-than-average start to Winter this year, and when you combine that with precipitation...well, that can mean more winter weather precipitation events in our future! As mentioned in the previous blog entry, today just to our north, New York and Pennsylvania are getting a slightly early start on their winter weather season with a heavy wet snow falling today into Saturday. Could this be a sign of things to come for us as those colder temperatures creep farther South over the next month? We'll be keeping you ahead of the storm.

Periods of Rain Thursday

After a drizzly early Thursday morning, periods of showers will continue to overspread Central Virginia today as an upper-level storm system tracks through the Midwest. This same system is also overriding much colder air at the surface in other parts of the country, bringing snow and winter mix precipitation from North Dakota to northern Minnesota and Wisconsin. As this storm progresses east, it may also bring a heavy, wet snowfall to parts of Central Pennsylvania today and Friday. Winter Weather advisories and warnings are in effect for that region to our north.
Up to a foot of snowfall accumulation is possible by Saturday!
For us in Central Virginia, though, we'll merely continue with this overcast, cool, drizzly weather into the weekend. However, the highest elevations of western Virginia may get a few wet snowflakes Saturday.

Wednesday, October 14, 2009

Weather Update

TODAY
A stray light shower or sprinkle will be possible south of I-64 early today. A better chance for rain will arrive later this afternoon and especially into the evening and tonight. Northeast winds will keep us cool – highs will struggle to reach the mid 50s.

THURSDAY
Periods of rain will be likely through the day on Thursday. Although it will make for a raw day, we definitely need the rain! We should receive .5 to 1” of rain by the end of the Thursday.

Tuesday, October 13, 2009

A Look At This Week's Rain Potential

Here is the rain forecast through the weekend. Right now it looks like northern Virginia will receive the most rain with totals ranging from 2 to 4". We will be tracking this storm system very carefully because any shift in its path will greatly impact these totals.


Monday, October 12, 2009

Mercury Falling

Cold high pressure over central Canada will build southeastward over the next several days, bringing the first true cool snap of the season to central Virginia. Tuesday will be the last warm and sunny day we see this week, as high temperatures are expected to remain in the 50s Wednesday through Friday. A series of upper-level disturbances will result in extensive cloud cover and a good opportunity for much-needed rain.

Saturday, October 10, 2009

Ice Cold Coors


A wintry mix of sleet and snow fell Friday night over Coors Field in Denver, leading to a postponement of game 3 of the National League Division series between the Phillies and Rockies. Snow is not uncommon in Denver this time of year, but the extent of early snowfall and very cold temperatures in the Rockies has been very impressive. Loveland Ski Resort in Colorado opened earlier this week, marking its earliest start to the ski season in 40 years. The cold air mass will move east this week, bringing cooler air to the Mid-Atlantic by Friday.

Weather Update

Widely scattered showers are moving across the area this morning. Showers will become more isolated by early afternoon and then we will be completely dry by this evening. Temperatures will steadily drop from the mid 70s this morning into the upper 60s this afternoon as cooler air settles into the region. Sunday is shaping up to be a great day, enjoy!

Thursday, October 8, 2009

Wind Returning to the Commonwealth

Strong southwest winds will develop during the day Friday, in response to a potent upper-level trough approaching the region from the west. Winds should not be as strong as they were on Wednesday, but still should be sustained in the range of 15 to 25 mph with higher gusts. The storm system will move through the area over the upcoming weekend, bringing scattered showers and a few thunderstorms to central Virginia.

Grab The Jacket This Morning!

There is definitely a chill in the air this morning. Clear skies and light winds allowed temps to dip into the upper 30s and low 40s for many locations across Virginia.


If you don't like the cold weather, be patient, warm air is building in the South and will head this way tomorrow!

Wednesday, October 7, 2009

Windy Afternoon

It will be blustery through the rest of this afternoon - northwest winds could gust as high as 40 mph between 1 and 5 PM. Winds will then quickly diminish after sunset.

Henri Update

Henri is a weak tropical storm with sustained winds of 45 mph. It still looks like this storm will be ripped apart by wind shear, so more than likely it will dissipate by Friday. We'll keep you posted!


Tuesday, October 6, 2009

Fall Freeze Stats & Possible Cool Plunge?

Some farmers have already mentioned to me their thoughts are trending toward the first Fall frost/freeze. Some are predicting an earlier frost or freeze than average, based on personal observations ranging from nuts to the activity of certain birds or animals. I am always fascinated by these nuggets of observational experience. Here are the climatological values for the first Fall freeze for Richmond:

Average First Fall Freeze (reaching 32 degrees F): October 29
Earliest First Fall Freeze on record: October 3, 1974
Latest First Fall Freeze on record: December 2, 1985
But maybe the farmers are onto something. As Aaron mentioned over the weekend, the long-range weather pattern is showing some indication that a strong cold front will move into Central Virginia around mid-October. Based on the latest data, it appears this strong cold front may arrive in Virginia around October 13-14th. The coldest temperatures would affect New England, but it does appear that we have a good chance of getting some of the cold plunge in the Commonwealth, too.
We'll be keeping an eye on this developing weather pattern!
--Carrie

Grace In The History Books

Grace has been absorbed Tuesday by a frontal boundary in the Northeast Atlantic, losing its tropical characteristics and weakening. The remnants of Grace will bring rough weather for that part of the Atlantic while continuing to be swept along with the approaching cold front.
Grace's remnants are moving north-northeast along this boundary, and it looks like the timing of the cold front and what's left of Grace will bring heavy rain to Central England later Tuesday.

Monday, October 5, 2009

Tropical Storm Grace: Cheerio To The UK


Based on long-range estimates of Tropical Storm Grace, the extra-tropical remnants of Grace will likely grace the British Isles Wednesday and Thursday. By that time, Grace will have weakened its maximum sustained winds, and also have lost its tropical characteristics. Still, Grace's remnants will be a strong low-pressure system sweeping through parts of Ireland and Britain.


Winds right now are about 70 mph sustained, and Grace is a rather tiny storm with tropical storm force winds extending only about 50 miles away from the center.
In fact, you can already see Tropical Storm Grace on the UK's regional satellite image:

You can see the eye of Grace in the bottom left of this image.

Fall Foliage Update

As Aaron mentioned on the Blog this weekend, Fall color is beginning to appear in the Commonwealth. Here is the latest update:

Along the Appalachian ridge, colors are expected to peak in late October.

Sunday, October 4, 2009

Grace Named In the Atlantic

We now have our 7th named storm of the season - Grace. This shouldn't affect the U.S. mainland, however, we will continue to track it!

Cold Plunge For Mid October?

The latest data is showing a blast of cold air for the middle of this month (October 12 to 15). This is still waaay far away, but it's definitely worth watching in the coming days!


Saturday, October 3, 2009

Harvest Moon Tonight

Although the Harvest Moon is often in September, technically speaking it is the full moon closest to the autumnal equinox, so this year it is in October. With clear skies tonight, you will be able to easily spot it in the sky...enjoy!

Peak Fall Colors

I've decided to dust off the good ol' fall foliage map and post it here on the blog. It's time to start planning those trips into the Blue Ridge!

Friday, October 2, 2009

Tracking Earthquakes

Although this has nothing to do with weather, I found it pretty interesting...

I stumbled across a pretty cool website today while looking for information about the earthquake in Indonesia. The USGS provides a map that plots all the earthquakes that have occurred over the past seven days for the entire globe!

Here's the link:

http://earthquake.usgs.gov/eqcenter/recenteqsww/

Thursday, October 1, 2009

Crisp, Cool Morning In Parts Of Virginia

Clearing skies and light winds in a dry air mass allowed some parts of Virginia to dip into the 30's Thursday morning. The coldest temperatures were along I-81 in the higher elevations and valleys in western parts of the state. Here are some of the lows from this morning:

Staunton 35
Lynchburg 37
Charlottesville 41
Danville 45
Farmville 46
Fredericksburg 46
Newland 46
Locust Grove 48
Coatesville 48