SAMPLE WEATHERCASTS

Monday, November 28, 2011

Freelancing At XETV In San Diego

I got to freelance at San Diego 6 XETV over the weekend. Great times!
 

Tuesday, August 23, 2011

Irene

I've posted my thoughts on Irene on my other blog:

http://sandiegoweathercenter.blogspot.com/


Thursday, July 28, 2011

Tropical Storm Don Forms In Gulf

The data is very consistent with Tropical Storm Don moving west/northwest over the next 36 hours. By that time, it will move inland through Texas, so Don will not intensify much. Regardless it is still worth watching. More than anything, this is good news for Texans, who really need a soaking rain. Some areas are 3" below normal for the past 30 days.



Sunday, May 29, 2011

Something Brewing In The Tropics?

Hurricane season officially starts June 1st and it already looks like we might have something brewing in the tropics. Latest data this morning shows something forming in the western Caribbean by the end of the upcoming workweek. Satellite imagery shows lots of thunderstorm activity in this area, but nothing too organized.


Regardless, wind shear will weaken in the tropics over the next few days, so this cluster could become better organized in the next few days. In fact, most of the global computer forecasts show an area of low pressure forming by the end of the upcoming workweek (indicated by the green circle in the western Caribbean).



Tropical systems typically form in the Gulf of Mexico and Caribbean early in June (see map below), so this is a plausible forecast. We will be watching this very closely over the next several days and will have more updates.

Thursday, May 5, 2011

April 2011: A Historic Month For Tornadoes

This is not the type of record you want to break, but April of 2011 will probably end up with more tornadoes than any other month in modern day history. There were 871 tornado reports from last month! These are preliminary numbers, so more than likely the total will drop by one or two hundred.

Regardless, the previous record in April was 267 tornadoes which occurred in 1974. The highest number of of tornadoes for any month was May of 2003 (May is typically the most active month), where there were 558 tornado reports. So more than likely April 2011 will shatter all old tornado records.

Here is a map of all the reports:


The top five states were Alabama (144), Mississippi (115), North Carolina (86), Texas (64) and Tennessee (54). Virginia ended up with 35, which is an unusually high amount. You can find the entire list at the following link:

http://www.spc.noaa.gov/climo/online/monthly/1104_summary.html

To put things into perspective, here is the map from May of 2003:


You can see that there significantly less tornadoes in the Mid-Atlantic, though it was a terrible month in the Midwest, especially around Kansas City and Springfield Missouri.

Saturday, April 16, 2011

At Least Four Confirmed Tornadoes In Virginia On Saturday

Severe thunderstorms raced across the area Saturday afternoon and produced widespread damage. At one point, storms were moving 55 to 70 mph. There are now at least four confirmed tornadoes in Virginia.

One tornado touched down in Augusta County (EF-1 with max winds 95 mph) and knocked down several trees and destroyed numerous barns.

A tornado is now confirmed in Dinwiddie County with a path around 8 miles long and 300 yards wide. Many homes were damaged along the path of this tornado.

Two more tornadoes were confirmed in Isle Of Wight and Gloucester counties. There was extensive damage in Gloucester with three fatalities. National Weather Service is going to survey the damage more today to see the strength of the tornado.

There was also wind damage in Halifax County where eight homes were destroyed with four minor injuries. National Weather Service will survey the damage today to see if this was from a tornado.

At one point, the Tri-Cities area was under a Tornado Warning, however, with the exception to a few toppled tress, there were no reports of major damage.

There were a few reports of hail in Crewe and Powhatan. We received pictures of quarter to golfball-sized hail.

Here are some maps which show all of the storm reports from today. The "W" represents wind damage, "H" is hail and "T" is tornado. North Carolina was hit hardest today, where there were nearly 100 tornado reports!


Sunday, April 10, 2011

What I'm Watching Heading Into Hurricane Season

Colorado State came out with their forecast for the upcoming hurricane season. They are calling for an above average season with 16 named storms, 9 hurricanes and 5 major hurricanes. Here are a few things we will be watching over the next couple months leading to the start of hurricane season.

La Nina

Hurricanes like warm ocean water and low wind shear. Wind shear is typically low during La Nina, which would lead to an active season. However, La Nina is rapidly weakening (see the map below), so the forecast isn't as clear-cut.




Atlantic Water Temperatures

As I stated above, hurricanes strive in warm ocean water. Sea surface temperatures (SST) have been above normal over the past few months, which points towards an active season.



NAO

The North Atlantic Oscillation (NAO) has an impact on the Trade Winds. We saw a dramatic shift to a positive NAO during January. This increased the Trade Winds and has consequently cooled the Atlantic waters slightly. If we remain in a positive phase, then ocean temperatures could continue to cool.



Conclusion

Colorado State has already decreased it's initial forecast for this upcoming hurricane season. If La Nina continues to weaken and NAO remains mostly positive, then we might see the number of named storms and hurricanes decrease. We will continue to track this and bring you more updates.

Tuesday, March 29, 2011

A Rainy Forecast Is A Good Thing

Although rain can be disruptive to our day-to-day lives, we desperately need some in our area. You can see on the graph below that we are 1.7" below normal for the year.


We aren't the only ones dealing with dry conditions. You can see on the map below that most of the Southeast is 2 to 8" below normal for rainfall this year.


Not surprisingly, numerous rivers and streams are now running below normal (indicated by the red and orange dots). The rivers to the west are near normal from the heavy rains we saw earlier this month (indicated by green dots).


Right now, moderate drought extends across central and southern Virginia.


Luckily, we will see an active weather pattern over the next several days. In fact, two back-to-back storm systems could bring 1 to 2" of rain from Wednesday into Thursday. This is great news!


Saturday, March 12, 2011

Winter 2010-2011 Recap: Cool & Dry

Wintry weather can sometimes randomly pop up in late March and early April. In fact, the latest snowfall in Richmond recorded history was on April 28, 1898, where there was 2" of snow. Regardless, for the most part, winter is over. So let's look at some of the stats.

TEMPERATURE
December was the 7th coldest in history (link http://www.erh.noaa.gov/er/akq/climate/special/RIC_AVE_T.pdf). The cold weather persisted into the first half of January, then the overall pattern changed. Temperatures generally remained above normal for the rest of winter. The map below shows that the entire Southeast U.S. experienced temperatures that were 2 to 6 degrees above normal for the month of February.



If you combine all months together, the overall average temperature for this winter was slightly below normal.


PRECIPITATION
There is no doubt about it: this winter was dry. We were roughly 2 to 4" below average across the entire state. Interestingly, we received 10.8" of snow, which is only slightly below the average of 11.9". Most of the snow fell in December and early January before the pattern change. You can see on the map below that we weren't the only ones dealing with dry conditions. It was even worse in Louisiana, Mississippi and Alabama.

Saturday, March 5, 2011

Here is a rough timeline for today's rain. The shades of green indicate light to moderate showers, while yellows and reds indicate downpours or possibly thunderstorms. There is a very slim chance for severe storms in central and southeast Virginia today.




Rain totals should range from around 0.75" to 1.25" (give or take 0.25"). This is great news considering that we are about 2.5" below normal for the year.


Severe Weather Checklist
  1. Instability (heat and humidity)
    Moisture should be high enough to support thunderstorms. Temperatures will be hindered by clouds and rain, especially along and west of I-95. Highs should climb into the mid 60s for central and southeast VA. This should be *just* warm enough for isolated thunderstorms.


  2. Trigger (something to spark thunderstorm development)
    A strong front will pass the area in the afternoon, which is typically ideal for severe storms.
  3. Wind Shear
    We will have strong speed shear (winds increase with height), and minor directional shear (winds change direction with height).
  4. Sunshine
    Clouds will prevent any sun for today, which in turn keeps us cooler.

This looks like yet another event where wind shear will be very high but instability will be low. If temperatures climbed into the mid 70s, we would have a bona fide severe weather threat. Regardless, we still have to watch this very closely today. If a thunderstorm develops, it could quickly become severe.

Sunday, February 27, 2011

Severe Thunderstorms Possible Monday

Summary:
A line of thunderstorms will race across the area from 3 PM to 10 PM on Monday. The strongest storms will be capable of damaging straight line winds and small hail.

Discussion:
Temperatures will soar into the upper 70s to near 80 on Monday. This heat will provide *just* enough fuel for thunderstorms later in the afternoon and evening.


Storms will initially start west of the Blue Ridge around midday. They should form into a squall line and then race our way. The leading edge of the storms will be moving into western parts of our area around 3 PM.


The atmosphere will only be marginally unstable once the storms arrive, so we could see some weakening of the squall. Nonetheless, any storms that survive the trek across the Blue Ridge will be capable of damaging wind gusts over 70 mph. There could also be some small hail with the strongest storms. Most of the rain will quickly taper after midnight.




Limiting Factors (technical):
Just like last time, we will have a highly sheared environment with only marginal instability. However, upper-level "lift" could overcome this obstacle.

CAPE, or energy in the atmosphere, will be somewhat limited. Here is a plot for tomorrow evening, which shows almost 1000 CAPE west of I-95 (not too impressive). In addition, CAPE is much less in central VA. This could lead to some weakening of storms, especially after sunset. The key will be sunshine...if we see more, then the air could become more unstable.

Shear is going to be very high. The upper level winds will be howling! This will add to the potential of some powerful downbursts. It could also help to maintain the strength of the squall line. On the flip side, it could also rip apart storms as they try to develop. This is something to watch closely tomorrow - shear vs instability.

Sunday, February 20, 2011

Long Range Outlook Into Early March

Brief Summary:

La Nina will continue to weaken heading into spring. NAO (North Atlantic Oscillation) will generally remain neutral or positive. Although we will see a brief cool down for the start of March, temperatures will remain roughly near or above average. Precipitation will stay near or below average. The chances for a significant snow (over 6") look slim to none.

Digging into the data (technical):

Meteorological winter is about to end (December through February), so it is now time to look at the overall pattern heading into spring. Earlier this winter, we had a strong La Nina, which typically brings mild and dry weather to our region. However, we experienced a strong -NAO (North Atlantic Oscillation), which is when a strong ridge in the jet stream persists over western Greenland and eastern Canada. This brought us cold and snowy weather for December and early January. This ridge eroded in late January, and we have been mild and dry ever since.

La Nina is starting to quickly weaken. In fact, we could be in neutral conditions by May or June. This is a plot of sea surface temperatures, which shows that Nina still exists, but it isn't as strong as earlier this winter. In addition, what you can't see is the water below, which is starting to warm.



Past La Ninas have brought us slightly cooler and wetter weather for March through May. However, this might not be the case this year because La Nina is weakening.



Here is a plot of NAO, which shows negative conditions early in the winter, and then neutral/positive conditions ever since mid January.


There are indications that NAO could turn slightly negative in early March, which would typically get any snow-lover excited. However, the ridge is too far east. I've posted the long range outlook for the upper-level atmosphere (first map), and temperatures for the lower atmosphere (second map). Notice on the first map how the ridge, indicated by the yellow blob, is located east of Greenland. Although this could bring us slightly below average temperatures, it is not in an ideal location for significant snow. Average highs for early March are in the mid 50s and average lows are in the mid 30s. We should generally stay near these numbers for early March. Of course, there will be some fluctuations.


Obviously, there could be some changes to the forecast, however, this isn't looking good for snow-lovers.

Saturday, February 19, 2011

Wind Gusts From Today

Wintergreen saw a gust of 71 mph...that's almost hurricane force winds! Here is a list of highest gusts from other areas across the state. You'll notice that winds were not as strong in southern Virginia. Luckily, winds will subside later tonight and the rest of the weekend looks nice!

Friday, February 18, 2011

High Fire Danger On Saturday

A front will sweep through the area early tonight and drag in extremely dry air for Saturday. In addition, we will see strong winds from the west/northwest sustained at 25 to 35 mph with gusts up to 45 mph. For these reasons, a Red Flag Warning has been issued from 9 AM to 9 PM on Saturday for high fire danger. Winds will eventually diminish by Saturday night.

Wednesday, January 26, 2011


Thursday, January 6, 2011

Update On Next Week's Storm

Over the last several days, computer forecasts have been showing the potential for a winter storm on January 10-11th. At this point I think there are two possible outcomes with this storm. As always, track means everything, so a lot can change from now and then!

I've named the first scenario "Southern Miss", which represents one computer forecast (00Z ECMWF). In this case, an upper-level storm system will race through the Deep South and into the Carolinas (a storm in the Pacific Northwest lags behind). This track will bring the highest accumulations to Arkansas, Tennessee, and North Carolina. In addition, this type of storm will bring snow into our area earlier...possibly all on Monday. Lastly, accumulations will be minimal in Central VA with higher amounts in southern VA.

I want to point out that the ECMWF ensemble (an average of several different runs of the same computer forecast), shows this storm pulling up the coast instead of shooting into the Atlantic. For this reason, I've put the chances of "Southern Miss" at 40%.



The next scenario I've named "Coastal Carolina" (yes, there is a college theme), which is based on another computer (GFS). This paints a much different picture, which I think is slightly more plausible than "Southern Miss". Notice how the energy in Pacific Northwest moves quicker and merges with the energy in the Deep South. This will allow the storm to deepen and move slower and up the coast of the Carolinas. This would bring a wide swath of heavy snow across Central VA and Western VA. If the track pulls farther off the coast, then the heaviest snow will shift east.

Right now, nothing is etched in stone. This is something we will be watching very carefully over the next few days and will bring you more updates.