Wednesday, June 30, 2010

Alex Update - 9:15 AM Wednesday

Alex is a weak Category 1 hurricane that should make landfall tonight along the northeastern coast of Mexico. We aren't expecting the remnants of this storm to affect our area. We are also still watching that batch of thunderstorms in the northern Gulf of Mexico. If they continue to stay over warm water, we could see a low pressure develop in the next couple days (though the chances are looking slim).


Tuesday, June 29, 2010

Alex Strengthens to a Hurricane


Alex became the first hurricane of the Atlantic season this evening, and the first June hurricane in the Atlantic Basin since Hurricane Allison in 1995. Could this be a sign of things to come for the rest of the season? Looking back at 1995, there were a total of 19 named storms, 11 of which were hurricanes, and it was the third most active season on record. Here we go...

Something To Watch

This has caught my eye over the past couple days. On the maps below, you can spot the remnants of Alex moving onshore in northern Mexico and southern Texas on Thursday. In addition, it appears that a small cluster of thunderstorms could potentially become an area of low pressure near the panhandle of Florida. Right now, the chances are slim that this could become a tropical storm, but it's definitely something we'll be watching through the rest of this week!


Alex Update - 6:30 AM Tuesday

With sustained winds at 70 mph, Alex is close to becoming a hurricane, which should occur later today. Computer forecasts have become more consistent on the track of the storm, so we shouldn't see much more of a northern shift. More than likely it will make landfall in the southern coast of Texas and the northeastern coast of Mexico.


Monday, June 28, 2010

Severe T-Storm Watch Until 8 p.m.


A severe thunderstorm watch is in effect for the counties highlighted in pink until 8 p.m. Damaging straight-line winds greater than 65 mph are the main threat, although some marginal hail around quarter-size is also possible. Any of these storms that develop this afternoon and evening should also have locally heavy downpours and frequent lightning. Stay with CBS6, we'll keep you ahead of the storm!

Alex Update Monday Morning


Tropical Storm Alex strengthened overnight as it moved back over the Gulf of Mexico from the Yucatan Peninsula. Maximum sustained wind speeds are now at 50 mph with storm motion continuing to the northwest at 6 mph. Alex should strengthen into at least a Category 1 hurricane before it makes landfall pre-dawn Thursday in northern Mexico. However, the track of Alex could trend more northerly toward Texas. It does appear that Alex's remnants will linger over Texas at the end of this week, posing a flooding risk to that state.

Sunday, June 27, 2010

Alex Update - 11:45 PM Sunday

Alex's track continues to trend farther north and could potentially threaten the southern coast of Texas. All data is in agreement with Alex strengthening to a hurricane in the next 24 to 36 hours.


We Need Rain...Now!

We are now 3.72" below normal for rainfall this year. Believe it or not, we were slightly drier at this time last year. The map below shows the departure from normal rainfall for the past 60 days. It is easy to see that most of the East Coast is suffering from dry conditions. It's even worse in parts of Texas, Oklahoma, Louisiana and Arkansas.

Alex Update - 5:00 PM Sunday

Alex has weakened to a tropical depression, but should quickly restrengthen back to a tropical storm once it moves over the warm waters of the southern Gulf. It still looks like it will make landfall as a hurricane somewhere along the northeastern coast of Mexico, though some of the latest data is pulling it a little farther north. We will continue to monitor this trend and bring the the latest later this evening.

Saturday, June 26, 2010

Alex Update - 11:30 PM Saturday

It still looks like Alex will briefly weaken tomorrow as it passes over the Yucatan Peninsula. Once it enters into the Gulf, it should strengthen back to a tropical storm and possibly a hurricane. Latest guidance still keeps this storm well south of the oil spill.



Today's Rain Totals

Alex Named This Morning

Tropical Storm Alex will cross the Yucatan Peninsula in the next 24 hours, which will cause it to weaken. Once it enters into the southwestern Gulf of Mexico, it will restrengthen back to at least a tropical storm. We will continue to keep you updated.


Friday, June 25, 2010

T.D. One Forms in the Caribbean


Tropical Depression One formed this evening across the western Caribbean, just off the coast of Nicaragua and Honduras. The depression will likely become tropical storm Alex tonight or early Saturday before making landfall on the Yucatan Peninsula. There is the potential for this system to regain tropical storm or even hurricane status as it emerges over the open waters of the western Gulf of Mexico.

Hurricane Hunter Aircraft Headed To Caribbean


The same tropical wave we've been monitoring for a few weeks as it has tracked from western Africa through the Atlantic into the Caribbean is now showing good signs of organization, as Zach mentioned in yesterday's blog entry. There is a high probability of this system becoming a tropical depression over the weekend as it tracks toward the Yucatan Peninsula, and it may strengthen into our first Tropical Storm Alex into next week. An Air Force "hurricane hunter" airplane is scheduled to fly to the disturbance in the Caribbean this afternoon to see if the low pressure center is strong and organized enough to be classified as a depression. Upper-level winds have been losing shear, which will provide a better environment for storm organization. The latest model forecast tracks show this low tracking in the vicinity of the Yucatan Peninsula then into the Gulf of Mexico.

Thursday, June 24, 2010

More Trouble Headed for the Gulf?


A disturbance that began across the central Atlantic a few weeks ago continues to move slowly through the Caribbean. The latest data on this disturbance indicates that a central area of low pressure is in the developing stages, and a tropical depression could form in the next day or two. The image above is a spaghetti plot of various tropical model guidance tracks. We'll have the latest on this disturbance on CBS 6.

Severe T-Storm Watch In Effect



A Severe Thunderstorm Watch is in effect until 8 p.m. for Northern and West-Central Virginia for storms capable of damaging wind gusts in excess of 65 mph and large hail. Any of the storms that track into this part of the state later this afternoon, though, will likely produce frequent lightning, gusty winds, heavy downpours, and potentially some small hail. A few isolated tornadoes are also possible. These storms are developing in response to an approaching cold front that is moving into a very hot and humid air mass over the Mid-Atlantic. You can see the bright white tops of the developing storms to Virginia's northwest ahead of the cold front in this visible satellite image:
These storms will track into northern Virginia this afternoon, and other storms could develop in Central Virginia later this afternoon as well.

Wednesday, June 23, 2010

Heat Advisory in Effect


A heat advisory is in effect Thursday for much of central Virginia, from 11 AM until 8 PM. High heat and humidity will combine to produce heat index values ranging from 100 to 105 across the advisory area. Drink plenty of fluids and stay in the shade as much as possible if you have to be outdoors for a prolonged period of time. Keep your fingers crossed for a few late-day showers and storms along an approaching cold front!

Hottest Temperatures in Two Years


Tuesday's high temperature recorded at Richmond International Airport was 98 degrees, matching our hottest temperature from last Summer and creeping closer to the century mark. The last time Richmond reached at least 100 degrees was June 10, 2008 with a high of 101. Today and tomorrow, we'll have a good shot of reaching 100 degrees. The record highs for the 23rd and 24th respectively are 101 (1988) and 100 (1948). Thursday we should get up to 100 degrees in Richmond, which would tie the record for the 24th. These temperatures around 100 degrees come on the heels of a heat wave that has been with us since the end of May. We recorded the warmest Spring on record in Richmond, and now we're on track for the warmest June (average temperature to date is 80 degrees!).

Number of 90-degree days this year:
April: 2
May: 5
June so far: 14

In addition to the heat, it's been dry this month. We've received 0.39" of rain in Richmond so far this June, which is currently in the running for second-driest June on record. The driest was 0.38" in 1980.
We could get isolated storms this afternoon and a few more late Thursday, but the chances in any one spot are low. However, if we can get one of those heavy storms to pass right over Richmond, it could cool our temperatures temporarily and help that rain deficit a tad.

Tuesday, June 22, 2010

Storms Possible Later Tuesday


Strong to severe storms are possible late Tuesday afternoon and evening in Central Virginia as an upper wave tracks through the Great Lakes region today and provides lift for storms. Thunderstorms are expected to develop mid-afternoon in the higher terrain of western Virginia, then track southeast through the late afternoon and evening into the rest of central Virginia. These storms will be capable of damaging straight-line winds, frequent lightning, and heavy downpours. There may be some hail in the strongest storms, as well. Ample low-level moisture is in the Mid-Atlantic to serve as fuel for storms with hot temperatures this afternoon generating convection. Stay with CBS6, we'll keep you ahead of the storm!

Monday, June 21, 2010

Summer Solstice Monday

The Summer Solstice, or the "official" start of Summer, is this morning at 7:28 a.m. Eastern. This is when, from our perspective on Earth, the axial tilt of the Earth is nearest the Sun.
The Sun appears to be at its "highest" above us as well, and as a result, today is our longest day of the year. In Richmond, our day length is 14 hours 45 minutes and 29 seconds from sunrise to sunset. The seasons are a result of the Earth's orbit around the Sun through the year, with the Earth's axial tilt being more inclined toward or away from the Sun's most direct rays at different times around the orbit (seasons are NOT the result of the Earth being closer to or farther away from the Sun in its orbit). This means while the Northern Hemisphere is most inclined toward the Sun (like us now!), the Southern Hemisphere is inclined away from the Sun's most direct solar rays. It is their Winter Solstice Down Under today.

(Northern Hemisphere Summer is the far left Earth in this diagram)

Sunday, June 20, 2010

Rain Totals - Last 24 Hours

The storms last night completely dissipated once they entered into central Virginia...except for one storm the affected northern parts of the Northern Neck. Here are the rough estimates of rainfall from Doppler Radar.

Friday, June 18, 2010

Tropics Update - Friday 6/18

We are currently tracking a tropical wave near the Windward Islands. All of the latest computer data keeps this storm moving to the west/northwest over the next several days. If this thing holds together and enters the Gulf of Mexico, it could possibly intensify into a tropical storm. We'll keep an eye on it and will bring you more updates in the coming days.



Wednesday, June 16, 2010

Severe Thunderstorm Watch in Effect Until 9 PM

Severe Risk Wednesday: Update


The slight risk area for Wednesday has expanded to cover the entire Mid-Atlantic region while an upper-level low pressure storm system tracks through the Great Lakes. Zach's discussion from the previous blog entry still holds, with damaging straight-line winds being our primary severe threat this afternoon and evening. However, in northern Virginia, there may be some directional wind shear this afternoon to produce rotation in any isolated storms that form, and thus tornadoes could occur.

Cloud-cover continues to be a limiting factor for storm development and heating today, as skies have remained overcast all morning in Central Virginia. Here's the visible satellite image at 9:30 AM:

The more clearing we get, the more we'll warm up this afternoon and have better instability for stronger storms. But as of 10 AM, the view over Richmond from Dominion Cam is still cloudy:

If we can't get the needed breaks in clouds this afternoon, the severe threat will likely be lower.

Tuesday, June 15, 2010

Severe Weather Possible Wednesday


Severe thunderstorms will be possible Wednesday afternoon and evening across much of Virginia. Surface dew points in the upper 60s and low 70s will combine with surface heating resulting in a moderate to very unstable atmosphere by afternoon. An approaching upper-level impulse and associated weak surface boundary will act as triggering mechanisms for storms, some of which will likely be severe. The environmental wind shear should be unidirectional, resulting in damaging straight-line winds as the primary severe mode. The axis of greatest shear and moisture should lie across north-central and northeastern Virginia. I would expect a severe thunderstorm watch to be issued for much of the area Wednesday afternoon. Farther north into Maryland and Pennsylvania, better dynamics and shear structure could result in a few tornadoes. The greatest limiting factor for storm development will be the extent of cloud cover associated with tonight's convection across the Southern Great Lakes and Ohio Valley. We'll have the latest on Wednesday's severe weather potential on CBS 6.

Tropics Update Tuesday


The area of showers and storms in the central Atlantic we've been monitoring this week is weakening today. The chances of this system organizing and strengthening into a Tropical Depression and then Tropical Storm Alex are diminishing. Even the cloud-cover is less today, as evidenced in the visible satellite image:

Movement is still west-northwest at 15 mph, but the system will be moving into less favorable atmospheric conditions with more wind shear. This will probably prevent the system that initially generated as an atmospheric wave off of western Africa from strengthening. In fact, most of the intensity forecasts have it going downhill over the next few days:

Monday, June 14, 2010

Tropics Update Monday

The area of convection in the Central Atlantic (bright white clouds on the right) we are monitoring continues to show signs of strengthening and better organization. This has a pretty good chance of becoming a Tropical Depression in the next couple of days, then earning the name "Alex" if it reaches Tropical Storm strength (39 mph sustained winds). The system is currently tracking West-Northwest at 15 mph about 1400 miles East-Southeast of the Windward Islands. Here is the latest composite tracking for this system:
And the latest intensity forecast:
Weak shear and warm sea surface temperatures should allow this system to organize and strengthen over the next 24-48 hours.
There is another wave just coming off of Africa behind it, and we will be watching that one over the coming days as well.

Sunday, June 13, 2010

Rain Totals

Newest Data From The Tropics

Looking at the latest computer data, there is still a lot of agreement with the speed and direction of the system in the Atlantic. It should continue to move WNW towards the Windward Islands over the next few days.


On the flip side, computer forecasts are all over the place with the strength of this thing.


Water temperatures are very warm in this region, and wind shear isn't too strong. I think we should see this system strengthen over the next couple days and possibly become Alex.

A broad area of convection (thunderstorms) continues to slowly organize in the central Atlantic. Water temperatures are very warm in this region, however, wind shear is still moderately high, which is temporarily inhibiting the development of this system.



Most of the computer forecasts have this system strengthening over the next 48 hours as it drifts slowly westward.



If this trend continues, we will have our first named storm of the season - Alex. We will be tracking this closely through the week and will bring you more updates!