Too much needed rain?Posted Aug30, 2006 at 10:41 AMErnesto has been the latest "semi-flop" of this hurricane season, coming ashore in Florida as a tropical storm rather than the hurricane it had the potential to be. All eyes now turn to its northward progression, and particularly for southwest Virginia, whether this will mean a round of heavy rain. It reminds me a lot of the late June set up, when we were very dry going in, but the 6-10 inches of rain that fell across the area still managed to flood a lot of creeks and rivers. We are in borderline drought status, so the ground can absorb a lot of rain that falls, but can Ernesto put us over the top into some flooding? Early odds favor eastern Virginia being more of the rain bullseye, but it's a close call. Here are a couple of links to keep you updated: Ernesto updatePosted Aug30, 2006 at 08:30 AMKevin's away this week and unable to blog on the latest track of Ernesto. The latest projected path from the National Hurricane Center puts Ernesto over the Carolinas and Virginia between Friday and Saturday. The projected track has moved west to east and then west again. Keep tabs on the storm's path. Post by John Jackson, online editor Hurricane ErnestoPosted Aug27, 2006 at 12:50 PMUPDATE 7 P.M.: Ernesto has at least temporarily weakened to a tropical storm with 60 mph winds, but is expected to regain hurricane strength before affecting Cuba and Florida later. ORIGINAL POST, 1 P.M.: Ernesto has become the season's first Atlantic basin hurricane this morning in the Caribbean. More and more, it looks like this storm is going to hook right, with current forecasts bringing Ernesto into west Florida on a path very similar to what Hurricane Charley followed in 2004. It's likely that will be adjusted, and at this point, it seems doubtful that Ernesto will be as strong as Charley. Crossing Cuba may take some gusto out of Ernesto. The storm may hook so far east as to not be a major factor in Southwest Virginia's weather, as a cool dip in the jet stream from Canada may shove Ernesto out into the Atlantic later this week. We're still in the zone of uncertainty for late week on Ernesto's path, so keep an eye on it. I will not be updating this blog frequently this week, but you can click here for the latest National Hurricane Center information on Ernesto. Hot weather ... but not for longPosted Aug26, 2006 at 06:00 PMRoanoke's high of 94 today was the hottest we've had since the early August heat wave that ended with a high of 96 on Aug. 4. It's our fifth straight day of 90-degree heat and our sixth in seven days. This is a much drier heat than what we experienced in early August, as dew points are hanging in the mid 50s to low 60s as opposed to the mid and upper 60s in early August. 
So expect a few more days of 90ish heat, and then some changes that will probably drop things into the 70s for highs and 50s for lows by late next week. Ernesto continues to be the wild card in all this, but this changing weather pattern may well serve to keep forcing Ernesto's track farther and farther east. Nervous New OrleansPosted Aug26, 2006 at 04:49 PM
Follow the latest information on Ernest on the National Hurricane Center Web site. UPDATE, 5 P.M.: There has already been a slight eastward shift on the forecast track. Click here for the latest 5-day track forecast for Ernesto. There will probably many shifts in the track over the next few days. Of course, Ernesto could become a potential heavy rain threat for Southwest Virginia if it continues shifting eastward. Ernesto could threaten Gulf of MexicoPosted Aug25, 2006 at 05:02 PM
Bad tornado outbreakPosted Aug25, 2006 at 04:33 PMSouth Dakota and Minnesota suffered a severe tornado outbreak on Thursday, with at least 25 reports of tornadoes. One tornado in Minnesota killed one person and injured 12. Click here for a complete listing and a map of Thursday's severe weather reports ... the red dots represent tornado reports. For some photos and storm chase accounts, go to the Stormtrack Web site, click on Chase Reports, and then on the 8/24/06 thread. New tropical depressionPosted Aug24, 2006 at 06:26 PM
Hot, but no longer humidPosted Aug23, 2006 at 06:10 PMWe've settled into a steady late August pattern of hot, dry days. Roanoke hit 90 today for the second day in a row and third in four days. Our daily high temperatures here in the valley have consistently been between 86 and 90 for 10 days straight now. But it's no longer humid: Today's mid-afternoon dew point was in the mid 50s, dropping the relative humidity into the 30 percent range. No significant change is expected at least through the weekend. Tropical Storm DebbyPosted Aug23, 2006 at 01:08 AM
In any event, Debby is more than a week from any potential U.S. impact, however slim the chance. Follow the latest on Debby on the National Hurricane Center web site. Forecast accuracy?Posted Aug22, 2006 at 03:00 PMI stumbled across a Web site called www.forecastadvisor.com that offers percentages of accuracy for forecasts from various entities for given locations over periods of a month and a year. I can't vouch one way or the other for this, but feel free to explore it and consider. It appears to show that most forecasts are about 80 percent accurate over time, which is generally the number I've seen most in research on modern forecast accuracy. Sometimes I get asked why I don't do a column comparing and rating weather forecasts from various organizations. One reason I will never do that, either online or in print, is because The Weather Channel is owned by Landmark Communications, Inc., which also owns The Roanoke Times. On the page where my twice-weekly weather columns appear online, you will see a Weather Channel forecast up top. But often I will refer to National Weather Service products, and both the column page and the blog page have links to the weather service's office in Blacksburg. I'll stick to writing about the weather itself and leave judgment of individual weather entities and forecasts to you, the reader. Tropical depression ... a LONG way outPosted Aug21, 2006 at 05:20 PMTropical Depression Four has formed this afternoon in the eastern Atlantic near the Cape Verde Islands. With a west-northwest to northwest track expected and questions about the storm's viability, it's doubtful at this time that it will ever be a player for the United States ... and even if it is, it would be many days coming. Follow the latest on TD 4 and other tropical weather at the National Hurricane Center Web site. Mean line of the stormsPosted Aug19, 2006 at 04:25 PM
For the latest warnings and radar, click to the National Weather Service Web site. UPDATE 11:15: These storms did make it through the Roanoke and New River valleys tonight with a few rumbles and some brief heavy rain. A sticky day with a front hanging in the area could lead to additional storms on Sunday. Dryness expandingPosted Aug18, 2006 at 05:40 PM
The rainfall deficit relative to normal for 2006 in Roanoke has reached almost 7 inches. The official measuring site at the Roanoke Regional Airport was 2 inches behind normal for July and now is 1 1/2 inches below normal for August ... so it's more apparent than ever now that the flooding downpours of late June are probably all that's saved us from a summer of dried-up reservoirs and water restrictions. 
A moderately dry summer followed by a cool, dry fall can lead to some spectacular fall colors ... we had a beautiful fall in dry 2001. But the dryness could also lead to an enhanced risk of autumn forest fires as the carpet of dead leaves builds. We've depended on active tropical seasons for our rain the last two years ... way too much of it in 2004, and surprisingly little of it in 2005, except for two days of rain before my early October wedding. Nobody has turned the tropical faucet on yet this season, and I'm beginning to wonder if it will get turned on at all beyond a trickle. WaterspoutsPosted Aug17, 2006 at 04:45 PMClick here to see some waterspout photos in the Tidewater area taken last Friday. A couple of these waterspouts touched down on land to officially be recorded as tornadoes. Development unlikelyPosted Aug17, 2006 at 03:49 PMThe National Hurricane Center cancelled a reconnaisance flight scheduled to check out the circulation east of the Carolinas today, which pretty much means the experts are throwing in the towel on the system's chance of becoming something more than a small swirl of clouds and rain. There is a short window of time for the storm to develop before shearing winds aloft become unfavorable for the storm to further strengthen, and it doesn't look like it will hit that window. And so it goes. We've now gone the longest into an Atlantic hurricane season without a hurricane since 2002. I don't hear many folks complaining, least of all me. Ten hurricanes hitting the U.S. in the past two years is quite enough. Area of tropical concernPosted Aug15, 2006 at 04:13 PMThe next potential area of interest for tropical development is a low pressure system about 300 miles off the coast of the Carolinas. (Latest satellite image here) Conditions favor only slow development, so it is not certain that anything will come of it ... but be aware, since this is so close to the U.S. mainland and could quickly affect an area frequented by travelers from Southwest Virginia. For the latest, go to the National Hurricane Center web site for the latest Tropical Weather Outlook. Record high of a different kindPosted Aug13, 2006 at 07:58 PMBlacksburg tied a record high temperature on Saturday, but not the kind we had during our early August heat wave. Blacksburg's high of 68 on Saturday tied the record for coolest high for Aug. 12, previously set in 1974. That high tempeature was 14 degrees below the normal temperature for the date. Lightning photosPosted Aug12, 2006 at 10:10 PM
Lightning (bigger version of photo above) Developing cumulonimbus, or "thunderhead" Remember that if you take any interesting or pretty weather photos, email them to me and I may showcase your work on this blog. Color us dryPosted Aug11, 2006 at 09:50 PM
Even with overnight rains, Roanoke is 6 1/4 inches below normal in rain for the year. Lynchburg is more than 8 inches below normal. Blacksburg apparently has been more blessed with rain this year: only a quarter inch below normal. How things changePosted Aug11, 2006 at 05:33 PMA week ago was the last of four days when temperatures hit 95 or higher in Roanoke, including a reading 99 a week ago Thursday. Today may well be the first of a couple or three days when temperatures fail to hit 80. Roanoke's high on this cloudy, damp day was 77 ...the coolest high since 74 on June 27, the last of our soaking rain days in June. We haven't had back-to-back days when the high failed to reach 80 since we ran off five of them June 10-14 ... very likely, Saturday will fail to make 80, and if there is lots of cloud cover, may fail to reach 75. (UPDATE 8/12: Saturday's high was 76) Blacksburg's high only reached 71 on Friday, the coolest high temperature in the Hokies' hometown since it made only 69 on June 13. While Roanoke's high was 10 degrees below normal and Blacksburg's 11 degrees, neither set a record for coolest high for the date. The coolest Aug. 11 high on record for Roanoke is 71 in 1989; for Blacksburg, it's an almost chilly 61 in 1970. When Roanoke's temperature finally dips below 70 sometime this evening or early Saturday, it will end a 12-day streak of low temperatures at or above 70 degrees for Roanoke. UPDATE 9:50 P.M.: Roanoke's temperature has fallen to 69, so this streak is over ... actually at 11 days, not 12, since it includes the first 10 days of August and the last day of July. Quiet in Atlantic, busy in western PacificPosted Aug10, 2006 at 05:05 PMAs this eerily quiet hurricane season continues in the Atlantic, things are not nearly as quiet in the western Pacific. China is suffering its eighth major tropical system of the year and most powerful typhoon (which is a hurricane by a different name) in 50 years. Click here for story. Dumbing down the weatherPosted Aug09, 2006 at 08:29 PMA TV weatherman in Houston no longer gives the dew point on his weather broadcasts ... and a newspaper columnist is applauding him. (Click here for the article) I'm aghast. I don't understand everything about the stock market ... but is that a good reason to quit reporting the Dow Jones average? The earned run average makes little sense to me, but should sportscasters never report it again when a pitcher enters the game? We're not going to dumb things down here. Last July 4, I wrote about the importance of the dew point: Click here and scroll down a few grafs to the 7/4/2005 entry entitled "The more heat, the less humidity" This same column went in the print editor of The Roanoke Times under the headline: "It's not the humidity, it's the dew point." Hurricane season forecasts loweredPosted Aug08, 2006 at 04:53 PMFollowing on the heels of the Colorado State University hurricane forecasters lowering their predictions for the number of named storms and hurricanes this season, the National Hurricane Center has followed suit today with a slight lowering of the 2006 Atlantic Basin tropical season forecast. Click here for a map from the hurricane center that succinctly shows why this season, with only 3 named storms and no hurricanes, is so different than the 2005 season, which had 9 named storms and 3 hurricanes by this date a year ago. It should be noted that these forecasts are still for more storms than the long-term average in the Atlantic basin ... but a repeat of the record-setting 2005 season is extremely unlikely. Isolated mayhemPosted Aug07, 2006 at 01:24 PMThere are no signs of large-scale inclement weather on the horizon ... heat waves, area-wide severe weather or flooding ... but it can still happen in isolated areas, like last night in Montgomery County when one small storm dumped several inches of rain on a tiny area, washing out a road. The muggy nights have set in: Roanoke has either tied or broken a record for warmest low for the date each of the last five days. Perhaps a cold front moving through tomorrow will drop our nighttime lows back a tad. Chris -- down for the count?Posted Aug05, 2006 at 05:00 PMThe National Hurricane Center threw in the towel this morning on Tropical Depression Chris, if you can in fact call it a depression now. Quoting the hurricane center: CHRIS FORECAST TO DISSIPATE OVER CUBA TODAY ... THIS IS THE LAST PUBLIC ADVISORY ISSUED BY THE NATIONAL HURRICANE CENTER ON THIS SYSTEM UNLESS REGENERATION OCCURS. This was the up-and-coming tropical storm a few days ago, expected to enter the Gulf of Mexico as a hurricane early this coming week. It's not entirely impossible that Chris will rise again, but it's highly doubtful, now that its circulation is becoming diffuse and it's crossing a mountainous land mass in Cuba. It would be fine with me if this hurricane season continues to underperform. Why I think we're done with pushing 100Posted Aug04, 2006 at 05:47 PM
We'll get back toward the low 90s by early next week, with daily chances of showers and thunderstorms, but long-term models are fairly consistent in wanting to develop a jet stream trough, or deep southerly dip, over the eastern U.S. through much of the next two weeks. The Climate Prediction Center 8-14 forecast map, a small version of which is embedded, reflects this: the blue area indicates a good chance of below-normal temperatures in the 8-14-day period. (Click here for the current 8-14-day and 6-10-day temperature forecast maps) If we get a fairly long-lasting trough over the next two weeks, that will mean two weeks of occasional cold frontal passages, often triggering rain and thunderstorms as they pass through. Heat will be building back into the central U.S. next week, but the clockwise circulation around this big heat-dome high pressure system over the Plains will only serve to help drive some cooler air south from Canada into the eastern U.S. It appears the heat will even be shifting a tad west with time, too. By the time the heat could build back from the central U.S. (which is not a certain proposition in itself), it would be late August, and time might run out before it could build back over us with the intensity to develop another heat wave. As we've seen this past week, it takes time to heat and dry things out enough to push the temperature toward 100. The gradually lowering sun angle and shortening days of late August and early September are more hard-pressed to drive a heat wave, and that's not even considering the possibility of tropical systems or the occasional pre-autumn shot of polar air disrupting the heating. That's why I think this past week will prove to be our hottest week of the year and will not be seriously challenged again. Is the heat wave really over?Posted Aug04, 2006 at 11:37 AMWith it 89 degrees at 11 a.m. in Roanoke following another sultry overnight low of 76, it seems likely that this is going to be another hot day. The front is a little tardy in arriving, but do expect scattered showers and thunderstorms to break out in this afternoon's heating before the temperature runs away too much. Still, we could make the mid 90s, and arguably that might stretch this heat wave one more day. Heat breaks with stormsPosted Aug03, 2006 at 06:05 PMIt's not unusual that a heat wave breaks with big thunderstorms, with so much energy available to lift towering cumulonimbus clouds into the sky once the high-level cap of hot air starts breaking down. 
We may see even more widespread thunderstorms on Friday as a cold front moves into this humid air. The front shows up nicely on the embedded satellite image as an arc of clouds to our northwest over Ohio and Indiana. The cold cloud tops of storms in western Virginia and North Carolina also show up as fluffy white puffs. Click here for a bigger version of the same satellite shot. For the record ...Posted Aug03, 2006 at 02:37 PMUPDATE 3:15 p.m: Light rain reported at Roanoke Regional Airport with the temperature down to 88 at 3 p.m. Quite likely, the quest for 100 is over for this heat wave, having only reached the mid 90s today. ORIGINAL ENTRY: Wednesday's record high temperature of 99 occurred at 3:20 p.m., not after 5 p.m., as we've reported here previously and in today's Roanoke Times. National Weather Service warning coordination meteorologist Phil Hysell told me by email today that a process used to determine high temperatures for the 5 p.m. climate report failed to pick up the 99-degree reading, so the high registered 97 at 5 p.m. Later, the 99-degree high was detected as having occurred at 3:20 p.m., and the weather service updated its information at that time. It was 97 degrees at 6 p.m. on Wednesday, though, still plenty hot. At 2 p.m., Roanoke is at 95 as the mercury tries to reach the triple-digits one last day. The record for the date is 100 set in 1963. (Click here to follow temperatures by the hour for Roanoke and other locations) Factors in favor of reaching 100: Several days of heat-baked ground and other surface materials, a downsloping west wind compressing the heat, as Chip Konrad, a University of North Carolina climate researcher formerly of Roanoke, commented on following an August 1 blog entry of mine. Factors against: More cumulus cloud development, and even some scattered showers (including in downtown Roanoke, I'm told by colleagues) and thunderstorms around. (Click here for current radar) Cool thought on a hot dayPosted Aug03, 2006 at 11:37 AMAs the temperature pushes through the 90s this afternoon struggling toward 100 on what is likely to be the last day of this current heat wave for us, click here for a reminder that the whole world isn't sweltering today. A sultry start to another hot dayPosted Aug03, 2006 at 10:06 AMFollowing Wednesday's record high for the date of 99, the overnight low temperature at Roanoke flirted with an all-time record for warmest low -- not just for the date, but for any day since records began kept in 1948 -- hanging at 79 for hours. Finally, this morning at 7 a.m., after the sun had come up, it dipped to 77, only one degree below the all-time record for warmest low in Roanoke, 78 on July 7, 1977. That will stand as the record warmest low for the date if it does not get below 73 before midnight tonight. That record dates to 1980. 99 degrees!Posted Aug02, 2006 at 09:33 PMHmmm ... my suspicion was right. Not only did it pop up 1 degree after 5 p.m in Roanoke., it popped up 2 degrees to 99 ... a new record high for the date, and our hottest day since it hit 100 on July 6, 1999. UPDATE 8/3, 3 p.m.: Wednesday's record high temperature of 99 occurred at 3:20 p.m., not after 5 p.m. National Weather Service warning coordination meteorologist Phil Hysell told me by email today that a process used to determine high temperatures for the 5 p.m. climate report failed to pick up the 99-degree reading, so the high registered 97 at 5 p.m. Later, the 99-degree high was detected as having occurred at 3:20 p.m., and the weather service updated its information at that time. Thursday will be our last day of this heat wave. If storms start firing early in the afternoon, it might not get any higher than the lower 90s. If that holds off and the sun bakes another day ... I wouldn't be surprised to see another run at 100. So most forecasts are hedging in the middle and calling for mid 90s. |
