Wednesday Temperature Predictions and Actual Observations: I did well with Raleigh and Greensboro, but Charlotte and Fayetteville baked in full sun all day when Raleigh and Greensboro had to deal with high cirrus off and on which held temperatures back some.
Raleigh-Durham: Wednesday 96; Actual 96
Greensboro: Wednesday 94; Actual 94
Fayetteville: Wednesday 97; Actual 100
Charlotte: Wednesday 96; Actual 99
More tomorrow on any thunderstorm activity and the incredible weather for August this weekend.
Wednesday, August 6, 2008
Tuesday, August 5, 2008
Something For The Weather Weenie's
Lets discuss something absolutely incredible that happened near Chicago last night. If your not well informed about meteorological terminology then this post may not be for you. Last night there was a nasty severe weather complex that raced through Chicago. There was a game at Wrigley Field and the had to evacuate due to a tornado warning. The only actual report I have seen that may indicate a tornado was a report of a funnel cloud. Most damage reports were from straight-line winds. In order to get any type of convection, you need instability, moisture, and lift. All three were in doubt present last night, and the amounts of some of them are insane.
Below are 00z August 5 (8pm August 4)soundings in the Chicago region.
00z Sounding out of Davenport, Iowa
00z Sounding out of Lincoln, Illinois.
One of the things that sticks out at me is how positively buoyant surface parcels are if they are lifted. The Convective Available Potential Energy (CAPE) was through the roof. This shows how much an air parcel can rise and also how quickly it can rise if it is lifted. Surface-based CAPE (SBCAPE) was 6,600 J/kg and Most Unstable Cape (MUCAPE) was nearly 7,000 J/kg. Lifted Indexes (LI's) was -13 and Precipitable Water was 1.93 inches. If you notice the the temperature profile (red) and dew-point profile (green), they are not together meaning there is some dry-air to overcome in the storms. This adds to the downward momentum from severe convection. There is even a parameter for this called DCAPE or downward CAPE. This was also through the roof on the Davenport sounding with a value of 1610 J/kg. You think these values are high.. just wait. The Lincoln sounding showed even more instability. SBCAPE and MUCAPE was nearly 8,500 J/kg.. I have no words for this.. that is just INSANE. To put it in perspective, we see SBCAPE and MUCAPE more towards 1500-3000 J/kg over the summer with occasional times where these values can get close to 4,000 J/kg. DCAPE at Lincoln was almost 2,000 Jkg. Still INSANE. Precipitable water was also 1.93 inches at Lincoln. So there is no question there was instability and moisture. What about lift? There was a surface front across the region, and even a minor shortwave in the middle levels that provided for necessary lift. Here is a 700mb analysis map at 00z. Pay attention to the minor dip in the lines near the Great Lakes. To the right of the dip is usually where lift is located..
Now for some video footage.... first one taken in Chicago looking towards Wrigley field.. with the eery tornado siren in the backgroud.. Notice how the stadium basically dissappears with the rain and strong winds ( reports of winds near 90 mph). The second is some footage from someone who went to the game. The third is some amazing footage of lightning I believe after the worst of the storm moved through.
Below are 00z August 5 (8pm August 4)soundings in the Chicago region.
00z Sounding out of Davenport, Iowa
00z Sounding out of Lincoln, Illinois.
One of the things that sticks out at me is how positively buoyant surface parcels are if they are lifted. The Convective Available Potential Energy (CAPE) was through the roof. This shows how much an air parcel can rise and also how quickly it can rise if it is lifted. Surface-based CAPE (SBCAPE) was 6,600 J/kg and Most Unstable Cape (MUCAPE) was nearly 7,000 J/kg. Lifted Indexes (LI's) was -13 and Precipitable Water was 1.93 inches. If you notice the the temperature profile (red) and dew-point profile (green), they are not together meaning there is some dry-air to overcome in the storms. This adds to the downward momentum from severe convection. There is even a parameter for this called DCAPE or downward CAPE. This was also through the roof on the Davenport sounding with a value of 1610 J/kg. You think these values are high.. just wait. The Lincoln sounding showed even more instability. SBCAPE and MUCAPE was nearly 8,500 J/kg.. I have no words for this.. that is just INSANE. To put it in perspective, we see SBCAPE and MUCAPE more towards 1500-3000 J/kg over the summer with occasional times where these values can get close to 4,000 J/kg. DCAPE at Lincoln was almost 2,000 Jkg. Still INSANE. Precipitable water was also 1.93 inches at Lincoln. So there is no question there was instability and moisture. What about lift? There was a surface front across the region, and even a minor shortwave in the middle levels that provided for necessary lift. Here is a 700mb analysis map at 00z. Pay attention to the minor dip in the lines near the Great Lakes. To the right of the dip is usually where lift is located..
Now for some video footage.... first one taken in Chicago looking towards Wrigley field.. with the eery tornado siren in the backgroud.. Notice how the stadium basically dissappears with the rain and strong winds ( reports of winds near 90 mph). The second is some footage from someone who went to the game. The third is some amazing footage of lightning I believe after the worst of the storm moved through.
Tuesday Temperature Recap
Well my initial thoughts last week on this current heat wave were current. NOTHING spectacular. No one saw a 100 degree reading today and it is very unlikely anyone will Wednesday either. Here are my predicted temperatures and actual observations for Tuesday, August 5. If anything I was slightly too high on my predictions. A high of 96 is nothing uncommon in the summertime in the Triangle area. I did horrible for Charlotte, and was a degree or two off at the rest of the locations. All my predictions were too high.
Raleigh-Durham: Tuesday 98; Actual 96
Greensboro: Tuesday 97; Actual 96
Fayetteville: Tuesday 99; Actual 98
Charlotte: Tuesday 99; Actual 95
To continue what I have been doing during this current heat wave I will make one more set of forecasts for Wednesday. Thursday should be around 90 and could even be slightly lower if there is more cloud cover and precipitation. Big changes appear to be coming with a pattern shift from upper level ridging to a deep upper level trough. As long as all surface features, such as the projected cold front, do not stall over NC we should have delightful summer weather Friday through the weekend. Temperatures will be in the middle to upper 80s during the day and middle 60s at night!
Wednesday Temperature Predictions:
Raleigh-Durham: Wednesday 96
Greensboro: Wednesday 94
Fayetteville: Wednesday 97
Charlotte: Wednesday 96
I will post the actual observations tomorrow night. One note again is that the record high for August 6 at RDU and Greensboro is 97. If tomorrow does in fact decide to be the hottest day of the heat wave, then these records could be in jeopardy, but I think debris clouds from thunderstorm activity to our NW and the chance for some showers and storms to make there way into the state later in the day could put a halt to the mercury rise.
Raleigh-Durham: Tuesday 98; Actual 96
Greensboro: Tuesday 97; Actual 96
Fayetteville: Tuesday 99; Actual 98
Charlotte: Tuesday 99; Actual 95
To continue what I have been doing during this current heat wave I will make one more set of forecasts for Wednesday. Thursday should be around 90 and could even be slightly lower if there is more cloud cover and precipitation. Big changes appear to be coming with a pattern shift from upper level ridging to a deep upper level trough. As long as all surface features, such as the projected cold front, do not stall over NC we should have delightful summer weather Friday through the weekend. Temperatures will be in the middle to upper 80s during the day and middle 60s at night!
Wednesday Temperature Predictions:
Raleigh-Durham: Wednesday 96
Greensboro: Wednesday 94
Fayetteville: Wednesday 97
Charlotte: Wednesday 96
I will post the actual observations tomorrow night. One note again is that the record high for August 6 at RDU and Greensboro is 97. If tomorrow does in fact decide to be the hottest day of the heat wave, then these records could be in jeopardy, but I think debris clouds from thunderstorm activity to our NW and the chance for some showers and storms to make there way into the state later in the day could put a halt to the mercury rise.
Monday, August 4, 2008
Monday's Actual Highs; Tuesday and Wednesday Predictions
The actual numbers are in for the cities I predicted for yesterday. Here are the predicted numbers and actual numbers.
Raleigh-Durham: Monday 94; Actual 94
Greensboro: Monday 93; Actual 92
Fayetteville: Monday 96; Actual 93
Charlotte: Monday 95; Actual 94
I did very well for Raleigh, Greensboro and Charlotte, but was too high in Fayetteville. The reason for the lower high temperature due to a thunderstorm that hit the area middle of the afternoon.
Tuesday will be much hotter and more humid across the entire area as the ridge of high pressure tries to nose into the state.
Below are my Tuesday and Wednesday predictions for Highs:
Raleigh-Durham: Tuesday 98; Wednesday 96
Greensboro: Tuesday 97; Wednesday 93
Fayetteville: Tuesday 99; Wednesday 97
Charlotte: Tuesday 99; Wednesday 96
I made some minor changes to Tuesday. I have a pretty good idea that these locations will not reach 100. Wednesday will be slightly lower due to more moisture, clouds, possible showers and the retreat of the upper ridge. Then, exactly how much the weather changes after Wednesday? Right now, it appears a nice push of cooler more Canadian summer air will make its way into the eastern United States by the end of the week!
Raleigh-Durham: Monday 94; Actual 94
Greensboro: Monday 93; Actual 92
Fayetteville: Monday 96; Actual 93
Charlotte: Monday 95; Actual 94
I did very well for Raleigh, Greensboro and Charlotte, but was too high in Fayetteville. The reason for the lower high temperature due to a thunderstorm that hit the area middle of the afternoon.
Tuesday will be much hotter and more humid across the entire area as the ridge of high pressure tries to nose into the state.
Below are my Tuesday and Wednesday predictions for Highs:
Raleigh-Durham: Tuesday 98; Wednesday 96
Greensboro: Tuesday 97; Wednesday 93
Fayetteville: Tuesday 99; Wednesday 97
Charlotte: Tuesday 99; Wednesday 96
I made some minor changes to Tuesday. I have a pretty good idea that these locations will not reach 100. Wednesday will be slightly lower due to more moisture, clouds, possible showers and the retreat of the upper ridge. Then, exactly how much the weather changes after Wednesday? Right now, it appears a nice push of cooler more Canadian summer air will make its way into the eastern United States by the end of the week!
Sunday, August 3, 2008
Tropical Storm Edouard Develops; Monday Forecast
Tropical Depression 5 formed this afternoon at 5pm and one hour later was classified as Tropical Storm Edouard with 45 mph winds. Edouard is disorganized currently and is not forecast to become a hurricane, but is over the warm waters of the Gulf and vertical wind shear is almost nonexistent so this one needs to be watched. Edouard appears to have no chance of moving northward into Louisana and the SE US as the ridge of high pressure will force Edourd to the W-SW over the next day or so. Landfall is projected to be somewhere near Houston/Galveston Texas region. Click the image for a Track Map and Infrared Satellite map using google maps from WeatherUnderground.
Closer to home, the heat becomes the major concern over the next three days. Monday should not be too extreme with low dewpoints leading to a more "comfortable" heat meaning heat indexes should not be over the actual temperatures by more than 3-5 degrees. Tuesday's heat will be more extreme with dewpoints in the upper 60s leading which will make it feel terrible and I would not be surprised if heat advisories are hoisted for Tuesday. Wednesday could be very similar as Tuesday. I still do not expect to see temperatures reach 100 either Tuesday or Wednesday. Again, like has been the case the last several weeks, the models are predicting too high of temperatures than what is actually being observed. Below are my predictions for Monday and Tuesday for select locations in NC. I will update tomorrow on Edouard (unless he rapidly strenghtens this evening), and refine the numbers for Tuesday as new data becomes available. Note that the record at RDU for Tuesday is 100 and for Wednesday is 97.
Raleigh-Durham: Monday 94; Tuesday 99
Greensboro: Monday 93; Tuesday 98
Fayetteville: Monday 96; Tuesday 99
Charlotte: Monday 95; Tuesday 100
Closer to home, the heat becomes the major concern over the next three days. Monday should not be too extreme with low dewpoints leading to a more "comfortable" heat meaning heat indexes should not be over the actual temperatures by more than 3-5 degrees. Tuesday's heat will be more extreme with dewpoints in the upper 60s leading which will make it feel terrible and I would not be surprised if heat advisories are hoisted for Tuesday. Wednesday could be very similar as Tuesday. I still do not expect to see temperatures reach 100 either Tuesday or Wednesday. Again, like has been the case the last several weeks, the models are predicting too high of temperatures than what is actually being observed. Below are my predictions for Monday and Tuesday for select locations in NC. I will update tomorrow on Edouard (unless he rapidly strenghtens this evening), and refine the numbers for Tuesday as new data becomes available. Note that the record at RDU for Tuesday is 100 and for Wednesday is 97.
Raleigh-Durham: Monday 94; Tuesday 99
Greensboro: Monday 93; Tuesday 98
Fayetteville: Monday 96; Tuesday 99
Charlotte: Monday 95; Tuesday 100
Friday, August 1, 2008
August Has Arrived
I posted on Tuesday about the potential for extreme heat the end of this weekend into next week. Well that looks like it is on hold until maybe Tuesday and Wednesday. The keyword here is maybe as again I am not confident in the model solutions and how high the temperatures are forecast to be in the coming days. Saturday will be no doubt be hot, but not as hot as the GFS (global model) says it will be (98). I predict a high of 95 (more in line with past two week trends and other guidance). That could be held down if there is more clouds and more showers and storms. Right now, it appears that another disturbance in the northwest flow aloft will come through during peak heating. Moisture should be on the rise again as currently the atmosphere is too dry to support precipitation. It is uncertain whether or not coverage will be isolated or more widespread.
Here are some statistics from the record breaking August 2007
90 degree days: 30
100+ degree days: 6 with 105 second hottest day recorded at RDU.
Precip: 0.91 inches ; normal August total: 3.78 inches
The big thing to note is 30 of the 31 days last August were above 90 with six of those being about 100. It was also extremely dry that month. Will we see another hot August? Luckily, we are heading into August with a bit more rainfall then we did last year heading into August, but the ground water is still low and could play a role in any hot spell that occurs including the one possible this coming week.
Here are some statistics from the record breaking August 2007
90 degree days: 30
100+ degree days: 6 with 105 second hottest day recorded at RDU.
Precip: 0.91 inches ; normal August total: 3.78 inches
The big thing to note is 30 of the 31 days last August were above 90 with six of those being about 100. It was also extremely dry that month. Will we see another hot August? Luckily, we are heading into August with a bit more rainfall then we did last year heading into August, but the ground water is still low and could play a role in any hot spell that occurs including the one possible this coming week.
Tuesday, July 29, 2008
Extreme Heat To Return?
I am still not totally convinced that extreme heat will return late this weekend into next week. You may have heard from several radio and TV outlets that triple digit heat may make a return. Model predictions show a massive heat ridge somewhere over the eastern United States starting this weekend and then heading into next week. I am in no way saying that this will definitely not happen, but the exact location of this ridge and exactly where the surface high pressure ends up sitting will make all the difference. I posted about this last week how model guidance for temperature forecast have been higher than what is actually occurring. Today was no different with RDU reaching 92 and some guidance yesterday showing highs in the mid to upper 90s. The same holds true for Wednesday through Friday. I feel most guidance is slightly to warm.
Here is a look at extended range temperature statistical guidance from the GFS(global forecast system model) for RDU.
WED: 95
THURS: 94
FRI: 98
SAT: 97
SUN: 99
MON: 102
TUES: 100
As you can see, the heat is predicting to get extreme by next week. Will this happen? Its possible given the pattern that appears to be coming, but this model has also been several degrees above the actual observed readings.
For Wednesday, with higher moisture in the air I would expect that there would be a good amount of cumulus clouds with some of them becoming storms. This should help to keep temperatures from getting higher than 93. Thursday will be very similar with perhaps more showers and storms. Then from there, it all depends on how the ridge at the surface and aloft align themselves into the weekend. Stay tuned.
Here is a look at extended range temperature statistical guidance from the GFS(global forecast system model) for RDU.
WED: 95
THURS: 94
FRI: 98
SAT: 97
SUN: 99
MON: 102
TUES: 100
As you can see, the heat is predicting to get extreme by next week. Will this happen? Its possible given the pattern that appears to be coming, but this model has also been several degrees above the actual observed readings.
For Wednesday, with higher moisture in the air I would expect that there would be a good amount of cumulus clouds with some of them becoming storms. This should help to keep temperatures from getting higher than 93. Thursday will be very similar with perhaps more showers and storms. Then from there, it all depends on how the ridge at the surface and aloft align themselves into the weekend. Stay tuned.
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