Very Disturbing PRELIM DISC from HPC

[toxictwister00]

Reading this thread is depressing.

But if we are going to be hot, we might as hell have record heat. Several years back it hit 100-102 or so about this time IIRC so if we get that hot it won't be unprecedented here but if we get to 105 to god forbid 110, that will be damn impressive.

Impressive, or depressing, or sickening indeed is BHM is forecasting highs at or above 100 in Tuscaloosa for the next 7 days (although their pin point forecast "only shows upper 90s today and around day 5 but their graphic shows 100 today)

Given the possible historic heat, will go ahead and pin this thread.

Ironic to say the least that we have this terrible heat coming when this morning it was or close to record lows here with a low of 57.

That's the spirit , that's basically how I'm looking at it too. I absolutely hate when it gets hot like this, but it'll be kinda fun to see just how high the mercury can climb into the 100s.

[GaWx]

Yep, it's the consistency of the model runs that gives me confidence in my upper 90s forecast for the mountains and easy low 100s for the Piedmont/Foothills areas. IMO, KATL tops 100 with no problem.

I agree. Despite the Euro almost definitely overdoing the heat quite a bit based on how it has done in the past/warm bias, (it will almost definitely gradually back down at 850 from its 3+ runs of an insane +29 C at KATL as it has begun to do with the newest run's +28 C and the 6Z GFS has cooled to near +25 C as of 0Z 6/30 from yesterday's +26 C) I could see a new alltime (since 1950 at 0Z) record high of near +25C at 850 at KATL and likely at least approach the +24C 850 record high. I need to check the current soil moisture, but I'm currently thinking that assuming mostly sunshine that there will be at least two days of ~103 F and that the alltime record high of 105 F could be challenged! All we'd need for a good shot at 103+ at KATL would be about +24 C at 850 with mostly sunshine.

[jds015]

Does anyone have any thoughts on how long this heat wave is going to be sticking around?

[GaWx]

Once again FFC has a horrible forecast. They go no higher than upper 90s the entire period for ATL. My current forecast has at least 3 days over 100 here, 103 on Saturday but this may well be too conservative. If the Euro 850mb forecast is correct, oh my. 106-107 not out of the question.

I think that going with ~103 F is very reasonable. Based on the actual day by day documentation of the last few years of a Euro warm bias along with it being a sig. outlier being that its +29 C 850's were a whopping 3C warmer than other models' +26C, I think that it is a very easy bet that the Euro's 850 forecast will gradually back down at least to +26 C and maybe even down to the +24 to +25 C area at 850 as we get closer to Friday. The newest Euro run (0Z Wed. 6/27) has started to cool with KATL at ~+28 C at 850 as of 0Z Sat. 6/30 after 3+ runs in a row of +29 C. There's still plenty of time for the Euro to fall to near +26 C and maybe even +25 C at 850 before the event is reached. By the way, today's 6Z GFS fcast for 0Z on 6/30 has cooled from yesterday's four GFS runs of +26 C to +25 C.

[griteater]

Does anyone have any thoughts on how long this heat wave is going to be sticking around?

No relief in sight per Euro Ensemble through at least mid next week.

MEX MOS numbers are climbing. For Fri-Sun, it's showing mid 90's for AVL, 103 each day for CLT, and 105/105/104 just west of CLT in Gastonia.

[Itunis]

I think that going with ~103 F is very reasonable. Based on the actual day by day documentation of the last few years of a Euro warm bias along with it being a sig. outlier being that its +29 C 850's were a whopping 3C warmer than other models' +26C, I think that it is a very easy bet that the Euro's 850 forecast will gradually back down at least to +26 C and maybe even down to the +24 to +25 C area at 850 as we get closer to Friday. The newest Euro run (0Z Wed. 6/27) has started to cool with KATL at ~+28 C at 850 as of 0Z Sat. 6/30 after 3+ runs in a row of +29 C. There's still plenty of time for the Euro to fall to near +26 C and maybe even +25 C at 850 before the event is reached. By the way, today's 6Z GFS fcast for 0Z on 6/30 has cooled from yesterday's four GFS runs of +26 C to +25 C.

Wow, despite the moderation the models are showing it looks like 100+ is a real possibility. Despite all the hate FFC gets I don't think we should criticize them too much just yes--as has been said 100+ is rare here, especially in June, and with a few days to go they want to be confident in their forecast before they forecast such extreme temps. I bet by the afternoon shift they'll up highs a bit if the models hold fast. The current forecast of several days of near-100 degree temps is sure to catch plenty of attention, and the news outlets here have been pretty good at letting people know that extreme heat is on the way.

[jburns]

Wow, despite the moderation the models are showing it looks like 100+ is a real possibility. Despite all the hate FFC gets I don't think we should criticize them too much just yes--as has been said 100+ is rare here, especially in June, and with a few days to go they want to be confident in their forecast before they forecast such extreme temps. I bet by the afternoon shift they'll up highs a bit if the models hold fast. The current forecast of several days of near-100 degree temps is sure to catch plenty of attention, and the news outlets here have been pretty good at letting people know that extreme heat is on the way.

Raleigh NWS keeps on creeping my temps up a degree or so each forecast period. It's now Friday 100, Saturday 102, Sunday 101.

[strongwxnc]

Depends on your definition of a heat wave.. But this current forecast increase in temps, should be on the down slide by Tuesday.

Does anyone have any thoughts on how long this heat wave is going to be sticking around?

[Itunis]

Raleigh NWS keeps on creeping my temps up a degree or so each forecast period. It's now Friday 100, Saturday 102, Sunday 101.

Same with our branch, but they've been more conservative. The forecast disco doesn't make them sound too concerned, as they only say we might be "flirting with heat advisory level heat indices". Kind of a disappointment--they should be harping on dangerous heat, as even their current forecast temps would have a significant impact on the area.

[Lookout]

Folks,

The 0Z GFS is sticking with its prior runs' bigtime/historic heat scenario with it stil having +26 C at 850 mb at KATL! That makes at least five GFS runs in a row showing that. The hottest 850 for KATL on record back to 1950 is +24 C.

Good stuff Larry, as always. I'm really curious though, how do you find the record for 850mb temps? That's not something I would think is easily found. Do you look at every day since then or is there an actual source you can go to that shows it?

[jburns]

Same with our branch, but they've been more conservative. The forecast disco doesn't make them sound too concerned, as they only say we might be "flirting with heat advisory level heat indices". Kind of a disappointment--they should be harping on dangerous heat, as even their current forecast temps would have a significant impact on the area.

Raleigh is really bullish for them. This is fro the 3am discussion.

...EXCESSIVE HEAT APPEARS LIKELY FRIDAY THROUGH THE WEEKEND...

DAILY HIGHS WILL REACH 100 TO 105 ACROSS MUCH OF CENTRAL NORTH

CAROLINA. HEAT INDICES WILL REACH 105 TO 110... POSSIBLY REACHING OR

EXCEEDING 110 ON SATURDAY. ALL TIME RECORD HIGHS ARE POSSIBLE

SATURDAY.

THERE APPEARS TO BE LITTLE EVIDENCE TO SUPPORT HOLDING BACK THE HEAT

ANY LONGER FOR OUR REGION. THE HIGH HEAT AND HUMIDITY WILL ALREADY

HAVE OVERSPREAD OUR REGION THURSDAY AFTERNOON AND NIGHT. THE CORE OF

THE RECORD PRODUCING HOT MID LEVEL RIDGE IS FORECAST TO MOVE FROM

ARKANSAS AND WESTERN TENNESSEE THURSDAY... TO OVER THE TENNESSEE

VALLEY FRIDAY... THEN EXTEND FROM TENNESSEE INTO GEORGIA SATURDAY...

AND STALL OVER GA/SC ON SUNDAY INTO MONDAY.

RESEARCH HAS SHOWN THAT CENTRAL NORTH CAROLINA IS MOST OFTEN

AFFECTED BY HISTORICAL HEAT WAVES WHEN THE CORE OF THE MID LEVEL

RIDGE IS LOCATED JUST TO OUR SW.

[FoothillsNC]

I have a full breakdown at my site (in the free "public" menu) if you wanna check it out. This heatwave is almost perfectly centered and has several good unique factors that 2006 and 2007 didn't have, including higher 850's, and perfect ridge placement and potential for maximum mixing (through deep levels) under no clouds, in Va, Carolinas and Ga especially. Will be an interesting learning event.

wxsouth.com

[eyewall]

I have a full breakdown at my site (in the free "public" menu) if you wanna check it out. This heatwave is almost perfectly centered and has several good unique factors that 2006 and 2007 didn't have, including higher 850's, and perfect ridge placement and potential for maximum mixing (through deep levels) under no clouds, in Va, Carolinas and Ga especially. Will be an interesting learning event.

wxsouth.com

It is times like these that make me wonder why I stay here. This could be the 3rd consecutive summer of brutality.

[GaWx]

Good stuff Larry, as always. I'm really curious though, how do you find the record for 850mb temps? That's not something I would think is easily found. Do you look at every day since then or is there an actual source you can go to that shows it?

Thanks, Lookout. Yes, I had to look at every hot day...old 850 mb level maps going back to 1950.

By the way, the 12Z gfs looks barely cooler for KATL at 850 but similar to the 6Z gfs with ~+25 C for the hottest.

[POWERSTROKE]

I have a full breakdown at my site (in the free "public" menu) if you wanna check it out. This heatwave is almost perfectly centered and has several good unique factors that 2006 and 2007 didn't have, including higher 850's, and perfect ridge placement and potential for maximum mixing (through deep levels) under no clouds, in Va, Carolinas and Ga especially. Will be an interesting learning event.

wxsouth.com

you have been dead on this year Robert. I am glad I could help convince you to do the site. You have been so accurate and have showed the passion you have for weather. I hope many on here will sign up and see what you are doing. I will be down in a couple of weeks. Stay cool!!!! Great Jet skiing weather!!

[jburns]

It is times like these that make me wonder why I stay here. This could be the 3rd consecutive summer of brutality.

This is what I hate.

Saturday Night: Mostly clear, with a low around 79.

[Snowless in Carrollton]

I have a full breakdown at my site (in the free "public" menu) if you wanna check it out. This heatwave is almost perfectly centered and has several good unique factors that 2006 and 2007 didn't have, including higher 850's, and perfect ridge placement and potential for maximum mixing (through deep levels) under no clouds, in Va, Carolinas and Ga especially. Will be an interesting learning event.

wxsouth.com

Also, we have a higher sun angle and longer days than we did in the heat wave of August 2007. Not sure if that plays a role or not.

[mempho]

This is what I hate.

Saturday Night: Mostly clear, with a low around 79.

It could be worse..you could live in Memphis....we had a low of 85 last year. It makes me want to vomit...really.

[buckeyefan1]

If anything, The Southeast's 3 hottest days will likely be from Saturday through Monday with a bit of a temperment down on Tuesday. Friday's the "warmup" so to speak. I believe Saturday KCAE will challenge the 107 degree all time reading while the potential exists for heat index values to exceed 115, likely some spots in South Carolina will exceed 120. It's very hard to believe KATL's June record monthly high is 101. HPC's going 103 on Fri, followed by 105 on Sat for KATL. KAVL 98 on Sat. Irregardless, there will likely be a very large and expansive issuance of excessive heat warnings focusing starting Fri through the region and continuing til Tuesday in which Wednesday looks to bring a bit of a moderation of the excessive temperatures as the flow flattens to more zonal.

I wouldn't doubt it.....sigh

Even if they do verify, I think the bigger question is what is the mixing depth during the peak heating hours? On August 21, 1983, the day that Asheville hit 100*, the mixing depth on the GSO sounding was nearly to 550mb. Even at 12Z, it was up to 700mb. If the depth of the true mid-level thicknesses can be tapped, I think widespread low 100s in the piedmont and midlands of NC/SC are likely.

Ugh.....

Reading this thread is depressing.

But if we are going to be hot, we might as hell have record heat. Several years back it hit 100-102 or so about this time IIRC so if we get that hot it won't be unprecedented here but if we get to 105 to god forbid 110, that will be damn impressive.

Impressive, or depressing, or sickening indeed is BHM is forecasting highs at or above 100 in Tuscaloosa for the next 7 days (although their pin point forecast "only shows upper 90s today and around day 5 but their graphic shows 100 today)

Given the possible historic heat, will go ahead and pin this thread.

Ironic to say the least that we have this terrible heat coming when this morning it was or close to record lows here with a low of 57.

This thread is depressing

I don't want record heat I've seen enough records broken here between the portals these past few years to last me a lifetime

[Hoosier]

12z 850 mb temps

[MotoWeatherman]

NAM 12z extracted shows 106 for ATL on Saturday for 2m Temps. Probably a bit overdone but it gonna be a scorcher.

Station ID: KATL Lat:   33.62 Long:  -84.44                                                        
NAM Model Run: 12Z 27JUN 2012
 HR Valid     2m Tmp 2m Dpt 10m Dir 10m Spd TPrcp CPrcp 1000-500 500mb 850mb 500mb MSLP TCC PRS WX   Tot    Snowfall  Vis
               Deg F  Deg F   deg      kt    in.   in.     Thk    GPH   Tmp   Tmp   mb   %  TEXT    Clouds      in    SM
  0 06/27 12Z   67     58       5       3    0.00  0.00    575    587   14.0  -5.6 1014   0          CLR       0.0   15.0
  3 06/27 15Z   79     53      77       7    0.00  0.00    575    588   13.1  -6.1 1016   0          CLR       0.0   15.0
  6 06/27 18Z   85     54      22       5    0.00  0.00    576    589   15.0  -6.2 1015   0          CLR       0.0   15.0
  9 06/27 21Z   88     55      26       5    0.00  0.00    577    589   17.3  -6.2 1014   3       190FEW247    0.0   15.0
 12 06/28 00Z   86     58      42       2    0.00  0.00    578    590   17.9  -6.2 1014   4       137FEW197    0.0   15.0
 15 06/28 03Z   80     56     159       2    0.00  0.00    577    591   17.8  -6.9 1016   0          CLR       0.0   15.0
 18 06/28 06Z   74     56     170       3    0.00  0.00    577    591   17.8  -6.5 1016   0          CLR       0.0   15.0
 21 06/28 09Z   69     55     204       3    0.00  0.00    576    591   17.3  -6.7 1017   0          CLR       0.0   15.0
 24 06/28 12Z   70     58     224       2    0.00  0.00    576    592   17.9  -7.1 1018   0          CLR       0.0   15.0
 27 06/28 15Z   86     59     271       7    0.00  0.00    577    593   18.0  -7.3 1018   0          CLR       0.0   15.0
 30 06/28 18Z   92     61     275       6    0.00  0.00    579    594   18.6  -7.6 1017   0          CLR       0.0   15.0
 33 06/28 21Z   95     62     269       7    0.00  0.00    581    594   20.6  -8.5 1016   0          CLR       0.0   15.0
 36 06/29 00Z   91     64     260       5    0.00  0.00    581    594   21.2  -8.3 1015   0          CLR       0.0   15.0
 39 06/29 03Z   85     62     244       5    0.00  0.00    581    595   20.9  -9.2 1016   0          CLR       0.0   15.0
 42 06/29 06Z   81     63     255       5    0.00  0.00    581    594   22.1  -9.8 1015   0          CLR       0.0   15.0
 45 06/29 09Z   77     62     257       6    0.00  0.00    580    594   23.0 -10.4 1015  33       197SCT199    0.0   15.0
 48 06/29 12Z   78     65     264       6    0.00  0.00    580    594   22.4 -10.5 1015  49       205SCT205    0.0   15.0
 51 06/29 15Z   91     68     285      10    0.00  0.00    581    594   23.2  -9.7 1015   0          CLR       0.0   15.0
 54 06/29 18Z   99     68     301       8    0.00  0.00    582    594   22.7  -9.0 1013   0          CLR       0.0   15.0
 57 06/29 21Z  102     67     288       7    0.00  0.00    584    593   24.6  -9.1 1010   0          CLR       0.0   15.0
 60 06/30 00Z   98     67     273       6    0.00  0.00    584    593   25.1  -9.6 1010   0          CLR       0.0   15.0
 63 06/30 03Z   92     67     256       5    0.00  0.00    583    593   24.6 -10.3 1012   0          CLR       0.0   15.0
 66 06/30 06Z   84     67     259       7    0.00  0.00    583    592   24.9 -10.9 1011   0          CLR       0.0   15.0
 69 06/30 09Z   80     67     272       6    0.00  0.00    582    592   25.2 -11.7 1012  77       194BKN194    0.0   15.0
 72 06/30 12Z   81     69     279       6    0.00  0.00    581    592   25.3 -11.7 1012  81       188BKN201    0.0   15.0
 75 06/30 15Z   93     70     307       7    0.00  0.00    581    592   26.0 -11.6 1013  61       215BKN229    0.0   15.0
 78 06/30 18Z  104     67       5       2    0.00  0.00    583    592   26.0 -10.8 1011  39       175SCT311    0.0   15.0
 81 06/30 21Z  106     65     227       4    0.00  0.00    584    592   27.3 -10.7 1009  15       313FEW430    0.0   15.0
 84 07/01 00Z   99     70     251       3    0.13  0.13    583    592   26.9  -8.1 1010  38 TSRA  102SCT407    0.0    1.7

[Cheeznado]

12Z Euro still insisting on 28C at 850 over north GA Friday and Saturday.....

[HurricaneTracker]

12Z Euro still insisting on 28C at 850 over north GA Friday and Saturday.....

Ouch. Under perfect conditions, that would translate to 105-110* surface temperatures. That does seem too warm to me, but it has been as consistent in this as the GFS has been with its 24-26C 850mb temps.

[Stormsfury]

I wouldn't doubt it.....sigh

Ugh.....

This thread is depressing

I don't want record heat I've seen enough records broken here between the portals these past few years to last me a lifetime

One bright spot I hope, is that the upcoming heat wave is as fleeting as the quick snap cold shots we had this past winter, hit hard, and gone in a flash.

[jburns]

One bright spot I hope, is that the upcoming heat wave is as fleeting as the quick snap cold shots we had this past winter, hit hard, and gone in a flash.

In this case, the flash could be spontaneous combustion.

[Stormsfury]

Even if they do verify, I think the bigger question is what is the mixing depth during the peak heating hours? On August 21, 1983, the day that Asheville hit 100*, the mixing depth on the GSO sounding was nearly to 550mb. Even at 12Z, it was up to 700mb. If the depth of the true mid-level thicknesses can be tapped, I think widespread low 100s in the piedmont and midlands of NC/SC are likely.

Positioning of the strongest heights along with the lee side trough I believe maximizes downsloping, particularly in the Piedmont. TD's should be able to mix out into the low-mid 60's (maybe lower) at the very least which will make the ambient temperature the bigger issue. Points Southward from KCAE, areas like Savannah, Charleston, and points about 50 miles inland from the coast will likely see dewpoint pooling, particularly in the afternoon when sea breeze circulations try to make progress inland, soaring dewpoints (soaring excessive heat warning criteria heat indices), but given NW flow aloft, that process will probably be delayed until very late in the afternoon.

Reanalysis 850mb Temperatures, 500mb streamlines Aug 21 1983

[griteater]

From Raleigh aftn update...

EARLY SEASON HEAT WAVE COMMENCES THIS PERIOD AS MID/UPPER LEVEL ANTI-CYCLONE OVER THE WESTERN TN VALLEY DRIFTS ESE TO A POSITION OVER GA BY SATURDAY. LOW LEVEL THICKNESSES AVERAGING AROUND 1460M...ABOUT 40M ABOVE NORMAL...YIELDING MAX TEMPS AS MUCH AS 11-14 F DEGREES ABOVE NORMAL. REVIEW OF WARM SEASON ANALOGS SUGGEST THAT CURRENT MODEL 850MB TEMP FORECAST (24-28 DEG C) MAY BE WAY TOO WARM...PRODUCING THE WELL ABOVE NORMAL THICKNESSES. THUS HAVE EDGE MAX TEMPS DOWN A COUPLE OF DEGREES FROM THE PREVIOUS FORECAST AND ENDED UP WITH MAX TEMPS FRIDAY 97-100 DEGS F...AND 98-102 ON SATURDAY.

[toxictwister00]

Afternoon forecast update from KFFC has added 100 for Saturday/Sunday now for ATL. Eventhough they have been sounding skeptical about it, I think they'll reconsider issuing Heat Advisories this weekend. They seemed to wanted to hold back on that call yesterday because of the heat index.

Saturday: Sunny and hot, with a high near 100.

Saturday Night: Mostly clear, with a low around 75.

Sunday: Mostly sunny and hot, with a high near 100.

[GaWx]

12Z Euro still insisting on 28C at 850 over north GA Friday and Saturday.....

I see it held at +28 C for KATL, itself, which is similar to today's 0Z Euro run and is 1 C cooler than yesterday's Euro runs' +29 C. I'm educatedly guessing that the Euro fcast will drop at least to +27 C by tomorrow's 12Z run and to at least down to +26 C by Friday's 12Z run for KATL as of 0Z on 6/30. It will be interesting to follow what actually occurs.

[Stormsfury]

Since I've gotten into this mode, I'm pulling up some reanalysis maps from some of the hottest temperatures I've found (as in all time records, trying to stick with June, but will include some selected high temperature records for varying locations, if I can find specific dates for areas). The August 21, 1983 map will also coincide with the all time North Carolina record temperature set with 110º at Fayetteville NC on that same day Asheville hit 100º. The day before it appears Georgia's all time state record was hit at Greenville, GA with 112º on August 20th, 1983 (and the map was nowhere near as impressive as the 8/21/83 reanalysis regarding 850mb temperatures and the highest 850mb temperature sat in SW VA).

I want to start with June 28th, 1954, in which Camden SC set (or tied) the all time hottest temperature record with 111º. Downslope maximized with compressional heating from a backdoor feature (as apparent with the upper low in the far NE US). 850mb temperatures well below the forecast 850mb for the upcoming weekend.

Columbia's 107º June record occurred on 6/27/1954, a feat that has been tied several times, the most recent being in August of 2007.

Camden's 111º on June 28th, 1954. (Thank Goodness for the Auto Save Feature!)

Charleston, SC had dual 104º readings (at that time was the all time record for KCHS, which would be broken on August 1st, 1999 at 105º). I used July 1986 for KCHS because of the impressive string of 100º days that occurred in that month, which I believe was 11 or 13 times that month, a feat that hasn't even come close since for KCHS.

July 21st, 1986 (00z) extreme heat Southeast, including the previous all-time record high for Charleston, SC. I also believe that Columbia's 107º also occurred many times in July 1986 including this date but I cannot find the information at the moment.

Just for comparison, this is last year June 20-21, 2011 when the Charleston area reached 102º two days in a row.

I can't right off hand think of any other days to look at and need to get some other things done at this time. All the forecasted 850mb temperatures are pretty much well over what we're seeing now but it boils down to favorable wind trajectories both surface and aloft to maximize full thickness potentials (also of course boils down to convective potential as well putting a hamper in some spots)