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Very Disturbing PRELIM DISC from HPC


Stormsfury

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So far, it's been quite mild across the region to start out June. in fact, last Saturday was the first 90 degree reading at KCHS the entire month, and most of the month has featured below normal temps. However, that unfortunately might potentially come to a halt as we near the end of June into July.

PRELIMINARY EXTENDED FORECAST DISCUSSION

NWS HYDROMETEOROLOGICAL PREDICTION CENTER CAMP SPRINGS MD

912 AM EDT MON JUN 25 2012

VALID 12Z FRI JUN 29 2012 - 12Z MON JUL 02 2012

...ALL-TIME JUNE RECORD HIGHS IN JEOPARDY ACROSS THE SOUTHEAST

THIRD OF THE COUNTRY...

PREFERENCES: 06Z GFS/00Z ECMWF FOR PRESSURES

00Z GEFS MEAN/00Z ECMWF FOR TEMPS AND POPS

THE GUIDANCE IS IN AGREEMENT THAT TROUGHING WILL PERPETUATE ACROSS

THE NORTHEAST AND NORTHWEST...WHILE MOST PLACES IN BETWEEN WILL BE

UNDER THE AEGIS OF AN EXPANSIVE WARM CORE RIDGE. WITHIN THE

WESTERLIES...THE 06Z GFS/00Z ECMWF WERE IN GOOD AGREEMENT

PRESSURE-WISE...SO USED THEM AS A TEMPLATE. IN THE SOUTHEAST...

THE NATIONAL HURRICANE CENTER'S/NHC'S LATEST GUIDANCE WAS

FOLLOWED...WHICH IS HEDGING TOWARDS THE QUICKER NON-UKMET

CONSENSUS. PLAYED DOWN THE PRECIPITATION THREAT DURING THE MEDIUM

RANGE PERIOD ACROSS THE SOUTHEAST AS THE SYSTEM IS NOW EXPECTED TO

TRACK MORE PROGRESSIVELY TO THE EAST.

LOCATIONS FROM THE CENTRAL PLAINS ACROSS THE MID-SOUTH/TENNESSEE

VALLEY INTO THE MID-ATLANTIC STATES AND CAROLINAS ARE EXPECTED TO

BAKE...SIZZLE...AND FRY THIS PERIOD DUE TO A BURGEONING WARM CORE

RIDGE BUILDING ACROSS THE REGION. THE 00Z ECMWF WAS THE HOTTEST

OF THE CURRENT GUIDANCE...WITH ITS ENSEMBLE MEAN EQUALLY

IMPRESSIVE. TO ACCOUNT FOR TEMPERATURE DIFFERENCES...WE FOLLOWED

A COMPROMISE OF THE 00Z GEFS MEAN AND 00Z ECMWF. TEMPERATURES AT

THE 850 HPA LEVEL ARE EXPECTED TO BE NEAR 27C/82F...WHICH WOULD

EQUATE TO TEMPERATURES APPROACHING 110F EACH AFTERNOON. IF DEBBY

DEPARTS FASTER THAN THE NHC FORECAST /OR REMAINS A STRONGER SYSTEM

THAN CURRENTLY ANTICIPATED/ ALONG THE LINES OF THE NON-UKMET

DETERMINISTIC GUIDANCE...HIGH TEMPERATURES COULD BE EVEN MORE

IMPRESSIVE IN ITS WAKE ACROSS THE SOUTHEAST AND MID-SOUTH.

ROTH

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I said this before and I'll say it again. YIKES! :yikes: I hope within the next day or two local and national forecasters start hyping this heatwave up if it continues to look this impressive on the models. Folks need time to start planning and preparing especially those who live without air conditioning.

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Been following this as well. ECMWF looked extremely warm at 850, with widespread +30, which looks overdone to me. The GFS though did have +27 over southern VA and northern NC Friday afternoon and the ridge placed just west, so that would equate to surface west winds mostly, which would only bring on more heat through downsloping, especially the Piedmont region.

There's a lot that could swing this either way. Ground moisture is one, and how much rain falls this week. I know its extremely dry in west Kentucky under where the core of the 594 heights will be on Thursday and Friday. Also, how much cirrus debris can drop southward from any MCC or frontal system in the Midwest...I know every year I see a cirrus canopy drop south to the Carolinas, which ends up messing up what would have been a truly miserable day, but it's hard to see that happening yet. But GFS does hint at a small cluster of storms in the Apps on Saturday (which would be slow movers , even assuming they break the extreme cap) And again on Saturday and Sunday evenings it generates some storms in north Alabama and the Tenn. Valley, so any debris from that would help some areas to stay under the absolute hot maxes forecasted.

One thing odd about this heat wave is the lack of a true round 594 height field. It's small and it ebbs and flows from Thursday, onward. Usually big heat waves have a very pronounced one. Also, the ECMWF is pushing that +30 temp very far east, I'm not sure I can recall ever seeing it even forecast that high a number this far east (its pretty common in western Plains heat waves though). Either way, going to get very hot, the only question is how hot. There's a lot of other factors that could hurt or help the temps achieve max status too, like where Debby's remains are and how strong it is. GFS lolligags it offshore Jacksonville, and if its in any kind of decent shape, that would be very bad news east of the Appalachians, through extreme subsidence and downsloping. It would be bad enough even without that there, but if things line up perfectly , widespread 100's are coming and some areas could surpass 105, maybe even touch 110, but I think a pretty wet ground may eat up some of the heat in part of the Carolinas, with recent convection.

Here's some stuff I put on my site earlier.

All time June Max temps through 2005:

post-38-0-46287000-1340646223_thumb.jpg

ECMWF surface temps Friday Forecast (120 hour issued 00z Mon)

post-38-0-58844800-1340646331_thumb.jpg

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The hottest June temperature in Asheville, NC is 99*F at the airport and 98*F in downtown (records go back to the 1870s here). Could we tie or top that here? It is really hard to get that warm here, but it obviously can be done. Is this the scenario that does it?

Point Forecast: Asheville NC

35.59°N 82.57°W Mobile Weather Information | En Español

Last Update: 2:47 pm EDT Jun 25, 2012

Forecast Valid: 4pm EDT Jun 25, 2012-6pm EDT Jul 2, 2012 Preview a redesign of the NWS forecast pages Late

Hi 86 °F Tonight

/images/wtf/hi_ntsra20.jpg

Isolated

Tstms

Lo 58 °F Tuesday

/images/wtf/few.jpg

Sunny

Hi 76 °F Tuesday

Night

/images/wtf/nskc.jpg

Clear

Lo 50 °F Wednesday

/images/wtf/skc.jpg

Sunny

Hi 83 °F Wednesday

Night

/images/wtf/nskc.jpg

Clear

Lo 56 °F Thursday

/images/wtf/few.jpg

Sunny

Hi 90 °F Thursday

Night

/images/wtf/nfew.jpg

Mostly

Clear

Lo 59 °F Friday

/images/wtf/hot.jpg

Hot

Hi 99 °F

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Yes...and the point forecast for Flat Creek, NC (just south of Weaverville) is for 100 on the nose. Impressive!

I'm getting concerned this heat isn't getting enough attention. We are talking about breaking (maybe even shattering) all time June maximum temperature records. And based on what I see on the GFS, it looks like it starts Thursday and goes into the following week. It is shaping up to be a prolonged heat wave.

Point Forecast: Asheville NC

35.59°N 82.57°W Mobile Weather Information | En Español

Last Update: 2:47 pm EDT Jun 25, 2012

Forecast Valid: 4pm EDT Jun 25, 2012-6pm EDT Jul 2, 2012 Preview a redesign of the NWS forecast pages Late

Hi 86 °F Tonight

/images/wtf/hi_ntsra20.jpg

Isolated

Tstms

Lo 58 °F Tuesday

/images/wtf/few.jpg

Sunny

Hi 76 °F Tuesday

Night

/images/wtf/nskc.jpg

Clear

Lo 50 °F Wednesday

/images/wtf/skc.jpg

Sunny

Hi 83 °F Wednesday

Night

/images/wtf/nskc.jpg

Clear

Lo 56 °F Thursday

/images/wtf/few.jpg

Sunny

Hi 90 °F Thursday

Night

/images/wtf/nfew.jpg

Mostly

Clear

Lo 59 °F Friday

/images/wtf/hot.jpg

Hot

Hi 99 °F

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Wow, not good. It's difficult to break 100 here; I don't think we've done so since 2007 (and that was in Atlanta, normally a bit hotter than we are). But it looks like triple digits are within reach here. FFC is only calling for 96 Friday, which is probably reasonable seeing that the miserable excuse for a TC will play a big part in how hot we get, and it seems to be pretty tough to figure out where she's going.

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Good thing we just had the car in the shop for it's 60,000 mile physical and new tires.. We're driving from Raleigh to Gatlinburg on Thursday, then poke around the mountains Friday and Saturday before coming home late on Sat. Really hating the fact that no one will be here to water the gardens during this hot and dry event. They wilt right now in 90° heat if I miss a spot for a couple days.

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sf - good to see a post from you. it usually means interesting weather lol. however, after reading the thread and about the heat i may take that back :) after a relatively mild and damp spring and early summer this heat will be a slap in the face. even if we end up not breaking any records, heat close or near to a record is still going to be sweltering

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Just like a lot of forecasters made a grave mistake with the initial track of Debby, I'm afraid some people may be going overboard with the weekend heat... I'm not saying its going to be hot but widespread low-mid 100's takes a lot of things to happen in order to pull it off across the Southeast.

I noticed one of the TV Mets is going with 97 in Asheville on Friday...really? 97? I don't ever remember in my lifetime Asheville getting much higher than 93 or 94.

Be careful with the numerical data from the GFS. All it would take is ground moisture or high cirrus debris to put a bust on those temps. 97-101 should be common for anyone outside of the North Carolina mountains but even ground moisture could play a trick on those temps or the slightest advection of moisture.

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It almost feels like winter when waiting on a developing snowstorm looking at some of the local forecasters' forecast for this heatwave. Noone seems to have the balls to put a 100 out there yet. Our FOX affiliate is getting close to doing it for this weekend which I think might be our best chance. The only ones who seem to be putting all the cards on the table are TWC, Accuweather, and Wunderground that I've seen. Speaking of Wunderground, I think they're getting a little carried away on the heat for Friday and Saturday forecasting 108 and 106 those days here respectfully.

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Just like a lot of forecasters made a grave mistake with the initial track of Debby, I'm afraid some people may be going overboard with the weekend heat... I'm not saying its going to be hot but widespread low-mid 100's takes a lot of things to happen in order to pull it off across the Southeast.

I noticed one of the TV Mets is going with 97 in Asheville on Friday...really? 97? I don't ever remember in my lifetime Asheville getting much higher than 93 or 94.

Be careful with the numerical data from the GFS. All it would take is ground moisture or high cirrus debris to put a bust on those temps. 97-101 should be common for anyone outside of the North Carolina mountains but even ground moisture could play a trick on those temps or the slightest advection of moisture.

i agree. No way the foothills or mountains approach the upper 90's with soil moisture so high around here.

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i agree. No way the foothills or mountains approach the upper 90's with soil moisture so high around here.

What soil moisture? We are WAY below normal in rainfall for the month! My grass is brown and the ground is rock hard. Any "moisture" will quickly go away today and tomorrow with a dry airmass and nearly clear skies. I think 97 is readily achievable in Asheville on Friday. Yes, I have the balls to say it!

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GFS MOS MEX is probably closer to reality, with 93 at AVL for Sat and Sun

Both the GFS and now the NAM are showing 850mb temperatures between +25 and +27 in the mountains on Friday and Saturday. Dry adiabatically, that results in a range of 100-104. Accounting for elevation, and using the latest 800mb temperatures of 22-24C, that should be easy mid-90s in Asheville. And that's just dry adiabatically. Accounting for dry soils and full sunshine, 95-98 seems likely to me on Friday and Saturday in the mountains.

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What soil moisture? We are WAY below normal in rainfall for the month! My grass is brown and the ground is rock hard. Any "moisture" will quickly go away today and tomorrow with a dry airmass and nearly clear skies. I think 97 is readily achievable in Asheville on Friday. Yes, I have the balls to say it!

Asheville Regional had a slight surplus in precip for the year going into the month...granted June has been dry but overall there is still plenty of ground moisture...if this was 5 years ago when we were a desert oasis, then I could buy your argument. One thing I will agree is that since June has been dry, we're in need for some rain because dry conditions can develop quickly in this pattern.

IMO I would be stunned if KAVL made it to 97...even more shocking is that if Asheville does make it to 97, then what will the high be along the immediate lee of the mountains?

Regardless, it will be interesting to see what happens.

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