FoothillsNC Posted June 14, 2011 Share Posted June 14, 2011 Text below is from the NWS Disco for SE GA. Can someone explain 'compressional heating ahead of the front'? FURTHER SOUTH IN GA THERE IS SOME RESTRICTION IN INSOLATION DUE TO THE SMOKE...BUT COMPRESSIONAL HEATING AHEAD OF THE FRONT...A NW TO NORTH SYNOPTIC FLOW OVER MANY AREAS INLAND AND LESS RISK OF CONVECTION POINTS TOWARD ANOTHER VERY HOT DAY. PRETTY MUCH EVERYWHERE NEAR AND EAST OF I-95 WILL REACH 95-100 DEGREES. As air goes from any higher location to a lower location, relative to sea level, the air is compressed. The reverse is when air goes from lower elevations to higher elevations, thats called expansional cooling. Both of these processes are just laws in Chemistry, and involve moisture in the airmass and pressure. "Dry and moist adiabatic temp. changes) . In this case air is going across the mtns in GA and toward the coastal regions in downslope motion, when you combine that with the fact there is little moisture to absorb any heating ( low dewpoints), and the sunshine currently, and a front in the area that squeezes the flow (thats friction...another heating process) then you can see how it gets hot at the surface. Same idea when a closed ridge of high pressure sits near or slightly west of the Apps. chain. Clockwise flow around the dome sinks even more coming off the Apps and heats further, which usually causes dewpoints to mix out. I've personally experienced that the last 3 Summers here when my Dewpoints were in the upper 40's in the afternoon, while just south and east were in the upper 50s, and evntually 60s' in the eastern piedmont...just perfect downsloping/compressional heating. Link to comment Share on other sites More sharing options...
griteater Posted June 14, 2011 Share Posted June 14, 2011 Thanks for the explanation Foothills. I just didn't think that downsloping off the mtns. would affect areas all the way to the coast. Link to comment Share on other sites More sharing options...
jrips27 Posted June 14, 2011 Share Posted June 14, 2011 Feels great at Turner Field. Nice breeze and low humidity! Link to comment Share on other sites More sharing options...
FoothillsNC Posted June 15, 2011 Share Posted June 15, 2011 missed being on this morning...glad its back. Here's what I woke up to this morning. It felt amazing and was much lower than forecast in the Carolinas, esp. this area. Next up is the quick turn around. The warm front will be ushering into TN and GA soon, should develop a quick but pretty intense line by this evening and crosses the Apps around midnight. Link to comment Share on other sites More sharing options...
dsaur Posted June 15, 2011 Share Posted June 15, 2011 The GFS continues to bring a low out of the gulf late in the period and drag it across Ga. This feels oddly familiar....oh, yeah, hoping for that snow showing way out in GoofyLand It is trying to give me showers in the near term, but I'm not holding my breath after this last weeks successes in mby. The cracks in the ground are now cracking around here. T Link to comment Share on other sites More sharing options...
jrips27 Posted June 15, 2011 Share Posted June 15, 2011 Glad this place is back up. Well today looks interesting as far as severe weather goes. SPC has issued a slight risk (see Robert's post for map.) We will have a moist and moderately unstable air mass in place. With highs in the low 90's here near Atlanta we will see CAPE climb. Also will have decent shear. From SPC: " THE MORE PROBABLE LOCATION FOR SEVERE STORMS LATER TODAY WILL RESIDE ALONG THE SRN FRINGE OF THE MORE WIDESPREAD CLOUDS AND CONVECTIVE OUTFLOW ACROSS PARTS OF KY/TN SWD ALONG RETREATING WARM FRONT INTO AL/GA. HERE...THE COMBINATION OF BOUNDARY LAYER DEWPOINTS IN THE 60S...STEEP MIDLEVEL LAPSE RATES AND CORRIDORS OF STRONGER DAYTIME HEATING WILL YIELD MLCAPE VALUES INCREASING TO 1500-3000 J/KG. SUPERCELLS AND BOWING STRUCTURES WILL BE POSSIBLE CONVECTIVE MODES GIVEN THE PRESENCE OF 40-45 KT DEEP WNWLY SHEAR. DAMAGING WINDS AND HAIL APPEAR TO BE THE PRIMARY HAZARDS WITH THE MOST INTENSE STORMS THROUGH THIS EVENING." Wouldn't be surprised to see some Severe Thunderstorm Watches go up later. Maybe even a Tornado Watch here or there. Link to comment Share on other sites More sharing options...
phil882 Posted June 15, 2011 Share Posted June 15, 2011 Really concerned about the afternoon potential across Tennessee and North Georgia... warm front is moving across the region currently, and we should be engulfed in a region of high CAPE and decent Shear. SPC mentioned bowing segments and supercells as the general storm mode this afternoon and its hard to disagree looking at the soundings. You won't often see such a favorable shear setup this far south during the summer. I'll have more in a bit when I update my blog. Link to comment Share on other sites More sharing options...
buckeyefan1 Posted June 15, 2011 Share Posted June 15, 2011 Glad this place is back up. Well today looks interesting as far as severe weather goes. SPC has issued a slight risk (see Robert's post for map.) We will have a moist and moderately unstable air mass in place. With highs in the low 90's here near Atlanta we will see CAPE climb. Also will have decent shear. From SPC: " THE MORE PROBABLE LOCATION FOR SEVERE STORMS LATER TODAY WILL RESIDE ALONG THE SRN FRINGE OF THE MORE WIDESPREAD CLOUDS AND CONVECTIVE OUTFLOW ACROSS PARTS OF KY/TN SWD ALONG RETREATING WARM FRONT INTO AL/GA. HERE...THE COMBINATION OF BOUNDARY LAYER DEWPOINTS IN THE 60S...STEEP MIDLEVEL LAPSE RATES AND CORRIDORS OF STRONGER DAYTIME HEATING WILL YIELD MLCAPE VALUES INCREASING TO 1500-3000 J/KG. SUPERCELLS AND BOWING STRUCTURES WILL BE POSSIBLE CONVECTIVE MODES GIVEN THE PRESENCE OF 40-45 KT DEEP WNWLY SHEAR. DAMAGING WINDS AND HAIL APPEAR TO BE THE PRIMARY HAZARDS WITH THE MOST INTENSE STORMS THROUGH THIS EVENING." Wouldn't be surprised to see some Severe Thunderstorm Watches go up later. Maybe even a Tornado Watch here or there. They give me hope for day 2 ...MID-ATLANTIC AND SERN STATES... A WEAKENING LEAD IMPULSE SHOULD BE MOVING ACROSS THE MID-ATLANTIC STATES/DELMARVA REGION DURING THE EARLY PART OF DAY 2...WITH NEUTRAL TO WEAK HEIGHT RISES IN ITS WAKE THROUGH THURSDAY AFTERNOON. SHOWERS AND EMBEDDED TSTMS ARE FORECAST TO TRACK ACROSS MD/VA/DEL AND NC THURSDAY MORNING/EARLY AFTERNOON...AND SHOULD TEND TO LIMIT STRONGER DESTABILIZATION ACROSS THESE AREAS. MEANWHILE... SSWLY LOW LEVEL WINDS WILL SPREAD MOISTURE NWD IN LEE OF THE SRN/CENTRAL APPALACHIANS. THIS COMBINED WITH SURFACE HEATING IN THE WAKE OF MORNING ACTIVITY AND AHEAD OF THE APPROACHING COLD FRONT SHOULD SUPPORT A NARROW CORRIDOR OF MODERATE INSTABILITY FROM CENTRAL VA INTO WRN NC...AND SWD ACROSS THE SERN STATES. EFFECTIVE BULK SHEAR SHOULD BE STRONGER /UP TO 35 KT/ ACROSS VA/NC SUPPORTIVE FOR POTENTIAL SUPERCELLS...WHILE FARTHER S...BULK SHEAR SHOULD BE MORE FAVORABLE FOR MULTICELLS ACROSS SC/GA. GIVEN THESE FACTORS COMBINED WITH SOME UNCERTAINTY IN DEGREE OF DESTABILIZATION WITH NWD EXTENT DUE TO EARLY DAY CONVECTIVE CLOUDINESS...15 PERCENT SEVERE PROBABILITIES WILL BE MAINTAINED WITH THIS OUTLOOK ISSUANCE. Link to comment Share on other sites More sharing options...
november rain Posted June 15, 2011 Share Posted June 15, 2011 missed being on this morning...glad its back. Here's what I woke up to this morning. It felt amazing and was much lower than forecast in the Carolinas, esp. this area. Next up is the quick turn around. The warm front will be ushering into TN and GA soon, should develop a quick but pretty intense line by this evening and crosses the Apps around midnight. Woke up to 61 here and it was so nice but I guess it will be time to pay for it come this weekend. Link to comment Share on other sites More sharing options...
phil882 Posted June 15, 2011 Share Posted June 15, 2011 The hi-res rapid refresh is really going crazy with the convection out to our west later this afternoon... I'm wondering if things might end up a little bit more discrete considering there really isn't a line of convection moving out of AR right now. Link to comment Share on other sites More sharing options...
POWERSTROKE Posted June 15, 2011 Share Posted June 15, 2011 Feels great at Turner Field. Nice breeze and low humidity! ashame they loss last night. I was there last year when it was 97 first week of August Link to comment Share on other sites More sharing options...
1234snow Posted June 15, 2011 Share Posted June 15, 2011 Like Weatherkid mentioned it is getting moist and unstable across TN, MS, AL and GA as thunderstorms are popping in most of TN at the moment. Precipitable Water: LI's: CAPE: Shear: Link to comment Share on other sites More sharing options...
jrips27 Posted June 15, 2011 Share Posted June 15, 2011 The hi-res rapid refresh is really going crazy with the convection out to our west later this afternoon... I'm wondering if things might end up a little bit more discrete considering there really isn't a line of convection moving out of AR right now. Wow that looks impressive. SPC mentions the possibility of a more supercell-like pattern in their forecast. I'm looking forward to reading your blog update! ashame they loss last night. I was there last year when it was 97 first week of August Yeah tough game last night. Those afternoon games can be brutal! Especially if your in the sun. Link to comment Share on other sites More sharing options...
1234snow Posted June 15, 2011 Share Posted June 15, 2011 New MD is out MESOSCALE DISCUSSION 1229 NWS STORM PREDICTION CENTER NORMAN OK 1054 AM CDT WED JUN 15 2011 AREAS AFFECTED...FAR ERN AR/SERN MO INTO SRN KY...MUCH OF TN...NRN MS AND AL CONCERNING...SEVERE POTENTIAL...WATCH LIKELY VALID 151554Z - 151800Z STORMS SHOULD INCREASE OVER THE NEXT FEW HOURS...AND A WATCH IS LIKELY FOR DAMAGING WINDS AND LARGE HAIL. SURFACE MAP SHOWS LOW PRESSURE TROUGH ROUGHLY ALONG THE MS RIVER AND TRAILING SWWD ACROSS AR. MORNING CONVECTION FORCED BY WARM ADVECTION WAS QUICKLY MOVING EWD ACROSS THE OH/TN VALLEYS ALLOWING FOR RAPID DESTABILIZATION BEHIND. TEMPERATURES WERE ALREADY INTO THE UPPER 80S WITH DEWPOINTS IN THE LOWER 70S F AT 16Z. FURTHER...MORNING SOUNDINGS SHOWED IMPRESSIVE MID LEVEL LAPSE RATES ON THE ORDER OF 7.5 - 8.0 C/KM WHICH WILL RESULT IN STRONG INSTABILITY. CAPPING SHOULD BE REMOVED OVER THE NEXT FEW HOURS WITH SEVERAL CLUSTERS OF STORMS FORMING WITH WEAKLY CONVERGENT LOW LEVEL FLOW. 40-50 KT MID LEVEL FLOW WILL SUPPORT STORM ORGANIZATION WITH TIME. GIVEN HIGH PRECIPITABLE WATER...STEEP LAPSE RATES AND THE PROBABILITY OF HAIL LOADED DOWNDRAFTS...DAMAGING DOWNBURSTS ARE LIKELY. Link to comment Share on other sites More sharing options...
NavarreDon Posted June 15, 2011 Share Posted June 15, 2011 missed being on this morning...glad its back. Here's what I woke up to this morning. It felt amazing and was much lower than forecast in the Carolinas, esp. this area. Next up is the quick turn around. The warm front will be ushering into TN and GA soon, should develop a quick but pretty intense line by this evening and crosses the Apps around midnight. Got down to 51.2 at the house Robert. I must say it was chilly after the start to June. Mowed the lawn yesterday with a solid cloud cover that reminded me of a fall or winter pattern not mid june. A nice break as I am headed to the Panhandle of FL later today. Someone forgot to turn the oven off there! Heat indicies up to 108 Link to comment Share on other sites More sharing options...
Weather Czar Posted June 15, 2011 Share Posted June 15, 2011 Got down to 51.2 at the house Robert. I must say it was chilly after the start to June. Mowed the lawn yesterday with a solid cloud cover that reminded me of a fall or winter pattern not mid june. A nice break as I am headed to the Panhandle of FL later today. Someone forgot to turn the oven off there! Heat indicies up to 108 Woke up to a nice 50 this AM. Got down to 62 inside the house. Link to comment Share on other sites More sharing options...
phil882 Posted June 15, 2011 Share Posted June 15, 2011 Here are my thoughts for severe weather this afternoon... activity is already underway across Tennessee and Alabama, and it should only intensify this afternoon under ample heating and as the warm front continues to progress eastward. Activity in Georgia and the Carolinas shouldn't get going until PVA moves across the area by 3-5 PM. http://www.avlweatherblog.com/ Link to comment Share on other sites More sharing options...
phil882 Posted June 15, 2011 Share Posted June 15, 2011 Right on cue... Severe Thunderstorm Watch gets issued. Link to comment Share on other sites More sharing options...
DaculaWeather Posted June 15, 2011 Share Posted June 15, 2011 Thanks Phil! Link to comment Share on other sites More sharing options...
jrips27 Posted June 15, 2011 Share Posted June 15, 2011 Here are my thoughts for severe weather this afternoon... activity is already underway across Tennessee and Alabama, and it should only intensify this afternoon under ample heating and as the warm front continues to progress eastward. Activity in Georgia and the Carolinas shouldn't get going until PVA moves across the area by 3-5 PM. http://www.avlweatherblog.com/ Thanks for a great update Phil. So do you think we will see a watch issued for areas further south later in the afternoon? Link to comment Share on other sites More sharing options...
Marion_NC_WX Posted June 15, 2011 Share Posted June 15, 2011 The GFS for the past 3 days has been extremely persistant in opening the Gulf/Atlantic moisture pump for the last week of this month. This current pattern should last though the weekend bringing hotter and more moist air into the region. Then as we get into early and especially middle part of next week, the strong ridge that has been baking the Southern Plains and Southern States totally breaks down allowing the winds quicky develop and long southerly fetch... By Day 10, there's a well defined 850/500 vort coming from the Gulf of Mexico and stalling out over the Southeast before being kicked out by Day 14... This would most definitely bring an enhanced shot as rainfall across the Southeast especially the closer you are to the Gulf Coast...I'm courious as to our MET'S take on what the GFS has been advertising... Link to comment Share on other sites More sharing options...
phil882 Posted June 15, 2011 Share Posted June 15, 2011 Thanks for a great update Phil. So do you think we will see a watch issued for areas further south later in the afternoon? I certainly wouldn't be surprised... but the watch box currently depicts the area that will have the highest shear being in closer proximity to the surface low... its gonna take a little longer in the afternoon for convection to start ramping up into GA and the Carolinas because convective inhibition is still in place... PVA should help to break the cap this afternoon and by 21z, CIN is much lower across Georgia and East Tennessee. Note how much lower CIN is by 21z over ETN and Georgia. Link to comment Share on other sites More sharing options...
buckeyefan1 Posted June 15, 2011 Share Posted June 15, 2011 Day 2 now covers all of SC,Central/East NC and SE GA ...MIDDLE AND SRN ATLANTIC STATES... AS MAIN UPPER TROUGH SHIFTS NORTH OF THE REGION...WLY WINDS ALOFT WILL INCREASE TO 35 KT IN VA/NC AREA TO 25 KT IN SERN GA/NRN FL. WEAK SURFACE INFLECTION/TROUGH ASSOCIATED WITH UPPER TROUGH SHOULD BE LOCATED ALONG OR JUST EAST OF THE APPALACHIANS DURING THE DAY. SSELY BOUNDARY WINDS EAST OF THE HIGHER TERRAIN/SURFACE TROUGH AND AT LEAST WEAK LARGE SCALE LIFT SHOULD RESULT IN AT LEAST SCATTERED THUNDERSTORMS. IN AREAS WHERE MORNING CLOUDS AND PCPN DO NOT INHIBIT HEATING SIGNIFICANTLY...AIR MASS SHOULD BECOME MODERATELY UNSTABLE. THIS INSTABILITY COMBINED WITH VEERING WIND PROFILES AND STRONGER MID LEVEL WINDS FAVOR MULTICELL STORMS AND PERHAPS AN ISOLATED SUPERCELL STRUCTURE OR TWO. SEVERE HAIL AND DAMAGING WINDS SHOULD OCCUR WITH THE MORE INTENSE STORMS...ESPECIALLY WHERE THE INSTABILITY IS MAXIMIZED DURING THE AFTERNOON/EARLY EVENING HOURS. Link to comment Share on other sites More sharing options...
WilkesboroDude Posted June 15, 2011 Share Posted June 15, 2011 Anyone else stuck in the 60s and clouds in western North Carolina? Jefferson,NC was down to 48degrees this morning. I see the flare up of severe weather in Tennessee but will that maintain its momentum crossing the mountains? Link to comment Share on other sites More sharing options...
juspeachy Posted June 15, 2011 Share Posted June 15, 2011 We just broke the 80 degree mark here...mostly cloudy. Link to comment Share on other sites More sharing options...
SN_Lover Posted June 15, 2011 Share Posted June 15, 2011 Get ready Charlotte, NC for another heatwave. Might be worse then the one we just had. Link to comment Share on other sites More sharing options...
strongwxnc Posted June 15, 2011 Share Posted June 15, 2011 RT @DopplerNC: GSP Doppler down until further notice... GSP's systems down as well. CAE (Columbia) providing backup #ncwx #scwx Link to comment Share on other sites More sharing options...
phil882 Posted June 15, 2011 Share Posted June 15, 2011 Storms are going up quicker than expected in NC mountains... this first round will be discrete in nature and may drop some large hail. Link to comment Share on other sites More sharing options...
phil882 Posted June 15, 2011 Share Posted June 15, 2011 RT @DopplerNC: GSP Doppler down until further notice... GSP's systems down as well. CAE (Columbia) providing backup #ncwx #scwx Bad timing with the current system moving in. Link to comment Share on other sites More sharing options...
jrips27 Posted June 15, 2011 Share Posted June 15, 2011 RT @DopplerNC: GSP Doppler down until further notice... GSP's systems down as well. CAE (Columbia) providing backup #ncwx #scwx That sucks for those who want to use it. Bad timing. Link to comment Share on other sites More sharing options...
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