Shawn Posted October 3, 2015 Share Posted October 3, 2015 Interesting, for those who thought it was over for the Central Midlands and Upstate. MESOSCALE PRECIPITATION DISCUSSION 0547NWS WEATHER PREDICTION CENTER COLLEGE PARK MD359 PM EDT SAT OCT 03 2015AREAS AFFECTED...PORTIONS OF NC, SC, NORTHERN GACONCERNING...HEAVY RAINFALL...FLASH FLOODING LIKELYVALID 031958Z - 040158ZSUMMARY...HEAVY RAINFALL WITHIN THE WARM CONVEYOR BELT OF ANOCCLUDED CYCLONE IS EXPECTED TO LENGTHEN/WORSEN THE FLASH FLOODEVENT. CATASTROPHIC FLASH FLOODING IS POSSIBLE.DISCUSSION...HEAVY RAIN CONTINUES TO FALL WITHIN THE WARM CONVEYORBELT OF AN OCCLUDED CYCLONE. WHILE CONVECTION HAS BEENCONCENTRATING OFFSHORE NEAR ITS TRIPLE POINT LOW, SOME COOLING HASBEEN NOTED ON SATELLITE IMAGERY IN THE WESTERN CAROLINAS ANDNORTHEAST GA. OTHER THUNDERSTORMS HAVE BEEN FORMING NEAR ACOASTAL FRONT IN EASTERN NC, AIMING TOWARDS AN AREA THAT HAVERECENTLY RECEIVED HEAVY RAINFALL IN SOUTHERN NC. PRECIPITABLEWATER VALUES OF 1.7-2.1" LIE ACROSS THIS AREA, AT LEAST 1.5 SIGMASABOVE THE MEAN FOR EARLY OCTOBER. INFLOW AT 850 HPA IS 30-50 KTS,ROUGHLY THE MAGNITUDE OF THE 850-400 HPA MEAN WIND. RAINFALLAMOUNTS DURING THE PAST SIX HOURS IN THIS REGION HAVE BEEN ROUGHLY3-6", WHICH HAS A RECURRENCE INTERVAL OF 10 YEARS. THE RAINFALLDURING THE PAST 24 HOURS HAS GENERALLY REACHED THE 100 YEARRECURRENCE INTERVAL, WITH ISOLATED AREAS REACHING THE 1000 YEARRECURRENCE INTERVAL, AND MORE RAIN IS COMING.THE CAM GUIDANCE INDICATES THAT ANOTHER 4-7" OF RAIN SHOULD FALLDURING THE NEXT SIX HOURS, COMPOUNDING CURRENT FLASH FLOOD ISSUES.RADAR ESTIMATES ACROSS THE PIEDMONT/SOUTHERN APPALACHIANS HAVEBEEN RUNNING ~50% TOO LOW, MASKING THE MAGNITUDE OF THE RAINFALLISSUES. IN THE MOUNTAINS, MUDSLIDES AND LANDSLIDES AREANTICIPATED. IN THE LOW LANDS, FLAT SHEETS OF WATER COULD RISE INAREAS WHERE RAIN RATES EXCEED 2" AN HOUR, WHOSE IMPACTS WOULD BESIGNIFICANT IN THE URBAN AREAS OF CHARLESTON, COLUMBIA, AUGUSTA,GREENVILLE/ SPARTANBURG, AND THE NORTHEASTERN ATLANTA SUBURBS.CONSIDERING THE AVAILABLE INSTABILITY AND THE EXPECTED INCREASE IN850 HPA INFLOW IN THE SOUTHERN APPALACHIANS, RAIN RATES OF 1.5"ARE POSSIBLE IN THE SOUTHERN APPALACHIANS WITH RATES CLOSER TO 3"AN HOUR POSSIBLE WHERE CELLS TRAIN CLOSER TO THE COASTAL FRONT INNORTHEAST GA, CENTRAL SC AND SOUTHERN NC. FLASH FLOODING ISLIKELY, WHICH COULD BECOME CATASTROPHIC GIVEN THE SATURATED SOILSAND ONGOING FLOODING IN THE REGION.ROTH Link to comment Share on other sites More sharing options...
NRVwxfan. Posted October 3, 2015 Share Posted October 3, 2015 It has warmed up, and its raining heavily here. Link to comment Share on other sites More sharing options...
Solak Posted October 3, 2015 Share Posted October 3, 2015 Not to make light of the situation, but how the heck do they know what a 1000 year occurrence is? Link to comment Share on other sites More sharing options...
NRVwxfan. Posted October 3, 2015 Share Posted October 3, 2015 Not to make light of the situation, but how the heck do they know what a 1000 year occurrence is? According to what someone way saying is that there is a .1% chance of a rain event like this occuring. So, its a probability thing. Link to comment Share on other sites More sharing options...
No snow for you Posted October 3, 2015 Share Posted October 3, 2015 Not to make light of the situation, but how the heck do they know what a 1000 year occurrence is? Standard deviation would be my guess. 1 day out of 365k? Link to comment Share on other sites More sharing options...
dwagner88 Posted October 3, 2015 Share Posted October 3, 2015 Not to make light of the situation, but how the heck do they know what a 1000 year occurrence is? Short answer: Statistics. Link to comment Share on other sites More sharing options...
Solak Posted October 3, 2015 Share Posted October 3, 2015 Thanks. Link to comment Share on other sites More sharing options...
sctvman Posted October 3, 2015 Share Posted October 3, 2015 Still a huge mess in the Lowcountry. CARTA bus service is closed down, there's many restaurants around downtown not open, losing an important weekend day, and the street closings are numerous. Watching the Alabama-Georgia game (the Gamecocks played poorly today) and Channel 5 is scrolling road closings. Link to comment Share on other sites More sharing options...
NRVwxfan. Posted October 3, 2015 Share Posted October 3, 2015 Still a huge mess in the Lowcountry. CARTA bus service is closed down, there's many restaurants around downtown not open, losing an important weekend day, and the street closings are numerous. Watching the Alabama-Georgia game (the Gamecocks played poorly today) and Channel 5 is scrolling road closings. Wow, thats not good. Looks like Bama is destroying Georgia right now. Link to comment Share on other sites More sharing options...
Stormsfury Posted October 3, 2015 Share Posted October 3, 2015 Don't look now but the next round us taking shape SSE of Charleston amd Dorchester Counties. It's clearly not done with us yet. Link to comment Share on other sites More sharing options...
rosie Posted October 3, 2015 Share Posted October 3, 2015 Flash flood warning here for Nottely and Hiawassee rivers. Steady rain all day. Link to comment Share on other sites More sharing options...
No snow for you Posted October 3, 2015 Share Posted October 3, 2015 What time is the line suppose to start to pivot? Link to comment Share on other sites More sharing options...
Stormsfury Posted October 3, 2015 Share Posted October 3, 2015 Charleston (CHS) has had 9.28" since the 12z observation on October 1st. Quick update: KCHS 6.44" at the 5pm climate data entry. Monthly total now 9.41" for Oct. Link to comment Share on other sites More sharing options...
Tony Sisk Posted October 3, 2015 Share Posted October 3, 2015 Weather forecasting models have become too much dependent on clown stats. I believe there needs to be some carefulness, because people are beginning to not have confidence in forecasting. Don't need to let the guard down. Link to comment Share on other sites More sharing options...
max100 Posted October 3, 2015 Share Posted October 3, 2015 Weather forecasting models have become too much dependent on clown stats. I believe there needs to be some carefulness, because people are beginning to not have confidence in forecasting. Don't need to let the guard down. Exactly, 20 inches of rain is insane, who the hell wants that in their backyard?? Link to comment Share on other sites More sharing options...
buckeyefan1 Posted October 3, 2015 Share Posted October 3, 2015 Weather forecasting models have become too much dependent on clown stats. I believe there needs to be some carefulness, because people are beginning to not have confidence in forecasting. Don't need to let the guard down. what? Link to comment Share on other sites More sharing options...
jburns Posted October 3, 2015 Share Posted October 3, 2015 what? Surely he didn't mean that the way it read. Link to comment Share on other sites More sharing options...
Cold Rain Posted October 3, 2015 Share Posted October 3, 2015 what? Yeah I was having trouble with that too. I think he meant that entire sentence without the word "models" in there. Link to comment Share on other sites More sharing options...
franklin NCwx Posted October 3, 2015 Share Posted October 3, 2015 Exactly, 20 inches of rain is insane, who the hell wants that in their backyard??Shetley? Been pouring here almost all day. Hope the rain tapers off soon. Link to comment Share on other sites More sharing options...
buckeyefan1 Posted October 3, 2015 Share Posted October 3, 2015 Surely he didn't mean that the way it read. Indeed Yeah I was having trouble with that too. I think he meant that entire sentence without the word "models" in there. Okay....I'll go with that story Anywho.......it's still raining here. My daughter in Spartanburg(Chesnee hwy) has this little trickle of a stream that runs across the street from her house. It is now an angry torrent Link to comment Share on other sites More sharing options...
No snow for you Posted October 3, 2015 Share Posted October 3, 2015 Do you mind me asking again. When is te tilt suppose to start? Link to comment Share on other sites More sharing options...
dsaur Posted October 3, 2015 Share Posted October 3, 2015 Indeed Okay....I'll go with that story Anywho.......it's still raining here. My daughter in Spartanburg(Chesnee hwy) has this little trickle of a stream that runs across the street from her house. It is now an angry torrent Darlin' I'm glad ya'll were able to repurpose those portals into rain generators! It's just when the rain comes out of a hell portal there is no way to control it, lol. I hope you don't end up with a bit too much Still, no better way to beat the drought, than to stomp it back thru the portals! Tony Link to comment Share on other sites More sharing options...
jshetley Posted October 3, 2015 Share Posted October 3, 2015 It has warmed up here and feels more tropical outside, with dewpoints up 10 degrees or so since this morning. It isn't time to let your guard down yet because of that change in dewpoints. It may be only in a few areas now, but if a band of thunderstorms forms and trains over an area, it may drop 3-5 inches in 1-2 hours. We had that happen here in 1990 after the major widespread rain had ended from a tropical storm. A band about 15 miles wide gave Union, Cherokee, eastern Laurens, and much of Spartanburg counties up to 5 inches of rain in 2 hours, on top of around 5-8 over the previous 3 days. Needless to say flash flooding was widespread and many creeks and rivers were above their floodstage for days. By the way, 1 such band is ongoing right now from near the Charleston doppler site, east southeast to the coast and beyond. That area is in trouble. Link to comment Share on other sites More sharing options...
yotaman Posted October 3, 2015 Share Posted October 3, 2015 What time is the line suppose to start to pivot? According to what I have read, it should start some time late tonight. Link to comment Share on other sites More sharing options...
Solak Posted October 4, 2015 Share Posted October 4, 2015 US National Weather Service Greenville-Spartanburg SC Just now · Here's the additional rainfall expected Tonight and Sunday. The axis of heaviest rainfall will shift south and west across the area to the Upper Savannah River Valley and Lower Piedmont of the Upstate. High water levels are occurring all across the area, so keep alert, even where lighter amounts of rainfall are expected. Turn around...Don't drown! #gawx #scwx #ncwx Link to comment Share on other sites More sharing options...
mackerel_sky Posted October 4, 2015 Share Posted October 4, 2015 Do you mind me asking again. When is te tilt suppose to start?Te tilt tas tarted! The heavy band is mostly S of CAE and GSP Link to comment Share on other sites More sharing options...
AJF0602 Posted October 4, 2015 Share Posted October 4, 2015 On top of the crazy flooding, charleston is under a severe thunderstorm warning now. Link to comment Share on other sites More sharing options...
sctvman Posted October 4, 2015 Share Posted October 4, 2015 For the last 45 minutes we have been under yellows here. Probably 2-3" just in the last 45 minutes to an hour. It just doesn't stop. Link to comment Share on other sites More sharing options...
Solak Posted October 4, 2015 Share Posted October 4, 2015 Incoming... round 4? 5? Link to comment Share on other sites More sharing options...
dan11295 Posted October 4, 2015 Share Posted October 4, 2015 Last 2 hours at CHS METAR KCHS 040056Z 12011KT 3SM R15/5500VP6000FT +TSRA BR SCT007 OVC014CB 23/22 A2956 RMK AO2 PK WND 10031/0043 WSHFT 0032 SLP010 OCNL LTGIC ALQDS TS ALQDS MOV NW P0162 T02330222 METAR KCHS 040156Z 15009KT 3SM R15/5500VP6000FT +TSRA BR SCT007 OVC011CB 23/22 A2958 RMK AO2 SFC VIS 4 SLP015 OCNL LTGIC NW-N TS NW-N MOV NW P0206 T02280217 3.68" in 2 hours.. Link to comment Share on other sites More sharing options...
Recommended Posts
Archived
This topic is now archived and is closed to further replies.