The Official 2014 Fall Discussion Thread

[FallsLake]

I love how RAH states that temps will "plunge" to near 80...... It's going to be a cold start to next week....

 

FOR SAT-TUE: STILL EXPECT A TRANSITION FROM THE WARM/HUMID WEATHER
TO MORE SEASONABLE CONDITIONS LATE IN THE WEEKEND. THE INITIAL MID
LEVEL TROUGH OVER ERN QUEBEC WILL CONTINUE SHIFTING EAST OVER THE
MARITIMES... WHILE A STRONG SLUG OF STRONG VORTICITY EMANATING FROM
A STRONG COLD VORTEX OVER THE BEAUFORT SEA WILL PUSH EASTWARD CLOSE
ON ITS HEELS... CROSSING HUDSON BAY ON SUNDAY. THIS SHOULD PUSH THE
SURFACE COLD FRONT TO JUST NW OF NC BY SUN... AND WELL INTO THE
STATE BY EARLY MON. BOTH THE GFS AND ECMWF TRACK THEIR COOL PARENT
HIGHS OVER THE ST LAWRENCE VALLEY/SRN QUEBEC MON/TUE... WITH THE
COLD FRONT PUSHING TO ERN NC AND ACROSS NWRN SC. THIS MODEL
AGREEMENT LEADS TO GROWING CONFIDENCE THAT THE PARENT HIGH WILL BE
DENSE ENOUGH TO PUSH THIS COOLER AIR WELL INTO CENTRAL NC...
ALTHOUGH IT MAY NOT HAPPEN UNTIL LATE SUN NIGHT INTO MON MORNING.
WILL FOLLOW THIS TREND WITH TEMPS HOLDING ABOVE NORMAL SAT/SUN (BUT
NOT AS WARM IN THE NORTH SUN DUE TO MORE CLOUDS) WITH HIGHS IN THE
MID 80S TO NEAR 90... BUT THEN EXPECT TEMPS TO PLUNGE FOR MON/TUE
WITH THICKNESSES DROPPING TO 10-20 M BELOW NORMAL... YIELDING HIGHS
NEAR 80 TO LOWER 80S. REGARDING PRECIP CHANCES... WE`RE LIKELY TO
SEE SCATTERED TO PERHAPS NUMEROUS SHOWERS AND STORMS LATE SAT
THROUGH AT LEAST SUN NIGHT... BOTH ALONG THE PREFRONTAL PIEDMONT
TROUGH AND AHEAD OF AND WITH THE FRONT ITSELF. SHOWER/STORM CHANCES
ARE EXPECTED TO PEAK SUN AFTERNOON. WITH THE MID LEVEL TROUGH AXIS
SWINGING THROUGH THE REGION MON... WE MAY SEE LINGERING CHANCES FOR
RAIN ESPECIALLY SOUTH AND EAST. THE SURFACE RIDGE NOSING IN FROM THE
NORTH LATE MON INTO TUE ACCOMPANIED BY LOWERING PW VALUES SHOULD
MEAN MOSTLY DRY WEATHER TUE... AS THE MID LEVEL TROUGH AXIS LIFTS NE
AWAY FROM THE REGION FOLLOWED BY WEAK MID LEVEL SHORTWAVE RIDGING
OVER THE CAROLINAS. -GIH
 

[FallsLake]

Just looking at the 0z GFS it looks like once we get the cool down Sunday/Monday that may be it for the real hot weather. I'm sure we'll get a hot day here and there but a full week of 90s and high humidity may be behind us (...until next year). It's kind of funny that the hottest week of the year came the first week of September. This has been an amazingly cool summer.

[Brick Tamland]

Looks like our friend the wedge will make a return on Monday and hang around a few days! I think the frequency of wedges this summer should bode well for wintry precip this winter, if we can keep them coming every week or two!

 

Yes, let's hope it continues into winter and doesn't shut off as soon as winter gets here.

[Brick Tamland]

Hopefully, there will be some storms around today. It would be nice to get a little rain. Looks like we're going to be on a roller coaster ride the next week with the temps. I am ready for fall.

[FallsLake]

Hopefully, there will be some storms around today. It would be nice to get a little rain. Looks like we're going to be on a roller coaster ride the next week with the temps. I am ready for fall.

Falls coming next week; well at least Fall like temps:

 

RAH afternoon discussion

......

HIGH TEMPS ON SATURDAY IN ADVANCE OF THE COLD FRONT ARE EXPECTED TO

GENERALLY BE IN THE UPPER 80S TO LOWER 90S. SUNDAY... HIGHS WILL BE

TRICKY AND DEPEND ON HOW PRECIP DEVELOPS AND HOW THICK THE CLOUD

COVER IS... COUPLED WITH THE RELATED TIMING OF THE FRONT. FOR NOW

WILL TREND HIGH TEMPS DOWNWARD A BIT IN COORDINATION WITH WPC`S

TIMING/PLACEMENT OF THE FRONT. THIS YIELDS HIGH TEMPS OF AROUND 80

NORTH TO THE UPPER 80S SOUTH. LOWS TEMPS SUNDAY MORNING ARE EXPECTED

TO BE IN THE MID 60S SOUTH TO UPPER 60S/NEAR 70 SOUTH. LOWS MONDAY

MORNING... WITH POSSIBLY SOME LINGERING SHOWERS... ARE EXPECTED TO

BE IN THE LOWER TO MID 60S NORTH TO MID TO UPPER 60S SOUTH.

MONDAY THROUGH WEDNESDAY: THE SURFACE FRONT IS EXPECTED TO STALL AS

IT MOVES OFFSHORE AND ENCOUNTERS THE GULF STREAM... WITH THE

POTENTIAL FOR AN AREA OF LOW PRESSURE OR TWO TO LIFT NORTHWARD ALONG

THE FRONT. THIS WILL LEAD TO A DRIER/LESS CLOUDS NW TO LINGERING

CHANCE OF SHOWERS EAST/MORE CLOUDS... AND MUCH COOLER TEMPS AS

SURFACE HIGH PRESSURE IS EXPECTED TO CONTINUE TO EXTEND INTO CENTRAL

NC FROM THE NORTHEAST. THUS... WILL GO WITH HIGHS TEMPS GENERALLY IN

THE 70S TO LOWER 80S... AND THIS MAY EVEN BE TOO WARM. LOWS IN THE

60S.

-- End Changed Discussion --

 

[Solak]

 

Falls coming next week; well at least Fall like temps:

 

That's not Fall ---- that's July temps~

[FallsLake]

That's not Fall ---- that's July temps~

Your so right. This upcoming cool down isn't anything we haven't seen through out this summer. This past week(90s & high humidity) really hurt. So it will still feel good. The long range GFS does show some indications of much lower dew points(40s). Once we can get that first sunny, 70 degree, and low humidity day we can say real fall weather is here. 

[Brick Tamland]

Thundering here right now and the wind is picking up.

[Snowless in Carrollton]

Your so right. This upcoming cool down isn't anything we haven't seen through out this summer. This past week(90s & high humidity) really hurt. So it will still feel good. The long range GFS does show some indications of much lower dew points(40s). Once we can get that first sunny, 70 degree, and low humidity day we can say real fall weather is here. 

I look forward to the day where we can say GOODBYE to dew points in the 70s. High humidity just wears my body out for some reason. I feel so tired right now and I haven't done anything all day.

[Kory]

The GFS is quite bullish in the 10+ day range.  It's showing an anomalously deep trough with some relief making to the south.  This is far out, so take it for what it's worth.  As far as the Euro, it shows the ridge holding firm for the Southeast with summer like conditions continuing.  

 

[Snowless in Carrollton]

For some reason I think the Euro may be right, maybe because even the GFS according to that map doesn't show the cooler air making it to FL. Hopefully we get a least a little relief. Not necessarily fall like temps, but temps more normal for September.

[WxJordan]

Temperatures should slide back closer to normal soon across the southeast. I think the GFS is overdone, and I think we will see temperatures in western areas slowly start to return back to average September values next week. Eastern areas will take longer as the ridge tries to break down. It is all dependent on how long that ridge holds on, but I do not expect to see widespread below average temperatures through the end of next week. If the EURO is correct, the ridge should hold on through mid September. If the GFS is correct, then the ridge should start to break down over the next seven days. Hard to say which one is correct, but I give the EURO a slight nod right now over the GFS.

[FallsLake]

Temperatures should slide back closer to normal soon across the southeast. I think the GFS is overdone, and I think we will see temperatures in western areas slowly start to return back to average September values next week. Eastern areas will take longer as the ridge tries to break down. It is all dependent on how long that ridge holds on, but I do not expect to see widespread below average temperatures through the end of next week. If the EURO is correct, the ridge should hold on through mid September. If the GFS is correct, then the ridge should start to break down over the next seven days. Hard to say which one is correct, but I give the EURO a slight nod right now over the GFS.

Glanced at last night's GFS(not euro) and it still shows the cool down for next week, but not sure how far south of NC this cool down will occur. The longer term (day 10 or so) looks real nice with cooler air across a greater part of the SE.  

 

 

<from RAH>

.LONG TERM /SUNDAY THROUGH WEDNESDAY/...

AS OF 330 AM THURSDAY...

SUN: GIVEN THE EXPECTED FASTER FRONTAL PROGRESSION...FRONTAL

CONVECTION SHOULD BE CONFINED TO THE SOUTHERN CWFA THROUGH EARLY-MID

AFTERNOON SUN...WITH JUST A SLIGHT CHANCE OF A POST-FRONTAL

SHOWER...IF THAT...ELSEWHERE. THE FRONT IS THEN FORECAST TO SLOW AS

IT DRIFTS OFFSHORE AND INTO THE VICINITY OF THE GULF STREAM THROUGH

MID-WEEK. A WEAK WAVE OF LOW PRESSURE...OR TWO...ARE APT TO DEVELOP

ALONG THE SLOWING FRONT...AS A WEAK TROUGH ALOFT SETTLES ACROSS THE

SE STATES AND INTERACTS WITH SEASONABLY STRONG BAROCLINICITY DRIVEN

BY THE CANADIAN AIR MASS SETTLING INTO THE WARM/MOIST GULF STREAM

WATERS.

SUN NIGHT-TUE: A RELATIVELY PROLONGED PERIOD OF NORTHEASTERLY LOW-

MID LEVEL FLOW ON THE WEST SIDE OF THE FRONTAL ZONE AND PROBABLE

WAVES OF LOW PRESSURE WILL BE PROBABLE THIS PERIOD...AND RESULT IN

MOSTLY CLOUDY CONDITIONS...AND A CHANCE OF LIGHT RAIN OVER THE

EASTERN CWFA...RANGING TO PARTIAL SUNSHINE AND GENERALLY DRY

CONDITIONS OVER THE WESTERN PIEDMONT. COOLER WITH HIGHS IN THE MID

70S AROUND 80 DEGREES. LOWS IN THE 60S.

TUE NIGHT-WED: SFC WAVES DEPART WITH LESSENING INFLUENCE OF THE

NORTHEASTERLY FLOW...WITH ASSOCIATED DECREASING CLOUDINESS...AND

SLIGHT MODERATION INTO THE UPPER 70S TO LOWER 80S.

[WxJordan]

Yes, the cooler NE flow will help to keep temperatures cooler through much of the North Carolina early next week, Not sure how far into South Carolina and Georgia the flow will make it, but I still anticipate average temperatures for this time of year to slightly above average. No 5-10+ degrees above average for a while after the weekend. But yes, it will be cooler next week.

 

Glanced at last night's GFS(not euro) and it still shows the cool down for next week, but not sure how far south of NC this cool down will occur. The longer term (day 10 or so) looks real nice with cooler air across a greater part of the SE.  

 

 

<from RAH>

.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
AS OF 330 AM THURSDAY...

SUN: GIVEN THE EXPECTED FASTER FRONTAL PROGRESSION...FRONTAL
CONVECTION SHOULD BE CONFINED TO THE SOUTHERN CWFA THROUGH EARLY-MID
AFTERNOON SUN...WITH JUST A SLIGHT CHANCE OF A POST-FRONTAL
SHOWER...IF THAT...ELSEWHERE. THE FRONT IS THEN FORECAST TO SLOW AS
IT DRIFTS OFFSHORE AND INTO THE VICINITY OF THE GULF STREAM THROUGH
MID-WEEK. A WEAK WAVE OF LOW PRESSURE...OR TWO...ARE APT TO DEVELOP
ALONG THE SLOWING FRONT...AS A WEAK TROUGH ALOFT SETTLES ACROSS THE
SE STATES AND INTERACTS WITH SEASONABLY STRONG BAROCLINICITY DRIVEN
BY THE CANADIAN AIR MASS SETTLING INTO THE WARM/MOIST GULF STREAM
WATERS.

SUN NIGHT-TUE: A RELATIVELY PROLONGED PERIOD OF NORTHEASTERLY LOW-
MID LEVEL FLOW ON THE WEST SIDE OF THE FRONTAL ZONE AND PROBABLE
WAVES OF LOW PRESSURE WILL BE PROBABLE THIS PERIOD...AND RESULT IN
MOSTLY CLOUDY CONDITIONS...AND A CHANCE OF LIGHT RAIN OVER THE
EASTERN CWFA...RANGING TO PARTIAL SUNSHINE AND GENERALLY DRY
CONDITIONS OVER THE WESTERN PIEDMONT. COOLER WITH HIGHS IN THE MID
70S AROUND 80 DEGREES. LOWS IN THE 60S.

TUE NIGHT-WED: SFC WAVES DEPART WITH LESSENING INFLUENCE OF THE
NORTHEASTERLY FLOW...WITH ASSOCIATED DECREASING CLOUDINESS...AND
SLIGHT MODERATION INTO THE UPPER 70S TO LOWER 80S.

[mackerel_sky]

Looking pretty wet the next 4 or 5 days, and this along with the cooler wedge is a combination we have needed for awhile. Yesterday was the first rain over a quarter inch in weeks!

[FallsLake]

Looking pretty wet the next 4 or 5 days, and this along with the cooler wedge is a combination we have needed for awhile. Yesterday was the first rain over a quarter inch in weeks!

Here's the NE flow / CADish look: 

http://www.aos.wisc.edu/weatherdata/avn/avn_cpres_h96.gif

http://www.aos.wisc.edu/weatherdata/avn/avn_c850_h96.gif

http://www.aos.wisc.edu/weatherdata/avn/avn_crhlia_h96.gif

 

As discussed above not sure how far south of NC this can go...

[Cold Rain]

Does the 12z Euro look wet between the 72-120 hour time frame?  It looks like it on eWall, but it's really hard to tell what QPF looks like.  RH looks good at 700 and 850.

[GaWx]

Does the 12z Euro look wet between the 72-120 hour time frame?  It looks like it on eWall, but it's really hard to tell what QPF looks like.  RH looks good at 700 and 850.

Yes. Your area and much of E NC get 1-2" of qpf hours 72-120 on the 12z Euro. It is the wettest area in the E US then.

[Cold Rain]

Yes. Your area and much of E NC get 1-2" of qpf hours 72-120 on the 12z Euro. It is the wettest area in the E US then.

 

Thanks man.  I thought it looked juicy.  Looks like an inverted trough of low pressure sets up.  The NAM looks wet in that time frame too, but it IS the long range NAM.  The CMC looks to develop and strengthen a low off the coast and track it to the NE.  The GFS looks just ho hum, not showing much of anything.

[griteater]

GFS and CMC ensembles both evolve into a western U.S. ridge, eastern U.S. trough in the 11-15 day period

[FallsLake]

The front coming though Sunday doesn't look to get as far south as it looked yesterday. This will allow better chances of rain through NC, but the cooler/dryer temps will not be as impressive. It looks to jump right back into the 80s by Tuesday and Wednesday. So if your waiting for that first "real" taste of Fall, you'll have to wait until the end of next week.

 

.LONG TERM /SUNDAY THROUGH THURSDAY/...
AS OF 340 AM FRIDAY...

SUN: THE COLD FRONT...WHOSE TIMING HAS SLOWED VERSUS THE FASTER
TREND IN NWP GUIDANCE NOTED YESTERDAY...IS NOW FORECAST TO ROUGHLY
BISECT CENTRAL NC FROM NW TO SE AT THE START OF THE DAY SUN...THEN
ONLY SLOWLY DRIFT SOUTHEASTWARD THROUGHOUT THE DAY. THE RESULT WILL
BE NUMEROUS TO WIDESPREAD SHOWERS AND STORMS OVER A LARGER PART OF
THE CWFA...OVER ALL BUT THE FAR NORTHERN AND NW PIEDMONT WHERE POP
WILL BE IN THE CHANCE RANGE...THROUGH THE AFTERNOON. NOT AS
WARM...WITH HIGHS IN THE LOWER 80S NW...TO UPPER 80S TOWARD KFAY-
KGSB-KCTZ. IN AN ENVIRONMENT CHARACTERIZED BY PRECIPITABLE WATER
VALUES NEAR TWO INCHES...FLOODING IN URBAN AND OTHER FLOOD PRONE
AREAS WILL BE POSSIBLE.

SUN NIGHT-MON NIGHT: THE FRONT IS THEN FORECAST TO SLOW AS IT INTO
EASTERN NC (NOT AS FAR EAST AS EARLIER PROGGED). FRONTAL CONVERGENCE
AND INVOF A WAVE OR TWO OF LOW PRESSURE FORECAST TO RIPPLE ALONG THE
FRONT...AND ISENTROPIC UPGLIDE ATOP IT...WILL PROMOTE A LIKELY
PROBABILITY OF SHOWERS AND STORMS THROUGH MON...PARTICULARLY OVER
THE EASTERN PIEDMONT AND COASTAL PLAIN. NORTHEASTERLY FLOW AND
ASSOCIATED MOSTLY CLOUDY CONDITIONS...AND CHANCE OF SHOWERS...WILL
PREVAIL OVER THE SOUTHERN AND WESTERN PIEDMONT. COOLER WITH HIGHS
MOSTLY IN THE 70S...AND LOWS 65 TO 70.

TUE-THU: SFC WAVES DEPART WITH LESSENING INFLUENCE OF THE
NORTHEASTERLY FLOW...WITH ASSOCIATED DECREASING CLOUDINESS...AND
MODERATION INTO THE UPPER 70S TO MIDDLE 80S. SHOWER AND STORM
CHANCES...JUST SLIGHT TO LOW CHANCE ONES...SHOULD BE CONFINED TO
EASTERN AREAS TUE...WITH TYPICAL POP DISTRIBUTION INVOF THE SEA
BREEZE AND MOUNTAINS AS CENTRAL NC REMAINS BETWEEN THE DEPARTING SFC
WAVES AND THE NEXT FRONT FORECAST TO ARRIVE LATE NEXT WEEK.

&&
 

[FallsLake]

Well folks it looks like fall will start(temp wise) next weekend for a good part of the SE. 6z GFS is definitely showing a strong cold front moving through around Friday/Saturday. This could very well be those first days with temps in the upper 60s/lower 70s, deep blue skies, and low humidity.

 

http://www.twisterdata.com/

[Jon]

Well folks it looks like fall will start(temp wise) next weekend for a good part of the SE. 6z GFS is definitely showing a strong cold front moving through around Friday/Saturday. This could very well be those first days with temps in the upper 60s/lower 70s, deep blue skies, and low humidity.

 

http://www.twisterdata.com/

ahhh....looks good

 

[Brick Tamland]

I just hope it's dry when the fall temps get here.

[Isopycnic]

I just hope it's dry when the fall temps get here.

you should move to the Waycross desert

[downeastnc]

Hmmmm from Brad P

 

http://www.wcnc.com/story/weather/2014/09/05/carolina-coast-tropical-trouble/15104835/?utm_content=buffereb180&utm_medium=social&utm_source=facebook.com&utm_campaign=buffer

[Cold Rain]

^ The NAM is quite robust with QPF in central and eastern NC this weekend.  The GFS, particularly the 0z version looks better than yesterday's run.  I'm guessing the Euro still paints a decent rainfall as well, from the looks of the RH fields on eWall.

[Brick Tamland]

Hmmmm from Brad P

 

http://www.wcnc.com/story/weather/2014/09/05/carolina-coast-tropical-trouble/15104835/?utm_content=buffereb180&utm_medium=social&utm_source=facebook.com&utm_campaign=buffer

 

That would probably catch a lot of folks off-guard.

[downeastnc]

That would probably catch a lot of folks off-guard.

 

Depends if it stayed offshore and was a weak TS then no biggie, if it is a Cat 3 that grazes the OBX then yeah but at best I think we are looking at a weak TS type system. However the model Brad uses in house did get it further east than most globals thus it looked a lot better than what the Euro/Nam etc have which is nothing but a low right on the coast moving north from Florida.

[Cold Rain]

Pretty decent discrepancy between the NAM and GFS through 84 hrs wrt precip amounts in the SE: