• Member Statistics

    16,019
    Total Members
    7,904
    Most Online
    BlckJckKhoWX
    Newest Member
    BlckJckKhoWX
    Joined

Archived

This topic is now archived and is closed to further replies.

John1122

August/September 2014 Pattern Discussion

Recommended Posts

This thread will close out the summer of 2014. This summer has pretty much been defined by cold fronts encroaching deeper than usual and basically a summer free of heat waves. Will it continue into fall?

Share this post


Link to post
Share on other sites

Cell(s) going up in northwest Alabama today (8/11) along an outflow. Upper support is meager, but there is a little more than yesterday and it's not the usual August zero. So, expect at least some good CG in North Alabama. Gosh that cell near Chattanooga yesterday as a noise maker. See text? I guess, but storms on the OFB today might have a little more local wind potential than the average August drifter. Enjoy!

Share this post


Link to post
Share on other sites

MESOSCALE DISCUSSION 1545
   NWS STORM PREDICTION CENTER NORMAN OK
   1240 PM CDT MON AUG 11 2014

   AREAS AFFECTED...KY...TN

   CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY

   VALID 111740Z - 111945Z

   PROBABILITY OF WATCH ISSUANCE...20 PERCENT

   SUMMARY...THUNDERSTORMS POSING A THREAT FOR LOCALLY STRONG TO
   DAMAGING WIND GUSTS AND TORRENTIAL RAIN ARE LIKELY TO INCREASE NEAR
   THE MIDDLE TN/KY BORDER AREA AND SOUTH ACROSS MIDDLE TN OVER THE
   NEXT FEW HOURS.

   DISCUSSION...VERY WARM AND UNSTABLE CONDITIONS HAVE DEVELOPED ALONG
   THE KY/TN BORDER EARLY THIS AFTERNOON IN THE WAKE OF A SMALL/WEAKLY
   ORGANIZED BUT PERSISTENT MCS MOVING INTO EASTERN KY. STRONGER
   SURFACE HEATING ACROSS NORTHERN/MIDDLE TN...AND A VERY MOIST AIRMASS
   WITH DEWPOINTS IN THE MIDDLE 70S F...HAVE CONTRIBUTED TO AN INCREASE
   IN SBCAPE TO AROUND 3000 J/KG OVER THE PAST COUPLE OF HOURS. NEW
   CONVECTION DEVELOPING ALONG THE MCS OUTFLOW...AND AHEAD OF A WEAK
   COLD FRONT...WILL LIKELY MOVE INTO THE INSTABILITY CORRIDOR THROUGH
   THE AFTERNOON HOURS. MODEST MID-LEVEL FLOW OF AROUND 30KT MAY RESULT
   IN GREATER STORM ORGANIZATION/PERSISTENCE WHILE LOW-LEVEL
   CONVERGENCE NEAR THE FRONT/OUTFLOW INTERSECTION FURTHER SUPPORTS
   REGENERATIVE CONVECTION AND POSSIBLE STORM MERGERS.

   WITH THE BULK OF CONVECTION LIKELY TAKING ON MULTICELLULAR
   CHARACTER...THE MAGNITUDE OF CAPE AND HIGH PW /AROUND 2 INCHES/
   FOCUSED NEAR THE OUTFLOW/FRONT INTERSECTION...AND ACROSS MIDDLE
   TN...SHOULD RESULT IN A GRADUAL INCREASE IN BOTH STORM COVERAGE AND
   VIGOR. STORMS MAY ALSO DEVELOP LINEARLY ALONG THE APPROACHING WEAK
   COLD FRONT LATER THIS AFTERNOON. DESPITE WEAK LAPSE RATES AND
   MARGINAL SHEAR...DEEP/WARM CLOUD LAYER AND ANOMALOUSLY HIGH MOISTURE
   CONTENT SUGGEST AT LEAST AN ISOLATED WET MICROBURST THREAT ALONG
   WITH PERHAPS A GREATER CHANCE FOR LOCALLY TORRENTIAL RAINFALL.

Share this post


Link to post
Share on other sites

I was hoping for some better rain than what we got here.If not for Thursday we basically got shut out here in Williamson Co., Fri-today.The Euro looks dry until next week,basically cape less until next Tues.,when it shows a front coming through.Looks like another pleasant rest of the week

Share this post


Link to post
Share on other sites

Yesterday Hixon and Soddy Daisy, northern suburbs, got hammered. East Brainerd area of Chattanooga got the shaft. Classic! Like Jag says, the good news is lower humidity and pleasant weather balance of the week. I'll take it!

 

Enjoy, because we should see a hot and humid back half of August. European weeklies and American CFS are lining up on that pattern. Model skill is up recently, and tropical connections finally line up with a hotter forecast. It is not intense, I would not call it a heat wave, but heat might match the July burst.

Share this post


Link to post
Share on other sites

Appears our late August heat will be associated with a dirty ridge most days. Surprise! This morning high-res guidance wants to pop up afternoon thundershowers over East Tenn. Tomorrow (Thursday) hints at still possible showers northeast Tenn. Outside of showers it will be hot and humid. Friday and Saturday might be the best chance of full sun everywhere.

 

Then early next week the east side of the heat ridge wants to weaken with a backdoor front approaching from North Carolina. Normally I'd fade that front under a good heat ridge, but this year is different. Any weakness in the ridge might open the door to underperforming heat. It's not like we have the classic mammoth 594 ridge. It is above 590, but any 594 heights cover little real estate and briefly. Well, it is summer 2014!

Share this post


Link to post
Share on other sites

TOR warning out for Madisonville and heading toward Tellico Plains. Lots of cells have popped up today in the unstable air mass on the east side of the developing ridge. ujegy6un.jpg

Share this post


Link to post
Share on other sites

Somebody on the Spotter Network reported a rotating wall cloud with that storm shortly after 3:00. Also some hail reported. Cell appears slightly less organized now at 3:40, at least not rotating as much. Today would have been a good day for a nice drive up I-75.

Share this post


Link to post
Share on other sites

MESOSCALE DISCUSSION 1588
   NWS STORM PREDICTION CENTER NORMAN OK
   0532 PM CDT WED AUG 20 2014

   AREAS AFFECTED...CNTRL/ERN KY...MIDDLE/ERN TN...NRN AL...NRN
   GA...FAR SWRN NC...FAR WRN VA

   CONCERNING...SEVERE THUNDERSTORM WATCH 468...

   VALID 202232Z - 210030Z

   THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 468
   CONTINUES.

   SUMMARY...THREAT FOR DAMAGING WINDS AND HAIL WILL CONTINUE ACROSS WW
   468. ISOLATED SVR IS POSSIBLE OUTSIDE OF THE WATCH ACROSS WRN MID
   TN...FAR NRN AL/GA...AND FAR ERN KY/WRN VA. SVR COVERAGE IS EXPECTED
   TO REMAIN ISOLATED WITH ANY ADDITIONAL WATCHES ACROSS THE REGION
   UNLIKELY.

   DISCUSSION...RECENT SURFACE OBSERVATIONS REVEAL THE AIRMASS ACROSS
   MIDDLE TN HAS COOLED SIGNIFICANTLY AS A RESULT OF CONVECTIVE
   OVERTURNING. HOWEVER...WRN MIDDLE TN...NRN AL...AND NRN GA ARE JUST
   NOW BEGINNING TO EXPERIENCE CONVECTION WITH SURFACE TEMPERATURES
   STILL IN THE LOW 90S AND DEWPOINTS IN THE MID 60S TO LOW 70S. SPC
   MESOANALYSIS ESTIMATES MLCAPE AROUND 3000 J PER KG. AS A
   RESULT...SOME SVR IS STILL POSSIBLE ACROSS THESE AREAS BUT THE LACK
   OF LARGE SCALE FORCING AND GENERALLY WEAK SHEAR PROFILES /0-6 BULK
   SHEAR LESS THAN 20 KT PER HTX VAD/ SHOULD KEEP THE SVR THREAT
   ISOLATED.

   BETTER SHEAR EXISTS ACROSS KY /0-6 BULK SHEAR AROUND 30 KT PER JKL
   VAD/ AND RECENT RADAR IMAGERY HAS SHOWN SOME HINTS OF COLD POOL
   AMALGAMATION. HOWEVER IN THE DOWNSTREAM ENVIRONMENT /ACROSS MID TN
   EWD INTO FAR WRN NC AND FAR WRN VA/...PERSISTENT CONVECTION AND/OR
   CLOUD COVER HAS LIMITED HEATING AND RESULTANT INSTABILITY. SOME
   ISOLATED SVR IS POSSIBLE OUTSIDE THE WATCH ACROSS FAR ERN KY AND FAR
   WRN VA BUT THE OVERALL THREAT SHOULD BE LIMITED BY MODEST
   INSTABILITY.

Share this post


Link to post
Share on other sites

At least dewpoints came off a bit. Hey Td 65-68 feels pretty good after 72-75 last week. Dews look manageable the rest of the week, but could get sticky again with scattered showers over the weekend. At least we know only 2-3 more weeks, maximum, of uncomfortable humidity. We are almost there...

Share this post


Link to post
Share on other sites

GFS builds some pretty big heat, especially for the western half of the Tennessee Valley in the 8-10 day range. Looking like 95+ degree max temps west of the Plateau for a few days as we head into the first week of September.

Share this post


Link to post
Share on other sites

Not quite so much on the 12Z Euro at least and FWIW, the GFS has quite a bit of afternoon convection so it should be at least somewhat moderated if the GFS is closer to the truth...I am ready for the first fall Canadian airmass!

Share this post


Link to post
Share on other sites

Not quite so much on the 12Z Euro at least and FWIW, the GFS has quite a bit of afternoon convection so it should be at least somewhat moderated if the GFS is closer to the truth...I am ready for the first fall Canadian airmass!

 

You and me both Mr Bob.  I can't wait for the first fall cold front that hits like a ton of bricks.  I have fond memories of going to school on a warm morning and walking home with a stiff breeze and cold air filtering in from the NW.

Share this post


Link to post
Share on other sites

I'm getting more and more concerned that this front this weekend is going to stall out to the north of my area leaving the humidity and 80's to stick around for a while longer.  The Euro and GFS OP's are both now hinting that the cold/dry push may not make it down this way.  Hopefully you guys in TN can cash in but even there is becoming a concern for me. 

Share this post


Link to post
Share on other sites

The forecast has gotten progressively warmer for next week, initially we were on tap to see some 40s by the middle of next week, looks like that is gone now. This weekend should still provide some decent temps for most of Tennessee and Southern Kentucky, even if it does stall before reaching northern Georgia, and Alabama.

Share this post


Link to post
Share on other sites

The forecast has gotten progressively warmer for next week, initially we were on tap to see some 40s by the middle of next week, looks like that is gone now. This weekend should still provide some decent temps for most of Tennessee and Southern Kentucky, even if it does stall before reaching northern Georgia, and Alabama.

 

The 18Z GFS confirms this...  It shows the front moving far enough south to drop DP's into the 50's for TN.  The model also seems to indicate the farther west you are in TN the drier and more comfortable the airmass will become.  Meanwhile here in Marietta I'll be about 50-75 miles too far SE to benefit from the drier air...... 

Share this post


Link to post
Share on other sites

The end of the real heat of summer is blowing past this afternoon. This is the 1st fall front to make its way through the area ( except for areas further south like Marietta). This next week is going to feel mighty nice!

Share this post


Link to post
Share on other sites

The end of the real heat of summer is blowing past this afternoon. This is the 1st fall front to make its way through the area ( except for areas further south like Marietta). This next week is going to feel mighty nice!

 

You guys enjoy it!  I'll have to wait for the next one.  Although it does seem like today may have been the last really hot and humid day. We topped out at 89 today with DP's in the low 70's, heat index was in the mid 90's today.  It appears that low 80's and DP's in the 60's are on tap for a while then perhaps the next front can drop the hammer and bring blue skies, low 70's and DP's in the 40's and 50's to all of us. 

Share this post


Link to post
Share on other sites

The end of the real heat of summer is blowing past this afternoon. This is the 1st fall front to make its way through the area ( except for areas further south like Marietta). This next week is going to feel mighty nice!

Shockingly the front actually cleared marietta and we are experiencing crashing DPs, falling temps and clearing skies. Looks like the rainy weekend got crushed a bit farther south than the models had been showing. I love it!

Share this post


Link to post
Share on other sites

On the control this afternoon,it's showing a mean trough coming down towards the end of the run.Even show the 850's  at 0 all the way into NW/Tn.I'm sure this will probably change again,but none the less it's showing it.

Share this post


Link to post
Share on other sites

Both the GFS and Euro control  today are showing something mischievous coming though maybe sometime around next weekend.Both are  showing some 0-6km shear at 60-70 kts

Share this post


Link to post
Share on other sites

Widespread fall temps in store for us guys over the next couple of nights in particular..  Mid-40's to Low 50's are going to be common with some possible upper 30's in the high mountain areas.  Fall is here my friends.

Share this post


Link to post
Share on other sites

  • Recently Browsing   0 members

    No registered users viewing this page.