Jump to content
  • Member Statistics

    17,606
    Total Members
    7,904
    Most Online
    ArlyDude
    Newest Member
    ArlyDude
    Joined

September 2012 Obs/Discussion Thread


Isopycnic

Recommended Posts

  • Replies 439
  • Created
  • Last Reply

Wow has anybody taken a look at the 18z GFS. That Low really seems to bomb out in the East next week. Big trough in the East and looks to be setting the stages for a split flow to set up across the country also. Reading the Winter forum from the New England threat HM was saying this is very El Nino looking for September which would be great news coming into this winter. Also great read up there about the upcoming winter from the New England thread. Also what a trough that would be for the East if this would be to verify.

Link to comment
Share on other sites

Big rain totals are coming in for the next five days in the SE along with a chance of severe weather East of the mountains. Some totals are as high as five inches in some spots. May need to start a thread on this.

I really have not followed the weather/models much lately but I sure hope so. Plus, given it's september, that is a big bonus if it happens since we are entering the dry season. Especially since lakes/creeks where I'm at are still low..despite having a respectable amount of rain lately. The water table must really be low here....so every drop is certainly needed.

Link to comment
Share on other sites

The keys to the upcoming forecast is where does the upper trough goes to the north, is there a phase with the south, upper streams, where does the surface low tracks, and which ways do the winds blow. The warm air advection at 850 mb is really strong, with tons of moisture rising to the north well ahead of the trough. Upper air divergence at the 200-300 mb level is also very good with a nice jet streak sliding south. The dynamics appear to be here for a big weather event for the southeast. The overall question remain where does the surface low tracks. For example, if the low pressure tracks over the mountains or just east of the mountains, this could be a major rain event for the mountains of NC, foothills, and piedmont of NC, GA, SC, and up the east coast. There could also be a severe threat with this system as wind shear and helicity is relatively high. CAPE appears to remain fairly low, but I believe the tornado threat is there in the piedmont and coastal sections of NC, SC, GA, and through VA. My current thinking is 1-2 inches across the piedmont of NC, 2-3 foothills of NC, 2-3 mountains, higher amounts in southern mountains of NC. SC, GA, VA, and eastern TN 1-2 inches with isolated higher amounts where thunderstorms train.

Very amazing system no matter what happens for this time of year in the southeast. We will see what continues to happens over the next few hours as the models continue to lock in on solutions.

Link to comment
Share on other sites

The keys to the upcoming forecast is where does the upper trough goes to the north, is there a phase with the south, upper streams, where does the surface low tracks, and which ways do the winds blow. The warm air advection at 850 mb is really strong, with tons of moisture rising to the north well ahead of the trough. Upper air divergence at the 200-300 mb level is also very good with a nice jet streak sliding south. The dynamics appear to be here for a big weather event for the southeast. The overall question remain where does the surface low tracks. For example, if the low pressure tracks over the mountains or just east of the mountains, this could be a major rain event for the mountains of NC, foothills, and piedmont of NC, GA, SC, and up the east coast. There could also be a severe threat with this system as wind shear and helicity is relatively high. CAPE appears to remain fairly low, but I believe the tornado threat is there in the piedmont and coastal sections of NC, SC, GA, and through VA. My current thinking is 1-2 inches across the piedmont of NC, 2-3 foothills of NC, 2-3 mountains, higher amounts in southern mountains of NC. SC, GA, VA, and eastern TN 1-2 inches with isolated higher amounts where thunderstorms train.

Very amazing system no matter what happens for this time of year in the southeast. We will see what continues to happens over the next few hours as the models continue to lock in on solutions.

Yes a very interesting pattern setting up for the month of September well the second half of September. I was just saying this kind of looks like an October pattern. As Lookout mentioned we usually enter into a dry period this month. Looking down the road also the GFS really wants to keep the trough over the East right into the beginning of October. At least we have some interesting weather shaping up with severe weather, heavy rain and maybe our first frost this month in parts of the mountains.

Link to comment
Share on other sites

Damming event setting up over interior NC. Cool and rainy outside (60 at RDU). Wife had me shut some windows. I'll sneak and open them later.

RAH update:

.......

HIGHS WILL BE DROPPED BACK 5-10 DEGREES FROM PREVIOUS FORECAST IN

THE RAIN COOLED AREAS... MID TO UPPER 60S NW RANGING TO THE UPPER

70S SE. THIS DROP IS DUE TO THE EXPECTED CONTINUATION OF SHOWERS...

DEVELOPMENT OF LOW CLOUDS... AND THE DEVELOPMENT OF A POTENTIAL

IN-SITU DAMMING EVENT IN THE PIEDMONT.

Link to comment
Share on other sites

The rain event has started early here......

FLOOD ADVISORY

NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC

421 PM EDT SUN SEP 16 2012

NCC111-162100-

/O.NEW.KGSP.FA.Y.0160.120916T2021Z-120916T2100Z/

/00000.N.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

MCDOWELL NC-

421 PM EDT SUN SEP 16 2012

THE NATIONAL WEATHER SERVICE IN GREENVILLE-SPARTANBURG HAS ISSUED AN

* URBAN AND SMALL STREAM FLOOD ADVISORY FOR HEAVY RAINFALL IN...

CENTRAL MCDOWELL COUNTY IN WESTERN NORTH CAROLINA...

* UNTIL 500 PM EDT

* AT 415 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED

THUNDERSTORMS WITH HEAVY RAINFALL ACROSS THE ADVISORY AREA. SINCE

3 PM...DOPPLER RADAR ESTIMATED THAT BETWEEN 1.75 TO 1.25 INCHES OF

RAIN HAS FALLEN NORTH OF MARION...ESPECIALLY OVER BUCK CREEK AND

TOMS CREEK. ADDITIONAL SHOWERS AND THUNDERSTORMS ARE EXPECTED

TO TRACK ACROSS THE MARION AREA THROUGH 5 PM...PROVIDING AN

ADDITIONAL INCH OF RAIN.

* RUNOFF FROM THIS EXCESSIVE RAINFALL WILL CAUSE MINOR FLOODING TO

OCCUR...ESPECIALLY ALONG SMALL STREAMS AND NEAR LOW WATER

CROSSINGS. STREET FLOODING ON INTERSTATE 70 JUST WEST OF HIGHWAY

221 IS LIKELY THROUGH 5 PM.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

EXCESSIVE RUNOFF FROM HEAVY RAINFALL MAY CAUSE LOW IMPACT FLOODING OF

SMALL CREEKS AND STREAMS...HIGHWAYS AND UNDERPASSES. DO NOT DRIVE

AROUND BARRICADES SET UP TO BLOCK WATER COVERED ROADWAYS. THE

BARRICADES ARE SET UP FOR YOUR PROTECTION.

&&

LAT...LON 3575 8191 3566 8191 3567 8210 3576 8209

$$

NED

Link to comment
Share on other sites

The main event is coming tomorrow night but a night heavy rain shower is pounding MBY ATM. VP2 has shown 3"+ per hour rain rates in the past 20 minutes. .46" in the bucket so far and still puring.

The models for days now have showed that some extremely strong omega will accompany this event, right ahead of the front, so we have all types of good lift coming. This is only the beginning. The actual duration + the rates is what's going to make some flood issues. The last time I seen something similar to this, remotely I guess, is the Christmas storm of 2010 I think, where just ahead of the front there was extreme rainfall rates. No wonder the models are still showing totals of 4" here and there. If its one thing that causes instant flooding, its the rates. I had two major episodes of that here this Summer, where the rates is what done the damage.

The rain event has started early here......

FLOOD ADVISORY

More to come. I think each of the offices of RAH, GSP FFC MRX HSX BHM RNK will have some type of flood watch or warnings issued before all is said and done.

Link to comment
Share on other sites

Archived

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

  • Recently Browsing   0 members

    • No registered users viewing this page.

×
×
  • Create New...