Jump to content
  • Member Statistics

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

Next severe weather event April 26-29


Recommended Posts

  • Replies 1.3k
  • Created
  • Last Reply

the new NAM looks worse for the MidSouth. There's a 70kt 850 jet in eastern and northern Ala and middle TN right about the peak of the system at 72 hours. Its that time all the models have the front getting whiplashed east as the sfc low begins to suddenly pull north across mid TN and KY. Thats the zone I'd place as the highest risk for tornadoes, TN midstate to central and northern Alabama. Huntsville seems to get hit hard in situations like this, that area is just prone for development, but anywhere near that zone is going to deal with extremely strong storms.

Link to comment
Share on other sites

It seems to be an ongoing trend for the longest time now. Each new run of the modeling keeps showing a slightly more powerful jet throughout, especially at the 300 and 500 which by the NAM is now showing around 100 kts. across northern AL and MS through southern AR (previously it was weaker and further west), so already there is strong indication of increased speed and directional shear, especially at the low levels. SW Indiana to NE AR gets slammed big time as well with torrential rainfall amounting +4 inches total during the 60 hr. The 21z SREF is showing some very scary values of the sig tornadic parameter on the high end across parts of the Gulf Coast states and western TN. It begs the question regarding what the 0z GFS will show for tonight. I wouldn't be surprised if a moderate risk ends up being painted over parts of the Southeast for tonight's latest convective outlook or tomorrow night.

SREF_prob_combined_sigtor__f042.gif

nam_pcp_066m.gif

Link to comment
Share on other sites

It seems to be an ongoing trend for the longest time now. Each new run of the modeling keeps showing a slightly more powerful jet throughout, especially at the 300 and 500 which by the NAM is now showing around 100 kts. across northern AL and MS through southern AR (previously it was weaker and further west), so already there is strong indication of increased speed and directional shear, especially at the low levels. SW Indiana to NE AR gets slammed big time as well with torrential rainfall amounting +4 inches total during the 60 hr. The 21z SREF is showing some very scary values of the sig tornadic parameter on the high end across parts of the Gulf Coast states and western TN. It begs the question regarding what the 0z GFS will show for tonight. I wouldn't be surprised if a moderate risk ends up being painted over parts of the Southeast for tonight's latest convective outlook or tomorrow night.

SREF_prob_combined_sigtor__f042.gif

nam_pcp_066m.gif

I hate to say this, but I really hope that we can get some good storms in the Charlotte metro from this. I would really love to be able to do some chasing in my backyard without having to drive. rolleyes.gif

Link to comment
Share on other sites

Reviewing the overall guidance, support is definitely there for the nasty outbreak to continue eastward after the front departs from the Arklatex region. All suggest the secondary shortwave to rapidly deepen after the initial wave heads northeastward through the OV. The combo of the strong mid/upper level jets with the aid of the second shortwave's capability to cause additional turning of the winds aloft should be an alarm of powerful shear, both speed and directional, for quick super cellular development. This should be a great concern for anyone living within the TN Valley because the way I'm seeing it, this just argues for a few of these super cells to spawn strong tornadoes/intense bowing action with winds kicking up +80 mph possible. The abundance of the moist flow, sufficient instability, amongst all other parameters should yield increased severe wx threat over what was previously expected further east. Even places further north of TN could get in on some rough action as the front should stay in tact even after passing through the Apps. I'm thinking this will be a repeat of the 4/4 event where the front showed aggressiveness despite the time of day that it passed. Though the tornadic threat is reduced once crossing into the Carolinas, it would still be wise to be on guard as a strong tornado or two can still occur associated with any approaching squall line and considering that it will be dark, this just makes matters worse for trying to see where a tornado may be. Of course, this also means very large hail could be in store for some associated with any strong storm/tornado. The more I look at this data, the greater my concern grows for substantial damage for towns, countrysides, cities, etc. A powerful dynamically-driven system such as this is rather frightening when you think about it. It's going to be quite a doozy once this ride gets going.

Will mention that as I suspected earlier, a moderate risk was possible:

day3otlk_0730.gif

KBMX:

bhmskewt66.png

Link to comment
Share on other sites

There's a 130+ mph jetstreak that places the TN valley and Apps then Carolinas in enhanced lift, as it pulls due north. The SFC low deepens as it tracks from central ARK to western TN , then shoots north toward Detroit or northern Ohio. During this process, the intial band of tornado probability will shift from ahead of the best shear in much of western TN stretching west to east, then orient more north to south, roughly northern MS, AL and toward central KY. By midnight that line will be approaching eastern TN, KY , Wva, western VA and western Carolinas to extreme N. GA. Then around sunrise the occluded low will probably do like the early April event and pull a thin line of severe toward northern NC and northward up into PA. It looks extremely similar in timing to the April 6 event overall, and the 5H turns neg. in almost the exact same spot.

post-38-0-77376300-1303666078.gif

the red zone is where I think the best chance of TOR will be.

post-38-0-20245500-1303666140.gif

your red zone lines up almost identical for the SPC 3 day risk.

Link to comment
Share on other sites

Here we go with another big 3-day severe weather outbreak....this time with two distinct disturbances. One entering TX/ OK today, and the other one entering the west coast today.

A rare 'moderate' risk it out for Day 3.....and the wording the SPC uses in the discussion is quite strong. In fact, 3 straight days of 45% hatched severe probabilities. This will be ugly.

Spent a lot of time talking about the next few days

[/url]
Link to comment
Share on other sites

FFC: Edited for emphasis.

AREA FORECAST DISCUSSION...UPDATED AVIATION

NATIONAL WEATHER SERVICE PEACHTREE CITY GA

750 AM EDT MON APR 25 2011

...SIGNIFICANT SEVERE WEATHER EVENT EXPECTED WEDNESDAY...

SEVERE THUNDERSTORMS EXPECTED TUE-WED. VOLATILE SITUATION DEVELOPING

THAT WILL BRING SEVERAL ROUNDS OF THUNDERSTORMS TO THE CWA.

THE PRIMARY AFFECT OF THIS ON THE FFC CWA WILL BE

TUE-WED...LIKELY IN THE FORM OF TWO TO POTENTIALLY THREE ROUNDS OF

THUNDERSTORMS. THE FIRST TWO WILL IMPACT MAINLY NW/NC GA...THE THIRD

WILL IMPACT THE ENTIRE CWA. THE FIRST AND LEAST DEFINITE ROUND OF

THUNDERSTORMS WILL COME TUE AFTERNOON AS THE INITIAL SOUTHERN PLAINS

SHORT WAVE LIFTS TOWARD THE OHIO VALLEY AND IS ABSORBED INTO THE

PARENT UPPER LOW. ECMWF/GFS BOTH HINT AT A REMNANT/POSSIBLY

REGENERATING SQUALL LINE REACHING THE NW PART OF THE CWA DURING PEAK

HEATING TUE AFTERNOON WITH HIGH CAPE/INSTABILITY AND WEAK SHEAR. A

FEW OF THESE THUNDERSTORMS COULD BE SEVERE IN THE NW/NC AREA DURING

THE AFTERNOON/EVENING. A BIGGER THREAT FOR SEVERE WEATHER IN NW/NC

GA COMES EARLY WED AS THE NEXT IMPULSE IN THE BROAD UPPER TROUGH

MOVES THROUGH TN/MS/AL. A SEVERE QLCS IS LIKELY TO BE ONGOING

OVERNIGHT TUE...APPROACHING NW/NC GA BY OR BEFORE 12Z...CONTINUING

INTO MID-MORNING. VERY HIGH SHEAR...WITH 0-3KM BULK SHEAR NEAR 50KTS

AND UNUSUALLY HIGH CAPE FOR EARLY MORNING...ON THE ORDER OF 2000

J/KG...IS PROGGED TO SHIFT INTO NW GA ACCOMPANYING THESE

THUNDERSTORMS. A SEVERE QLCS IS LIKELY...CAPABLE OF SUPPORTING

DAMAGING WINDS AND TORNADOES.

THE FINAL UPPER SHORT WAVE ROTATES

INTO THE PARENT LOW WEDNESDAY AFTERNOON WITH A STRONG NEGATIVE TILT.

A STRONG COLD FRONT WILL ACCOMPANY THIS FEATURE. THE DEGREE OF EARLY

MORNING CONVECTIVE DEBRIS CONTAMINATION WILL LARGELY PLAY INTO THE

DEGREE OF SEVERITY OF AFTERNOON CONVECTION. HOWEVER...EASTERN AND

SOUTHERN AREAS WILL LARGELY REMAIN UNAFFECTED BY THE MORNING

ACTIVITY...AND WITH EXTREME SHEAR AND HIGH INSTABILITY IN

PLACE...SUPERCELL THUNDERSTORM DEVELOPMENT APPEARS LIKELY.

FINALLY...THERE WILL ALSO BE CONCERN FOR HEAVY RAINFALL ACROSS NW/NC

GA...AS THESE REPEATED ROUNDS OF THUNDERSTORMS TRACK ACROSS THE SAME

REGION. STREAMS/CREEKS IN THIS REGION ARE HIGH FROM RECENT PREVIOUS

EVENTS. AT THIS POINT...EXCESSIVE RAINFALL IS PROGGED TO REMAIN JUST

NW OF THE CWA...BUT RAINFALL OF 2-3 INCHES NW GA OVER THE 2-DAY

PERIOD WILL AT A MINIMUM RESULT IN SOME RIVER FLOODING. AN ESF WILL

BE ISSUED THIS MORNING TO ADDRESS THIS SITUATION.

Link to comment
Share on other sites

post-38-0-72697900-1303735711.gif

post-38-0-99213900-1303735727.gif

this is an extremely dynamic setup for the TN valley. The NAM would be a very bad outbreak in TN, northern MS, AL and eventually in eastern TN, KY and northern GA. Beyond that, it weakens as it comes across the Apps and re-develops Thursday, but not as strong as what happens west of the mountains. The GFS though is faster and maintains more a tornado threat east of the Apps, the timing is pretty bad however.

post-38-0-59432700-1303735873.gif

Link to comment
Share on other sites

It sure has been a crazy year for severe weather. Not sure where we stand but it has to be on up there at the top of the list because it seems like every single front is producing a lot of severe weather.

Hope I do better though than the last couple. Haven't had much to brag about since that severe line went through.

Link to comment
Share on other sites

Severe thunderstorms in North Georgia.

Cell 1

Severe Thunderstorm

Fulton County, GA

DBZ: 62

Severe Hail: 40%

Hail: 90:

Max Size: 1.00"

Top: 30,000

VIL: 41 kg/m2

Site: KATL

Cell 2

Severe Thunderstorm

Lumpkin County, GA

DBZ: 55

Severe Hail: 30%

Hail: 100%

Max Size: 0.75"

Top: 26,000

VIL: 36 kg/m2

Site: KHTX

There's a third below that is moving northward to the northwest of Gainesville similar to cell 2. It's been strengthening for a while now and is nearing Dahlonega.

Link to comment
Share on other sites

CAE..................

.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...

-- Changed Discussion --THE WARM AND MOIST SOUTHERLY FLOW WILL CONTINUE. THE NAM AND GFSSHOW H5 HEIGHTS SLIGHTLY DIFLUENT WITH A SHORTWAVE TROUGHAFFECTING MAINLY THE NORTHWEST PART OF THE FORECAST AREA LATETUESDAY AFTERNOON OR EVENING. A WELL-DEFINED SURFACE FEATUREAPPEARS LACKING WITH SHALLOW MOISTURE. CHANCE POPS APPEARREASONABLE WITH SLIGHTLY HIGHER VALUES IN THE NORTHWEST PART WHERETHERE SHOULD BE STRONGER LIFT ASSOCIATED WITH THE SHORTWAVETROUGH. IT WILL BE RELATIVELY COLD ALOFT. THE NAM INDICATES H5TEMPERATURES NEAR -11 WITH TOTAL TOTALS AROUND 50. THE MODERATEINSTABILITY PLUS DRY AIR IN THE MIDDLE LEVELS AIDING DOWNDRAFTSSUPPORTS POSSIBLE SEVERE THUNDERSTORMS. THE TEMPERATURE GUIDANCEWAS CONSISTENT. BEST DYNAMICS FOR STORMS APPEAR TO BE WEDNESDAYAFTERNOON AND WEDNESDAY EVENING. NAM GIVES LIS -4/-5 WITH CAPES2000-3000 J/KG DURING THIS PERIOD WITH TOTALS AROUND 50 AND PWVALUES 1.5-1.6 INCH. NAM ALSO GIVES A STRONG H850 SOUTH TOSOUTHWEST JET OF 40-50 KNOTS WEDNESDAY AFTERNOON AND WEDNESDAYEVENING. PREVIOUS 12 KM NAM RUN HAD STRONGER SHEAR BUT 12Z RUNGIVES 0-3 KM HELICITY VALUES 200-300 M2/S2. THE 12Z 80 KM NAM ISSHOWING AN AREA OF STRONG OMEGA ON THE NORTHEAST GULF INCLUDINGTHE FLORIDA PANHANDLE WEDNESDAY AFTERNOON. SOMETIMES CONVECTION INTHIS REGION TAKE DEPLETE ENERGY TO PRODUCE STRONG THUNDERSTORMS.WILL CONTINUE TO MONITOR CHANGING DYNAMICS WITH SYSTEM. ALSO...SPCHAS THE UPSTATE OF SOUTH CAROLINA IN A SLIGHT RISK AREA FOR MAINLYTUESDAY AFTERNOON. THERE IS A MODERATE RISK LOCATED WELL TO THEWEST IN ARKANSAS...WESTERN TENNESSEE AND NORTHWEST MISSISSIPPI.SPC SLIDES THE SLIGHT RISK TO COVER MOST OF SOUTH CAROLINAWEDNESDAY AHEAD OF THE COLD FRONT. THE MODERATE RISK REMAINS TOTHE WEST BUT IS VERY CLOSE TO ATL IN NORTHWEST GA AND OVER MOST OFTENNESSEE.-- End Changed Discussion --

Link to comment
Share on other sites

FFC doesn't seem to be overly concerned with the storm system this week. Looks like most of it will be to our north, but we could still get some severe weather....

THIS FRONT STILL LOOKS LIKE OUR BEST

CHANCE FOR SEVERE STORMS OVER THE NEXT 7 DAYS. BOTH OF THE MODELS

SHOW THE BEST MOISTURE AND DYNAMICS STAYING NORTH OF THE AREA...BUT

THERE WILL STILL BE ENOUGH MOISTURE...INSTABILITY...AND SHEAR FOR

SEVERE STORMS TO OCCUR.

Link to comment
Share on other sites

FFC doesn't seem to be overly concerned with the storm system this week. Looks like most of it will be to our north, but we could still get some severe weather....

THIS FRONT STILL LOOKS LIKE OUR BEST

CHANCE FOR SEVERE STORMS OVER THE NEXT 7 DAYS. BOTH OF THE MODELS

SHOW THE BEST MOISTURE AND DYNAMICS STAYING NORTH OF THE AREA...BUT

THERE WILL STILL BE ENOUGH MOISTURE...INSTABILITY...AND SHEAR FOR

SEVERE STORMS TO OCCUR.

Yea completely different with this mornings AFD. They mentioned possible supercells/tornadoes.

Link to comment
Share on other sites

Archived

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

Guest
This topic is now closed to further replies.
  • Recently Browsing   0 members

    • No registered users viewing this page.

×
×
  • Create New...