Jump to content
  • Member Statistics

    17,601
    Total Members
    7,904
    Most Online
    ArlyDude
    Newest Member
    ArlyDude
    Joined

Severe Thread: August 1- 12


Recommended Posts

  • Replies 69
  • Created
  • Last Reply

700mb rule does not apply in the Northern Plains due to higher ground elevation according to John Daviess. I'm not really sure how to judge capping in that case.

That's a good point, forgot about that. The H7 temps aren't overly inhibiting in this case anyway, FGF's CWA looks good per the 00z NAM.

Link to comment
Share on other sites

Do you see much of a tornado threat Andy?

Given the backed LL wind fields, if we can get discrete supercells ahead of the front (40-50 kts of 0-6 km bulk shear), I think there should be a threat given progged LCL heights. That is an "if" however, and I have concerns whether storms can initiate in time to take advantage of more favorable parameters. Dewpoint mixing could also be an issue.

Would still like to see an increase in the strength of the LLJ (like the 12z NAM showed), with stronger height falls owing to a bit of a faster eastward progression of the upper level trough.

Link to comment
Share on other sites

Tomorrow has the threat of some severe storms, and isolated tornadoes, then on Saturday, a lower threat, and then out east in the Ohio Valley and Northeast, a significant outbreak with tornadoes appears possible on sunday, Sunday appears to be the biggest day from this system coming out of Canada

Link to comment
Share on other sites

Tomorrow has the threat of some severe storms, and isolated tornadoes, then on Saturday, a lower threat, and then out east in the Ohio Valley and Northeast, a significant outbreak with tornadoes appears possible on sunday, Sunday appears to be the biggest day from this system coming out of Canada

Jumping the gun a bit I think.

FWIW, the 18z NAM looks to have discrete convection based on its precip outputs tomorrow later afternoon/evening in the eastern Dakotas and western MN. Based on progged LL helicity/instability, these could have tornadic potential. It also appears to be a lot more spotty with CINH compared to some earlier runs.

Link to comment
Share on other sites

* AT 636 PM MDT...TRAINED WEATHER SPOTTERS REPORTED A TORNADO NEAR

GOLDENEYE STATE WILDLIFE MANAGEMENT AREA...OR 5 MILES SOUTHWEST OF

BIG SPRINGS. DOPPLER RADAR SHOWED THIS TORNADO MOVING EAST AT 15

MPH.

Link to comment
Share on other sites

Town of Imperial needs to be on the lookout. Slow mover though.

prob go west of there if it holds together that long given current movement. this thing's in the middle of nowhere mostly.

Link to comment
Share on other sites

Day 1.

...UPPER MIDWEST TO NEB...

SCATTERED TO LOCALLY NUMEROUS TSTMS ARE FCST TO DEVELOP DURING

AFTERNOON...AS STRENGTHENING COLD FRONT...SFC LOW...INVERTED TROUGH

AND RELATED CONVERGENCE MAXIMA IMPINGE UPON FAVORABLY MOIST AND

DIABATICALLY HEATED BOUNDARY LAYER. DAMAGING HAIL...STG-SVR GUSTS

AND A TORNADO OR TWO ARE POSSIBLE.

ASSORTED MEASURES OF VERTICAL SHEAR WILL BE STRENGTHENING WITH TIME

DURING AFTERNOON...ESPECIALLY INVOF LOW...WARM FRONT AND TROUGH

WHERE RELATIVELY BACKED SFC WINDS CONTRIBUTE TO ENLARGED 0-1 AND 0-3

KM AGL HODOGRAPHS. FCST WIND PROFILES YIELD 40-50 KT EFFECTIVE

SHEAR MAGNITUDES FROM SERN SD NWD THROUGH CYCLONE PAST GFK AREA AND

EWD OVER ADJOINING PORTIONS WRN MN...WHERE LOW-LEVEL SRH ALSO MAY BE

MAXIMIZED. LCL HEIGHTS WILL BE ON HIGH END OF SPECTRUM BUT

TORNADOES STILL MAY OCCUR WITH A SUPERCELL OR TWO IN REGIME NEAR LOW

AND TROUGH. MODIFIED MODEL SOUNDINGS SUGGEST MLCAPE 1500-3000 J/KG

IS POSSIBLE...AIDED BY STEEP LOW-MIDDLE LEVEL LAPSE RATES AND

MID-60S F. CLUSTER OF TSTMS MAY PERSIST FROM AFTERNOON/EARLY

EVENING ACTIVITY AND MOVE EWD OVER PORTIONS WRN/CENTRAL MN...WITH

RISK FOR DAMAGING GUSTS AND OCNL HAIL.

DEEPER MIXING AND HIGHER LCL ARE FCST SWD ACROSS SERN SD INTO

NEB...ALONG WITH GRADUAL LESSENING OF BOTH SRH AND DEEP-LAYER SHEAR

WITH SWD EXTENT. NONETHELESS...COMBINATION OF FRONTAL

LIFT...DIABATICALLY WEAKENED CINH...WELL-MIXED SUBCLOUD LAYER...AND

AT LEAST MRGL DEEP-TROPOSPHERIC SHEAR SUGGEST SCATTERED MULTICELL

SVR IS POSSIBLE FOR SEVERAL HOURS DURING AFTERNOON AND EVENING.

Link to comment
Share on other sites

Very impressive soundings coming out of the latest runs of the RAP in northeastern SD tomorrow afternoon/evening, if that cap goes, especially along the northern axis of instability, and you get supercells moving into LL shear like this...

1ovh8w.jpg

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...