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July 21-? Severe Weather


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Negatively-tilted trough + solid bulk shear (35-50 kts) + 3000-5000 j/kg CAPE + somewhat minimal CIN = trouble...

NAM is even more impressive, showing 60-70 kts of bulk shear in Minnesota on Saturday.

It is a complicated scenario as of right now. Model guidance are all pretty consistent on the overall mean trough, but there will be at least 3 embedded speed maxes/PV anomalies rotating around the base of the mean trough as this systems slowly develops across the western US into the plains. This throws out quite a bit of small scale variablity by Saturday afternoon, not to mention there may be an ongoing MCS into portions of MN during the early day. Global guidance does seem less impressive than the operational NAM, and in either scenario much of the region looks to be strongly capped with forcing along the front the main/only contributor to DMC initiation above the cap. While this is usually a common feature for larger potential severe weather events (good capping through much of the afternoon), laying out severe probs would be difficult at this time for SPC. The synoptic differences amongst the guidance owing to the 2-3 anomalies rounding the mean trough would have signifiacnt differences ranging from strength of the frontal zone/potential initiation to wind fields aloft and subsequent shear. NAM verbatim would be a potentially significant threat with the progged instability/frontal forcing/shear fields.

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FWIW, the parallel NAM supports the operational NAM in suggesting a strong PV anomaly and subsequent potent shortwave rounding the base of the mean trough into MN on Saturday. While the I give little credence to the NAM operational these days, the NAM parallel has proven its worth and lends a little credibility to the NAM operational solution.

post-999-0-86107900-1311216722.gif

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GFS still not as bullish on any waves rounding the base of the mean trough as the two NAMs are, but it still initiates DMC along the warm front and prefrontal trof in the late afternoon, and it certainly is more impressive than the last couple runs. Deep later shear looks a tad better with great low level turning in a high CAPE environment. I am slightly more interested in this threat than a day or two ago.

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The ECMWF made slow strides towards something more significant on Saturday, still not as impressive as the NAM or UK, but slower and stronger with the mid level wave than a day ago with a stronger surface reflection.

The EC:

post-999-0-12883500-1311228483.gif

And the NAM looking UK:

post-999-0-59005700-1311228511.gif

With the latest suite of 00Z guidance and the general trend the last day, I would have to think a Day 3 will be laid out by SPC.

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The ECMWF made slow strides towards something more significant on Saturday, still not as impressive as the NAM or UK, but slower and stronger with the mid level wave than a day ago with a stronger surface reflection.

The EC:

post-999-0-12883500-1311228483.gif

And the NAM looking UK:

post-999-0-59005700-1311228511.gif

With the latest suite of 00Z guidance and the general trend the last day, I would have to think a Day 3 will be laid out by SPC.

The wording in the day 2 outlook for Friday is already rather strong:

...UPR MS VLY WWD ACROSS THE NRN PLAINS...

LLVL MOISTURE...CHARACTERIZED BY 70S SFC DEW POINTS...WILL BEGIN TO

SURGE NWD FRI AS SLY FLOW ACCELERATES AHEAD OF THE NEXT UPR SYSTEM.

CONCOMITANT INCREASE IN H85-H7 TEMPERATURES WILL RESULT IN A FAIRLY

SUBSTANTIAL CAP...PARTICULARLY ALONG/SW OF THE MO RVR VLY.

HOWEVER...00Z GFS/NAM AND 12Z ECMWF HINT THAT A SUBTLE SUB-TROPICAL

WAVE MAY EJECT AHEAD OF THE PRIMARY TROUGH... REACHING PARTS OF

SD/ND BY MID-AFTN FRI. STRONG DIABATIC HEATING...STEEP MID-LVL

LAPSE RATES...AND WEAK ASCENT/MOISTENING OF THE BASE OF THE EML WILL

PROBABLY YIELD WDLY SCTD SFC-BASED TSTM INITIATION ALONG THE WARM

FRONT/LEE LOW IN SRN ND AND NRN/CNTRL SD. 0-8KM SHEAR WILL BE MORE

THAN SUFFICIENT FOR SUPERCELLS WITH ALL FACETS OF SVR WEATHER

PSBL...INCLUDING TORNADOES. LACK OF SUBSTANTIAL FORCING AND

QUESTION ON NUMBER OF STORMS GIVEN WARM MID-LVL TEMPS PRECLUDES

HIGHER SVR PROBABILITIES ATTM...BUT SIGNIFICANT SVR WEATHER COULD

OCCUR SHOULD STORMS INDEED FORM. WHETHER SFC-BASED STORMS FORM OR

NOT...LLJ INCREASING TO 40 KTS AND INCREASING LARGE-SCALE ASCENT

ASSOCIATED WITH THE PARENT TROUGH WILL CONTRIBUTE TO CONSIDERABLE

ELEVATED TSTMS FRI NIGHT FROM THE ERN DAKOTAS SEWD INTO THE UPR MS

VLY. IT IS CONCEIVABLE THAT SRN FRINGES OF ACTIVITY COULD BE

SUFFICIENTLY ROOTED AT THE SFC FOR DMGG WIND THREATS TO SPREAD EWD

TOWARD THE UPR MS VLY OVERNIGHT...OTHERWISE...ELEVATED STORMS WILL

PRIMARILY BE MRGLLY SVR WITH HAIL/HVY RNFL.

MEANWHILE...COMPARATIVELY STRONGER FORCING FOR ASCENT WILL SPREAD

ACROSS THE NRN ROCKIES INTO THE NRN HIGH PLAINS FRI AFTN/EVE.

HIGH-BASED STORMS DEVELOPING OVER THE HIGHER TERRAIN WILL ENCOUNTER

AN INCREASINGLY UNSTABLE ENVIRONMENT OVER ERN MT/WRN ND FRI EVENING.

STRENGTHENING VERTICAL SHEAR AND ROBUST MID-LVL LAPSE RATES WILL

FOSTER BOTH SUPERCELLS AND FAST MOVING LINE SEGMENTS WITH HIGH

WINDS/HAIL AND PSBLY A COUPLE TORNADOES. THIS ACTIVITY WILL LIKELY

JOIN STORMS FARTHER E OVERNIGHT RESULTING IN A RATHER EXPANSIVE AREA

OF CONVECTION ACROSS THE NRN PLAINS FRI NIGHT.

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Ok, this is hilarious, and thought you guys may get a kick out of it. It relates to potential svr wx, so I decided to put it here. :P

http://www.youtube.c...h?v=Fb4O-_8f9jw

What on earth is he talking about?

What is a "HAARP Ring", and what does that have to do with anything? He sounds like he is rambling. He talks like he is showing something significant, but makes absolutely no sense. He says "oh wow' alot , but apparently, the significance of that is known only to him.

I couldn't stick with the video... I have a very short attention span when it comes to rambling speech. He just keeps talking about the ring pattern in the radar return, but doesn't explain it's significance, if any.

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00z NAM painting an interesting picture across Southern MN perhaps into WI for Saturday, with 35-45 kts of bulk shear, ample CAPE, potentially eroded CIN, a lot of theta-e and decent-looking hodos. However, morning convection may play a big role in this setup.

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00z NAM painting an interesting picture across Southern MN perhaps into WI for Saturday, with 35-45 kts of bulk shear, ample CAPE, potentially eroded CIN, a lot of theta-e and decent-looking hodos. However, morning convection may play a big role in this setup.

Good chance I'll be in Madtown Saturday. Hopefully there is the opportunity for something interesting to pop.

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