58 replies to this topic

[OceanStWx]

[KokomoWX]

Quote

MESOSCALE DISCUSSION 0145
NWS STORM PREDICTION CENTER NORMAN OK
0221 PM CST THU FEB 23 2012

AREAS AFFECTED...PORTIONS OF THE OH RIVER VALLEY

CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE

VALID 232021Z - 232145Z

CONVECTION IS EXPECTED TO INCREASE ACROSS PORTIONS OF THE OH RIVER
VALLEY OVER THE NEXT 2-4 HOURS. TORNADO WATCH MAY BE REQUIRED TO
ACCOUNT FOR THIS INCREASING THREAT.

SFC WARM FRONT CONTINUES ITS SLOW NWD RETREAT AS IT LIFTS ACROSS SRN
IND/IL...WWD INTO A WELL DEFINED SFC LOW ALONG I-70 OVER CNTRL MO.
OVER THE LAST FEW HOURS A RAPIDLY EXPANDING SHIELD OF LOW-MID CLOUDS
HAS DEVELOPED WITHIN WARM ADVECTION ZONE ACROSS SRN IL/SWRN IND INTO
WRN KY. THIS CERTAINLY REFLECTS THE MOISTENING/ASCENT PROCESS THAT
SHOULD SPREAD NEWD TOWARD THE WARM FRONT ACROSS THE OH VALLEY INTO
THE EVENING HOURS. LATEST OA FIELDS SUGGEST A NARROW AXIS OF
INSTABILITY...MUCAPE ON THE ORDER OF 500-1500 J/KG...HAS OVERSPREAD
WRN KY. IF THIS AIRMASS CAN ADVECT INTO THE WARM FRONTAL ZONE PRIOR
TO CONVECTIVE INITIATION THEN AN ENHANCED RISK OF ROBUST
UPDRAFTS...POSSIBLY SUPERCELLULAR IN NATURE...COULD EVOLVE. LATEST
VIS IMAGERY DOES NOT CURRENTLY SUGGEST INDIVIDUAL UPDRAFTS HAVE
DEEPENED APPRECIABLY BUT CONTINUED LARGE SCALE ASCENT SHOULD
ENCOURAGE STRONGER UPDRAFTS OVER THE NEXT FEW HOURS. WILL CONTINUE
TO MONITOR THIS REGION FOR POSSIBLE TORNADO WATCH.

..DARROW.. 02/23/2012


ATTN...WFO...ILN...LMK...IND...PAH...

Attached Files

•  mcd0145.gif   27.46K   0 downloads

[blue60007]

I'm liking the EVV-SDF-CVG corridor right now for the best chance of severe storms. Threat for a more organized QLCS later this evening increases as you get east of SDF and go into E KY and S OH.

[PSUBlizzicane2007]

LMK is showing a bust for SDF and points westward atm.

[SouthernNJ]

There is a discrete storm to the west of Frankfort KY.
It popped up quickly compared to the other storms
to the south of it.

[SouthernNJ]

Beginning to detect a circulation in the Frankfort storm as it approaches.

[OceanStWx]

SouthernNJ, on 23 February 2012 - 07:02 PM, said:

There is a discrete storm to the west of Frankfort KY.
It popped up quickly compared to the other storms
to the south of it.

That storm looks like it might still be slightly elevated right now, but it's close. Wouldn't take much to root in the boundary layer.

Still a ways to go before a severe hail threat though (about 7 kft).

[OceanStWx]

Nice little left split off that storm. Would have been nice to have some dual-pol to see if it picked up on the two updrafts.

[OceanStWx]

Looks like a little more concentrated, rapid development on a line from SDF to FTK.

[OceanStWx]

Nice updraft just south of KLVX, but it's in a tough position. Partially in the cone of silence, and right on the zero isodop so it's hard to tell rotation. Some suggestion there is a weak meso in there though.

[CapitalKid]

Im in Frankfort. Its pretty quiet right now. Like a light shower really. But the lightning has been pretty spectacular when it strikes.

[SouthernNJ]

OceanStWx, on 23 February 2012 - 07:31 PM, said:

Nice updraft just south of KLVX, but it's in a tough position. Partially in the cone of silence, and right on the zero isodop so it's hard to tell rotation. Some suggestion there is a weak meso in there though.

This storm does have an interesting reflectivity signature. I am not too concerned
about a lot of overall severe weather in this region, but more so about a random
storm splitting or merging and turning into a quick tornado like last night in Rome
Georgia.

[SouthernNJ]

Even if the storm between Elizabethtown and Louisville is not severe, it
is still a dangerous one to be anywhere outdoors in.

[OceanStWx]

SouthernNJ, on 23 February 2012 - 08:05 PM, said:

Even if the storm between Elizabethtown and Louisville is not severe, it
is still a dangerous one to be anywhere outdoors in.

It's getting close. Very nice reflectivity core suspended aloft right now. 70 dBZ up to 16kft and 50 dBZ over 20 kft.

[OceanStWx]

Interesting that their warning made no mention of winds. I guess their thinking must be that this one is also elevated.

[OceanStWx]

Mid level meso strengthening, WER showing up now at 3.1 and 4.0 degrees.

[SouthernNJ]

OceanStWx, on 23 February 2012 - 08:14 PM, said:

Interesting that their warning made no mention of winds. I guess their thinking must be that this one is also elevated.

Also interesting is that there was no mention of "radar has indicated some weak rotation"
as an action statement. It seemed to be an important one in case something formed
within a couple of minutes.

[OceanStWx]

SouthernNJ, on 23 February 2012 - 08:21 PM, said:

Also interesting is that there was no mention of "radar has indicated some weak rotation"
as an action statement. It seemed to be an important one in case something formed
within a couple of minutes.

I think these warned storms are just too far into the cold air. The cells trying to develop around Taylor and Green Counties have a little better shot to have a circulation that affects the surface.

[SouthernNJ]

OceanStWx, on 23 February 2012 - 08:38 PM, said:

I think these warned storms are just too far into the cold air. The cells trying to develop around Taylor and Green Counties have a little better shot to have a circulation that affects the surface.

Assuming a report of 1-inch hail is not forthcoming, would this have been a case where
having access to a dual-polarization radar could have been able to prevent a false alarm?
I know it is supposed to help distinguish between regular hail and melting hail.

[OceanStWx]

SouthernNJ, on 23 February 2012 - 09:00 PM, said:

Assuming a report of 1-inch hail is not forthcoming, would this have been a case where
having access to a dual-polarization radar could have been able to prevent a false alarm?
I know it is supposed to help distinguish between regular hail and melting hail.

It's possible. There is still no explicit radar signature to hail size indicator with dual-pol, but it will lead to greater confidence of large hail (> 2"). There were reports of lots of dime size hail, so it is possible this would have looked similar to quarter size hail even with dual-pol.

I think FAR improvement will be most noticeable with lots of pea size hail and rain versus quarter size hail. Melting hail or hail mixed with rain gives a different signal with dual-pol, as wet hail is the most powerful reflector.

[SouthernNJ]

OceanStWx, on 23 February 2012 - 09:03 PM, said:

It's possible. There is still no explicit radar signature to hail size indicator with dual-pol, but it will lead to greater confidence of large hail (> 2"). There were reports of lots of dime size hail, so it is possible this would have looked similar to quarter size hail even with dual-pol.

I think FAR improvement will be most noticeable with lots of pea size hail and rain versus quarter size hail. Melting hail or hail mixed with rain gives a different signal with dual-pol, as wet hail is the most powerful reflector.

Thanks for the response. As far as this storm goes, I believe they made the correct decision
to warn for it. Dime size hail covering the ground is still very hazardous, especially for
individuals driving on a busy roadway.

[Jim Martin]

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 1030 PM EST

FOR SOUTHEASTERN HIGHLAND...EXTREME NORTHWESTERN SCIOTO...SOUTHERN

ROSS...WESTERN PIKE AND NORTHEASTERN ADAMS COUNTIES...



AT 1007 PM EST...RADAR CONTINUED TO INDICATE A SEVERE THUNDERSTORM

CAPABLE OF PRODUCING QUARTER SIZE HAIL. THIS STORM WAS LOCATED NEAR

SINKING SPRING...MOVING NORTHEAST AT 60 MPH.



LOCATIONS IMPACTED INCLUDE...

KINCAID SPRINGS...PIKE LAKE...BAINBRIDGE...PIKETON AND WAVERLY.



IN ADDITION...POPLAR GROVE...ELM GROVE...IDAHO...BUCHANAN...

SUMMITHILL...KNOCKEMSTIFF AND LAKE WHITE ARE NEAR THE PATH OF THIS

STORM.

I couldn't resist there... Knockemstiff? LOL

[SouthernNJ]

Looks like the forcing finally kicked in.

[andyhb]

Cells rapidly organizing between LVX and OHX.

Edit: Cell west of Bowling Green went svr warned.