Threat of severe weather

Today poses the greatest threat of severe weather in the South since last spring. There were at least 14 reports of tornadoes yesterday and two fatalities in the town of Paris, in Northeast Missouri. This morning the SPC edged the Moderate Risk area a little farther south into Tennesse, almost to North Alabama. A Public Severe weather Outlook has also been issued.

The Mobile NWS has issued numerous tornado warnings this morning for counties in southwestern Alabama and western Florida.

The SPC has now issued a new mesoscale discussion regarding the potential for supercell development from my location and points west. An excerpt...

MESOSCALE DISCUSSION 2108

NWS STORM PREDICTION CENTER NORMAN OK

1026 AM CDT THU OCT 18 2007

CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE

TRENDS ARE BEING CLOSELY MONITORED FOR AN

INCREASING SEVERE THREAT AND THE POSSIBILITY

OF ONE OR MORE WATCHES...PERHAPS BY EARLY

AFTERNOON.

...SEVERE THREAT WILL INCREASE CORRESPONDINGLY

WITHIN STRONG DEEP LAYER SHEAR FAVORABLE FOR

SUPERCELLS...BETWEEN STRONG SOUTHWESTERLY

POLAR AND SUBTROPICAL JET AXES. ALTHOUGH LOW-

LEVEL SHEAR MAY ONLY BE CHARACTERIZED BY WEAK

CLOCKWISE TURNING WITH HEIGHT...HODOGRAPHS

BENEATH 30-40 KT SOUTHWESTERLY 850 MB FLOW

WILL BE FAVORABLE FOR TORNADOES...WHICH COULD

BECOME STRONG.

Parts of Oklahoma, Arkansas, Kansas, and Missouri under the gun

...CNTRL/SRN PLAINS EWD INTO THE MID/LOWER MS VALLEY...

--A POTENTIALLY SIGNIFICANT SEVERE WEATHER EPISODE IS EXPECTED THIS AFTERNOON AND TONIGHT WITH A THREAT OF STRONG...LONG-TRACKED TORNADOES–

THESE STORMS ARE EXPECTED TO INCREASE IN COVERAGE AND INTENSITY THROUGH THE DAY WHILE MOVING / DEVELOPING NEWD TOWARD THE LOWER MO VALLEY WITH THE POTENTIAL FOR EMBEDDED SUPERCELLS CAPABLE OF HAIL...DAMAGING WINDS AND PERHAPS A COUPLE TORNADOES.

MORE SIGNIFICANT... SEVERE STORM DEVELOPMENT IS ANTICIPATED IN WAKE OF EARLIER STORM ACTIVITY LATER THIS AFTERNOON FROM VICINITY OF SURFACE LOW OVER SWRN KS SWD/SEWD ALONG DRY LINE INTO WRN/CNTRL OK AND FAR N-CNTRL TX. THE COMBINATION OF MODERATE INSTABILITY AND MODERATE TO STRONG LOW AND DEEP-LAYER SHEAR SUGGEST A HIGH LIKLIHOOD OF SUPERCELLS CAPABLE OF LARGE HAIL...DAMAGING WINDS AND TORNADOES...A FEW OF WHICH COULD BE STRONG AND LONG-TRACKED. THIS
IS ESPECIALLY THE CASE FROM SERN KS AND ERN OK INTO AR AND SRN MO THIS EVENING AND TONIGHT WHERE DEEP-LAYER FORCING FOR ASCENT WILL BE CONCENTRATED IN ADVANCE OF PRIMARY SHORT WAVE TROUGH.

ELSEWHERE...TSTMS WILL BECOME INCREASINGLY NUMEROUS TODAY OVER PARTS OF THE LOWER MS VALLEY INTO THE MID SOUTH WITHIN A VERY MOIST AND
MODERATELY UNSTABLE AIR MASS RETURNING NWD. FORECAST SOUNDINGS INDICATE VERTICAL SHEAR PROFILES QUITE SUPPORTIVE OF SUPERCELLS CAPABLE OF TORNADOES /SOME STRONG

SUPERCELLS WILL REMAIN POSSIBLE OVERNIGHT WITH A THREAT OF TORNADOES... LOCALLY STRONG WIND GUSTS AND SOME HAIL.



Update by Dew 10/17/07 at 3:30: Just to offer some reference as to what Alabama Mike is talking about... NW Louisiana... right now... looks pretty intense. Let's all drool together. I'd like to add a laptop and GPS to that list, Mike. ;-)

Time to prepare for Thursday

I posted more about this over on my page. What are your thoughts on this potential event?

Action to come in the tropics?

From James Spann's afternoon discussion today on Alabamawx.com:

Interesting to note the 12Z GFS also develops some kind of tropical system around May 31 over the far Southeast Gulf of Mexico; it then moves across South Florida and northeast into the Atlantic. Then, on June 3, it develops a whopper of an eastern U.S. upper trough which sweeps much cooler air down into Alabama. But, all of this is pure voodoo at this stage of the game. Just interesting to watch.

The models have been hinting at this consistently in runs all week long. Lets keep our eyes open for this!

Look out Texas

Here is an exerpt from the SPC's discussion this morning...

VERTICAL SHEAR PROFILES ARE FORECAST TO BECOME QUITE FAVORABLE FOR TORNADIC SUPERCELLS IN ADVANCE OF THE SURFACE LOW AND EWD ALONG AND EVEN S OF THE WARM FRONT INTO E/NE TX. A FEW DISCRETE SUPERCELLS WILL LIKELY DEVELOP ALONG THE DRYLINE AND PERHAPS IN THE OPEN WARM SECTOR BY MID AFTERNOON AND MOVE ENEWD INTO THE REGION OF STRONGER LOW-LEVEL SHEAR. BOUNDARY LAYER DEWPOINTS IN THE MID-UPPER 60S AND LARGE HODOGRAPHS WITH EFFECTIVE SRH OF 400-500 M2/S2 APPEAR SUPPORTIVE OF SUPERCELLS WITH STRONG TORNADOES LATE THIS AFTERNOON INTO THIS EVENING ACROSS NE TX.