Indystorm

Excerpt from Memphis AFD for Monday-Wed, with expectation of more negatively tilted trough TOMORROW EXPECT A GREATER RISK OF SEVERE WEATHER AS A TROUGH SHIFTS OUT OF THE PLAINS. A 50-60 KNOT LLJ WILL DEVELOP OVER WESTERN PORTIONS OF THE MIDSOUTH MONDAY AFTERNOON. MODELS NOW HAVE THIS TROUGH MORE NEGATIVELY TILTED THAN PREVIOUS RUNS. ABUNDANT MOISTURE WILL REMAIN IN PLACE...ESPECIALLY ACROSS EAST ARKANSAS WHERE PW`S WILL RANGE FROM 1.5 TO 1.75 INCHES. DEWPOINTS IN THE MIDDLE 60S WILL PRODUCE CAPES BETWEEN 1500 AND 2000 J/KG AND LIFTED INDICES WILL RANGE FROM -6 TO -8 DEGREES. LOW AND MID LEVEL DYNAMICS SHOULD RESULT IN SUFFICIENT SHEAR TO SUPPORT SUSTAINED UPDRAFTS AND SUPER CELLULAR THUNDERSTORMS. DEEP DRY AIR ALOFT WILL LIKELY RESULT IN LARGE HAIL. SOUTHERLY FLOW WILL INCREASE ON MONDAY REPLENISHING THE SUPPLY OF WARM MOIST AIR ACROSS THE MIDSOUTH. SPEEDS WILL LIKELY BE SUSTAINED BETWEEN 20 AND 30 MPH WITH GUSTS TO 40 MPH. A WIND ADVISORY WILL LIKELY BE NEEDED. STORMS WILL CONTINUE ON TUESDAY...BUT LACK OF UPPER LEVEL SUPPORT WILL RESULT IN LESS OF A THREAT FOR SEVERE STORMS. IT STILL LOOKS LIKE WEDNESDAY HAS THE POTENTIAL TO DEVELOP INTO A MAJOR OUTBREAK. THIS STORM WILL BE ONE OF THE MORE DYNAMIC SYSTEMS I HAVE SEEN IN A WHILE. FORECAST SOUNDINGS INDICATE INCREDIBLE 0-3KM SRH VALUES OVER 1500M/S2 EARLY WEDNESDAY MORNING...AND MORE REALISTIC VALUES AROUND 300-600 DURING THE DAY. MODELS ALSO NOW FEATURE A 80KT LLJ CENTERED OVER MEMPHIS LATE TUESDAY NIGHT. THE MID LEVEL SHORTWAVE DOES NOT LOOK QUITE AS NEGATIVELY TILTED THIS..RUN BUT IT IS STILL VERY AMPLIFIED. SURFACE WINDS WILL BACK AS A SURFACE LOW TRACKS FROM CENTRAL ARKANSAS INTO WESTERN KENTUCKY RESULTING IN LONG CURVED HODOGRAPHS SUPPORTIVE OF SEVERE THUNDERSTORMS. TORNADOES...POSSIBLY STRONG LONG TRACKED TORNADOES...LARGE HAIL AND DAMAGING WIND ARE ALL POSSIBLE ON WEDNESDAY.

Well< Mac, I have relatives both dead and alive from Anna ne to Marion area. Have been to CAPE many times so I have a strong interest in far southern IL. at this time of year weatherwise especially.

Use this map only as a rough guide for Monday evening and watch how parameters unfold as we get closer to the event, Mac.

As an interested layman, this recent discussion is reminding me that there is more to forecasting than model hugging, like synoptics.

Reuters reports that Henry Margusity says that there could be up to 300 tornadoes the next two weeks from OK to Ohio. With this pattern he may not be exaggerating.

Even without looking at any parameter other than today's 18z GFS precip maps for 120, 126, and 130 hrs. I would be worried. They create extensive precip blotchiness from WI down to ne TX and then form a major squall line. Geesh!

The thing that strikes me at this distance out is the track of the lows farther nw than we have seen with our most recent svr outbreaks, across IA and WI, leading to a larger geographical extent of the warm sector.