We have seen some weakening of the line over Northwest Alabama this morning as it moves into rain cooled air from the earlier storms.
That is good news.
But it is temporary.
Look at those dewpoints ahead of the line. 70F at Columbus. 69F at Tuscaloosa. 67F at Birmingham.
With a couple of hours of heating this morning, the storms will have more to draw on in the way of instability. Damaging winds will be a strong possibility as well as spin up tornadoes along the line.
A tornado warning is in effect for the area south of Starkville MS heading toward Columbus.
This will keep the severe threat going for several hours and you will have to keep up your guard.
In addition, flooding will be a serious concern. These storms have a lot of moisture to work with and are dumping some impressive rainfall amounts in short periods. This on top of the excessive rainfall amounts from the weekend will lead to flash flooding.
Here is a new Mesoscale Discussion from the folks at SPC…
ACUS11 KWNS 061222
SWOMCD
SPC MCD 061222
GAZ000-ALZ000-TNZ000-MSZ000-LAZ000-ARZ000-061345-
MESOSCALE DISCUSSION 0729
NWS STORM PREDICTION CENTER NORMAN OK
0722 AM CDT WED MAY 06 2009
AREAS AFFECTED…PORTIONS NERN LA…MS…WRN/CENTRAL/NRN AL…SRN
MIDDLE TN…NWRN GA.
CONCERNING…SEVERE THUNDERSTORM WATCH 251…253…
VALID 061222Z – 061345Z
THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH
251…253…CONTINUES.
NEW WW OR LOCAL EXTENSION OF EXISTING WWS MAY BE REQUIRED FOR
PORTIONS MS/AL SE OF ONGOING WW AREAS…GIVEN POTENTIAL FOR MCS WITH
DAMAGING WINDS TO MOVE SEWD INTO COUNTIES NOT PRESENTLY COVERED BY
EITHER…WITHIN NEXT 1-2 HOURS. NERN PORTION OF THIS COMPLEX WILL
CONTINUE TO MOVE ESEWD OVER REMAINING NRN PORTIONS WW 251.
ACTIVITY CONTINUES TO FORWARD-PROPAGATE INTO VERY MOIST AND WEAKLY
CAPPED BOUNDARY LAYER AIR THAT IS FCST TO BECOME MORE UNSTABLE
DURING NEXT FEW HOURS AS INSOLATION BEGINS TO WARM SFC PARCELS.
MLCAPES 1000-2000 J/KG SHOULD BE COMMON OVER PRECONVECTIVE AIR MASS
IN MS/AL. MEANWHILE CAPPING EVIDENT IN 12Z JAN RAOB SHOULD BE
ERODED BY HEATING…THEN REMOVED BY FORCE OF ASCENT ALONG LEADING
EDGE OF SQUALL LINE. EFFECTIVE SHEAR MOSTLY IN 40-50 KT RANGE WILL
CONTINUE…WITH MEAN WIND VECTOR ALIGNED DIAGONALLY TO CONVECTIVE
BAND. MAIN THREAT WILL CONTINUE TO BE DAMAGING GUSTS…ESPECIALLY
ACCOMPANYING LEWP/BOW FEATURES. ISOLATED/MRGL SVR HAIL AND BRIEF
QLCS-TYPE TORNADIC SPINUPS ALSO ARE POSSIBLE…BUT FOR OVERALL
IMPACT…SECONDARY TO WIND THREAT.
..EDWARDS.. 05/06/2009
…PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT…
ATTN…WFO…MRX…FFC…OHX…BMX…HUN…MOB…MEG…JAN…
