CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE
VALID 272058Z - 272300Z
MONITORING FOR AN INCREASING SEVERE THREAT...WHICH COULD INITIALLY
OCCUR ACROSS PORTIONS OF THE REGION INTO THE 23Z-02Z TIME FRAME. A
WATCH MAY BE NEEDED THIS EVENING.
A WEAK COLD FRONT CONTINUES TO MAKE A GRADUAL EASTWARD PROGRESSION
TOWARD THE UPPER MS RIVER VALLEY AT MID AFTERNOON WITHIN A
NORTHEAST-SOUTHWEST ORIENTED CORRIDOR FROM WESTERN WI TO
SOUTH-CENTRAL IA/NORTHWEST MO. MODEST LOW-LEVEL MOISTURE...WITH
SURFACE DEWPOINTS GENERALLY IN THE 50S F...OTHERWISE CONTINUES TO
STEADILY INCREASE WITH NORTH-NORTHEASTWARD EXTENT IMMEDIATELY AHEAD
OF THE FRONT. NEAR/AHEAD OF THIS FRONT...LOW-LEVEL CONVERGENCE
REMAINS MODEST AS WINDS AT/JUST ABOVE THE SURFACE HAVE CONTINUED TO
VEER PER SURFACE OBSERVATIONS/REGIONAL DERIVED WIND DATA.
HOWEVER...A LOW-AMPLITUDE EASTWARD-MOVING SHORTWAVE TROUGH/SPEED MAX
CURRENTLY OVER SD/SOUTHWEST MN PER WATER VAPOR IMAGERY MAY PROVIDE
AN IMPETUS FOR AT LEAST ISOLATED DEEP CONVECTIVE DEVELOPMENT OVER
THE NEXT FEW HOURS...AS INHIBITION OTHERWISE CONTINUES TO ERODE
WITHIN THE MODESTLY MOIST NEAR-FRONTAL WARM SECTOR.
WHILE CONFIDENCE IN CONVECTIVE DETAILS ARE NOT PARTICULARLY
HIGH...AN ASSORTMENT OF NUMERICAL GUIDANCE INCLUDING A NUMBER OF 15Z
SREF MEMBERS IMPLY THAT SUCH DEVELOPMENT WILL BE MORE PROBABLE INTO
THE 23Z-02Z TIME FRAME ESPECIALLY ACROSS FAR EASTERN IA/FAR
NORTHWEST IL AND ADJACENT PARTS OF NORTHERN MO...ALTHOUGH A GRADUAL
DEEPENING OF THE CUMULUS FIELD HAS BEEN NOTED AS FAR NORTHEAST AS
SOUTHWEST WI AT MID-AFTERNOON. IF/WHERE DEEP CONVECTIVE DEVELOPMENT
DOES OCCUR INTO THIS EVENING...STRONG EFFECTIVE SHEAR /45-50 KT OR
GREATER/ WILL SUPPORT ORGANIZED/SUSTAINED STORMS INCLUDING INITIAL
MODE SUPERCELLS CAPABLE OF SEVERE HAIL/PERHAPS A TORNADO...WITH
DAMAGING WINDS A POSSIBILITY AS WELL. CONVECTIVE TRENDS WILL
CONTINUE TO BE MONITORED FOR A POSSIBLE WATCH.
..GUYER.. 03/27/2012
...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...
ATTN...WFO...LOT...MKX...DVN...ARX...DMX...
LAT...LON 41099298 42569163 43789064 43698967 42328921 40329133
41099298
