[MCD] SWOMCD

Mon May 22 23:54:14 UTC 2006

ACUS11 KWNS 222351
SWOMCD
SPC MCD 222350 
SDZ000-NDZ000-MTZ000-WYZ000-230215-

MESOSCALE DISCUSSION 0942
NWS STORM PREDICTION CENTER NORMAN OK
0650 PM CDT MON MAY 22 2006

AREAS AFFECTED...PORTIONS S-CENTRAL/SERN MT...WRN SD...CENTRAL/NRN
WY...EXTREME SWRN ND.

CONCERNING...SEVERE THUNDERSTORM POTENTIAL 

VALID 222350Z - 230215Z

CONVECTIVE COVERAGE IS EXPECTED TO INCREASE ACROSS THIS REGION
THROUGH REMAINDER AFTERNOON INTO EARLY EVENING...WITH CORRESPONDING
INCREASE IN POTENTIAL FOR DAMAGING GUSTS AND LARGE HAIL.  AREA WILL
BE MONITORED FOR POSSIBLE WW.

SFC MESOANALYSIS SHOWS WEAK SFC LOWS NEAR GTF AND NEAR CPR. 
QUASISTATIONARY FRONTAL ZONE -- ALSO ACTING AS EFFECTIVE DRYLINE --
EXTENDING SEWD FROM GTF SFC LOW ACROSS SERN CORNER MT TO NEAR RAP. 
CONFLUENCE/WIND SHIFT LINE EXTENDS FROM CPR SFC LOW NWD TO INTERSECT
FRONTAL/DRYLINE BOUNDARY ROUGHLY 30-50 S MLS.  AXES OF SFC PRESSURE
FALLS ARE EVIDENT ALONG OR JUST E OF BOTH OF THESE
BOUNDARIES...HELPING TO MAINTAIN ASSOCIATED CONVERGENCE.  IN
ADDITION...LARGE SCALE ASCENT AND VERTICAL SHEAR EACH IS FCST TO
INCREASE ACROSS THIS REGION THIS EVENING IN CONJUNCTION WITH
1. INCREASING MIDLEVEL DPVA AHEAD OF PHASED/NEWD-MOVING MID/UPPER
LEVEL TROUGHS -- NOW EVIDENT IN MOISTURE CHANNEL IMAGERY OVER GREAT
BASIN AND NRN AZ...
2. CONTINUED ISALLOBARIC FORCING AND BACKING OF FLOW INVOF
FRONTAL/DRYLINE BOUNDARY...AND
3. INCREASING LOW LEVEL WAA ASSOCIATED WITH LLJ STRENGTHENING TO
40-50 KT ALONG WRN BORDER OF DAKOTAS AFTER DARK.

UNTIL THEN...MODIFIED RUC SOUNDINGS SUGGEST SFC TEMPS WILL REMAIN
WARM ENOUGH TO SUPPORT SFC-BASED BUOYANT PARCELS WITH MLCAPES
500-1000 J/KG SW OF FRONT WHERE SFC DEW POINTS REMAIN IN 30S/40S
F...AND 1000-2000 J/KG ALONG AND NE OF BOUNDARY WITH DEW POINTS 50S
F.

..EDWARDS.. 05/22/2006

...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...

ATTN...WFO...BIS...UNR...CYS...BYZ...GGW...RIW...TFX...

46600511 45220276 43020287 43020401 43510410 43490605
42940608 42410611 42360692 42790765 44620791 46820874 