Mesoscale Discussion 365

Issued

Mar 26, 2012, 9:17 PM CDT (02:17 UTC)

Expired

Mar 26, 2012, 11:15 PM CDT

In force

118 min

Issued by

the Storm Prediction Center

The Rapid City radar (KUDX), 190 km from the middle of the area, began a volume at 02:18 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

879 
ACUS11 KWNS 270217
SWOMCD
SPC MCD 270217 
SDZ000-NDZ000-NEZ000-270415-

MESOSCALE DISCUSSION 0365
NWS STORM PREDICTION CENTER NORMAN OK
0917 PM CDT MON MAR 26 2012

AREAS AFFECTED...PORTIONS SRN ND...CENTRAL/WRN SD...NWRN/N-CENTRAL
NEB.

CONCERNING...SEVERE THUNDERSTORM WATCH 111...

VALID 270217Z - 270415Z

THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 111
CONTINUES.

CONTINUE WW ALONG/AHEAD OF OCCLUDED/COLD FRONT DESCRIBED BELOW.
PORTIONS NRN NEB AND SRN SD WILL BE MONITORED FOR ADDITIONAL WW.

SFC MESOANALYSIS AT 02Z SHOWED PRIMARY LOW PRESSURE AREA MANIFEST AS
BINARY CYCLONE OVER EXTREME E-CENTRAL MT W BHK...AND BIGHORNS OF
N-CENTRAL WY.  OCCLUDED FRONT ARCHED SEWD ACROSS SWRN ND AND NWRN SD
TO TRIPLE-POINT LOW...WHICH LIKELY WAS COLLOCATED WITH SRN FRINGE OF
TSTM AREA OVER NWRN SD.  COLD FRONT ARCHED SSEWD THEN SWD ACROSS
CHERRY COUNTY NEB...THEN SWWD OVER NERN CO...AND WAS FOLLOWED BY 6-9
MB PER 3-HR PRESSURE RISES OVER NERN NEB AND SWRN SD.  SRN PORTION
OF OCCLUDED FRONT...AND COLD FRONT...WERE MOVING GENERALLY EWD TO
NEWD AT ABOUT 35-45 KT...EXCEPT WHERE ACCELERATED TO NEARLY 60 KT BY
MESOBETA-SCALE OUTFLOW REINFORCEMENT OVER SERN SD.  SHARPLY-DEFINED
WARM FRONT WAS DRAWN NEAR AIO-SUX-MBG-PIR LINE THEN OVER SRN ZIEBACH
COUNTY.  WRN PORTION OF THIS BOUNDARY WILL BE OVERTAKEN FROM W-E BY
OCCLUDED/COLD FRONTS.

GREATEST POTENTIAL FOR DAMAGING GUSTS WILL BE WITHIN ABOUT 50-75 NM
N OF WARM FRONT.  IN THAT TRANSITION ZONE...RELATIVELY STABLE PRE
WARM-FRONTAL LAYER MAY BE SHALLOW ENOUGH TO PERMIT DAMAGING OUTFLOW
WINDS...AIDED BY MOMENTUM TRANSFER VIA INTENSE GRADIENT FLOW
ALOFT...TO PENETRATE TO SFC.  AIR MASS WILL BECOME MORE STABLE WITH
NWD EXTENT DUE TO GREATER FRONTAL-LAYER DEPTH.  MEANWHILE...ANY
TSTMS IMPINGING ON WARM SECTOR WILL BE CAPABLE OF SVR WINDS AS THEY
MOVE OVER RELATIVELY HIGH DEW-POINT DEPRESSIONS AND DCAPE VALUES
RESIDING ATOP ANY SKIN-LAYER COOLING EFFECTS.  LIMITING FACTOR FOR
THAT REGIME SO FAR HAS BEEN TSTM COVERAGE...HOWEVER ARC OF
CONVECTION IS BUILDING ALONG COLD FRONT FROM GRANT COUNTY NEB TO
JONES COUNTY SD AS OF 02Z.  NUMEROUS INSTANCES OF SVR NON-TSTM WINDS
ALSO HAVE CHARACTERIZED COLD FRONT BAND POST-FRONTAL AIR OVER NERN
WY...SWRN SD AND NWRN NEB DURING PAST COUPLE HOURS.  DAMAGING GUSTS
MAY CONTINUE TO OCCUR WELL AWAY FROM TSTMS.

..EDWARDS.. 03/27/2012

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

ATTN...WFO...FSD...ABR...BIS...LBF...UNR...

LAT...LON   43280100 44110130 44910197 46020252 46610248 47200116
            47199953 46849903 45919858 44829842 43899824 42919859
            42079975 41760046 41660125 41470167 42630118 43280100

Mesoscale Discussions in South Dakota, 2012Mesoscale Discussions in North Dakota, 2012Mesoscale Discussions in Nebraska, 2012Every mesoscale discussion in 2012

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.