SPC MCD 171510
SCZ000-GAZ000-171745-
MESOSCALE DISCUSSION 0894
NWS STORM PREDICTION CENTER NORMAN OK
1010 AM CDT TUE MAY 17 2005
AREAS AFFECTED...ERN SC AND SERN GA
CONCERNING...SEVERE THUNDERSTORM POTENTIAL
VALID 171510Z - 171745Z
THUNDERSTORMS ARE EXPECTED TO INCREASE IN COVERAGE AND INTENSITY
INTO EARLY AFTERNOON ACROSS PARTS OF SC AND SERN GA. A COUPLE OF
THESE STORMS MAY BE CAPABLE OF PRODUCING HAIL AND/OR HIGH WINDS.
PARTS OF THE REGION WILL BE INCLUDED IN A SLGT RISK IN THE NEXT DAY
1 OUTLOOK.
ABUNDANT LOW LEVEL MOISTURE BENEATH MODEST LAPSE RATES OF 6-6.5 C/KM
AND DIURNAL HEATING WERE CONTRIBUTING TO THE STRENGTHENING
INSTABILITY ACROSS ERN SC LATE THIS MORNING. WEAK INHIBITION AND
FOCUSED ASCENT ALONG BACKDOOR COLD FRONT AND RESIDUAL STATIONARY
FRONT SHOULD AID STORM DEVELOPMENT OVER THE NEXT COUPLE OF HOURS.
DEEP LAYER SHEAR IS EXPECTED TO REMAIN MARGINAL FOR STORM
ORGANIZATION GIVEN 15-20KT MID LEVEL FLOW. HOWEVER...MAGNITUDE OF
CAPE...PRESENCE OF LOW LEVEL BOUNDARIES...AND DRIER MID LEVEL AIR
SPREADING ACROSS THE AREA FROM THE WEST...WILL ALL LEND SUPPORT FOR
A FEW WEAKLY ORGANIZED STORM CLUSTERS CAPABLE OF HAIL AND STRONG
OUTFLOW WIND GUSTS.
..CARBIN.. 05/17/2005
...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...
ATTN...WFO...ILM...CHS...CAE...GSP...JAX...FFC...TAE...
31478108 31008176 30828360 31208439 31388447 31858428
32338386 32808298 33488216 34278164 34628118 34688066
34667986 33807879 33187907 32527994 32048069
NNNN
ZCZC SPCSWOMCD ALL
ACUS11 KWNS 171753
SPC MCD 171753
SDZ000-NDZ000-MTZ000-WYZ000-172000-
MESOSCALE DISCUSSION 0895
NWS STORM PREDICTION CENTER NORMAN OK
1253 PM CDT TUE MAY 17 2005
AREAS AFFECTED...ERN MT....WRN DAKOTAS
CONCERNING...SEVERE THUNDERSTORM POTENTIAL
VALID 171753Z - 172000Z
THE CHANCE FOR SEVERE THUNDERSTORMS WILL CONTINUE TO INCREASE ACROSS
PORTIONS OF ERN MT AND THE WRN DAKOTAS EARLY THIS AFTERNOON. A
SEVERE THUNDERSTORM WATCH MAY BE NEEDED OVER PARTS OF THE REGION
WITHIN A COUPLE OF HOURS.
ONE INTENSE SUPERCELL WAS ALREADY TRACKING NWD THROUGH PHILLIPS
COUNTY MT WITHIN LEFT-FRONT QUADRANT OF STRONGLY DIFFLUENT MID LEVEL
WIND MAX. ADDITIONAL STORMS ARE EXPECTED TO DEVELOP ACROSS THE
REGION THROUGH THIS AFTERNOON AS STRONG MID/UPPER LEVEL TROUGH LIFTS
NEWD FROM NRN/CNTRL WY. ALTHOUGH INSTABILITY IS EXPECTED TO REMAIN
LIMITED... STRONG DYNAMIC FORCING FOR ASCENT WILL CONTINUE TO ACT ON
WARMING AND MOISTENING LOW LEVEL AIR MASS NEAR SURFACE LOW AND
ASSOCIATED FRONTAL BOUNDARIES. RESULTING CONVECTION WILL BE SITUATED
IN A STRONGLY SHEARED ENVIRONMENT WITH LOW LEVEL SELY UPSLOPE FLOW
TOPPED BY 50-60KT SLY FLOW AT MID LEVELS. INITIAL STORMS MAY EXHIBIT
SUPERCELL CHARACTERISTIC WITH HAIL AND HIGH WINDS POSSIBLE. ACTIVITY
MAY ALSO ORGANIZE INTO SHORT LINE SEGMENTS ALONG THE ADVANCING COLD
FRONT LATER TODAY WITH A CHANCE FOR DAMAGING WINDS.
..CARBIN.. 05/17/2005
...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...
ATTN...WFO...ABR...BIS...UNR...BYZ...GGW...
44990448 45790632 46550742 48400763 48870715 48930394
48670184 45430007 43670002 43260213 44620397
NNNN
ZCZC SPCSWOMCD ALL
ACUS11 KWNS 171829
SPC MCD 171829
NEZ000-SDZ000-172030-
MESOSCALE DISCUSSION 0896
NWS STORM PREDICTION CENTER NORMAN OK
0129 PM CDT TUE MAY 17 2005
AREAS AFFECTED...SRN SD AND WRN NEB
CONCERNING...SEVERE THUNDERSTORM POTENTIAL
VALID 171829Z - 172030Z
A SEVERE TSTM WATCH MAY BE NEEDED ACROSS PARTS OF NEB AND SRN SD
WITHIN 1-2 HOURS.
DESPITE LIMITED LOW LEVEL MOISTURE AND STRONG CAP ACROSS THE CNTRL
PLAINS THIS AFTERNOON...SFC HEATING AND STRONG DYNAMIC FORCING ARE
EXPECTED TO PROMOTE SCATTERED STORM INITIATION ALONG ADVANCING COLD
FRONT/DRYLINE FROM SCNTRL SD TO WRN NEB IN THE NEXT FEW HOURS.
LATEST LBF SOUNDING SUGGESTS STRONG CAP IS HOLDING ACROSS THIS
REGION. HOWEVER...LATEST SFC OBSERVATIONS DEPICT RAPID WARMING
OCCURRING AHEAD OF THE DRYLINE/COLD FRONT FROM NWRN KS ACROSS WRN
NEB. WHEN THE LBF SOUNDINGS IS ADJUSTED WITH THIS WARM SECTOR AIR
MASS IT APPEARS THAT REMAINING INHIBITION COULD BE ELIMINATED
THROUGH STRONG FRONTAL FORCING. THIS SCENARIO IS FURTHER SUPPORTED
BY LATEST SHORT TERM MODEL QPF FROM THE RUC/NAM AND EXPERIMENTAL
WRF. THESE MODELS SUGGEST THAT STORMS WILL DEVELOP NEAR THE FRONT
AND BUILD FROM NNW TO SSE ACROSS SWRN SD INTO NEB IN THE 20-22Z TIME
FRAME.
STORMS MAY EVENTUALLY EVOLVE INTO A SQUALL LINE GIVEN LINEAR FORCING
ON THE FRONT AND DEEP LAYER MERIDIONAL FLOW. DEEP LAYER SHEAR
APPROACHING 30KT WILL SUPPORT CELL/UPDRAFT PERSISTENCE AND SOME
CHANCE FOR BOWING SEGMENTS WITH WIND DAMAGE AS WELL AS HAIL.
..CARBIN.. 05/17/2005
...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...
ATTN...WFO...GID...LBF...UNR...GLD...
43200211 43629999 42069889 40069827 40080188 41220199
43070222
NNNN
ZCZC SPCSWOMCD ALL
ACUS11 KWNS 172229
SPC MCD 172229
NEZ000-SDZ000-172300-
MESOSCALE DISCUSSION 0897
NWS STORM PREDICTION CENTER NORMAN OK
0529 PM CDT TUE MAY 17 2005
AREAS AFFECTED...SD THROUGH NEB
CONCERNING...SEVERE THUNDERSTORM WATCH 283...
VALID 172229Z - 172300Z
WW 283 WILL BE REPLACED SHORTLY BY ANOTHER WW THAT WILL EXTEND
FARTHER EAST INTO SD...NB AND SWD TO THE KS BORDER.
..DIAL.. 05/17/2005
...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...
ATTN...WFO...FSD...OAX...ABR...GID...LBF...UNR...
40159954 41200067 43050074 44420215 45770104 44979928
40559779
NNNN
ZCZC SPCSWOMCD ALL
ACUS11 KWNS 172320
SPC MCD 172320
SDZ000-NDZ000-MTZ000-180045-
MESOSCALE DISCUSSION 0898
NWS STORM PREDICTION CENTER NORMAN OK
0620 PM CDT TUE MAY 17 2005
AREAS AFFECTED...ERN MT...WRN ND THROUGH NW SD
CONCERNING...SEVERE THUNDERSTORM WATCH 284...
VALID 172320Z - 180045Z
THREAT OF ISOLATED HAIL AND STRONG WIND GUSTS CONTINUES FROM ERN MT
THROUGH SWRN ND INTO NWRN SD...BUT OVERALL THREAT APPEARS MARGINAL.
IF CURRENT TRENDS CONTINUE...WW 284 MIGHT BE CANCELLED BEFORE ITS
EXPIRATION TIME OF 03Z.
EARLY THIS EVENING A COLD FRONT EXTENDS THROUGH SERN MT INTO NWRN SD
FROM A SURFACE LOW IN ERN MT. A WARM FRONT EXTENDS SEWD FROM THE LOW
THROUGH NRN SD WITH AN OCCLUDED BOUNDARY FROM NERN MT NWWD INTO
SASKATCHEWAN. AN AXIS OF MODEST INSTABILITY EXISTS FROM ERN MT SEWD
THROUGH WRN ND AND NWRN SD IN VICINITY OF AND E OF THE COLD FRONT
WITH MLCAPE FROM 800 TO 1200 J/KG. LARGE SCALE ASCENT DOWNSTREAM
FROM NEGATIVELY TILTED SHORTWAVE TROUGH MOVING NEWD THROUGH WY WILL
MAINTAIN A FAVORABLE ENVIRONMENT FOR STORMS TO CONTINUE DEVELOPING
NEXT SEVERAL HOURS ALONG THE COLD FRONT. OTHER STORMS MAY DEVELOP
FARTHER EAST INTO ND WITHIN THE ZONE OF WARM ADVECTION ASSOCIATED
WITH THE INTENSIFYING LOW LEVEL JET. THE PRIMARY MID LEVEL JET AXIS
REMAINS S OF THE REGION. AS A RESULT... DEEP LAYER VERTICAL SHEAR IS
NOT PARTICULARLY STRONG AND GENERALLY SUPPORTIVE OF MULTICELL
STORMS. GIVEN ONLY MODEST VERTICAL SHEAR AND INSTABILITY...THE ONSET
OF NOCTURNAL COOLING AND CHARACTER OF THE ONGOING STORMS...OVERALL
THREAT APPEARS SOMEWHAT LIMITED.
..DIAL.. 05/17/2005
...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...
ATTN...WFO...BIS...UNR...BYZ...GGW...
45410377 46830534 48750620 49000399 48380309 46580239
45390253
NNNN
ZCZC SPCSWOMCD ALL
ACUS11 KWNS 180119
SPC MCD 180119
SDZ000-NEZ000-180315-
MESOSCALE DISCUSSION 0899
NWS STORM PREDICTION CENTER NORMAN OK
0819 PM CDT TUE MAY 17 2005
AREAS AFFECTED...CNTRL AND ERN SD THROUGH CNTRL NEB
CONCERNING...SEVERE THUNDERSTORM WATCH 285...
VALID 180119Z - 180315Z
ISOLATED LARGE HAIL AND DAMAGING WIND REMAIN POSSIBLE NEXT FEW HOURS
AS SQUALL LINE MOVES EAST THROUGH SD AND NEB. GREATEST SEVERE THREAT
IS EXPECTED TO REMAIN OVER THE NEB PORTION OF THE LINE. PORTION OF
LINE NOW OVER SRN SD WILL BEGIN MOVING EAST OF WW 285 BY 02Z...BUT
ANOTHER WW EAST OF SD PORTION OF 285 IS NOT EXPECTED AT THIS TIME.
THIS EVENING A SQUALL LINE EXTENDS FROM NWRN SD SEWD INTO S CNTRL SD
THEN SWD INTO EXTREME S CNTRL NEB NEAR THE KS BORDER. THE LINE IS
MOVING EAST AT 25 TO 30 KT AND IS PASSING THROUGH THE AXIS OF
MAXIMUM INSTABILITY WITH MLCAPE AROUND 1500 J/KG. FARTHER EAST...THE
00Z ABERDEEN SOUNDING SHOWS PRESENCE OF A MID LEVEL INVERSION AND
MODEST CAPE. STRENGTHENING LOW LEVEL JET OVER THE CNTRL AND NRN
PLAINS DOWNSTREAM FROM EJECTING NEGATIVELY TILTED SHORTWAVE TROUGH
WILL MAINTAIN STRONG STORM RELATIVE INFLOW AND CONVERGENCE ALONG THE
GUST FRONT AND SUGGESTS STORMS SHOULD PERSIST OVERNIGHT. THE THREAT
OF ISOLATED DAMAGING WIND AND LARGE HAIL WILL LIKELY CONTINUE
ANOTHER FEW HOURS...ESPECIALLY OVER NEB. HOWEVER...THERMODYNAMIC
PROFILES WILL BECOME INCREASINGLY MARGINAL AS THE LINE BEGINS MOVING
EAST OF THE AXIS OF MAXIMUM INSTABILITY AND AS THE BOUNDARY LAYER
STABILIZES.
..DIAL.. 05/18/2005
...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...
ATTN...WFO...FSD...OAX...ABR...GID...LBF...
40439928 42949894 43899950 45370088 45670048 45199893
44209739 42729705 40329836
NNNNZCZC SPCSWOMCD ALL
ACUS11 KWNS 180340
SPC MCD 180340
KSZ000-NEZ000-180445-
MESOSCALE DISCUSSION 0900
NWS STORM PREDICTION CENTER NORMAN OK
1040 PM CDT TUE MAY 17 2005
AREAS AFFECTED...ERN SD...S CNTRL THROUGH ERN NEB AND NRN KS
CONCERNING...SEVERE THUNDERSTORM WATCH 285...
VALID 180340Z - 180445Z
SOME HAIL AND GUSTY WINDS MAY ACCOMPANY THE STRONGER STORMS ALONG
THE SQUALL LINE FROM ERN SD THROUGH ERN NEB AND INTO N CNTRL KS.
HOWEVER...OVERALL SEVERE THREAT IS EXPECTED TO CONTINUE A GRADUAL
DECREASE. PRIMARY THREAT APPEARS TO BE TRANSITIONING TO HEAVY RAIN
FROM N CNTRL KS NEWD INTO S CNTRL NEB...BUT SOME HAIL WILL ALSO
REMAIN POSSIBLE NEXT COUPLE HOURS. WW 285 WILL EXPIRE AT 05Z AND
ANOTHER WW IS NOT ANTICIPATED AT THIS TIME.
PORTION OF SQUALL LINE FROM NERN NEB THROUGH SD HAS UNDERGONE A
SIGNIFICANT WEAKENING TREND AS THE LEADING GUST FRONT MOVED EAST OF
THE AXIS OF STRONGER INSTABILITY AND INTO A MORE STRONGLY CAPPED
ENVIRONMENT. FARTHER SW...SOME BACKBUILDING HAS BEEN OCCURRING ALONG
THE S CNTRL NEB PORTION OF THE LINE WHERE STRONG LIFT IS BEING
SUPPORTED BY A SLY 50-60 KT LOW LEVEL JET IMPINGING ON THE SEWD
MOVING COLD FRONT/OUTFLOW BOUNDARY. STORMS ALONG THIS PART OF THE
LINE HAVE BECOME ORIENTED SW-NE NEARLY PARALLEL TO THE MID-UPPER
FLOW. THIS SUGGEST THE STORMS WILL CONTINUE TO TRAIN NEXT FEW HOURS
WITH AN ATTENDANT THREAT OF VERY HEAVY RAIN.
..DIAL.. 05/18/2005
...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...
ATTN...WFO...OAX...TOP...GID...DDC...GLD...
39889935 40729859 41629755 40049725 39059978
NNNNZCZC SPCSWOMCD ALL
ACUS11 KWNS 180558
SPC MCD 180558
IAZ000-NEZ000-SDZ000-180700-
MESOSCALE DISCUSSION 0901
NWS STORM PREDICTION CENTER NORMAN OK
1258 AM CDT WED MAY 18 2005
AREAS AFFECTED...NERN NEB AND WEST CENTRAL IA
CONCERNING...SEVERE THUNDERSTORM POTENTIAL
VALID 180558Z - 180700Z
ISOLATED STORMS WITH MARGINALLY SEVERE HAIL ARE POSSIBLE ACROSS NERN
NEB AND EXTREME WEST CENTRAL IA THE NEXT HOUR OR SO. STORMS EXPECTED
TO REMAIN TOO ISOLATED FOR A WW.
SMALL CLUSTER OF ELEVATED STORMS...LOCATED ABOUT 30 E OF OLU...ARE
MOVING NEWD AT 35-40 KT. STORM APPEARS TO BE MOVING ALONG SURFACE
FRONT AND MAY BE ACCOMPANIED BY A SMALL WAVE AS STRONGER CONVECTION
APPEARS TO BE IN CONJUNCTION WITH WEAK WARM ADVECTION WING TO THE
EAST OF THE WAVE. STRONG LOW LEVEL JET APPEARS TO BE SUPPLYING
ADDITIONAL LIFT AND STEEP LAPSE RATES AND SHEAR ABOVE CAPPING
INVERSION BETWEEN 700-850 MB IS SUFFICIENT TO MAINTAIN STRONG
UPDRAFTS. STORMS MAY PRODUCE MARGINALLY SEVERE HAIL THE NEXT HOUR OR
SO...BUT STORMS SHOULD SLOWLY WEAKEN AS THEY MOVE FURTHER NEWD AWAY
FROM STEEPER LAPSE RATES AND LOW LEVEL JET SLOWLY WEAKENS.
..IMY.. 05/18/2005
...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...
ATTN...WFO...DMX...FSD...OAX...
41299657 41539696 42129707 42529670 42529608 42099568
41909555 41519556 41339599
NNNN