SPC MD 1453

MD 1453 CONCERNING SEVERE POTENTIAL...WATCH UNLIKELY FOR SE MT...NE WY...NW SD...FAR SW ND
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MESOSCALE DISCUSSION 1453
NWS STORM PREDICTION CENTER NORMAN OK
0928 PM CDT WED JUL 23 2014

AREAS AFFECTED...SE MT...NE WY...NW SD...FAR SW ND

CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY 

VALID 240228Z - 240400Z

PROBABILITY OF WATCH ISSUANCE...20 PERCENT

SUMMARY...AN ISOLATED SEVERE THREAT MAY CONTINUE FOR ANOTHER HOUR OR
TWO ACROSS FAR SE MT AND MAY AFFECT NW SD/SW ND AS WELL. THE
ACTIVITY SHOULD REMAIN ISOLATED AND WW ISSUANCE APPEARS UNLIKELY.

DISCUSSION...THE LATEST SFC ANALYSIS SHOWS A TROUGH EXTENDING FROM
CNTRL MT SEWD INTO NCNTRL WY WITH A MOIST CORRIDOR LOCATED IN FAR
ERN MT. SFC DEWPOINTS ARE IN THE LOWER TO MID 60S F WITH THE LATEST
RAP DATA SHOWING MODERATE TO STRONG INSTABILITY ALONG THE MOIST
CORRIDOR. SEVERE STORMS ARE ONGOING ALONG THE INSTABILITY GRADIENT
IN POWDER RIVER COUNTY MT. THIS ACTIVITY IS LOCATED NEAR THE CENTER
OF AN UPPER-LEVEL RIDGE AND IS WEAKLY FORCED. THE LACK OF
LARGE-SCALE ASCENT SHOULD KEEP CONVECTIVE DEVELOPMENT RELATIVELY
ISOLATED. HOWEVER...THE MODERATE TO STRONG INSTABILITY ALONG WITH 40
TO 50 KT OF DEEP-LAYER SHEAR MAY BE ENOUGH FOR SUPERCELL
DEVELOPMENT. ANY STORM THAT EXHIBITS ROTATION SHOULD BE CAPABLE OF
PRODUCING HAIL. MARGINALLY SEVERE WIND GUSTS WILL ALSO BE POSSIBLE
ESPECIALLY AS THE CELLS MATURE AND MOVE CLOSER TO THE STRONGER
INSTABILITY OVER THE NEXT HOUR OR TWO.

..BROYLES/EDWARDS.. 07/24/2014

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

ATTN...WFO...BIS...UNR...BYZ...

LAT...LON   45900625 45070622 44310541 44520381 45750318 46530390
            46420527 45900625 

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SPC MD 1452

MD 1452 CONCERNING SEVERE POTENTIAL...WATCH POSSIBLE FOR CNTRL AND NRN MT
        
MD 1452 Thumbnail Image

MESOSCALE DISCUSSION 1452
NWS STORM PREDICTION CENTER NORMAN OK
0852 PM CDT WED JUL 23 2014

AREAS AFFECTED...CNTRL AND NRN MT

CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE 

VALID 240152Z - 240345Z

PROBABILITY OF WATCH ISSUANCE...60 PERCENT

SUMMARY...A SEVERE THREAT APPEARS LIKELY TO DEVELOP ACROSS NRN AND
CNTRL MT LATER THIS EVENING. WIND DAMAGE AND HAIL WILL BE THE
PRIMARY THREATS. WW ISSUANCE MAY BE NEEDED AS STORM COVERAGE
INCREASES.

DISCUSSION...THE LATEST SFC ANALYSIS SHOWS A 1006 MB LOW IN FAR WRN
MT WITH EASTERLY FLOW IN PLACE ACROSS MUCH OF CNTRL AND ERN MT. A
CORRIDOR OF LOW-LEVEL MOISTURE IS IN PLACE ACROSS NERN MT WHERE SFC
DEWPOINTS ARE IN THE LOWER TO MID 60S F AND MODERATE INSTABILITY IS
ALREADY IN PLACE. THUNDERSTORMS ARE DEVELOPING UPSTREAM FROM THE
AXIS OF MODERATE INSTABILITY...JUST TO THE NORTHEAST OF THE
CONTINENTAL DIVIDE NEAR HELENA MT. THUNDERSTORMS ARE ALSO INITIATING
TO THE WEST OF GLASGOW MT. THE ACTIVITY NEAR THE CONTINENTAL DIVIDE
SHOULD EXPAND IN COVERAGE AND MOVE INTO THE MCD AREA OVER THE NEXT
HOUR. AS THIS CONVECTION ENCOUNTERS MODERATE INSTABILITY...SEVERE
THUNDERSTORM DEVELOPMENT MAY OCCUR. OTHER STORMS SHOULD INITIATE
NEAR THE INSTABILITY AXIS IN NE MT. THE THERMODYNAMIC ENVIRONMENT
ALONG WITH DEEP-LAYER SHEAR ON THE ORDER OF 50 TO 60 KT SHOULD BE
SUPPORTIVE OF SUPERCELLS AND ISOLATED LARGE HAIL. WIND DAMAGE WILL
ALSO BE POSSIBLE AS THE CELLS MATURE LATER ON THIS EVENING.
SHORT-TERM MODELS FORECAST INDICATE THAT A CLUSTER OF STRONG TO
SEVERE STORMS WILL ORGANIZE AND MOVE NEWD ACROSS NRN MT LATE THIS
EVENING SUGGESTING WW ISSUANCE MAY BECOME NECESSARY.

..BROYLES/EDWARDS.. 07/24/2014

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

ATTN...WFO...BYZ...GGW...TFX...

LAT...LON   48720706 48220535 47250500 46320547 45940898 46431121
            48581185 48890960 48720706 

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