807 ACUS01 KWNS 280048 SWODY1 SPC AC 280046 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0746 PM CDT FRI MAR 27 2015 VALID 280100Z - 281200Z ...NO SVR TSTM AREAS FORECAST... ...SUMMARY... SHOWERS AND A FEW THUNDERSTORMS WILL AFFECT SOUTH FLORIDA AND THE KEYS THIS EVENING. OTHER SHOWERS AND PERHAPS ISOLATED/EMBEDDED THUNDERSTORMS MAY ALSO DEVELOP ACROSS PARTS OF THE OREGON/SOUTHEAST WASHINGTON/NORTHERN IDAHO VICINITY OVERNIGHT. ...DISCUSSION... A LARGE UPPER TROUGH CONTINUES A GRADUAL EWD ADVANCE ACROSS THE ERN U.S. THIS EVENING...WITH AN ASSOCIATED SURFACE COLD FRONT CROSSING CENTRAL PORTIONS OF THE FL PENINSULA ATTM. SHOWERS CONTINUE OVER THE SRN HALF OF THE PENINSULA...WITH EMBEDDED THUNDERSTORMS NOW CONFINED TO FAR S FL AND THE KEYS. THIS ACTIVITY WILL GRADUALLY MOVE SEWD/OFFSHORE OVERNIGHT AS THE FRONT CONTINUES ITS SEWD ADVANCE. FARTHER W...A LARGE RIDGE ALOFT REMAINS IN CONTROL -- THOUGH A COMPACT SHORT-WAVE TROUGH NOW OFF THE PAC NW COAST IS PROGGED TO SHIFT EWD INTO/ACROSS WA/OREGON OVERNIGHT. THE CU FIELD ACROSS CENTRAL OREGON AND THE CASCADES HAS SHOWN SOME INCREASE OVER THE PAST COUPLE OF HOURS IN CONJUNCTION WITH DIURNAL HEATING/WEAK DESTABILIZATION...AND INCREASING UVV WITH THE APPROACH OF THE UPPER TROUGH LATER THIS EVENING MAY SUPPORT DEVELOPMENT OF SHOWERS AND POSSIBLY A FEW THUNDERSTORMS. THIS ACTIVITY SHOULD SPREAD NEWD ACROSS SERN WA AND INTO NRN ID THROUGH THE END OF THE PERIOD...THOUGH RISK FOR LIGHTNING SHOULD DIMINISH INTO THE OVERNIGHT HOURS. ..GOSS.. 03/28/2015  739 ACUS01 KWNS 280511 SWODY1 SPC AC 280509 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1209 AM CDT SAT MAR 28 2015 VALID 281200Z - 291200Z ...NO SVR TSTM AREAS FORECAST... ...SUMMARY... ISOLATED THUNDERSTORMS WILL BE POSSIBLE ACROSS PARTS OF THE NORTHERN GREAT PLAINS THIS AFTERNOON AND EVENING. ...DISCUSSION... A LARGE-SCALE UPPER TROUGH OVER THE ERN U.S. IS FORECAST TO CONTINUE MOVING GRADUALLY EWD TODAY...WEAKENING WITH TIME AS IT APPROACHES THE E COAST. IN ITS WAKE...A LOWER-AMPLITUDE FLOW FIELD IS PROGGED OVER THE REMAINDER OF THE CONUS. WITHIN THIS FLATTER FLOW FIELD...A VIGOROUS SHORT-WAVE TROUGH IS FORECAST TO MOVE OUT OF THE NRN ROCKIES AND THEN TURN ESEWD INTO THE NRN PLAINS THROUGH THE SECOND HALF OF THE PERIOD. THIS TROUGH WILL BE ACCOMPANIED AT THE SURFACE BY A COLD FRONT -- WHICH IS PROGGED TO SHIFT RAPIDLY SEWD ACROSS THE NRN AND CENTRAL PLAINS THROUGH EARLY SUN. WHILE SCANT BOUNDARY-LAYER MOISTURE WILL RESIDE AHEAD OF THE SURFACE FRONT...DIURNAL HEATING COMBINED WITH STEEPENING LAPSE RATES ALOFT WILL LIKELY YIELD MEAGER CAPE DEVELOPMENT ATOP A WELL-MIXED BOUNDARY LAYER. ISOLATED THUNDERSTORM DEVELOPMENT OVER THE NRN HIGH PLAINS APPEARS POSSIBLE...WITH ANY CONVECTION THEN SPREADING QUICKLY SEWD ACROSS THE DAKOTAS THROUGH THE EVENING. WHILE A LOCALLY STRONGER GUST MAY OCCUR IF A SUSTAINED CELL OR TWO WERE TO EVOLVE...EVEN A LOW /5%/ PROBABILITY SEVERE RISK AREA APPEARS UNWARRANTED ATTM. ..GOSS/LEITMAN.. 03/28/2015  916 ACUS02 KWNS 280555 SWODY2 SPC AC 280554 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1254 AM CDT SAT MAR 28 2015 VALID 291200Z - 301200Z ...NO SVR TSTM AREAS FORECAST... ...SUMMARY... ISOLATED THUNDERSTORMS ARE POSSIBLE SUNDAY EVENING/NIGHT FROM THE RED RIVER OF THE SOUTH TOWARDS THE SOUTHERN APPALACHIANS...WITH A VERY LOW PROBABILITY FOR SEVERE HAIL. ...SYNOPSIS... A SHORTWAVE TROUGH FROM MANITOBA TO THE UPPER MIDWEST AT 12Z/SUN WILL AMPLIFY OVER THE GREAT LAKES WITH ASSOCIATED SURFACE CYCLONE TRACKING E MAINLY OVER ONTARIO. ATTENDANT COLD FRONT WILL REACH THE APPALACHIANS TO DEEP SOUTH...WITH TRAILING PORTION BECOMING QUASI-STATIONARY OVER TX. A WEAK UPPER TROUGH SHOULD APPROACH BAJA CA WITH A DOWNSTREAM UPPER JET OVERSPREADING THE SRN GREAT PLAINS. ...RED RIVER/ARKLATEX... 28/00Z RAOBS ALONG THE WRN/CNTRL GULF COAST SAMPLED A RATHER DRY AIR MASS CHARACTERIZED BY MEAN MIXING RATIOS BETWEEN 3-5 G/KG. GOES PW IMAGERY INDICATES THIS CONTINENTAL POLAR INTRUSION HAS OVERSPREAD THE NRN 3/4 OF THE GULF BASIN. ALTHOUGH WEAK RETURN FLOW HAS COMMENCED OVER THE FAR WRN GULF AND WILL BECOME INCREASINGLY PERVASIVE AS WELL AS STRENGTHEN ON D2...THE 10-12 G/KG MEAN MIXING RATIOS DEPICTED ACROSS GUIDANCE ALONG THE FRONT BY 30/00Z APPEARS A BIT OVERDONE. WITH PERSISTENT WLYS BETWEEN 850-700 MB...A STOUT EML /MOST REPRESENTATIVE IN WARM SECTOR NAM SOUNDINGS/ WILL LIKELY PRECLUDE SURFACE-BASED TSTM DEVELOPMENT DURING THE DAY. LOWER-LEVEL CONVERGENCE IS PROGGED TO STRENGTHEN SUN EVENING ALONG THE FRONTAL ZONE AND THIS MIGHT BE SUFFICIENT TO YIELD NEGLIGIBLE MUCIN FOR ELEVATED PARCELS N OF THE FRONT. GUIDANCE DIFFERS GREATLY ON THE DEGREE OF NIGHTTIME CONVECTIVE QPF. IF STORMS WERE TO DEVELOP...A MARGINAL RISK FOR SEVERE HAIL MAY OCCUR GIVEN VERY STEEP MID-LEVEL LAPSE RATES AND MODEST EFFECTIVE SHEAR. UNCONDITIONAL PROBABILITIES...WHILE NON-ZERO...DO NOT APPEAR TO BE AOA 5 PERCENT THIS OUTLOOK. ...MID-SOUTH TO SRN APPALACHIANS... CONFIDENCE IS HIGHER IN THE DEVELOPMENT OF AT LEAST ISOLATED TSTMS E OF THE LOWER MS VALLEY SUN NIGHT. 700-MB HEIGHT FALLS SHOULD OVERSPREAD THIS REGION ON THE PERIPHERAL INFLUENCE OF THE AMPLIFYING GREAT LAKES TROUGH. IN CONJUNCTION WITH LOWER-LEVEL WAA ALONG THE SURFACE FRONT WITHIN THE LEFT-EXIT REGION OF THE SRN-STREAM UPPER JET...SETUP SHOULD FOSTER ELEVATED CONVECTION FORMING LATE EVENING INTO THE OVERNIGHT. ALTHOUGH MID-LEVEL LAPSE RATES WILL INITIALLY BE STEEP...WEAK BUOYANCY...MODEST CLOUD-BEARING SHEAR AND CLUSTER MODE SHOULD LIMIT HAIL SIZE TO SUB-SEVERE. ..GRAMS.. 03/28/2015  410 ACUS03 KWNS 280730 SWODY3 SPC AC 280729 DAY 3 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0229 AM CDT SAT MAR 28 2015 VALID 301200Z - 311200Z ...NO SVR TSTM AREAS FORECAST... ...SUMMARY... THUNDERSTORMS ARE POSSIBLE ACROSS PARTS OF THE SOUTHERN STATES DURING THE PERIOD. ...SYNOPSIS... AMPLIFIED SHORTWAVE TROUGH CENTERED OVER THE LOWER GREAT LAKES SHOULD PROGRESS OFF THE NORTHEAST/NEW ENGLAND COAST BY EARLY TUE AS AN UPSTREAM IMPULSE TRACKS FROM THE SRN PRAIRIE PROVINCES TOWARDS THE UPPER GREAT LAKES. THIS WILL EFFECTIVELY MAINTAIN MID-LEVEL W/NWLYS OVER THE S-CNTRL/SOUTHEAST STATES. A WEAK SHORTWAVE IMPULSE W OF BAJA CA SHOULD MOVE INTO NW MEXICO BY 12Z/TUE. AT THE SURFACE...A COLD FRONT WILL PUSH ACROSS THE SOUTHEAST BEFORE DECAYING MON NIGHT. TRAILING PORTION OF THIS BOUNDARY SHOULD SLOWLY ADVANCE N AS A WEAK WARM FRONT OVER THE SRN GREAT PLAINS. ...CNTRL OK TO WRN AR AREA... WITH SOME STRENGTHENING OF LOW-LEVEL WAA MON EVENING/NIGHT...MOST GUIDANCE /OUTSIDE OF THE SREF/ SUGGESTS ELEVATED CONVECTION WILL FORM N OF A DIFFUSE/SLOW-MOVING WARM FRONT INITIALLY OVER N TX. ON THE SW PERIPHERY OF ANY DEVELOPMENT...STEEP MID-LEVEL LAPSE RATES AND MUCAPE AOA 1000 J/KG COULD SUPPORT A NARROW CORRIDOR OF SEVERE HAIL. BUT MODEST DEEP-LAYER SHEAR AND PROBABLE CLUSTER MODE SHOULD LIMIT HAIL SIZE. GIVEN THESE FACTORS ALONG WITH LOW CONFIDENCE ON WHERE SUCH A CORRIDOR MIGHT BE LATE D3...WILL DEFER POSSIBLE MARGINAL RISK PROBABILITIES TO LATER OUTLOOKS. ...BIG BEND OF TX... GUIDANCE DIFFERS BOTH WITH THE EXTENT OF MODIFIED GULF MOISTURE RETURN UP THE RIO GRANDE VALLEY BENEATH A STOUT EML AND THE STRENGTH OF MID-LEVEL SWLYS AHEAD OF THE NW MEXICO SHORTWAVE IMPULSE. THIS RENDERS LOW CONFIDENCE IN WHETHER LATE AFTERNOON/EVENING TSTMS WILL DEVELOP OVER THE HIGHER TERRAIN AND THE DEGREE OF DEEP-LAYER SHEAR DESPITE VEERING OF THE WIND PROFILE WITH HEIGHT. ..GRAMS.. 03/28/2015  922 ACUS48 KWNS 280900 SWOD48 SPC AC 280859 DAY 4-8 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0359 AM CDT SAT MAR 28 2015 VALID 311200Z - 051200Z ...DISCUSSION... ORGANIZED SEVERE POTENTIAL IS EVIDENT EACH DAY BETWEEN D4-7/TUE-FRI OVER PARTS OF THE CENTRAL TO SOUTHERN STATES...BUT WITH VERY LOW MESOSCALE PREDICTABILITY. ONE FEATURE OF INTEREST IS A WEAK SRN-STREAM SHORTWAVE IMPULSE INITIALLY OVER NW MEXICO. GUIDANCE CONTINUES TO TRACK THIS IMPULSE E ACROSS THE GULF COAST REGION...WITH THE ECMWF REMAINING A CONSISTENT OUTLIER IN DEPICTING MESOSCALE AMPLIFICATION NEAR THE LOWER MS VALLEY AROUND D5-6. A MORE POTENT SHORTWAVE TROUGH IS STILL PROGGED IN THE NRN STREAM REACHING THE UPPER MIDWEST INTERNATIONAL BORDER AROUND D5. THE EVOLUTION OF THIS TROUGH AND AN UPSTREAM SHORTWAVE IMPULSE ENTERING THE WEST AROUND D6 BECOME QUITE DIVERGENT IN GUIDANCE LATE WEEK. HOWEVER ON THE BROADER-SCALE...THERE IS CONSISTENCY IN THE FORMATION OF AN INTENSE QUASI-ZONAL UPPER JET BISECTING THE CONUS. ALTHOUGH RUN-TO-RUN CONTINUITY IS LOW...THERE HAS BEEN A TREND FOR INDICATING CYCLOGENESIS FROM THE LEE OF THE SRN ROCKIES TO THE MIDWEST/GREAT LAKES. VERY STRONG FLOW FIELDS OVERSPREADING THE NRN PERIPHERY OF A MODERATELY MOIST WARM SECTOR WOULD CERTAINLY FAVOR ORGANIZED SEVERE POTENTIAL SOMEWHERE IN THIS PATH. IF/WHEN MODEL CONSISTENCY INCREASES...SEVERE WEATHER PROBABILITIES AOA 15 PERCENT WILL LIKELY BE INTRODUCED IN LATER OUTLOOKS. ..GRAMS.. 03/28/2015  547 ACUS01 KWNS 281243 SWODY1 SPC AC 281242 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0742 AM CDT SAT MAR 28 2015 VALID 281300Z - 291200Z ...NO SVR TSTM AREAS FORECAST... ...SUMMARY... ISOLATED THUNDERSTORMS WILL BE POSSIBLE ACROSS PARTS OF THE NORTHERN GREAT PLAINS THIS AFTERNOON THROUGH TONIGHT. OTHER ISOLATED THUNDERSTORMS MAY ALSO OCCUR THIS AFTERNOON ACROSS PARTS OF WYOMING. ...NRN PLAINS AREA LATER TODAY INTO TONIGHT... A PRONOUNCED SHORTWAVE TROUGH OVER WA/ORE THIS MORNING WILL MOVE EWD OVER THE NRN ROCKIES TODAY...BEFORE TURNING ESEWD OVER THE NRN PLAINS TONIGHT AS THE WAVE PROGRESSES DOWNSTREAM FROM THE PERSISTENT RIDGE OVER THE ROCKIES. A BELT OF ASCENT/MOISTENING IMMEDIATELY AHEAD OF THE SHORTWAVE TROUGH...WHERE ISOLATED LIGHTNING STRIKES HAVE BEEN OBSERVED OVERNIGHT...WILL SPREAD EWD ACROSS MT TODAY. BY MID-LATE AFTERNOON...SURFACE HEATING/MIXING WILL STEEPEN LOW-LEVEL LAPSE RATES...REDUCE CONVECTIVE INHIBITION...AND SUPPORT THE FORMATION OF A FEW HIGH-BASED THUNDERSTORMS IN THIS BELT OF ASCENT ACROSS ERN MT. MARGINAL LOW-LEVEL MOISTURE AND INVERTED-V PROFILES COULD SUPPORT GUSTY OUTFLOW WINDS LATE THIS AFTERNOON ACROSS ERN MT ALONG A SURFACE COLD FRONT ACCOMPANYING THE MIDLEVEL TROUGH. OVERNIGHT...ELEVATED CONVECTION WILL PERSIST ACROSS THE NRN PLAINS IN ASSOCIATION WITH LOW-LEVEL WAA AND DIFFERENTIAL CVA. ABSOLUTE MOISTURE CONTENT WILL BE LIMITED...BUT THERE SHOULD BE SUFFICIENT MIDLEVEL MOISTENING IN THE STEEP LAPSE RATE ENVIRONMENT TO WEAK BUOYANCY. ..THOMPSON/MOSIER.. 03/28/2015  437 ACUS01 KWNS 281623 SWODY1 SPC AC 281622 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1122 AM CDT SAT MAR 28 2015 VALID 281630Z - 291200Z ...THERE IS A MRGL RISK OF SVR TSTMS OVER PARTS OF EASTERN MT INTO THE WESTERN DAKOTAS... ...SUMMARY... ISOLATED THUNDERSTORMS WILL BE POSSIBLE FROM PARTS OF MONTANA AND WYOMING INTO THE NORTHERN GREAT PLAINS THIS AFTERNOON THROUGH TONIGHT. A FEW OF THE STORMS COULD PRODUCE DAMAGING WIND GUSTS. ...MT/WY/SD/ND... WATER VAPOR LOOPS SHOW A PROGRESSIVE SHORTWAVE TROUGH MOVING INTO WESTERN MT. THIS AREA OF LARGE SCALE LIFT ASSOCIATED WITH THIS FEATURE WILL MOVE EASTWARD INTO EASTERN MT BY MID AFTERNOON. FORECAST SOUNDINGS IN THIS REGION SHOW STEEP LOW/MID LEVEL LAPSE RATES...FAST TROPOSPHERIC WINDS...AND SUFFICIENT LOW/MID LEVEL MOISTURE FOR THE DEVELOPMENT OF SCATTERED FAST-MOVING SHOWERS AND THUNDERSTORMS. A FEW OF THESE STORMS OVER EASTERN MT AND THE WESTERN DAKOTAS WILL POSE A RISK OF LOCALLY GUSTY/DAMAGING WINDS. ELSEWHERE...NO SEVERE STORMS ARE EXPECTED TODAY. ..HART/JEWELL.. 03/28/2015  220 ACUS02 KWNS 281718 SWODY2 SPC AC 281717 DAY 2 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1217 PM CDT SAT MAR 28 2015 VALID 291200Z - 301200Z ...NO SVR TSTM AREAS FORECAST... ...SUMMARY... A FEW THUNDERSTORMS WITH SMALL HAIL MAY AFFECT AREAS FROM SOUTHEAST OKLAHOMA AND NORTHEAST TEXAS...EASTWARD TO THE TENNESSEE VALLEY AND SOUTHERN APPALACHIANS...FOR SUNDAY EVENING AND NIGHT. SEVERE THUNDERSTORMS WILL BE UNLIKELY. ...SYNOPSIS... A MIDLEVEL SHORTWAVE TROUGH CURRENTLY CROSSING PARTS OF NRN ID AND MT WILL EXTEND FROM THE UPPER MS VALLEY TO THE CNTRL PLAINS BY THE START OF THE D2/SUN PERIOD. THIS FEATURE WILL THEN TRACK TO THE GREAT LAKES REGION THROUGH THE PERIOD WHILE BEING OVERTAKEN BY AN UPSTREAM DISTURBANCE AMPLIFYING FROM ONTARIO AND MANITOBA. A COLD FRONT ACCOMPANYING THESE EVOLVING MIDLEVEL FEATURES WILL ADVANCE EWD/SEWD ACROSS PARTS OF THE CNTRL/ERN/SRN CONUS. BY EARLY MON MORNING...THE FRONT WILL LIE ALONG THE APPALACHIANS...CURVING WWD TOWARD THE LOWER MS VALLEY AND REACH FARTHER W INTO N TX. ...SE OK AND NE TX EWD TO THE TN VALLEY AND SRN APPALACHIANS... LIMITED TIME HAS ELAPSED SINCE THE PRIOR FRONTAL INTRUSION INTO THE GULF OF MEXICO...YIELDING INSUFFICIENT OPPORTUNITY FOR ANY MORE THAN MODEST RETURN OF POORLY MODIFIED GULF MOISTURE INTO D2/SUN. RAOBS ACROSS THE CNTRL/WRN GULF COAST AT 12Z THIS MORNING INDICATE PW VALUES AOB 0.7 INCH...INDICATIVE OF THE DEEP DRY AIR CURRENTLY IN PLACE. FURTHERMORE...THE FLOW AOA H85 IS EXPECTED TO EXHIBIT PRIMARILY A WLY COMPONENT...OWING TO THE LOW-AMPLITUDE NATURE OF THE AFOREMENTIONED SHORTWAVE TROUGH THAT WILL BE DISPLACED TO THE N OF THE REGION. FOR ALL OF THESE REASONS...THE DEARTH OF MOISTURE SHOULD BE A LIMITING FACTOR FOR SVR-TSTM POTENTIAL ON D2/SUN. REGARDLESS...ISOLATED THUNDERSTORMS MAY DEVELOP SUN EVENING/NIGHT WITHIN THE FRONTAL ZONE IN THE PRESENCE OF SUFFICIENT LOW-LEVEL MOISTURE. WITH ENHANCED MIDLEVEL LAPSE RATES ACCOMPANYING AN EML PLUME BEING ADVECTED INTO THE REGION FROM THE W...AND GIVEN AROUND 20-30 KT OF EFFECTIVE BULK SHEAR...SMALL HAIL MAY OCCUR WITH SOME OF THE MOST INTENSE STORMS. THE GREATEST POTENTIAL FOR SUCH ACTIVITY WOULD BE FROM SRN AR AND VICINITY TO THE TN VALLEY AND SRN APPALACHIANS. THIS WILL BE AT THE ERN EDGE OF THE EWD-SPREADING EML PLUME AND WITHIN A ZONE OF STRONGER LOW-LEVEL WAA ALONG A FRONT-PRECEDING LLJ. HOWEVER...STRONGER DEEP FORCING FOR ASCENT WILL NOT PHASE WITH THE RETURNING LIMITED MOISTURE...LARGELY MITIGATING SVR-TSTM POTENTIAL. ...ELSEWHERE... ISOLATED THUNDERSTORMS MAY BE ONGOING ACROSS PORTIONS OF IA AT THE START OF THE D2/SUN PERIOD WITHIN THE ZONE OF STRONGER DEEP FORCING FOR ASCENT IMMEDIATELY PRECEDING THE SHORTWAVE TROUGH. SIMILAR ACTIVITY MAY SPREAD DOWNSTREAM ACROSS PARTS OF IL BEFORE DISSIPATING...WHILE THE STRONGER ASCENT OUTPACES STEEPER MIDLEVEL LAPSE RATES. ISOLATED THUNDERSTORMS MAY ALSO DEVELOP OVER THE HIGHER TERRAIN OF NRN NM AND SRN CO IN RESPONSE TO DIURNALLY ENHANCED OROGRAPHIC CIRCULATIONS AMIDST SUFFICIENT MOISTURE/MARGINAL INSTABILITY. SEVERE THUNDERSTORMS ARE NOT EXPECTED. ..COHEN.. 03/28/2015  676 ACUS11 KWNS 281847 SWOMCD SPC MCD 281847 SDZ000-NDZ000-MTZ000-WYZ000-281945- MESOSCALE DISCUSSION 0155 NWS STORM PREDICTION CENTER NORMAN OK 0147 PM CDT SAT MAR 28 2015 AREAS AFFECTED...PORTIONS OF ERN MT...WRN ND...NWRN SD...NERN WY CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY VALID 281847Z - 281945Z PROBABILITY OF WATCH ISSUANCE...5 PERCENT SUMMARY...SCATTERED THUNDERSTORMS ARE EXPECTED TO DEVELOP DURING THE AFTERNOON HOURS...WITH A RISK FOR ISOLATED DAMAGING GUSTS. A WATCH IS NOT EXPECTED. DISCUSSION...A POTENT SHORTWAVE TROUGH ACROSS NRN ID/WRN MT WILL MOVE EAST THIS AFTN...WITH MOISTENING/ASCENT DEVELOPING OVER THE DISCUSSION AREA DURING THE NEXT SEVERAL HOURS. LOWER-MID TROPOSPHERIC WIND FIELDS WILL ALSO INCREASE WITH RAP FORECAST SOUNDINGS DEPICTING WNWLY 2-6 KM WINDS INCREASING TO 45-55 KTS. DESPITE LIMITED MOISTURE /PW VALUES GENLY AOB 0.5 INCHES/...MODEST DESTABILIZATION THIS AFTERNOON AHEAD OF A COLD FRONT WILL RESULT IN MUCAPE OF 250-500 J/KG. IN THE PRESENCE OF STRONG BACKGROUND WIND FIELDS A FEW HIGH-BASED THUNDERSTORMS WILL BE CAPABLE OF DAMAGING GUSTS...A SCENARIO SUPPORTED BY RECENT HIGH-RES GUIDANCE FROM THE 1ZZ NCEP HRRR AND 12Z NSSL WRF. THE OVERALL SEVERE THREAT SHOULD REMAIN ISOLATED AND A WW IS NOT ANTICIPATED. ..BUNTING/HART.. 03/28/2015 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...ABR...BIS...UNR...BYZ...GGW...RIW... LAT...LON 44930411 44800705 45030814 45460858 46160819 46700789 47640708 48250580 48260483 48290356 48250256 48160143 46920128 46120151 45500254 44930411  523 ACUS11 KWNS 281857 SWOMCD SPC MCD 281857 COR SDZ000-NDZ000-MTZ000-WYZ000-281945- MESOSCALE DISCUSSION 0155 NWS STORM PREDICTION CENTER NORMAN OK 0157 PM CDT SAT MAR 28 2015 AREAS AFFECTED...PORTIONS OF ERN MT...WRN ND...NWRN SD...NERN WY CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY VALID 281857Z - 281945Z CORRECTED FOR TYPO PROBABILITY OF WATCH ISSUANCE...5 PERCENT SUMMARY...SCATTERED THUNDERSTORMS ARE EXPECTED TO DEVELOP DURING THE AFTERNOON HOURS...WITH A RISK FOR ISOLATED DAMAGING GUSTS. A WATCH IS NOT EXPECTED. DISCUSSION...A POTENT SHORTWAVE TROUGH ACROSS NRN ID/WRN MT WILL MOVE EAST THIS AFTN...WITH MOISTENING/ASCENT DEVELOPING OVER THE DISCUSSION AREA DURING THE NEXT SEVERAL HOURS. LOWER-MID TROPOSPHERIC WIND FIELDS WILL ALSO INCREASE WITH RAP FORECAST SOUNDINGS DEPICTING WNWLY 2-6 KM WINDS INCREASING TO 45-55 KTS. DESPITE LIMITED MOISTURE /PW VALUES GENLY AOB 0.5 INCHES/...MODEST DESTABILIZATION THIS AFTERNOON AHEAD OF A COLD FRONT WILL RESULT IN MUCAPE OF 250-500 J/KG. IN THE PRESENCE OF STRONG BACKGROUND WIND FIELDS A FEW HIGH-BASED THUNDERSTORMS WILL BE CAPABLE OF DAMAGING GUSTS...A SCENARIO SUPPORTED BY RECENT HIGH-RES GUIDANCE FROM THE 17Z NCEP HRRR AND 12Z NSSL WRF. THE OVERALL SEVERE THREAT SHOULD REMAIN ISOLATED AND A WW IS NOT ANTICIPATED. ..BUNTING/HART.. 03/28/2015 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...ABR...BIS...UNR...BYZ...GGW...RIW... LAT...LON 44930411 44800705 45030814 45460858 46160819 46700789 47640708 48250580 48260483 48290356 48250256 48160143 46920128 46120151 45500254 44930411  085 ACUS01 KWNS 281938 SWODY1 SPC AC 281936 DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0236 PM CDT SAT MAR 28 2015 VALID 282000Z - 291200Z ...THERE IS A MRGL RISK OF SVR TSTMS OVER PARTS OF EASTERN MT INTO THE WESTERN DAKOTAS... ...SUMMARY... ISOLATED THUNDERSTORMS WILL BE POSSIBLE FROM PARTS OF MONTANA AND WYOMING INTO THE NORTHERN GREAT PLAINS THIS AFTERNOON THROUGH TONIGHT. A FEW OF THE STORMS COULD PRODUCE DAMAGING WIND GUSTS. ...20Z UPDATE TO THE DAY-1 CONVECTIVE OUTLOOK... THE WRN BOUND OF THE MARGINAL AREA HAS BEEN SHIFTED WWD ACROSS PORTIONS OF MT. FOR ADDITIONAL INFORMATION REGARDING THE RISK OF ISOLATED DMGG WIND GUSTS ACROSS THE MARGINAL AREA...PLEASE REFER TO RECENTLY ISSUED MESOSCALE DISCUSSION 155. ..COHEN.. 03/28/2015 .PREV DISCUSSION... /ISSUED 1122 AM CDT SAT MAR 28 2015/ ...MT/WY/SD/ND... WATER VAPOR LOOPS SHOW A PROGRESSIVE SHORTWAVE TROUGH MOVING INTO WESTERN MT. THIS AREA OF LARGE SCALE LIFT ASSOCIATED WITH THIS FEATURE WILL MOVE EASTWARD INTO EASTERN MT BY MID AFTERNOON. FORECAST SOUNDINGS IN THIS REGION SHOW STEEP LOW/MID LEVEL LAPSE RATES...FAST TROPOSPHERIC WINDS...AND SUFFICIENT LOW/MID LEVEL MOISTURE FOR THE DEVELOPMENT OF SCATTERED FAST-MOVING SHOWERS AND THUNDERSTORMS. A FEW OF THESE STORMS OVER EASTERN MT AND THE WESTERN DAKOTAS WILL POSE A RISK OF LOCALLY GUSTY/DAMAGING WINDS. ELSEWHERE...NO SEVERE STORMS ARE EXPECTED TODAY.