Monday, May 30, 2011

Post date: May 30, 2011 2:26:17 PM

0915 CDT: Today's SPC prediction is a bit different from last night. I think we'll probably shift southwest before things start bubbling up...

1130 CDT: We have left Sioux Falls, SD and are tentatively headed towards Bassett, NE...

1300 CDT: The updated SPC forecast is out.

DAY 1 CONVECTIVE OUTLOOK

NWS STORM PREDICTION CENTER NORMAN OK

1121 AM CDT MON MAY 30 2011

VALID 301630Z - 311200Z

...THERE IS A MDT RISK OF SVR TSTMS THIS AFTERNOON INTO EARLY TONIGHT FROM CENTRAL NEB TO ERN SD...WRN MN...AND EXTREME SE ND...

...THERE IS A SLGT RISK OF SVR TSTMS FROM NORTHWEST OK NORTHWARD ACROSS MUCH OF THE CENTRAL/NORTHERN PLAINS...

A BROAD UPPER TROUGH IS PRESENT TODAY OVER THE WESTERN STATES...WITH A SHORTWAVE TROUGH EVIDENT IN WATER VAPOR IMAGERY ROUNDING THE BASE OF THE TROUGH OVER NM. THIS FEATURE WILL LIFT NORTHWARD ACROSS THE HIGH PLAINS THIS AFTERNOON AND EVENING...LEADING TO AN ACTIVE ZONE OF SEVERE THUNDERSTORMS FROM CENTRAL KS INTO THE DAKOTAS AND WESTERN MN.

...NEB/DAKOTAS/MN...

A WEAK SURFACE COLD FRONT CURRENTLY EXTENDS FROM SOUTHEAST ND INTO NORTH CENTRAL NEB. THIS FRONT WILL MOVE ONLY SLOWLY SOUTHEASTWARD TODAY...AND WILL LIKELY RETREAT NORTHWARD LATER TODAY OVER ND/MN AS CYCLOGENESIS OCCURS OVER THE REGION. THE FRONT WILL SERVE AS THE PRIMARY FOCUS FOR THUNDERSTORM INITIATION THIS AFTERNOON AS FULL SUNSHINE OCCURS IN THE WARM SECTOR. AFTERNOON MLCAPE VALUES OF 3000+ J/KG ARE EXPECTED...ALONG WITH A NARROW AXIS OF WEAK CINH ALONG THE FRONT.

PRESENT INDICATIONS ARE THAT STORMS WILL FORM ON THE FRONT AROUND 21Z FROM THE TRIPLE POINT OVER CENTRAL NEB NORTHWARD INTO THE EASTERN DAKOTAS. STRONG WINDS THROUGH THE TROPOSPHERE WILL PROMOTE SUPERCELL STORM STRUCTURES. HOWEVER...ORIENTATION OF FRONT TO UPPER WINDS MAKE STORM-MODE FORECASTS COMPLEX. INITIAL STORMS MAY POSE A RISK OF TORNADOES. BUT A RATHER QUICK EVOLUTION TO A SQUALL LINE APPEARS LIKELY WITH EMBEDDED BOWS POSSIBLE. THROUGH THE EVENING...LARGE HAIL AND DAMAGING WINDS ARE EXPECTED ALONG THE SQUALL LINE AS IT MOVES INTO WESTERN NEB AND NORTHWEST IA.

2300 CDT: We had a great chase day --- nice structure, large hail (up to 4"), a little mammatus, a gustnado and possibly also a landspout --- but no tornado. All in all, though, we had a blast! For some pictures from the day, GO HERE. Now I need SLEEEEEEEEEP!