Sunday, May 29, 2011

Post date: May 29, 2011 2:01:56 PM

0815 CDT: The setup for today doesn't look quite as good this morning as it did last night before I went to bed. It will be very interesting to see what Charles has in mind for us as a result. Tomorrow, though, looks to be a GREAT chase day! Hopefully today will end up being a good one as well.

0900 CDT: Here's a time-lapse of last Monday's chase. As you will see, sometimes the chase is more interesting than the tornado!

1000 CDT: SOMEBODY has been VERY bad!!!

1245 CDT: Well, our chase once again became a non-chase day... *frown* The conditions were simply not conducive to tornadoes, so instead, we're hanging around Norfolk, NE at the moment. A few folks are taking care of some laundry needs, and then we'll head to Sioux Falls, SD for the night. In all probability, that should put us in a good position for what appears to be a VERY good chase day tomorrow. *crosses fingers* Here's the updated map for tomorrow, along with a portion of the forecast discussion:

...ERN DAKOTAS/UPPER MS VALLEY TO THE CENTRAL PLAINS... NEGATIVE-TILT OF UPPER TROUGH INTO THE NRN PLAINS... STRENGTHENING WIND FIELDS/SHEAR AND MODERATE INSTABILITY SUPPORT AN UPGRADE TO A MODERATE RISK FOR VERY LARGE HAIL... A STRONG TORNADO OR TWO AND DAMAGING WINDS ACROSS PARTS OF THE ERN DAKOTAS/MID MO VALLEY TO UPPER MS VALLEY. SLY LOW LEVEL WINDS THROUGH THE DAY WILL MAINTAIN NWD MOISTURE RETURN WITH SURFACE DEWPOINTS IN THE MID-UPPER 60S REACHING THE NRN EXTENT OF THE WARM SECTOR OVER THE ERN DAKOTAS/UPPER MS VALLEY MONDAY MORNING/AFTERNOON. PLUME OF STEEP MIDLEVEL LAPSE RATES EXTENDING NNEWD ALONG AND E OF THE DRY LINE COMBINED WITH SURFACE HEATING WILL CONTRIBUTE TO A MODERATELY UNSTABLE AIR MASS /MLCAPE 2000-2500 J PER KG/. GIVEN THE EXPECTED INCREASE IN DEEP LAYER ASCENT AS THE NEGATIVELY TILTED TROUGH MOVES ACROSS THE CENTRAL/NRN PLAINS... THE STRONG CAP ALONG THE DRY LINE SHOULD BEGIN TO WEAKEN BY MID AFTERNOON SUPPORTING CONVECTIVE INITIATION. DEGREE OF INSTABILITY AND EFFECTIVE BULK SHEAR /45-55 KT/ WITH VECTORS GENERALLY PARALLEL TO THE DRY LINE/COLD FRONT WILL SUPPORT STORM ORGANIZATION. ALTHOUGH A LINEAR MODE SHOULD BE PREDOMINATE... SOME CROSSING OF THE SHEAR VECTORS TO THE INITIATING BOUNDARIES SUGGESTS EMBEDDED SUPERCELLS WILL ALSO BE POSSIBLE. GIVEN THESE FACTORS... ALL FACETS OF SEVERE WEATHER ARE EXPECTED DURING THE LATE AFTERNOON AND EARLY EVENING. STRENGTHENING WIND FIELDS AND GREATER LINEAR FORCING AS THE SYSTEM BECOMES MORE NEGATIVELY-TILTED SUGGESTS AN MCS WITH AN ENHANCED DAMAGING WIND THREAT WILL BE POSSIBLE AS STORMS MOVE INTO WRN MN AND NWRN IA.

2200 CDT: We have moved to Sioux Falls, SD now and are looking forward to a great chase day tomorrow. The SPC has already made it a MODERATE RISK day, and conditions look... well... I don't want to jinx it.

Anyway, here's today's travel map: