Intermediate Update
*14Z Intermediate Update*
You had checked SPC already, but found the site to be not updated. In fact, the most up-to-date convective outlook you could find was a Day 3 from two days ago (thus valid today):
2-day-old Day 3 outlook
DAY 3 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
...THERE IS A SLGT RISK OF SVR TSTMS MUCH OF GREAT PLAINS...
...SYNOPSIS...
BASIC SYNOPTIC PATTERN ACROSS CONUS WILL BE CHARACTERIZED BY RIDGING ALOFT FROM HUDSON BAY TO FL...AND DEEP WRN TROUGH. SRN STREAM LOW -- NOW EVIDENT IN MOISTURE CHANNEL IMAGERY OVER MEX -- IS FCST TO EJECT ACROSS LOWER MS VALLEY DAY-2...WEAKENING CONSIDERABLY BY DAY-3 WHEN IT MOVES THROUGH MEAN RIDGE POSITION. OF GREATER CONSEQUENCE WILL BE MID/UPPER LEVEL CYCLONE THAT SHOULD EVOLVE FROM WRN STATES TROUGH. DISCREPANCIES IN STRENGTH AND POSITIONING OF THIS LOW THAT BEGIN TO APPEAR IN DAY-2 BECOME QUITE PRONOUNCED DAY-3...WITH VARIOUS SREF MEMBERS AND OPERATIONAL PROGS PREDICTING CYCLONE CENTER ANYWHERE FROM NERN MT TO ERN CO. NONETHELESS...PROGS ARE IN CLOSER AGREEMENT ON STRONG/SECONDARY SHORTWAVE TROUGH EXPECTED TO DIG SWD THEN EWD ACROSS AZ/NM DURING PERIOD.
AT SFC...MULTIPLE CYCLONE CENTERS ARE POSSIBLE WITHIN ELONGATED AREA OF LOW PRESSURE FROM WRN DAKOTAS TO WRN KS TO SW TX OVER CENTRAL/NRN HIGH PLAINS...CORRESPONDING TO COMBINED LEE TROUGH/PACIFIC FRONT/DRYLINE POSITION. SPECIFIC LOCATION/STRENGTH OF THESE LOWS WILL BE INFLUENCED STRONGLY BY CHARACTERISTICS OF MID/UPPER CYCLONE AND REMAIN QUITE UNCERTAIN ATTM. DESPITE THAT...PRIND WAA AND RAPID NWD SPREAD OF MOISTURE IS LIKELY IN BROAD WARM SECTOR...FROM TX AT LEAST INTO NRN NEB/SRN SD...SUPPORTING SVR PROBABILITIES AOA CATEGORICAL OUTLOOK THRESHOLD. NARROWER CORRIDOR OF FAVORABLE LOW LEVEL THERMODYNAMICS MAY EXTEND FARTHER NW ACROSS DAKOTAS...SUPPORTING CONDITIONAL SVR THREAT REPRESENTED ATTM BY 5 PERCENT PROBABILITY LINES.
...GREAT PLAINS STATES...
ELONGATED AREA OF RELATIVELY MAXIMIZED SVR POTENTIAL IS EXPECTED
ALONG/E OF DRYLINE/LEE TROUGH...AND S OF SFC WARM FRONT THAT
GENERALLY WILL EXTEND FROM SD ESEWD ACROSS IA. OPTIMAL BOUNDARY
LAYER THERMODYNAMICS SHOULD OCCUR IN RELATIVELY NARROW BUT VERY LONG PLUME WHERE FAVORABLE RETURN FLOW MOISTURE -- WITH DEW POINTS POTENTIALLY 60S F -- JUXTAPOSE WITH STEEPENING LAPSE RATES AHEAD OF MID/UPPER TROUGH. MORE MERIDIONAL COMPONENT OF MID/UPPER FLOW...ALONG WITH MOST INTENSE DEEP-LAYER FORCING...ARE EXPECTED FROM ROUGHLY WRN OK NWD. WINDS ALOFT OVER CENTRAL PLAINS WILL BE STRONGLY PARALLEL TO PRIMARY ZONE OF LOW LEVEL FORCING INVOF LEE TROUGH/DRYLINE. STRONGER CAPPING AND POTENTIALLY WEAKER LOW LEVEL WINDS/SMALLER HODOGRAPHS ARE POSSIBLE WITH SWD EXTENT ACROSS W TX...BUT ALSO...GREATER SFC HEATING AND MOISTURE DURING AFTERNOON...ALONG WITH GREATER DIRECTIONAL SHEAR.
CONSIDERABLE VARIATION REMAINS POSSIBLE IN STORM MODE AND TIMING OF INITIATION...AND FCST VERTICAL SHEAR PROFILES SUPPORT BOTH DISCRETE/SUPERCELLULAR AND LINEAR/MIXED MODES THROUGHOUT GREAT PLAINS. MORE CONCENTRATED/INTENSE SVR EVENT MAY OCCUR...INCLUDING SIGNIFICANT SVR POTENTIAL...HOWEVER UNCERTAINTIES ABOUT MESOSCALE PROCESSES AND MOST PROBABLE MODES OF DEVELOPMENT PRECLUDE MORE SPECIFIC AREA OF GREATER PROBABILITIES ATTM.