Hail in South Dakota, May 17, 2005

AREA FORECAST DISCUSSION FOR SOUTHEAST SD/SOUTHWEST MN/NORTHWEST IA
NATIONAL WEATHER SERVICE SIOUX FALLS SD
330 AM CDT TUE MAY 17 2005

.DISCUSSION...
MAIN STORY IN THE SHORTER TERM IS THE STRONG UPPER TROF PASSAGE MOVG
VERY SLOWLY THRU THE FSD FA TUE EVENING THRU WED AFTN. IN THE NEAR
TERM...CONVECTION HAS FIRED PRIMARILY IN SW MN...WITH SOME ACCAS
SHRA MOVG EWD TOWARD KSUX IN NERN NEB. THE SW MN CONVECTION IS
ASSOCIATED WITH A WEAK MID LVL WAVE AND DECENT LOW LVL JET...
COUPLED WITH A SUBTLE WMFNT TO THE N OF THE FSD FA. THE FIRST TS GOT
GOING JUST N OF BROOKINGS COUNTY AROUND 11 PM...AND GRADUALLY BUILT
SWD AS IT MOVED EWD INTO THE LOW LVL JET. WL FOLLOW THIS CONVECTION
EWD THRU THE PRE DAWN HRS...NOT IN ANY HURRY TO LEAVE WITH WK MID
LVL WINDS AT 10 TO 15 KTS. REALLY CANNOT TOTALLY RULE OUT SMALL POPS
THROUGHOUT THE CWFA IN THE MORNING HRS AFTER SUNRISE DUE TO SOME
INSTABILITY ALOFT AND NO SHORTAGE OF ACCAS ON THE IR. WL LIKELY GET
OUR MIDDAY BREAK...THEN AM CONCERNED ABOUT MORE DEVELOPMENT NEAR THE
LEFTOVER SFC WMFNT IN OUR FAR NE IN THE EARLY AFTN...BUILDING SLGTLY
SWD THRU THE AFTN HRS COVERING MUCH OF OUR EAST. THEN LATE THIS
AFTN...INTERACTION IN OUR WRN QUARTER OF THE FA WITH THE STRONG
WAVE. BOTH SFC AND ELEVATED CAPES ARE WELL ABV 1000 J/KG IN OUR WRN
THIRD THIS AFTN...AND MID LVL WINDS IN OUR WRN QUARTER ACTUALLY DO
INCREASE TO 25 TO 35 KTS. INSTABILITY IS ALSO QUITE HIGH IN OUR
WEST...SO INTITIAL LATE AFTN AND EVENING SVR CHCS IN OUR WRN THIRD
ARE DEFINITELY THERE...PARTIALLY DUE TO THE WINDS WHICH IS NEXT.

NOW TO THE WINDS. OPTED TO NOT ISSUE A WIND ADVY THRU THE CWFA ATTM.
H85 WINDS DO PICKUP THRU THE AFTN HRS IN THE 35 TO 40 KT RANGE PER
THE NAM...WITH LESS GRADIENT IN OUR FAR WEST. HOWEVER WITH
PERSISTENT WAA...SOMETIMES THESE SSE WINDS JUST DO NOT MIX FULLY
ENUF TO MEET THE CRITERIA. NOW IRONICALLY...AM ACTUALLY MORE
CONCERNED ABOUT A WIND ADVY IN OUR ERN HALF THRU PART OF TONIGHT.
NAM LOW LVL JET REALLY STARTS TO CRANK AT 50 TO 55 KTS IN THE EAST
WITH MOST SNDGS NOT TEMP INVERTED YET...SUGGESTING MOIST ADIABATIC
LAPSE RATES. A COUPLE OF NAM SNDGS SHOW A SUBTLE INVERSION NEAR
H9...AND OF COURSE AFTER DARK PREDICTING MIXING IS ALWAYS TRICKY. SO
ATTM...NOT BRAVE ENUF TO PULL THE TRIGGER ON A WIND ADVY TONIGHT BUT
SOMETHING TO WATCH...ESP ON THE BUFFALO RIDGE. SO BACK TO SVR
POTENTIAL...SOME STORMS MAY REACH SVR WIND CRITERIA BY DEFAULT IN
OUR WRN THIRD WITH THE VERY STOUT LOW LVL WINDS THRU THE EVENING
HRS. MIXED AND MATCHED GUIDANCE TEMPS TODAY AND TONIGHT...AND REALLY
DID NOT CHANGE PREV FCST TEMPS VERY MUCH AS THEY STILL LOOK GOOD.

AS MENTIONED ABOVE...THE UPPER TROF HAS NO REAL PUSH BEHIND IT AND
VERY SLOWLY MOVES EWD TONIGHT AND WED IN THIS AREA. CONVECTION CHCS
ARE OBVIOUSLY GOOD TONIGHT...AND WITH THE WEAK MID LVL WINDS...THERE
COULD BE SOME SLOW MOVG DOUSERS AROUND. ON WED...INSTABILITY WRAP
AROUND SHRA WL PROBABLY BE FOUND IN OUR WRN CWFA AND FUTURE SHIFTS
WL LIKELY WANT TO GO HIGHER THAN SLGT CHCS IN THE WEST...WITH A
STRONG TROWAL TYPE SITUTATION GOING ON OUT THERE. IN THE EAST...MID
LVL WAVE HAS STILL NOT CLEARED YET WITH SW FLOW ALOFT SO SCT TS WL
GET GOING AGAIN THRU THE AFTN HRS...COUPLED WITH THE MID LVL THTE
RIDGING EXTENDING EWD ORIENTED FM NW TO SE. BIG DISCRENPANCIES EXIST
BETWEEN THE NAM/GFS H85 TEMPS SO WED HIGHS ARE PROBLEMATIC.
HOWEVER...PREFER THE SLOWER NAM SOLN THRU THIS WHOLE EVENT WITH THE
WK MID LVL FLOW...SO BELIEVE THAT THE H85 TEMPS ON THE GFS MAY BE
TOO COOL. THEREFORE TRENDED MORE TOWARD THE WARMER GUIDANCES.

MID/UPPER WAVE SLOWLY OOZES SEWD THRU TIME ON WED NIGHT AND THU...
WHICH WL GIVE RAPIDLY CLEARING SKIES ACROSS OUR WEST...MOVG INTO THE
ERN CWFA ON THU. AGAIN...BIG DIFFERENCES BETWEEN H85 TEMPS IN THE
WED NIGHT THRU THU NIGHT TIMEFRAME BETWEEN THE NAM/GFS...AND THIS
TIME OPTED TOWARD COOLER GUIDANCES AT NIGHT WITH THE DRIER AIR AND
LIGHTER WINDS...AND SPLIT THE DIFFERENCE BETWEEN THE MET/MAV ON THU
DAY. NO CHANGES TO THE EXTENDED ATTM.

&&

.FSD WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.

&&

MJF

<!doctype html>
<html lang="en">
<head>
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width, initial-scale=1">
  <title>Service Notice</title>
  <link rel="stylesheet" href="index.css">
</head>
<body>
  <main class="wrap">
    <section class="card" role="status" aria-live="polite">
      <div class="status" id="status">Temporary Notice</div>
      <h1 id="headline">This service is currently unavailable.</h1>
      <p id="message1">
        The site you requested is temporarily down for maintenance or an unexpected outage.
      </p>
      <p id="message2">
        Please try again in a few minutes.
      </p>
      <p class="small" id="detail">
        If you are an administrator, restore upstream service and remove the redirect/fallback rule when normal operations resume.
      </p>
    </section>
  </main>
  <script src="index.js"></script>
</body>
</html>