Severe Thunderstorm Warning 22, NWS Glasgow, MT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GLASGOW MT
149 PM MDT SUN MAY 13 2007

.SHORT TERM...FOR NORTHEAST MONTANA...TONIGHT THROUGH TUESDAY...
FORECAST CONCERN FOR TONIGHT WILL BE ANY SVR WX IN THE
CWA...MAINLY SOUTH AND EAST AS FRONTAL BOUNDARY AND CIRRUS
SHIELD MOVE INTO NW PORTIONS OF THE CWA. 18Z GGW SOUNDING STILL
INDICATED A CAP ALTHOUGH SHALLOW...BUT STILL GOOD INSTABILITY AND
MOISTURE PARAMETERS. COMPACT UPPER LOW NOW IN ID PANHANDLE WITH COLD
FRONT ACROSS NWRN CWA TO NEAR GGW. LARGE AREA OF CONVECTION ALONG
AND BEHIND FRONT TENDING TO STABILIZE AIRMASS WTIH CIRRUS BLOWOFF
INHIBITING HEATING NORTH. BEST THREAT FOR ANY SVR WX LOOKS TO KEEP
SOUTH AND EAST OF GGW WHERE SFC ANALYSIS SHOWS HIGH CAPES WITH DEWPOINTS
MID 50S AND DECENT DIRECTIONAL SHEAR. GOES SOUNDER HAS BEEN
SHOWING LIS OF -6 TO -8 SE OF GGW WITH SFC LOW IS DEVELOPING
FARTHER EAST INTO SD. STILL GOOD SFC GRADIENT DEVELOPING AND WILL
ISSUE A LAKE WIND ADVISORY TONIGHT.  STRONG FRONTOGENSIS DOES
CONTINUE TO SET UP AROUND 00Z AS THERMAL GRAIDENT TIGHTENS. THE
MAIN UPPER DYNAMICS SHIFT EAST ALONG CANADIAN BORDER OVERNIGHT
WITH STRONGEST LIFT MOVING ACROSS THE GGW CWA BETWEEN 00Z-06Z. GFS
TENDS TO MOVE LARGE MCS TYPE AREA OF PCPN TO EARN BORDERS BY 12Z
WITH UPPER LOW SLOWING DOWN SLIGHTLY. HAVE INCREASED POPS ACROSS
THE AREA TONIGHT HELD ON TO HIGHER POPS IN EAST AFTER 06Z MON AND
DURING THE DAY WITH SLOWER TIMING AND NW FLOW ALOFT. ON
TUESDAY...HIGH AMPLITUDE RIDGE AXIS SHIFTS EAST INTO MT WITH RETURN
TO WARMING MAX TEMPS.

.LONG TERM...TUESDAY NIGHT THROUGH SUNDAY...
GOOD AGREEMENT THAT THE EXTENDED PERIOD STARTS WITH A BUILDING UPPER
RIDGE ACROSS THE NORTHERN ROCKIES.  THROUGH THE MIDDLE OF THE WEEK
THIS WILL KEEP THE LOCAL AREA IN A FAIRLY STABLE AND DRY NORTHWEST
FLOW ALOFT.  AN UPPER LOW WHICH IS NOW VISIBLE ON SATELLITE IN THE
GULF OF ALASKA BEGINS TO DROP SOUTHEAST TOWARD THE BRITISH COLUMBIA
COAST LATE IN THE WEEK.  THIS WILL CAUSE THE UPPER FLOW ACROSS THE
STATE TO BACK MORE INTO THE SOUTHWEST AND INCREASE THE CHANCE OF
SHOWERS AND THUNDERSTORMS TOWARD NEXT WEEKEND. STILL SOME
UNCERTAINLY THIS FAR OUT AS TO HOW QUICKLY THE UPPER TROUGH PUSHES
INLAND AND THE AMPLITUDE OF THE TROUGH. IN ANY CASE IT LOOKS LIKE
IT WILL BE COOLER AND SOMEWHAT UNSETTLED UNTIL THE TROUGH PASSES
SOMETIME LATE IN THE WEEKEND OR EARLY NEXT WEEK.  LOWERED THE SKY
GRIDS A BIT FOR THE MIDDLE OF THE WEEK AND RAISED TEMPERATURES A
BIT ACROSS THE WESTERN ZONES WEDNESDAY...AND ACROSS MOST OF THE
CWA FOR LATE IN THE WEEK. OVERALL THE ONGOING FORECAST IS IN VERY GOOD
SHAPE AND ASIDE FROM A FEW TWEAKS NO SIGNIFICANT CHANGES ARE
PLANNED. CB

&&

.AVIATION...
A COLD FRONT WILL CROSS THE AREA THIS EVENING WITH SCATTERED SHOWERS
AND THUNDERSTORMS.  A FEW STORMS MAY TURN SEVERE WITH WIND GUSTS IN
EXCESS OF 50 KTS AND HAIL.  THE BEST CHANCE OF SEVERE WEATHER WILL
BE FROM 00-06Z IN THE VICINITY OF KGDV.  BEHIND THE FRONT LOWER
CLOUDS AND SHOWERS WITH MVFR CEILINGS ARE EXPECTED.  NORTH TO
NORTHEAST WIND OF 15 TO 25 KTS AND GUSTY WILL BACK INTO THE
NORTHWEST BEHIND THE COLD FRONT THIS EVENING. CB

&&

.CLIMATE...
THE MONTH OF MAY IS OFF TO A WARM AND WET START AT GLASGOW.  THROUGH
5/12 THE AVERAGE TEMPERATURE OF 58.5 DEGREES IS 6.2 DEGREES ABOVE
THE 30-YEAR AVERAGE.  1.18 INCHES OF RAIN HAS FALLEN SO FAR THIS
MONTH...WHICH IS 64 HUNDREDTHS OF AN INCH ABOVE AVERAGE.  IT IS THE
WARMEST START TO THE MONTH OF MAY SINCE 1993. CB

&&

.GLASGOW WATCHES/WARNINGS/ADVISORIES...
LAKE WIND ADVISORY FROM 6 PM THIS EVENING TO 4 AM MDT MONDAY FOR
FORT PECK LAKE.

&&

WEATHER.GOV/GLASGOW

<!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>

<!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>