Area Forecast Discussion
Issued by NWS Duluth, MN

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000
FXUS63 KDLH 200019 AAA
AFDDLH

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE DULUTH MN
719 PM CDT FRI SEP 19 2014

.UPDATE...
ISSUED AT 718 PM CDT FRI SEP 19 2014

INITIAL BAND OF RAIN SHOWERS AND A FEW EMBEDDED TSTORMS HAS MOSTLY
CLEARED THE DULUTH CWA AS OF 7 PM..WITH THE EXCEPTION OF PARTS OF
NW WISCONSIN. THE REMAINING LIGHT RAIN SHOULD EXIT THE SE PART OF
THE CWA IN ANOTHER 2-3 HOURS AS TRAILING LOBE OF FORCING FOR
ASCENT MOVES EAST WITH LEAD S/W TROF AXIS.

SECOND TRAILING LOW AMPLITUDE WAVE LOCATED ALONG THE RED RIVER
WILL BE QUICKLY TO FOLLOW OVERNIGHT. THE KINEMATIC ENVIRONMENT IN
ADVANCE OF THIS WAVE IS QUITE SUPPORTIVE OF SEVERE CONVECTION AT
THIS MOMENT WITH SUFFICIENT CAPE/SHEAR FOR SUPERCELLS AND EVEN
DECENT LOW LEVEL/NEAR-SURFACE SHEAR. OBSERVATIONS BEAR THIS OUT
WITH FAIRLY LONG LIVED SUPERCELL STORM OVER FAR NW MN ATTM. WHILE
THIS ACTIVITY SHOULD BECOME ELEVATED AND LESS INTENSE WITH
TIME..MOST SHORT RANGE MESOSCALE GUIDANCE BRINGS SOME SORT OF
SMALL CONVECTIVE COMPLEX ACROSS THE NRN CWA OVERNIGHT..AND WE HAVE
UPDATED THE FORECAST TO TREND POPS AND WEATHER IN THAT DIRECTION.

OTHERWISE..THE STANDARD CHANGES TO THE SHORT TERM GRIDS WERE MADE
TO ACCOUNT FOR CURRENT OBSERVATIONAL TRENDS AND LATEST GUIDANCE.

&&

.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 308 PM CDT FRI SEP 19 2014

UPPER LEVEL JET AXIS OVER THE FA AT 19Z WILL BE MOVING E OF THE AREA
BY 00Z AND TAKING ITS UPPER SUPPORT WITH IT. MEANWHILE...A SERIES OF
VORT MAXES WAS ALSO AFFECTING THE FA. THIS COMBO WAS DRIVING THE
RAIN OVER MUCH OF THE AREA THIS AFTERNOON. AT THE SFC...A WARM FRONT
WAS PUSHING THROUGH THE FA AS SEEN IN SFC TEMPS RISING EVEN UNDER
THE CLOUD SHIELD. A COLD FRONT WAS REACHING EASTERN ND AT 19Z AND
WILL BE THE FOCUS FOR ADDITIONAL SHOWERS AND THUNDERSTORMS LATE THIS
AFTERNOON AND ESPECIALLY TONIGHT. APPEARS ATTM THAT A CLEARING TREND
MAY OCCUR FOR A TIME LATE THIS AFTERNOON. HOWEVER...CLOUDS WILL
QUICKLY DEVELOP ALONG AND AHEAD OF THE FRONT AND FILL IN. GUSTY SFC
WINDS WILL CONTINUE UNTIL SUNSET WHEN LOW LEVEL INVERSION SETS UP.

THE COLD FRONT IS EXPECTED TO BISECT THE FA FROM N TO S BY 06Z.
SHOWERS AND STORMS WILL INITIATE ALONG AND AHEAD OF THE FRONT. BEST
UPPER LEVEL SUPPORT WILL BE ALONG THE INTERNATIONAL BORDER WHERE A
VORT MAX WILL BE DRIFTING THROUGH...AND IN NW WI WHERE UPPER LEVEL
DIVERGENCE WILL BE ENHANCED DUE TO A DEPARTING JET LET. ATTEMPTED TO
ALIGN POPS TO ACCOUNT FOR THESE FEATURES. THE FRONT IS PROGGED TO
REACH THE EASTERN EDGE OF THE WI FA BY 12Z SATURDAY. A DRYING TREND
WILL FOLLOW BEHIND THE FRONT WITH WEAK SFC RIDGING. TRENDED POPS
DOWNWARD AFTER 06Z.

THE FRONT COMPLETELY EXITS SATURDAY MORNING ALLOWING THE SFC RIDGING
TO COVER THE FA BY 15Z. LEFT SOME POPS OVER THE EASTERN EDGE OF THE
AREA FOR ANY LEFTOVER RAIN. HAVE NO RAIN MENTIONED FROM 15Z TO 18Z
SATURDAY. AFTER 18Z...BEGIN TO RAMP THINGS UP AS A DIGGING UPPER
LEVEL TROF DRIVES ANOTHER COLD FRONT THROUGH THE FA. FORCING IS
MAXIMIZED BY MID AFTERNOON AS THE NOSE OF AN UPPER LEVEL JET
ARRIVES. HAVE POPS OVER THE ENTIRE AREA AFTER 21Z WITH THE HIGHEST
OVER THE MN ZONES. SOME STORMS MAY BE ON THE STRONG SIDE IN THE MID
AFTERNOON AS THERMODYNAMIC PROFILES SUGGEST. MUCAPE APPROACHES 500
J/KG BUT INSTABILITY AXIS IS OVER THE SOUTHERN MN ZONES. WILL LEAVE
OUT THE MENTION FOR NOW AS CONFIDENCE IS LOW.

.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 308 PM CDT FRI SEP 19 2014

A COLD FRONT AND SHORTWAVE WILL CONTINUE TO MOVE THROUGH THE
NORTHLAND SATURDAY NIGHT WITH A CHANCE FOR SHOWERS AND STORMS. SOME
OF THE STORMS COULD BE QUITE STRONG EARLY IN THE EVENING WITH STRONG
FORCING ALONG THE FRONTAL BOUNDARY. WE HAVE POPS HIGHEST OVER OUR
CENTRAL/EASTERN ZONES IN THE EVENING. THE FORCING WILL PARTIALLY
MAKE UP FOR A LACK OF INSTABILITY AND MARGINAL SHEAR.

HIGH PRESSURE WILL START TO BUILD IN ON SUNDAY AND MOST AREAS WILL
BE DRY. THERE MAY BE SOME LINGERING SHOWERS OVER EASTERN AREAS...BUT
ANY SHOWERS SHOULD BE LIGHT.

HIGH PRESSURE WITH RIDGING ALOFT WILL KEEP THE NORTHLAND DRY SUNDAY
NIGHT THROUGH TUESDAY. A TROUGH WILL THEN START TO IMPACT THE AREA
TUESDAY NIGHT INTO THURSDAY NIGHT WITH A CHANCE FOR SHOWERS/STORMS.

HIGHS SUNDAY WILL BE IN THE UPPER FIFTIES TO MIDDLE SIXTIES...THEN
BE IN THE SIXTIES THROUGH MID WEEK. HIGHS LATE IN THE WEEK LOOK TO
REBOUND INTO THE LOWER TO MIDDLE SEVENTIES FOR MUCH OF THE
NORTHLAND.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SATURDAY EVENING)
ISSUED AT 718 PM CDT FRI SEP 19 2014

MVFR/IRF CEILINGS AND VISIBILITY ARE EXPECTED AT MOST TAF SITES
THRU TONIGHT AND INTO LATE MORNING SATURDAY AS MOIST AIRMASS
REMAINS IN PLACE ATOP GROUND THAT HAS COOLED SUFFICIENTLY WITH THE
RECENT COLD WEATHER TO RESULT IN RATHER WIDESPREAD STRATUS AND
ADVECTION FOG. RAPIDLY MOVING DISTURBANCE WILL BRING ANOTHER ROUND
OF TSRA TO KINL/KHIB TAF SITES OVERNIGHT. A BRIEF PERIOD OF
MINIMAL CHANCES FOR PRECIP MORNING INTO THE MIDDAY HOURS SATURDAY
IN BETWEEN SYSTEMS..AND CEILINGS ARE EXPECTED TO SLOWLY LIFT
DURING THIS TIME. ANOTHER UPPER LEVEL WAVE AND STRONGER SURFACE
COLD FRONT WILL APPROACH THE REGION SATURDAY AFTERNOON..WITH MORE
WIDESPREAD THUNDERSTORM ACTIVITY EXPECTED TO DEVELOP THE LAST 3-5
HOURS OF THIS TAF PERIOD.

&&

.PRELIMINARY POINT TEMPS/POPS...
DLH  58  67  51  61 /  40  70  70  20
INL  52  64  47  59 /  60  80  70  10
BRD  57  69  49  67 /  10  70  20  10
HYR  59  68  49  64 /  40  60  70  20
ASX  58  68  50  60 /  50  60  70  30

&&

.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
LS...NONE.
&&

$$

UPDATE...MILLER
SHORT TERM...GSF
LONG TERM...MELDE
AVIATION...MILLER





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