Area Forecast Discussion
Issued by NWS Duluth, MN

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000
FXUS63 KDLH 211152 AAA
AFDDLH

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DULUTH MN
652 AM CDT MON JUL 21 2014

.SHORT TERM...(TODAY THROUGH TUESDAY)
ISSUED AT 318 AM CDT MON JUL 21 2014

SHORT TERM FOCUS IS ON HEADLINES AND POTENTIAL MCS TONIGHT. SFC
PRESSURE ANALYSIS AT 07Z FOUND SFC RIDGING BUILDING NWD THROUGH THE
FA ON A SLY FLOW. AN OUTFLOW BOUNDARY FROM STORMS IN ONTARIO WAS
KNIFING THROUGH THE FA AND LOCATED NEAR GPZ TO ELO AND THE CANADIAN
BORDER. AS THIS OUTFLOW ENCOUNTERS THE H7 CAP OF 10C...ONLY SOME
CLOUDS WERE FORMING ALONG THE BOUNDARY. HAVE REMOVED THE POPS
THROUGH 12Z. MAINTAINED THE PRIOR FORECAST OF NO POPS THROUGH 18Z
TODAY. A WSW FLOW ALOFT AND A SLY LOW LEVEL FLOW WILL PERSIST
THROUGH THE DAY. A HOT AND HUMID AIRMASS ON THE SLY FLOW WILL RESULT
IN MAX TEMPS IN THE MIDDLE TO UPPER 80S...WITH SOME ISOLD TEMPS
AROUND 90. 70S ALONG THE N SHORE OF LAKE SUPERIOR. SFC DEWPOINTS ARE
STILL FORECAST TO REACH INTO THE UPPER 60S ALONG THE CANADIAN BORDER
TO THE LOWER TO MIDDLE 70S ALONG THE SOUTHERN EDGE OF THE FA. HEAT
INDICES WILL REACH INTO THE 80S AND 90S. HEAT ADVISORY CRITERIA WILL
BE MET OVER THE SW QUAD OF THE FA INTO PINE AND BURNETT
COUNTIES...BUT NOT UNTIL 18Z WITH SOME IMPROVEMENT BY 00Z/22. AS A
RESULT HAVE ADJUSTED THE BEGIN AND END TIMES FOR THE ADVISORY
ACCORDINGLY AND REMOVED SOME COUNTIES FROM THE ADVISORY.

ADJUSTMENTS WERE ALSO MADE TO THE POPS FOR THIS AFTERNOON. LATEST
MODEL GUIDANCE SUGGESTS THAT THE THUNDERSTORMS WILL HOLD OFF UNTIL
AFTER 21Z. THIS IS WHEN SHORT WAVE ENERGY REACHES EASTERN ND AND
BEGINS TO DEVELOP STORMS. HOWEVER...H7 CAP TEMPS OF 10-14C WILL
COVER THE FA AND PRECLUDE STORMS FROM REACHING THE WESTERN FA. ONLY
HAVE SMALL POPS THROUGH 23Z.

MODELS ARE CONSISTENT WITH THE FORMATION OF AN MCS OVER EASTERN ND
AND WESTERN MN ABOUT 00Z AND MOVING OVER THE FA THROUGH 12Z.
DAMAGING WINDS AND HEAVY RAIN WILL BE THE MAIN THREATS. WITH THE HOT
AIRMASS TO BE OVERCOME...NOT EXPECTING HAIL. FOR SEVERE DETAILS
CHECK THE SPC DAY 1 OUTLOOK. HAVE ATTEMPTED TO ALIGN THE HIGHEST
POPS TO ACCOMPANY THE MCS AS IT CROSSES AND TO MATCH THE NEIGHBOR
OFFICES.

ON TUESDAY...THE MCS WILL CONTINUE TO MARCH OUT OVER LAKE SUPERIOR
IN THE MORNING AND HAVE POPS DIMINISHING IN THE MORNING FROM W TO E.
BY TUESDAY AFTERNOON...THE MCS WILL HAVE EXITED THE AREA COMPLETELY
WITH HIGH PRESSURE BUILDING IN BEHIND. LINGERED A POP OVER PRICE
COUNTY IN THE AFTERNOON FOR ANY BACKWASH LEFTOVER.

.LONG TERM...(TUESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 318 AM CDT MON JUL 21 2014

THE UPPER LEVEL RIDGE WILL BUILD OVER THE HIGH PLAINS WHILE SFC HIGH
RESIDES OVER THE UPPER GREAT LAKES FOR MIDWEEK. THIS WILL GIVE THE
NORTHLAND SEASONAL TEMPERATURES AND DRIER WEATHER. THE RIDGE WILL
BREAK DOWN LATE IN THE WEEK AS AN UPPER LEVEL LOW MAKES LANDFALL INT
HE PACIFIC NORTHWEST AND DIGS INTO THE RIDGE. IN RESPONSE...LOW
PRESSURE WILL DEVELOP OVER THE HIGH PLAINS. THE LOW WILL BRING A
COLD FRONT THROUGH THE NORTHLAND ON SATURDAY...BUT RETURN FLOW AHEAD
OF THE SYSTEM COULD CAUSE SOME SHOWERS AND THUNDERSTORMS AS EARLY AS
FRIDAY...MAINLY IN WESTERN AREAS OF THE FORECAST AREA.  THE THREAT
OF SHOWERS AND STORMS WILL THEN PERSIST THROUGH THE WEEKEND AS THE
SYSTEM MOVES THROUGH. THE GFS IS MUCH STRONGER WITH THIS LOW AND
EVEN CLOSES IT OFF OVER NRN MN ON SUNDAY...WHILE THE ECMWF KEEPS IT
OPEN UNTIL LATER IN THE WEEK...CLOSES IT THEN HAS IT RETROGRADING
INTO THE GREAT LAKES.  AS EXPECTED THE GFS PRECIP GUIDANCE IS MUCH
MORE ROBUST THAT THE ECMWF...BUT BETTER DEFINITION OF THIS SYSTEM
WILL COME WITH SUBSEQUENT RUNS.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 642 AM  CDT MON JUL 21 2014

VFR CONDITIONS WILL FOUND OVER THE NORTHLAND TODAY...WITH THE
EXCEPTION OF SOME VERY EARLY MORNING FOG THAT WILL LIFT BY 14Z. A
COLD FRONT WILL MOVE THROUGH THIS EVENING AND TONIGHT AND CAUSE
WIDESPREAD THUNDERSTORMS.

&&

.PRELIMINARY POINT TEMPS/POPS...
DLH  86  66  76  49 /  10  90  30   0
INL  86  63  76  50 /  10  80  10   0
BRD  89  69  80  55 /  10 100  10   0
HYR  88  71  81  53 /  10  90  30  10
ASX  88  68  76  51 /  10  90  50  10

&&

.DLH WATCHES/WARNINGS/ADVISORIES...
MN...HEAT ADVISORY FROM 1 PM THIS AFTERNOON TO 7 PM CDT THIS EVENING
     FOR MNZ025-026-033>036-038.

WI...HEAT ADVISORY FROM 1 PM THIS AFTERNOON TO 7 PM CDT THIS EVENING
     FOR WIZ006.

LS...NONE.
&&

$$

SHORT TERM...GSF
LONG TERM...CLC
AVIATION...CLC






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