000
FXUS63 KDLH 180448
AFDDLH

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DULUTH MN
1148 PM CDT FRI MAY 17 2013

.AVIATION...06Z TAFS.
THUNDERSTORMS HAVE DEVELOPED/SPREAD INTO THE BRD AREA WITH MORE
SHOWERS MOVING THROUGH EAST CENTRAL MN AND INTO NW WI. EXPECT MORE
SHOWERS TO DEVELOP AND AFFECT ALL TERMINALS EXCEPT INL THROUGH THE
EARLY MORNING. BY MID MORNING...ADDITIONAL STORMS ARE EXPECTED TO
AFFECT MOST SITES WITH INL NOT IMPACTED UNTIL 21Z. A BREAK IN THE
PCPN AFTER 21Z AT THE OTHER SITES UNTIL THE NEXT ROUND AFFECTS THE
TERMINALS ABOUT 03Z.

&&

.PREV DISCUSSION... /ISSUED 818 PM CDT FRI MAY 17 2013/

UPDATE...RAIN HAS FINALLY DEVELOPED OVER THE FA SOUTHERN TIER OF
THE FA. THIS IS UNDER A SMALL LINE OF REFLECTIVITIES SEEN ON
RADAR. THIS INITIAL BATCH WILL NOT LAST LONG. MORE SIGNIFICANT
ROUND OF SHOWERS EXPECTED AFTER 06Z WITH WAA AND LLJ IMPINGING ON
THE FA. HAVE REMOVED THE MENTION OF THUNDER TONIGHT DUE TO LACK OF
INSTABILITY. MADE SOME OTHER MINOR ADJUSTMENTS AND TO POPS TO
REFLECT CURRENT TREND.

PREV DISCUSSION... /ISSUED 619 PM CDT FRI MAY 17 2013/

AVIATION...00Z TAFS.
VFR ACROSS MUCH OF THE FA THROUGH ABOUT 06Z. THE EXCEPTION IS AT
BRD WHERE MVFR CIGS WITH VCSH UNTIL 19Z. ELSEWHERE...MVFR CIGS
WITH AREAS OF SHOWERS WILL SPREAD INTO THE AREA AFTER 06Z. LEFT
THE MENTION OF THUNDER AT ALL LOCATIONS IN THE AFTERNOON. PCPN
WILL END BRIEFLY AROUND 21Z.

PREV DISCUSSION... /ISSUED 308 PM CDT FRI MAY 17 2013/

SHORT TERM...THROUGH SATURDAY.

MOST OF THE CWA WAS DRY AS OF 20Z...WITH SOME LIGHT RETURNS OVER
THE FAR NORTH THAT MAY SPIT OUT SOME SPRINKLES.

WATER VAPOR IMAGERY SHOWED THE UPPER TROUGH ALONG THE WESTERN
CONUS COAST THIS AFTERNOON...AND IT`S STILL FORECAST TO MOVE EAST
TOWARD THE REGION...STRETCHING FROM THE PACIFIC NW INTO THE FOUR
CORNERS REGION BY 00Z SUNDAY. WAA WILL CONTINUE TONIGHT...STRENGTHENING
IN THE LOW LEVELS AS THE NIGHT PROGRESSES. WE ARE SEEING A
RESPONSE ACROSS PORTIONS OF CENTRAL AND SOUTHERN
MINNESOTA/WISCONSIN ALREADY WITH INCREASING SHOWERS. STABILITIES WILL
GRADUALLY DROP OVERNIGHT...AND WE SHOULD SEE SHOWERS AND
THUNDERSTORMS EXPAND AS THE NIGHT PROGRESSES FROM SOUTH TO NORTH.

THE STRONGEST FGEN/WAA OCCURS ACROSS NORTHERN AREAS ON
SATURDAY...SO WE HAVE THE HIGHEST POPS THERE...WITH THE LOWEST
OVER OUR NORTHWEST WISCONSIN ZONES. STABILITIES WILL DROP FURTHER
ON SATURDAY...AND WITH THE WARM FRONT DRAPED NEAR OR JUST SOUTH OF
THE NORTHLAND...FORCING WILL REMAIN FOR A MENTION OF
SHOWERS/STORMS THROUGH THE DAY.

EXPECT LOWS TONIGHT FROM 35 TO 40 OVER FAR NORTHEASTERN
MINNESOTA...TO 45 TO 52 OVER OUR FAR SOUTHERN ZONES.

HIGHS SATURDAY WILL BE DEPENDENT ON RAIN COVERAGE. WE HAVE HIGHS
FROM THE MID SIXTIES FAR NORTH...TO THE MID TO UPPER SEVENTIES
SOUTH. AREAS AROUND LAKE SUPERIOR WILL REMAIN MUCH COOLER WITH AN
ONSHORE FLOW CONTINUING.

LONG TERM...SATURDAY NIGHT THROUGH THURSDAY NIGHT.

THE ACTIVE WEATHER PATTERN WILL CONTINUE THROUGH THE REST OF THE
WEEKEND AND INTO THE MIDDLE PART OF NEXT WEEK...WITH RAIN SHOWERS
AND CHANCES FOR THUNDERSTORMS. THE UPPER TROUGH OVER THE ROCKIES
WILL CONTINUE TO DIG SEWD INTO THE PLAINS SAT NIGHT AND SUNDAY AS A
SFC LOW DEVELOPS OVER KS/NE WITH AN INVERTED TROUGH EXTENDING NWD
INTO THE ERN DAKOTAS AND NW MN. STRONG WAA AND MOISTURE TRANSPORT
FROM THE SOUTH WILL ADVECT IN AHEAD OF THE LOW DURING THE DAY SUNDAY
AND ALLOW THE ATMOSPHERE TO BECOME RELATIVELY UNSTABLE OVER MUCH OF
THE UPPER MIDWEST. THERE WILL BE TWO POTENTIALLY SIGNIFICANT PARTS
TO THIS WEATHER SYSTEM. THE INITIAL CONCERNS WILL BE WITH THE
CHANCES FOR THUNDERSTORMS...MAINLY ELEVATED SAT NIGHT AND SUN
MORNING...BUT EVENTUALLY MORE SFC BASED AND POSSIBLY STRONGER SUN
AFTERNOON/EVENING. THE SLOW PROGRESSION OF THE LOW TO THE EAST WILL
ALLOW FOR A PROLONGED PERIOD OF WAA AND DESTABILIZATION ACROSS A
GOOD PORTION OF THE NORTHLAND...MOST SIGNIFICANTLY OVER THE SRN
COUNTIES. THE INTERACTION OF THIS INSTABILITY AXIS...THE SFC
TROUGH/FRONTAL ZONE AND STRONG DYNAMICS ALOFT WILL ALL CONTRIBUTE TO
THE POTENTIAL FOR A NUMBER OF STRONG...AND POSSIBLY A FEW SEVERE
STORMS SUNDAY/SUN NIGHT. BY EARLY MONDAY THE MAJORITY OF THE
INSTABILITY IS EXPECTED TO HAVE MOVED TO THE E/SE...DECREASING THE
STORM POTENTIAL FROM N TO S.

THE OTHER PLAYER WITH THIS SYSTEM WILL BE THE HEAVY RAINFALL THAT
WILL OCCUR OVER A 3-4 DAY PERIOD. AT THIS TIME IT APPEARS MOST OF
THE NORTHLAND WILL RECEIVE AROUND 1-3 INCHES OF RAIN DURING THIS
TIME...WITH LOCALIZED 4 INCH OR GREATER AMTS POSSIBLE ACROSS
N-CENTRAL MN. A TIGHT THERMAL GRADIENT WILL BE ALIGNED WITH THE SFC
TROUGH ACROSS NRN MN...AND THE LOCATION/MOVEMENT OF THIS FEATURE
WILL BE A MAJOR FACTOR IN DETERMINING WHERE THE HEAVIEST RAIN AMTS
OCCUR. THERE COULD BE BOTH LOCALIZED/SHORT TERM HYDRO CONCERNS...AND
LONG TERM/WIDESPREAD RIVER FLOODING THAT RESULTS FROM THIS SYSTEM.

TEMPERATURES ON SUNDAY WILL BE QUITE WARM AWAY FROM LAKE SUPERIOR.
HIGHS INLAND WILL REACH INTO THE 70S AND LOWER 80S...WITH 50S AND
LOWER 60S NEAR THE LAKE. A COOL DOWN STARTS MON AND TUE WITH HIGHS
ONLY IN THE 50S AND 60S. THE COOL WET PATTERN WILL CONTINUE THROUGH
MOST OF THE WEEK...AND A PERSISTENT NE WIND OFF LAKE SUPERIOR WILL
ONLY MAKE CONDITIONS FEEL COOLER.

AVIATION...18Z TAF ISSUANCE.

VFR CIGS THIS AFTERNOON WILL GRADUALLY LOWER LATE AFTERNOON/EARLY
EVENING WITH RAIN CHANCES INCREASING THROUGH THE EVENING. WILL
ALSO SEE THE POTENTIAL FOR VCTS TO DEVELOP FROM SOUTH TO NORTH
TONIGHT...WITH THE BEST CHANCE AFTER 12Z SAT MORNING. CIGS WILL
LOWER TO MVFR AT TIMES DURING AND AFTER RAIN SHOWERS. COULD ALSO
SEE REDUCED VSBYS IN LIGHT FOG.

&&

.POINT TEMPS/POPS...
DLH  44  60  53  68 /  60  50  50  70
INL  45  64  53  64 /  10  60  80  80
BRD  51  76  61  77 /  60  60  80  70
HYR  46  76  58  78 /  40  50  20  60
ASX  45  71  54  74 /  70  60  30  50

&&

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

$$

AVIATION...GSF