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000
FXUS63 KDLH 210309 AAC
AFDDLH

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE DULUTH MN
1009 PM CDT MON MAY 20 2013

.UPDATE...
REDUCED THE MENTION OF THUNDER CHANCES OVER THE NWRN HALF OF THE
FORECAST AREA...AND CONFINED THE CHC OF T-STORMS TO MAINLY NW WI
LATE TONIGHT/EARLY TUE MORNING. OTHERWISE...NO MAJOR CHANGES MADE
TO THE FORECAST. STILL EXPECTING SCATTERED RAIN SHOWERS OVER MUCH
OF THE AREA WITH EMBEDDED STORMS POSSIBLE LATE. RAIN CONTINUES
TOMORROW WITH ANOTHER ROUND OF STORMS POSSIBLE OVER WI IN THE
AFTERNOON.

&&

.PREV DISCUSSION... /ISSUED 627 PM CDT MON MAY 20 2013/

AVIATION...00Z TAF ISSUANCE...
NRN TERMINALS WILL CONTINUE WITH IFR/MVFR CIGS AND PERIODS OF MVFR
VSBYS IN RAIN SHOWERS/PATCHY FOG WITH PERSISTENT NE
WINDS...GUSTING 20 TO 25 KT. BRD TERMINAL WILL HAVE A COUPLE HOURS
OF THUNDER POSSIBLE THIS EVENING...BUT QUICKLY BECOME ENTRENCHED
IN IFR/MVFR CIGS AND FOG...WITH VCSH THROUGH THE NEXT 24 HOURS.
THE DLH TERMINAL WILL CONTINUE TO SEE PERSISTENT NE WINDS AROUND
20 KT...WITH GUSTS TO 30 KT THROUGH THE NEXT 24 HOURS. LIFR CIGS
AND VSBYS WILL BE POSSIBLE AT DLH THROUGH TOMORROW. HYR SITE WILL
HAVE THE BEST POTENTIAL FOR THUNDER THIS EVENING...AND AGAIN TUES
AFTERNOON. COULD ALSO HAVE A PERIOD OF LIGHT FOG AND LOW MVFR CIGS
TONIGHT.

PREV DISCUSSION... /ISSUED 517 PM CDT MON MAY 20 2013/

UPDATE...
A PROLONGED PERIOD OF DENSE FOG ACROSS WESTERN LAKE SUPERIOR
TONIGHT AND EARLY TOMORROW HAVE PROMPTED A DENSE FOG ADVISORY FOR
ALL NEAR SHORE WATERS OF WESTERN LAKE SUPERIOR.

PREV DISCUSSION... /ISSUED 304 PM CDT MON MAY 20 2013/

SHORT TERM.../NOW - TUESDAY/

THE FOCUS IN THE SHORT TERM IS THE THREAT OF SEVERE WEATHER AND
HEAVY RAIN ASSOCIATED WITH ADDITIONAL RAIN SHOWERS AND
THUNDERSTORMS TODAY AND TONIGHT...ESPECIALLY ALONG AND NEAR A
WARM FRONT STRETCHING ACROSS THE SOUTHERN FORECAST AREA. A NEARLY
STACKED LOW PRESSURE SYSTEM IN THE FAR EAST CENTRAL DAKOTAS IS
CONTINUING TO PUMP MOISTURE INTO THE NORTHLAND. MUCH OF THE RAIN
SHOWERS THAT WERE AFFECTING THE NORTHLAND EARLY THIS MORNING HAVE
MOVED NORTH OR WEST OF THE FORECAST AREA THIS AFTERNOON.
HOWEVER...THE LATEST HIGH RESOLUTION MODELS HAVE BEEN INDICATING A
LINE OF SCATTERED SHOWERS AND STORMS WILL MOVE INTO THE SOUTHERN
FORECAST AREA THIS AFTERNOON OR EARLY THIS EVENING NEAR OR ALONG
THE WARM FRONT. INDEED...SCATTERED SHOWERS AND THUNDERSTORMS NORTH
OF THE TWIN CITIES AND ARE APPROACHING THE SOUTHERN FORECAST AREA.
SOME OF THESE STORMS COULD BE STRONG TO SEVERE LATE THIS AFTERNOON
AND EARLY THIS EVENING AND WILL NEED EXTRA MONITORING. I AM ALSO
CONTINUING A FLASH FLOOD WATCH ACROSS THE ENTIRE NORTHLAND DUE TO
THE POTENTIAL PCPN FROM THESE SHOWERS AND STORMS ON ALREADY
SATURATED GROUNDS ACROSS PARTS OF THE FORECAST AREA DUE TO THE
HEAVY RAIN THE PAST FEW DAYS.

AT 2000Z/300PM...THERE WAS A NEARLY STACKED LOW PRESSURE SYSTEM
WOBBLING AROUND NEAR THE FAR EAST CENTRAL DAKOTAS. AN ASSOCIATED
WARM FRONT STRETCHED EAST ACROSS THE SOUTHERN BRAINERD LAKES
REGION AND ACROSS NORTHWEST WISCONSIN. WIDESPREAD RAIN SHOWERS
COVERED THE EASTERN DAKOTAS...NORTHWEST MINNESOTA...AND A BIT OF
THE FAR NORTHWESTERN AND WESTERN FORECAST AREA. SCATTERED SHOWERS
AND WEAK THUNDERSTORMS WERE NORTH OF THE TWIN CITIES AND BEGINNING
TO MOVE INTO THE SOUTHERN FORECAST AREA IN THE WARM SECTOR. MOST
OF THE FORECAST AREA HAD MODERATE TO QUITE GUSTY EASTERLY WINDS
WITH THE STRONGEST WINDS NEAR LAKE SUPERIOR. SOUTHERLY WINDS WERE
FOUND SOUTH OF THE WARM FRONT. TEMPERATURES WERE IN THE 40S AND
50S IN THE COLD SECTOR...AND IN THE 60S AND 70S IN THE WARM
SECTOR. DEW POINTS WERE IN THE 40S AND LOWER 50S IN THE COLD
SECTOR...WHILE IN THE UPPER 50S TO LOW 60S IN THE WARM SECTOR.
MOST OF THE NORTHLAND HAD CLOUDY SKIES...SAVE FOR PARTS OF NW
WISCONSIN THAT HAD PARTLY TO MOSTLY CLOUDY SKIES. THERE WERE A
COUPLE OBSERVATIONS OF FOG NEAR LAKE SUPERIOR...INCLUDING AT
DULUTH AND ALONG THE NORTH SHORE.

THIS AFTERNOON AND THIS EVENING...ANOTHER ROUND OF SHOWERS AND
THUNDERSTORMS WILL LIKELY MOVE INTO THE SOUTHERN FORECAST THIS
AFTERNOON AND MOVE NORTH INTO THIS EVENING. THE STORMS WILL LIKELY
WEAKEN THIS EVENING WITH THE SETTING SUN. PARTS OF THE SOUTHERN
FORECAST AREA...PARTICULARLY NW WISCONSIN...COULD SEE STRONG TO
SEVERE THUNDERSTORMS THIS AFTERNOON AND EARLY THIS EVENING. IT
APPEARS THE BEST ENVIRONMENT FOR THUNDERSTORM GROWTH AND
ORGANIZATION WILL BEST ACROSS FAR EAST CENTRAL MINNESOTA AND NW
WISCONSIN WHERE THE NAM12 INDICATES CAPE COULD APPROACH 1500
J/KG...DEEP LAYER (0-6 KM) WIND SHEAR WILL BE 25 TO 35 KNOTS...THE
LOW LEVEL JET WILL BE AT ABOUT 20 TO 30 KNOTS...DEW POINTS WILL BE
AROUND 60 DEGREES...AND THERE WILL BE MUCH BETTER FLOW ALOFT DUE
TO THE ORIENTATION OF THE JET STREAM. IT WOULD NOT BE SURPRISING
TO SEE SOME STORMS WITH LARGE HAIL AND DAMAGING WINDS ACROSS THIS
AREA...AND WE MAY NEED A CONVECTIVE WATCH AT SOME POINT. IN THE
MEANTIME...MUCH OF THE NORTHERN FORECAST WILL MAINLY SEE SHOWERS
AND MAYBE SOME WEAK THUNDERSTORMS IN THE COLD SECTOR. THERE COULD
CONTINUE TO BE PATCHY FOG ALONG AND NEAR THE LAKE SUPERIOR
SHORELINE DUE TO THE STRONG AND MOIST EASTERLY WINDS COMING OFF
LAKE SUPERIOR.

LATE TONIGHT...THE THREAT OF THUNDERSTORMS SHOULD MAINLY COME TO
AN END BY MIDNIGHT...BUT THERE IS A SLIGHT CHANCE OF ONGOING WEAK
STORMS ACROSS PARTS OF INLAND NW WISCONSIN. THERE COULD STILL BE
PATCHY FOG ALONG AND NEAR THE LAKE SUPERIOR SHORELINE.

TUESDAY...THE WOBBLING STACKED LOW MAY BEGIN TO SHIFT EAST INTO
SOUTHERN OR CENTRAL MINNESOTA...BUT THE ECMWF KEEPS IT NEARLY
STATIONARY IN THE DAKOTAS. WHATEVER THE TRACK...THE NORTHLAND
SHOULD STILL SEE LIKELY CHANCES OF ADDITIONAL RAIN SHOWERS. THE
WARM FRONT SHOULD BE MORE SOUTH THAN IT IS TODAY...SO ANY STORMS
SHOULD BE LIMITED TO THE FAR SE FORECAST AREA WHERE THERE COULD BE
A FEW STRONG STORMS. HIGH TEMPERATURES SHOULD BE LIMITED TO THE
UPPER 40S AND 50S IN THE COLD SECTOR...BUT THE 60S TO LOW 70S IN
THE WARM SECTOR. THERE COULD CONTINUE TO BE SOME GUSTY EASTERLY
WINDS AND PATCHY FOG ALONG AND NEAR THE LAKE SUPERIOR SHORELINE.

LONG TERM.../TUESDAY NIGHT - SUNDAY/

THE CUT OFF LOW WILL FINALLY PASS TO THE SOUTH OF THE WESTERN
LAKE SUPERIOR REGION WED...EXITING THE REGION TO THE EAST WED
NIGHT. WINDS WILL REMAIN GUSTY OUT OF THE NE THROUGH THE DAY
WED...THEN GRADUALLY SUBSIDE WED NIGHT WITH BUILDING CANADIAN HIGH
PRESSURE. THE LATEST MODEL RUNS ARE IN GOOD AGREEMENT THAT MUCH
DRIER DRY AIR ASSOCIATED WITH THE HUDSON BAY HIGH RAPIDLY ADVECTS
WESTWARD ACROSS LAKE SUPERIOR AND OVER THE NE HALF OF THE CWA WED
NIGHT...CLEARING OUT THE REMAINING CLOUDS/SHOWERS BY EARLY
THURSDAY MORNING. THE HIGH WILL BRING A TRANSITION TO COLD AIR
ADVECTION WITH FALLING H85 TEMPS INTO THE SINGLE DIGITS WED NIGHT
THROUGH THURSDAY. LATEST SOUNDINGS SHOW THE RESULTING STEEP LAPSE
RATES WILL ALLOW FOR DEEP MIXING THURS AFTERNOON AND FALLING DEW
POINTS/RH. THE FORECAST AREA THEN BECOMES POSITIONED IN BETWEEN
THE DEPARTING HIGH OVER THE GREAT LAKES...AND AN AMPLIFYING RIDGE
OVER THE UPPER MIDWEST THROUGH THE WEEKEND.

AVIATION.../18Z TAF ISSUANCE/

SHOWERS AND A FEW THUNDERSTORMS WILL CONTINUE TO BE POSSIBLE
ACROSS THE FORECAST THIS AFTERNOON AND TONIGHT. CONDITIONS WILL
VARY FROM LARGELY FROM VFR AT KHYR...TO VLIFR AT KDLH. LOW
PRESSURE WILL CONTINUE TO ROTATE THROUGHOUT THE AREA...KEEPING
PERSISTENT LOW CLOUDS AND RAIN SHOWERS THROUGH TUESDAY.

&&

.POINT TEMPS/POPS...
DLH  42  50  41  53 /  70  80  70  60
INL  44  54  43  66 /  80  60  30  30
BRD  48  59  47  58 /  60  70  60  60
HYR  49  64  45  58 /  70  70  60  60
ASX  43  48  41  51 /  70  70  60  70

&&

.DLH WATCHES/WARNINGS/ADVISORIES...
MN...FLASH FLOOD WATCH THROUGH TUESDAY MORNING FOR MNZ010>012-018>021-
     025-026-033>038.

WI...FLASH FLOOD WATCH THROUGH TUESDAY MORNING FOR WIZ001>004-006>009.

LS...DENSE FOG ADVISORY UNTIL 11 AM CDT TUESDAY FOR LSZ121-140>148.

     SMALL CRAFT ADVISORY UNTIL 11 AM CDT WEDNESDAY FOR LSZ121-148.

     SMALL CRAFT ADVISORY FROM 4 AM TUESDAY TO 11 AM CDT WEDNESDAY
     FOR LSZ140>147.

     GALE WARNING UNTIL 4 AM CDT TUESDAY FOR LSZ140>147.

&&

$$

SHORT TERM...TENTINGER