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000
FXUS63 KDLH 191729 AAB
AFDDLH

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE DULUTH MN
1229 PM CDT WED JUN 19 2013

.UPDATE...
S/W TROF IS PROGRESSING SEWD THRU ONTARIO EARLY THIS
AFTERNOON..WITH APPROACHING COLD FRONT. OTHER SHOWERS AND WEAK
TSTORMS ARE TRYING TO DEVELOP ALONG THE INTERNATIONAL BORDER
BETWEEN KINL AND LK SUPERIOR. FOR THIS AFTERNOON..WE HAVE MADE
ONLY SMALL ADJUSTMENTS TO THE FORECAST..MAINLY TO FINE TUNE HOURLY
TRENDS ON TEMPS/WINDS/SKY COVER. MOST SIGNIFICANT CHANGES WERE TO
NUDGE DEWPOINTS UPWARD A BIT IN LINE WITH OBSERVATIONAL
TRENDS..AND TO ADJUST POPS UPWARD OVER THE NORTH/NORTHEAST..AND
DOWNWARD SLIGHTLY IN THE WEST AND SOUTH.

FAIRLY DECENT AXIS OF LOW LEVEL FGEN IS FORECAST TO DEVELOP IN
VICINITY OF THE CANADIAN BORDER THIS EVENING/OVERNIGHT..AT THE
NORTHEAST PERIPHERY OF THE ADVANCING MOISTURE GRADIENT IN THE LOW
LEVELS. THUS..WE EXPECT BEST CHANCES OF PRECIP TO PERSIST OVER THE
MN ARROWHEAD THIS EVENING AND INTO THURSDAY MORNING. AT THIS
TIME..IT APPEARS THAT BEST CHANCES OF TSTORMS ASSOCIATED WITH
APPROACHING WAVE FROM THE NRN ROCKIES WILL REMAIN WEST OF THE DLH
CWA TONIGHT.

&&

.AVIATION...18Z TAF ISSUANCE...
THERE ARE ONLY FEW/SCT LOW AND/OR HIGH CLOUDS ACROSS NE MINNESOTA
AND NW WISCONSIN EARLY THIS AFTERNOON. WHILE VFR CONDITIONS WILL
LIKELY CONTINUE THROUGH TOMORROW MORNING...MUCH OF THE REGION HAS
A LOW THREAT OF SHOWERS AND THUNDERSTORMS LATER THIS AFTERNOON AND
THROUGH TOMORROW MORNING. EXPECT INCREASING LOW LEVEL CUMULUS
DEVELOPING THROUGH THE AFTERNOON. ANY SHOWERS AND STORMS COULD
BRING BRIEF MVFR CIGS AND VSBYS TO THE REGION...AND WE WILL NEED
TO MONITOR FOR DEVELOPMENT BEFORE ADDING MUCH MVFR TO THE
FORECASTS. ALSO...THERE IS A LOW THREAT OF BRIEF FOG LATE TONIGHT
AND TOMORROW MORNING...BUT CONFIDENCE AT THIS POINT IS TO
INTRODUCE IT.

.PREV DISCUSSION... /ISSUED 639 AM CDT WED JUN 19 2013/

AVIATION...

VFR CONDITIONS WERE OCCURRING THIS MORNING ACROSS THE
NORTHLAND...WITH SCATTERED TO BROKEN CLOUDS FROM 6-10KFT DRIFTING
THROUGH. A FRONTAL BOUNDARY...SHORTWAVE...WAA AND INCREASING
MOISTURE WILL ALL LEAD TO CHANCES FOR SHOWERS OR A THUNDERSTORM
OVER PORTIONS OF THE NORTHLAND THIS AFTERNOON AND TONIGHT.
KINL/KHIB WILL HAVE THE BEST CHANCE AT SEEING SOME RAIN THIS
AFTERNOON AND EARLY EVENING.

PREV DISCUSSION... /ISSUED 355 AM CDT WED JUN 19 2013/

CURRENT...WARM ADVECTION REGIME HAS DEVELOPED ACROSS THE CWA AS
SFC HIGH SHIFTS EAST AND RETURN FLOW IS UNDERWAY. LITTLE TO NO SFC
CONVERGENCE AS A BROAD ANTICYCLONIC FLOW EXISTS IN THE BDRY LYR. A
DISORGANIZED AREA OF CLOUDS OVER THE SERN CWA APPEARS TO BE ASSOCIATED
WITH AN AXIS OF 85H MSTR TRANSPORT AS DEPICTED ON LATEST RAP13.
A SECOND AREA OF CLOUDS IS LOCATED OVER THE NWRN CWA WHERE 85/70H
LAPSE RATES HAVE LOWERED TO 6C TO 7C/KM. THIS IS OCCURRING AHEAD OF
A DEVELOPING 85H THETAE AXIS FROM NE NODAK INTO SWRN ONTARIO AHEAD
OF APPROACHING SFC BDRY. SFC TEMPS HAVE LOWERED TO MID 30S IN
ARROWHEAD WITH MID 50S OVER BRD LAKES REGION.

TODAY...WARM ADVECTION PATTERN WILL CONTINUE WITHIN ANTICYCLONICALLY
CURVED BDRY LYR FLOW. A GRADUAL MOISTENING OF ATMOSPHERE WILL OCCUR
OVER THE CWA WITH A CORRESPONDING INCREASE IN INSTABILITY. BASED
HIGHER POPS ON AREA OF GREATER INSTABILITY DEVELOPING WITH DIURNAL
HEATING OVER MN ZONES.

TONIGHT...SFC BDRY OVER MANITOBA/ONTARIO WILL APPROACH NRN BORDER
WITH POSSIBILITY OF ADDITIONAL CONVECTIVE DEVELOPMENT. ANY
CONVECTION WOULD THEN TEND TO SLIDE SE TOWARDS ARROWHEAD/LAKE
SUPERIOR REGION OVERNIGHT. CONFIDENCE NOT HIGH ON PLACEMENT OF
HIGHER POPS OVERNIGHT.

TOMORROW...SFC PATTERN BECOMES MORE COMPLICATED BY DEVELOPING
INVERTED SFC TROUGH OVER WRN CWA...FROM SFC LOW PRESSURE OVER SRN
PLAINS. NRN BDRY WILL BECOME ABSORBED WITHIN OVERALL WARM
ADVECTION REGIME SOMEWHERE ACROSS NRN MN ZONES. POPS SHOULD
INCREASE AS PWATS/INSTABILITY INCREASE AND FORCING IN BDRY LYR IS
ENHANCED BY TROUGH AND OLD SFC BDRY IN THE NORTH. A SLIGHT RISK OF
SVR STORMS IS POSSIBLE WEST OF A INTL FALLS TO TWIN PORTS TO
SPOONER LINE. MAX TEMPS SUBJECT TO CHANGE BASED ON CLOUD COVERAGE
AND PRECIPITATION. INCREASING HUMIDITY LEVELS MAY LEAD TO
DEVELOPMENT OF FOG OVER LAKE SUPERIOR WITH ADDITIONAL UPDATES
REQUIRED.

EXTENDED...THURSDAY NIGHT THROUGH TUESDAY.

THIS PERIOD WILL BE AN ACTIVE ONE...ESPECIALLY THROUGH THE
WEEKEND...WITH SEVERAL CONVECTIVE COMPLEXES POSSIBLE ACROSS THE
REGION. SEVERE STORMS AND HEAVY RAIN WILL BOTH BE THREATS.

IT`S STILL TOO EARLY TO PINPOINT TIMING AND LOCATION OF THE
THUNDERSTORM COMPLEXES...BUT THE MODELS DO SEEM TO AGREE ONE WILL
MOVE THROUGH THE NORTHLAND THURSDAY NIGHT. AN UPPER RIDGE OVER THE
NORTHLAND WILL BE OVER THE REGION EARLY IN THE PERIOD...BUT
GRADUALLY SHIFT EAST LATE IN THE WEEKEND. THE AIRMASS WILL BECOME
INCREASINGLY MORE UNSTABLE WITH TIME THROUGH THE WEEKEND. MOISTURE
TRANSPORT INTO THE NORTHLAND THURSDAY NIGHT SHOULD HELP MAINTAIN A
COMPLEX OF STORMS THAT DEVELOP FURTHER WEST DURING THE
AFTERNOON...AND DEEP LAYER FLOW/CORFIDI VECTORS SHOW A EAST TO
EAST-SOUTHEAST MOVEMENT OF THE COMPLEX OF STORMS. PWAT VALUES RISE
TO 1.4 TO 1.6 INCHES BY 12Z FRIDAY. THESE STORMS WILL POSE A SEVERE
THREAT ACROSS THE NORTHLAND...WITH HAIL...DAMAGING WINDS AND HEAVY
RAIN ALL THREATS. THE MODELS ARE OFFERING DIFFERENT SOLUTIONS WITH
THE LOW LEVEL FRONTAL LOCATION AND WHERE THE MAIN AREA OF STORMS
WILL TRACK. THE GFS IS FURTHER NORTH WITH THE OTHER MODELS A BIT
MORE SOUTH...BUT STILL AFFECTING OUR CWA.

THERE IS CONSENSUS THERE WILL BE A LOWER CHANCE FOR STORMS AT SOME
POINT ON FRIDAY...EARLIER IN THE WEST AND LATER IN THE EAST...AS THE
OVERNIGHT STORMS DEPART. HOWEVER...WITH PLENTY OF INSTABILITY AND
MOISTURE OVER THE REGION STORMS WILL REMAIN POSSIBLE. MORE STORMS
ARE EXPECTED TO DEVELOP FRIDAY NIGHT INTO SATURDAY...WITH CONFIDENCE
IN HOW THINGS DEVELOP DIMINISHING FRIDAY NIGHT INTO SUNDAY. THE
MODELS SHOW SIGNIFICANT DIFFERENCES IN WHERE THE FRONTAL BOUNDARY
WILL BE...WITH THE GFS FURTHER NORTH. TYPICALLY...THE MORE SOUTHERN
FRONTAL LOCATION IS A BETTER BET AND HOPEFULLY THE MODELS COME INTO
BETTER AGREEMENT.

THERE ALSO IS CONSENSUS AMONG THE MODELS OF LOWERING CHANCES FOR
PRECIP SUNDAY NIGHT INTO MONDAY AS SOME DRYING OCCURS AS THE UPPER
LOW LIFTS INTO MANITOBA AND THE COLD FRONT PASSES THROUGH.

WE HAVE HIGHS FROM THE MID SEVENTIES TO LOWER EIGHTIES FRIDAY INTO
SATURDAY. MUCH COOLER VALUES WILL OCCUR AROUND LAKE
SUPERIOR...ESPECIALLY ON SATURDAY...AS A BRISK ONSHORE FLOW IS
EXPECTED. HIGHS SUNDAY AND MONDAY SHOULD BE A BIT WARMER WITH MOSTLY
UPPER SEVENTIES TO LOWER EIGHTIES. TEMPERATURES WILL LIKELY NEED
SOME ADJUSTMENT...AS COVERAGE AND TIMING OF THE THUNDERSTORMS WILL
HAVE A BIG IMPACT ON THE HIGHS.

&&

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

$$

SHORT TERM...MILLER
AVIATION...GROCHOCINSKI