Area Forecast Discussion
Issued by NWS Duluth, MN

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FXUS63 KDLH 050841
AFDDLH

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DULUTH MN
341 AM CDT TUE MAY 5 2015

.SHORT TERM...(TODAY THROUGH WEDNESDAY)
ISSUED AT 341 AM CDT TUE MAY 5 2015

HIGH PRESSURE DEPARTING TO THE EAST TODAY BEFORE A WARM FRONT LIFTS
NORTH INTO THE REGION ON WEDNESDAY LEADING TO INCREASED LOW-LEVEL
MOISTURE AND A CHANCE FOR RAIN. GENERALLY MILD TODAY THROUGH THE
SHORT TERM.

TODAY...DRY AND MILD. SUNNY...WITH INCREASING CLOUDS FROM SOUTH TO
NORTH LATE IN THE DAY ASSOCIATED WITH AN ENCROACHING WARM FRONT.
AFTERNOON RELATIVE HUMIDITY FALLING TO THE 15 TO 25 PERCENT RANGE
SIMILAR TO YESTERDAY. HIGH TEMPERATURES ALSO SIMILAR TO YESTERDAY
IN THE UPPER 60S TO LOW 70S. WINDS OVER LAND WILL BE OUT OF THE
SOUTHEAST AT 10 TO 15 MPH...STRONGEST FROM THE BRAINERD LAKES
REGION EAST TO THE INTERSTATE 35 CORRIDOR WHERE A FEW GUSTS UP TO
AROUND 20KTS WILL BE POSSIBLE. STRONGEST WINDS WILL NOT BE
COINCIDENT WITH THE LOWEST RELATIVE HUMIDITY...AND THUS DO NOT
EXPECT RH/WINDS TO APPROACH CRITICAL FIRE WEATHER CONDITIONS.

TONIGHT...INCREASING CLOUDS FROM SOUTH TO NORTH AS A WARM FRONT
MOVES ACROSS THE REGION. INCREASING LOW LEVEL MOISTURE THROUGH THE
NIGHT WITH DEW POINTS RISING INTO THE 50S BY TUESDAY MORNING. A
ROUND OF SHOWERS/T-STORMS WILL BE POSSIBLE ASSOCIATED WITH THE
INITIAL PUSH OF MOISTURE. THE LARGE-SCALE GUIDANCE WAS FAIRLY
AGGRESSIVE WITH REGARD TO PRECIP WITH ECMWF/GEM/GFS ALL DEPICTING A
FAIRLY WET SCENARIO WHILE THE HIGHER RES GUIDANCE WAS LESS
AGGRESSIVE. IN GENERAL...EXPECT A BRIEF 2-4 HOUR WINDOW OF LIGHT TO
MODERATE PRECIP IN ANY ONE LOCATION...WITH TOTAL RAINFALL AMOUNTS
FROM THIS FIRST ROUND OF PRECIP LESS THAN A TENTH OF AN INCH. DRY
AIR AT LOW/MID LEVELS COULD LIMIT PRECIP THAT ULTIMATELY REACHES THE
GROUND...AND AM ALSO NOT PARTICULARLY IMPRESSED WITH THERMODYNAMIC
PROFILE WITH REGARD TO SUPPORTING THUNDERSTORMS. LLJ DEVELOPMENT
WILL BE CRITICAL TO SUSTAINING STORMS...WHICH SHOULD OVERCOME THE
LESS-THAN-STELLAR MID-LEVEL LAPSE RATES AND MARGINAL MUCAPE.
OVERNIGHT LOWS IN THE UPPER 30S TO NEAR 40 WHERE SKIES REMAIN MOSTLY
CLEAR OVERNIGHT ALONG THE TIP OF THE ARROWHEAD...ELSEWHERE WARMER IN
THE 40S TO NEAR 50.

WEDNESDAY...FIRST ROUND OF SHOWERS/STORMS MOVES NORTH FOLLOWED BY A
SECOND ROUND OF PRECIPITATION IN THE LATE AFTERNOON...WITH PRECIP
POSSIBLY BEING DELAYED UNTIL THE EVENING HOURS. DID NOT WANT TO MAKE
ANY DRASTIC CHANGES TO POPS...BUT AT THIS POINT GUIDANCE IS TRENDING
TOWARDS A FAIRLY LENGTHY BREAK IN PRECIP. THIS IS DUE TO MID-LEVEL
RIDGING THAT WILL BRIEFLY DEVELOP OVER THE REGION DURING THE DAY
BEFORE THE MAIN UPPER LOW ARRIVES. LOW LEVEL FLOW WILL BE ALMOST DUE
SOUTH FROM THE GULF UP THROUGH THE UPPER MIDWEST WHICH WILL CAUSE
DEW POINT VALUES TO RISE TO NEAR 60...AND 0-1KM MIXING RATIO VALUES
NEAR 10 G/KG...APPROACHING TO EXCEEDING THE 90TH PERCENTILE
CLIMATOLOGY. HOWEVER...WITHOUT THE LARGE SCALE FORCING AVAILABLE TO
SUPPORT PRECIP NOR ANOTHER FRONTAL BOUNDARY PASSAGE TO PROVIDE SMALL
SCALE ASCENT...THIS WELL-ABOVE-NORMAL MOISTURE MAY NOT BE FULLY
UTILIZED TO BRING THE MUCH-NEEDED PRECIP ACROSS THE REGION. HIGHS
SIMILAR TO TUESDAY...UPPER 60S TO LOW 70S...WITH EAST WINDS ACROSS
WESTERN LAKE SUPERIOR LEADING TO COOLER TEMPERATURES BY LAKE
SUPERIOR AND ESPECIALLY ACROSS THE NORTH SHORE WHERE HIGHS MIGHT
ONLY REACH THE 50S.

.LONG TERM...(WEDNESDAY NIGHT THROUGH MONDAY)
ISSUED AT 341 AM CDT TUE MAY 5 2015

CONFIDENCE INCREASING FOR A WET AND UNSETTLED EXTENDED PERIOD.

A SHORT WAVE POSITIONED IN THE DAKOTAS WILL DEEPEN INTO A CLOSED
H85/SFC LOW OVER THE DAKOTAS WED NIGHT...PUSHING EAST ACROSS
NORTHWEST MINN THURSDAY...THEN WILL LIFT INTO ONTARIO FRIDAY. THE
STRENGTHENING PRESSURE GRADIENT FROM THE APPROACHING LOW AND
ASSOCIATED WARM FRONT WILL RESULT IN GUSTY SOUTHERLY WINDS FOR
INLAND AREAS. LOCATIONS NEAR LAKE SUPERIOR CAN EXPECT GUSTY EAST
WINDS WITH MUCH COOLER TEMPERATURES THROUGH THE END OF THE WEEK.

THE PROLONGED PERIOD OF RETURN FLOW AND INCREASED
MOISTURE/INSTABILITY WILL BRING PERIODS OF RAIN WITH EMBEDDED
THUNDERSTORMS WEDNESDAY NIGHT...MAINLY OVER THE MN ZONES. THE SFC
LOW WILL SWEEP A COLD FRONT ACROSS THE NORTHLAND DURING THE THURSDAY
AFTERNOON THROUGH THURSDAY NIGHT PERIOD...BRINGING THE BEST CHANCE
FOR WIDESPREAD RAIN AND THUNDERSTORMS. AT THIS TIME...LOCATIONS
NORTH CENTRAL MINNESOTA ARE EXPECTED TO RECEIVE THE BRUNT OF THE
PRECIPITATION...BEING NEAREST TO THE CENTER OF THE LOW AND BEST
FORCING. LATEST NAM/GFS BUFR SOUNDINGS AT KINL/KHIB/KELO ALL SUGGEST
A PERIOD OF HEAVY RAIN DURING THE LATE AFTERNOON/EARLY EVENING THURS
TIME FRAME AS PROFILES BECOME DEEPLY SATURATED WITH PWAT VALUES
APPROACHING 1.5" AND LONG SKINNY CAPE.

LATEST ECM/GEM/GFS ARE IN GOOD AGREEMENT THAT UPPER LVL RIDGING
RETURNS BRIEFLY AROUND SATURDAY...BEFORE ANOTHER AREA OF LOW
PRESSURE LIFTS ACROSS THE PLAINS AND INTO THE WESTERN LAKE SUPERIOR
REGION LATE IN THE WEEKEND AND INTO NEXT WEEK.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1237 AM CDT TUE MAY 5 2015

VFR CONDITIONS EXPECTED THROUGH THE TAF PERIOD.  RIDGE OF HIGH
PRESSURE OVER THE GREAT LAKES TO SLIDE SOUTHEAST THROUGH THE
PERIOD...ALLOWING SOUTH TO SOUTHEAST SURFACE FLOW TO DEVELOP OVER
THE REGION AFTER 14Z TUESDAY.  A WARM FRONT TO PUSH TOWARDS THE
REGION AFTER 18Z TUESDAY...WHICH SHOULD SPREAD MID AND HIGH CLOUDS
ABOVE 5KFT OVER THE TERMINALS FROM THE SOUTH THROUGH THE END OF THE
TAF PERIOD. SOME CONFIDENCE IN GETTING SHOWERS TO MOVE INTO KBRD AND
KHYR AFTER END OF TAF PERIOD...BUT SHOULD BE SCATTERED IN NATURE
WITH MVFR CEILINGS.


&&

.PRELIMINARY POINT TEMPS/POPS...
DLH  66  45  62  51 /   0  20  30  30
INL  72  43  69  57 /   0  10  40  40
BRD  72  52  70  60 /   0  60  60  60
HYR  70  45  72  59 /   0  30  40  20
ASX  69  42  66  57 /   0  20  30  20

&&

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

$$

SHORT TERM...JJM
LONG TERM...GRANING
AVIATION...LE






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