Area Forecast Discussion
Issued by NWS Duluth, MN

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000
FXUS63 KDLH 251735 AAB
AFDDLH

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE DULUTH MN
1235 PM CDT SAT JUL 25 2015

.UPDATE...
ISSUED AT 1235 PM CDT SAT JUL 25 2015

UPDATED 18Z AVIATION DISCUSSION BELOW...

&&

.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 244 AM CDT SAT JUL 25 2015

THE NORTHLAND WILL BE UNDER NORTHWEST FLOW ALOFT EARLY IN THE
PERIOD WITH AN UPPER RIDGE BUILDING OVER THE REGION ON SUNDAY.
TODAY WILL BE LESS HUMID THAN YESTERDAY  WITH DEWPOINTS MAINLY IN
THE UPPER FIFTIES TO LOWER SIXTIES BUT IT WILL BE WARMER WITH MOST
AREAS RISING INTO THE MIDDLE 80S. THERE WILL BE SEVERAL RELATIVELY
WEAK FEATURES CREATING OPPORTUNITIES FOR CONVECTION TODAY INTO
SUNDAY. WE GENERALLY FOLLOWED AN ENSEMBLE APPROACH AND HAVE SOME
LOW POPS WHERE THERE WAS MOST CONSENSUS AMONG THE OPERATIONAL
MODELS AND CAMS.

WE ADDED POPS MAINLY THIS AFTERNOON OVER PORTIONS OF FAR NORTHERN
MINNESOTA WHICH WILL BE NEAR OF JUST DOWNSTREAM FROM A LOW LEVEL
TROUGH BEST SEEN AT 925MB IN THE ECMWF/GFS. THERE WERE SOME
CONVECTION OVER SOUTHEAST MANITOBA AS OF 08Z...BUT IT LOOKS LIKE
THIS AREA SHOULD REMAIN NORTH OF THE INTERNATIONAL BORDER
THIS MORNING. STEEPER LAPSE RATES WILL BE PRESENT ACROSS THE
NORTHLAND AND FORECAST SOUNDINGS SHOW SEVERAL HUNDRED J/KG OF
MLCAPE DEVELOPING THIS AFTERNOON. IT IS ALSO POSSIBLE A FEW
THUNDERSTORMS COULD DEVELOP ALONG THE LAKE BREEZE THAT SHOULD
AFFECT PORTIONS OF LAKE/COOK COUNTIES THIS AFTERNOON.

WE KEPT A MENTION OF SHOWERS/STORMS IN THE FAR NORTHERN TONIGHT
INTO SUNDAY MORNING AS THE LOW LEVEL TROUGH MOVES FURTHER SOUTH
AND A WEAK SHORTWAVE MOVES THROUGH. WE ALSO KEPT SOME POPS IN OUR
SOUTHERN ZONES ON SUNDAY AS ANOTHER WAVE IMPACTS THAT AREA. SUNDAY
WILL BE WARM AS WELL WITH HIGHS IN THE 80S.

.LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY)
ISSUED AT 244 AM CDT SAT JUL 25 2015

HOT...HUMID...AND STORMS POSSIBLE THROUGH THE FIRST HALF OF THE WORK
WEEK WITH A STRONG COLD FRONT MOVING THROUGH MID-WEEK RESULTING MUCH
MORE COMFORTABLE CONDITIONS THROUGH THE END OF THE WEEK.

ON THE SYNOPTIC SCALE THE PATTERN WE HAVE BEEN IN FOR THE PAST FEW
WEEKS REMAINS GENERALLY UNCHANGED WITH AN UPPER LEVEL RIDGE OVER THE
SOUTHERN PLAINS AND A TROUGH IN THE WEST. THROUGH THE BEGINNING OF
THE WEEK THE RIDGE AXIS WILL GRADUALLY SHIFT FROM THE UPPER GREAT
LAKES TO LOWER GREAT LAKES. A WELL ORGANIZED UPPER LOW WILL DEEPEN
OVER THE GREAT BASIN REGION SUNDAY INTO MONDAY THEN EJECT EASTWARD
OVER ROCKIES ALONG THE INTERNATIONAL BORDER THEN INTO SOUTHERN
SASKATCHEWAN/MANITOBA. FOR MONDAY AND TUESDAY THIS WILL RESULT IN
SOUTHWESTERLY FLOW AND THUS WARM AND MOIST AIR BEING ADVECTED
IN...PROBABLY THE HIGHEST HEAT INDEX VALUES OF THE SUMMER SO FAR.
TUESDAY INTO TUESDAY NIGHT A STRONG COLD FRONT WILL THROUGH FROM
WEST TO EAST BRINGING MUCH NEEDED RELIEF AS A ZONAL TO SLIGHTLY
NORTHWESTERLY FLOW ALOFT RESULTS IN MORE SEASONABLE TEMPS FOR THE
SECOND HALF OF THE WEEK.  IN THE WAKE OF THE UPPER LOW THE SOUTHERN
RIDGE BUILDS TO THE WEST...WITH A RIDGE AXIS NEAR OR WEST OF THE
ROCKIES BY THE END OF THE WEEK.

BEST CHANCE FOR STORMS IS GOING TO BE TUESDAY INTO WEDNESDAY
ASSOCIATED WITH THE COLD FRONT. THERE IS SOME DIFFERENCES IN MODEL
SOLUTIONS WITH REGARDS TO HOW CONVECTION MAY EVOLVE ON TUESDAY...BUT
GUIDANCE COMES INTO A BETTER AGREEMENT TUESDAY NIGHT INTO WEDNESDAY
AS A STRONG LLJ DEVELOPS AS THE COLD FRONT CROSSES THE
NORTHLAND...RESULTING IN LATE AFTERNOON STORMS CONTINUING THROUGH
THE NIGHT. WITH THE INCREASED MOISTURE AHEAD OF THE FRONT...PWAT
VALUES WILL BE 2-3 STANDARD DEVIATIONS ABOVE NORMAL...WHICH COULD
RESULT IN HEAVY RAINFALL TUESDAY NIGHT INTO WEDNESDAY...THOUGH AT
THIS POINT IT APPEARS STORM MOTIONS SHOULD BE FAST ENOUGH TO
PRECLUDE A WIDESPREAD FLOOD THREAT.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 12345 CDT SAT JUL 25 2015

SURFACE RIDGE FORECAST TO CONTINUE SOUTHEASTWARD MOVEMENT THIS
AFTERNOON AND TONIGHT. A WEAK TROUGH/WARM FRONT WILL MOVE INTO
NORTH- CENTRAL MINNESOTA BY 26.00Z WITH BACKING WINDS TO THE WEST
OF THE BOUNDARY. SCATTERED TO ISOLATED SHOWERS AND THUNDERSTORMS
ARE POSSIBLE ALONG AND EAST OF THE FRONT...WITH THE BEST CHANCE OF
VCSH FOUND AT INL/BRD/HIB. VFR CIGS/VSBYS ARE EXPECTED THROUGH
THIS EVENING BEFORE AREAS OF FOG DEVELOP OVERNIGHT RESULTING IN
MVFR VSBYS. THERE IS A CHANCE HYR/BRD/HIB MAY SEE A BRIEF PERIOD
OF IFR VSBYS...BUT CONFIDENCE IN TIMING WAS TOO LOW TO INCLUDE IN
PREVAILING GROUP. CONDITIONS IMPROVE QUICKLY AFTER SUNRISE ON
SUNDAY WITH PREVAILING VFR EXPECTED FOR THE REMAINDER OF THE
FORECAST PERIOD.

&&

.PRELIMINARY POINT TEMPS/POPS...
DLH  85  65  85  63 /  10  10  10  10
INL  85  59  87  63 /  20  20  10  10
BRD  87  63  85  65 /  10  20  20  10
HYR  85  59  84  62 /   0  10  10  10
ASX  84  62  86  61 /  10  10  10  10

&&

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

$$

SHORT TERM...MELDE
LONG TERM...JJM
AVIATION...HUYCK


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