Area Forecast Discussion
Issued by NWS Twin Cities, MN

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000
FXUS63 KMPX 312058
AFDMPX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
358 PM CDT MON AUG 31 2015

.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 358 PM CDT MON AUG 31 2015

A COLD FRONT IS NOW ENTERING THE NW EDGE OF THE MPX CWA...BUT STRONG
CAPPING...LIMITED MOISTURE...AND WEAK FORCING ARE ALL CONSPIRING
MAKE THIS A DRY FRONT. WITH THE UPPER WAVE DRIVING THIS FRONT NOW
HEADING NE ALONG THE MANITOBA/ONTARIO BORDER...DO NOT SEE THE STATUS
OF THE FRONT BEING A DRY ONE CHANGING THROUGH THE NIGHT...SO REMOVED
WHAT LITTLE POPS WE HAD FOR TONIGHT. BEING CLOSER TO THE FRONT...WE
HAVE SEEN SOUTH WINDS INCREASE TODAY...WHICH HAS RESULTED IN ABOUT A
5 DEGREE INCREASE IN BOTH TEMPERATURES AND DEWPOINTS THIS AFTERNOON.
OUTSIDE OF WRN WI...WHERE THE STRATUS HAS HELD STRONG...TEMPERATURES
HAVE WARMED NICELY INTO THE LOW/MID 80S...WITH WIDESPREAD DEWPOINTS
IN THE LOW 70S AS WELL NOW.

OF COURSE THE THEME OF THE OVERNIGHT HOURS SINCE THURSDAY NIGHT HAS
BEEN THE EXPANSION OF LOW STRATUS ACROSS THE AREA. WELL...THAT IS
NOT EXPECTED TO BE AS MUCH OF AN ISSUE HERE TONIGHT. ONE...THE
PREFRONTAL REGION WE ARE IN HAS BEEN STRATUS FREE THE LAST FEW
NIGHTS. IN ADDITION...FORECAST SOUNDINGS FROM THE NAM ARE NOT AS
MOIST IN THE LOW LEVELS AND NOT LOOKING AS FOGGY/STRATUSY AS THEY
HAVE SINCE FRIDAY MORNING. BASED ON 950 MB RH AND SREF PROBS FOR
CEILINGS UNDER 3K FT...EXPECT STRATUS TO FORM TONIGHT OVER NORTHERN
WISCONSIN AND TRY TO BUILD SOUTH INTO WRN WI. EVEN THOUGH WE ARE NOT
EXPECTING AS MUCH STRATUS TUESDAY MORNING...IT DOES NOT MEAN WE WILL
BE WAKING UP TO BLUE SKIES. INSTEAD...WE WILL BE REPLACING THE SUB
1K FOOT CLOUDS WITH MID/UPPER LEVEL CLOUDS ASSOCIATED WITH THE
REMNANTS OF THE FRONT MOVING INTO WRN MN NOW.

AS FOR THE FRONT...WITH THE UPPER WAVE DRIVING IT GETTING FARTHER
AND FARTHER NORTHEAST OF THE AREA...ITS EASTWARD PROGRESSION WILL
COME TO A HALT OVERNIGHT...WITH IT WASHING OUT ACROSS THE MPX AREA
ON TUESDAY. AS A RESULT...NOT EXPECTING ANY PRECIP TOMORROW...SO
HAVE REMOVED WHAT LITTLE POPS WE HAD IN WRN WI FOR TUESDAY
AFTERNOON. THE WEATHER FOR TUESDAY LOOKS VERY SIMILAR TO TODAY IN
TERMS OF TEMPERATURE AND DEWPOINTS WITH ONLY DIFFERENCES BEING SOME
MORE MID/HIGH LEVEL CLOUDS TOMORROW AND LIGHTER SOUTH WINDS.

.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 358 PM CDT MON AUG 31 2015

LITTLE CHANGE TO THE LONG TERM FORECAST...AND UNFORTUNATELY NO
BETTER CLARITY ON THE TIMING AND CHANCES OF PRECIPITATION FOR
LABOR DAY WEEKEND. TEMPERATURES IN THE MID TO UPPER 80S WITH DEW
POINTS HANGING AROUND THAT 70 DEGREE MARK FOR THE NEXT SEVERAL
DAYS IS LIKELY.

THE UPPER RIDGE ACROSS THE CENTER OF THE CONUS WILL REMAIN IN
PLACE THROUGH THE WEEK...WITH A SUBTLE SHORTWAVE INDICATED ALONG
THE MN/IA BORDER BY BOTH THE EC AND GFS ON WEDNESDAY NIGHT.
REMAINED CONSISTENT WITH SLIGHT CHANCE POPS AND SOME CHANCE POPS
IN EXTREME SOUTHERN MN. THESE POPS ARE THERE TO ACCOUNT FOR THE
CHANCE A FEW SHOWERS AND ISOLATED THUNDERSTORMS ARE ABLE TO
OVERCOME THE CAP. OTHER THAN VORTICITY ADVECTION...THERE IS NOT A
LOT OF UPPER LEVEL SUPPORT FOR MUCH IN TERMS OF PRECIP...SO STILL
THINKING MOST PEOPLE WILL MISS OUT ON ANY RAIN...BUT MUST REMAIN
CONSISTENT WITH THE CHANCE FOR ISOLATED TO SCATTERED ACTIVITY AT
THIS TIME.

THE NEXT CHANCE FOR PRECIP COMES AGAIN THURSDAY NIGHT INTO FRIDAY
AS WAVE THAT ORIGINATES IN THE EASTERN PACIFIC IS PULLED NORTHEAST
WHILE AN IMPRESSIVE UPPER TROUGH DEEPENS OVER THE PACIFIC
NORTHWEST. THE EC/GFS/GEM ALL INDICATE THIS WAVE ADVANCING
NORTHEAST AND THROUGH THE UPPER MIDWEST FROM THURSDAY THROUGH
FRIDAY NIGHT /AND POSSIBLY LINGERING INTO SATURDAY/. THE 12Z RUN
OF THE EC IS INTERESTING TO SAY THE LEAST...WITH THIS FEATURE
SUDDENLY INTENSIFYING RAPIDLY FRIDAY AS IT MOVES FROM COLORADO TO
MINNESOTA. I`M NOT BUYING INTO THIS QUITE YET...BUT IT HAS SHOWN
RUN TO RUN CONSISTENCY IN SOME SORT OF UPPER WAVE TAKING THIS
COURSE. STUCK WITH LOW POPS FOR NOW AS TIMING AND PLACEMENT...AND
QUESTIONS ABOUT THE STRENGTH OF THIS WAVE ARE ALL UNCERTAIN AT
THIS POINT.

FOR THE MAIN SYSTEM WE HAVE BEEN SEEING FOR THE LATTER HALF OF
LABOR DAY...WE GAINED NO ADDITIONAL CLARITY ON EXPECTATIONS FOR
IT. IT WILL MOVE EASTWARD ALONG THE US/CANADIAN BORDER FROM THE
PACIFIC NORTHWEST...BUT AS THIS FEATURE MOVES FURTHER EAST...THE
GFS AND EC DIVERGE ON THE HANDLING OF IT...QUITE A BIT. THE EC
WANTS TO STRENGTHEN THE UPPER RIDGE ACROSS THE CENTRAL
PLAINS...PUSHING THE STRONG UPPER LOW FURTHER NORTH AS IT MOVES
EAST...TOWARD HUDSON BAY...AND SLOWING THIS SYSTEM DOWN QUITE A
BIT. THE GFS STILL TAKES IT THROUGH THE UPPER MIDWEST AND IS MUCH
FASTER. THE BOTTOM LINE REMAINS...THERE IS QUITE A BIT OF
DISAGREEMENT AMONGST THE GUIDANCE FOR THIS WEEKEND. SO...STUCK
WITH CHANCE POPS THAT ARE ALMOST CERTAINLY SPREAD ACROSS TO BROAD
OF AN AREA...SPATIALLY AND TEMPORALLY. THIS WILL CHANGE ONCE THE
GUIDANCE BEGINS DEMONSTRATING SOME BETTER AGREEMENT.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 123 PM CDT MON AUG 31 2015

FOR THE FOURTH DAY IN A ROW...WE GOT TO START WITH IFR OR WORSE
STRATUS AND TODAY...ITS EAU THAT GETS STUCK WITH IT THE
LONGEST...THOUGH EVEN THEY SHOULD CLEAR OUT BY 20Z. ONCE THE
STRATUS DISSIPATES...ANOTHER QUIET DAY IS EXPECTED...THOUGH WITH
BREEZIER SOUTH WINDS. FRONT MOVING ACROSS THE DAKOTAS WILL SLIP
INTO WC MN THIS EVENING...WHERE IT WILL WASH OUT. NO ACTIVITY IS
EXPECT ALONG THE FRONT...WITH NOTHING MORE THAN A BAND OF MID
LEVEL CLOUDS COMING IN WITH IT. FOR STRATUS TONIGHT...NAM BUFR
SOUNDINGS FINALLY NOT SHOWING MUCH POTENTIAL FOR FOG/STRATUS...AT
MN TERMINALS ANYWAYS. IN ADDITION...SREF PROBS FOR CIGS UNDER 3K
FT ARE GREATEST IN NORTHERN WI. CURRENT EXPECTATIONS FOR STRATUS
IS THAT IT WILL ORIGINATE OVER NRN WI AND BUILD SOUTH THROUGH THE
NIGHT...WHICH IS WHY IFR CIGS WERE BROUGHT BACK TO RNH/EAU FOR
NOW.

KMSP...KEPT STRATUS MENTION OUT FOR TONIGHT. ONE...FRONTAL
BOUNDARY WILL BE CLOSER TO US TONIGHT...WHICH IS EXPECTED TO PUSH
THE STRATUS REGION FARTHER EAST AS WELL...SO EXPECT MID LEVEL
CLOUDS AS OPPOSED TO LOW STRATUS. IN ADDITION...FORECAST SOUNDINGS
FROM THE NAM ARE SHOWING THE LOW LEVELS NOT BEING AS MOIST
TONIGHT. STILL WILL HAVE TO KEEP AN EYE ON STRATUS POTENTIAL
TONIGHT...BUT FEELING MORE CONFIDENT THAT WE WILL NOT BE DEALING
WITH IT AT MSP TUESDAY MORNING.

/OUTLOOK FOR KMSP/

WED...VFR. WINDS S 10-15 KTS.
THU-FRI...CHC MRNG IFR CIGS. WINDS S 10-15 KTS.


&&

.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&

$$

SHORT TERM...MPG
LONG TERM...SPD
AVIATION...MPG


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