Area Forecast Discussion
Issued by NWS Twin Cities, MN

Home | Current Version | Previous Version | Graphics & Text | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
000
FXUS63 KMPX 020931
AFDMPX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
431 AM CDT THU OCT 2 2014

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 339 AM CDT THU OCT 2 2014

LOOKING AT WIND OBS THE PAST COUPLE OF HOURS...IT LOOKS LIKE THE
COLD FRONT WHICH JUST BARELY MADE IT INTO WRN MN WEDNESDAY EVENING
HAS FINALLY STARTED TO MOVE. STARTING TO SEE MORE LIGHT NW WIND OBS
IN MN AND AT 330 AM...THE WIND SHIFT LOOKS TO BE PRETTY CLOSE TO
I-35. THE MOISTURE BOUNDARY THOUGH HAS NOT FOLLOWED THE WIND
SHIFT...AS IT WAS STILL BACK ALONG A RWF TO BRAINERD LINE AT 330 AM.
LIGHT WINDS AND A JUICED BOUNDARY LAYER THANKS TO RAINS WEDNESDAY
HAS ALLOWED FOR SOME RATHER UGLY CONDITIONS TO DEVELOP ALONG AND
EAST OF THE MOISTURE BOUNDARY. WITH WINDS REALLY NOT PICKING UP MUCH
TODAY...COMBINED WITH UPPER CLOUDS MOVING OVER THE TOP OF THE
STRATUS/FOG...NOT EXPECTING THE LOW STRATUS TO GO VERY FAR TODAY.
GIVEN THE MOSTLY CLOUDY SKIES AND THE EXPECTATION OF ANOTHER RAINY
AFTERNOON...CUT BACK ON HIGHS ACROSS MUCH OF THE AREA...KEEPING THEM
MAINLY IN THE LOWER 60S...THOUGH DEPENDING ON WHERE THE MAIN PRECIP
BAND SETS UP TODAY...THERE WILL LIKELY BE A STRIP ACROSS THE CENTER
OF THE CWA THAT REMAINS IN THE 50S.

AS ALLUDED TO ABOVE...THERE IS ANOTHER ROUND OF PRECIP ON ITS WAY.
CURRENTLY ITS DOWN ACROSS NE NEB AND SE SODAK. THE PRECIP THAT WILL
BE COMING THIS DIRECTION WILL BE ROOTED ON A STRONG BAND OF FGEN IN
THE H7-H6 LAYER. THE 02.00 GFS AND NAM AGREE ON THIS BAND...BUT
DIFFERED SIGNIFICANTLY ON WHERE IT WOULD GO. THE GFS HAS THE CENTER
OF THE BAND GOING UP A RWF/STC LINE...WHILE THE NAM WAS WE OVER
ALONG AND EVEN A LITTLE EAST OF AN AEL/EAU LINE...THOUGH THE 02.06
NAM DID SHIFT THE BAND WEST. WHEN LOOKING AT THE
RAP/HRRR/HOPWRF/NMM/ARW...THEY ALL AGREE NICELY WITH WHAT THE GFS
HAS...SO FAVORED THE POP/QPF FORECAST TODAY TOWARD A GFS/CAM BLEND.
OTHER CHANGE MADE TO THE FORECAST WAS TO REMOVE THE MENTION OF
THUNDER...AS ELEVATED INSTABILITY WILL BE REMAINING SOUTHEAST OF THE
MPX CWA.

TONIGHT...PRECIP WILL QUICKLY CLEAR OUT OF WRN WI BETWEEN 2Z AND 6Z.
BEHIND THIS PRECIP...WE WILL START TO SEE SOME STRONGER PRESSURE
RISES MOVE INTO WRN MN. THIS WILL START BRINGING IN SOME BETTER THAN
10 KT WINDS OUT INTO WRN MN LATE IN THE NIGHT. THE OTHER ADVANTAGE
TO THE INCREASING PRESSURE GRADIENT AND WINDS IS THAT THIS WILL
FINALLY HELP FLUSH THE LOW STRATUS OUT OF THE MPX AREA.

.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 339 AM CDT THU OCT 2 2014

THE FOCUS ON FRIDAY REMAINS ON THE STRONG NORTHWEST FLOW AND NEAR
WIND ADVISORY CONDITIONS IN WESTERN MN AS THE SURFACE LOW MOVES
EAST OF THE FORECAST AREA AND DEEPENS OVER THE GREAT LAKES. WE ARE
BECOMING A BIT MORE COMFORTABLE IN HOLDING OFF ON ISSUING A WIND
ADVISORY GIVEN THE SLIGHT DOWNWARD TREND IN THE FORECAST WINDS
SPEEDS AT THE TOP OF THE BOUNDARY LAYER. YESTERDAY`S NAM WAS
SHOWING MORE 44-49KTS NEAR THE TOP OF THE CHANNEL AND THIS
MORNING`S RUN...ALONG WITH THE GFS ARE GENERALLY 38-43KTS. WE WILL
STILL BE EFFICIENT IN BRING THESE WINDS TO THE GROUND DUE TO THE
GOOD MIXING.

THE SLOWER TREND WITH THIS INCOMING SYSTEM ALSO MEANS MOST OF
FRIDAY COULD BE PRECIP FREE AS WE END UP IN THE DRY SLOT...WITH
THE TRAILING WEAK TROUGH AND UPPER LOW NOT SWINGING THROUGH UNTIL
FRIDAY NIGHT. THE TIMING MIGHT ACTUALLY SUPPORT A FEW MORE SNOW
FLAKES MIXING IN LATE FRIDAY NIGHT AND EARLY SATURDAY MORNING AS
TEMPERATURE PROFILE COLLAPSE AND THE FREEZING LEVEL DROPS TO NEAR
1000FT WHILE THE LIGHT PRECIP IS STILL ONGOING IN THE EASTERN HALF
OF MN AND IN WESTERN WI. THE SURFACE TEMP AND GROUND TEMP ARE TOO
WARM FOR EVEN MINOR ACCUMULATIONS...BUT NONETHELESS WE`RE ABOUT A
COUPLE WEEKS AHEAD OF SCHEDULE FROM WHEN WE TYPICALLY SEE OUR
FIRST FLAKES. THE GFS/NAM/ECMWF/GEM ALL HAVE SNOW ACCUMULATIONS
ACROSS FAR NORTHERN MN...WITH THE POTENTIAL FOR DOUBLE DIGIT
/INCHES/ SNOWFALL IN SOUTHERN MANITOBA AND ONTARIO.

CYCLONICALLY CURVED FLOW AND COOL FALL AIR WILL REMAIN IN PLACE
THROUGH EARLY NEXT WEEK. IT SHOULD ALSO BE MAINLY DRY. THE ECMWF
IS STILL MORE AGGRESSIVE IN BRINGING BACK WARMER TEMPS BY THE
MIDDLE OF NEXT WEEK AS IT JETTISONS A CLOSED UPPER LOW IN THE
APPALACHIANS AND LIFTS THE MAIN LONGWAVE TROUGH NORTH OF THE CONUS
FASTER THAN THE GFS. THE PATTERN IS EVOLVING SLOWER AND TEMPS
EARLY NEXT WEEK SHOULD REMAIN COOLER THAN WHAT WAS FORECAST
YESTERDAY AND THE DAY BEFORE. IT`S GOING TO BE TOUGH TO SHAKE THE
40S AND 50S UNTIL AT LEAST TUESDAY...MAYBE WEDNESDAY DEPENDING ON
CLOUD COVER.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1254 AM CDT THU OCT 2 2014

TWO CONCERNS THE TAF PERIOD ARE THE DENSE FOG IN THE PROCESS OF
FORMING AND THE TIMING OF RAIN LATE THIS MORNING INTO THE
AFTERNOON. AT 6Z...THE FRONT IS ONLY TO ABOUT A RWF TO LONG
PRAIRIE LINE. EAST OF THE FRONT IT IS UGLY...WITH LIFR CIGS
QUICKLY BECOMING 1/4SM OR LESS FG. AXN WILL REMAIN WEST OF THE
FOG...AM HOPING THE FRONT WILL WORK THROUGH RWF ENOUGH TO KEEP
THEM OUT OF THE FOG...BUT WILL BE CLOSE. FOR STC/MSP/RNH/EAU...
CONFIDENCE IS HIGH THAT DENSE FOG WILL BE A SIGNIFICANT ISSUE
THROUGH 15Z. ONLY QUESTION REALLY IS WHEN DOES IT HAPPEN. HAVE IT
HAPPENING AT MSP THE LATEST. AREA OF RAIN CURRENTLY IN CENTRAL NEB
WILL BE HEADING THIS WAY THIS MORNING. STUCK CLOSE TO A
GFS/HRRR/RAP/HOPWRF BLEND FOR BRINGING RAIN ACROSS ALL MN
TERMINALS THIS MORNING AND WI TERMINALS THIS AFTERNOON. WINDS WILL
REMAIN FAIRLY LIGHT THROUGH TODAY...BUT THU EVENING...WE WILL
FINALLY START TO GET SOME PRESSURE RISES INTO WRN MN...MARKING THE
BEGINNING OF WHAT WILL BE A BREEZY THU NIGHT AND FRIDAY.

KMSP...HAVE HIGH CONFIDENCE IN DENSE FOG SIGNIFICANTLY IMPACTING
THE MORNING PUSH THIS MORNING AT MSP. GIVEN HOW WIDESPREAD THE
DENSE FOG IS AROUND THE CITIES AT 6Z...MSP WILL NOT BE ESCAPING
THE FOG. THE MAIN QUESTION IS HOW LOW TO GO WITH VSBYS...BUT
CURRENT TAF MAY NOT BE LOW ENOUGH. THERE IS A HIGH CHANCE THAT
VISIBILITIES THIS MORNING WILL DROP BELOW AIRPORT MINIMUMS...WITH
SIGNIFICANT IMPACTS TO AIRPORT ARRIVAL RATES LIKELY BETWEEN 10Z
AND 14Z. AFTER THAT...STUCK CLOSE TO WHAT THE PREVIOUS TAF HAD
FOR THE TIMING OF RAIN INTO THE FIELD...AND LOOKS LIKE WE WILL SEE
ANOTHER SEVERAL HOUR ROUND OF RAIN THIS AFTERNOON...MUCH LIKE WE
SAW YESTERDAY. BY THE END OF THE TAF...MSP WILL START FEELING THE
STRONGER WINDS...BUT THE MORE SIGNIFICANT NW WINDS AND GUSTS WILL
NOT NEED TO SHOW UP UNTIL THE LAST 6 HOURS OF THE 12Z TAF PACKAGE.

/OUTLOOK FOR KMSP/
FRI...MAINLY MVFR WITH CHC -SHRA. WINDS WNW 20G30 KTS.
SAT...VFR. WINDS NW 10-15 KTS.
SUN...VFR. WINDS NW 10 KTS.


&&

.MPX WATCHES/WARNINGS/ADVISORIES...
MN...DENSE FOG ADVISORY UNTIL 10 AM CDT THIS MORNING FOR MNZ042>045-
     049>053-057>063-065>070-074>078-082>085-091>093.

WI...DENSE FOG ADVISORY UNTIL 10 AM CDT THIS MORNING FOR WIZ014-015-
     023>026.

&&

$$

SHORT TERM...MPG
LONG TERM...CLF
AVIATION...MPG







USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.