Area Forecast Discussion
Issued by NWS Twin Cities, MN

Home | Current Version | Previous Version | Graphics & Text | Print | Product List | Glossary Off
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

000
FXUS63 KMPX 170641
AFDMPX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
141 AM CDT THU APR 17 2014

.UPDATE...FOR 06Z AVIATION DISCUSSION BELOW

&&

.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 352 PM CDT WED APR 16 2014

SFC ANALYSIS PUTS THE SFC LOW OVER BLUE
EARTH/LE SUEUR/WASECA COUNTIES IN MN WITH A WMFNT SNAKING NEWD
BETWEEN KLVN/KSYN ON TO EAU CLAIRE/CLARK COUNTIES IN WI. THE CDFNT
THEN SNAKES WSWWD THRU KJYG AND BETWEEN KOTG/KMJQ IN SWRN MN. PRECIP
CONTINUES TO SURGE NEWD IN ADVANCE OF THE LOW PRES CNTR...WITH LGT
RAIN S OF THE TWIN CITIES METRO WHILE MOD-HVY SNOW CONTINUES TO FALL
OVER MUCH OF NRN AND WRN PORTIONS OF THE WFO MPX CWFA. SNOWFALL
RATES OF 1-2 IN/HR CAN BE EXPECTED IN N-CENTRAL PORTIONS OF THE AREA
THRU THE NEXT COUPLE OF HRS AS THE LOW PRES CENTER ROTATES TO THE
ENE. NOT LOOKING FOR THAT MUCH WARMER AIR TO THE S TO MAKE MUCH MORE
OF A NWD PUNCH THAN IT HAS ALREADY MADE. THEREFORE...ANY AREAS
CURRENTLY HAVING SNOW WILL STAY AS SNOW THRU THE DURATION OF THIS
EVENT. AN AREAS EXPERIENCING RAIN OR A RAIN/SNOW MIX WILL THEN
GRADUALLY CHANGE OVER TO SNOW. THERE ARE A COUPLE OF OTHER KEY
FEATURES EVIDENT ON SATELLITE IMAGERY AND IN RAP/NAM MODELS THAT
WILL PLAY IMPORTANT ROLES IN THE PRECIP DEPICTION THRU THE EARLY
EVENING. A DRY SLOT THAT SHOWED UP NICELY IN ERN SD EARLY TDA HAS
SHOWN SIGNS OF CLOSING...ESPECIALLY NOW THAT IT SHOWS UP IN SWRN MN
ON KMPX RADAR. IT STILL IS THERE...BUT NOT AS LARGE AS
EARLIER...INDICATING THAT THE LOWER LEVELS OF THE ATMOS CONTINUE TO
SATURATE. THIS MEANS CONTINUED PRECIP DURATION WITH LITTLE BREAKS
THRU LATE EVENING. IN ADDITION...RAP/NAM SHOW THE UPPER LVL TROF
NUDGING THE SFC LOW ACRS SRN MN HAS TRYING TO PIVOT AS IT SWINGS
THRU TO A MORE NEGATIVE POSITION. THIS WOULD ENHANCE LIFT WITH
COLDER AIR SURGING IN ON THE BACKSIDE OF THE SYSTEM...WHILE MOISTURE
STILL REMAINS FAIRLY DEEP. THIS COMBINATION WOULD THEN POTENTIALLY
CREATE ADDITIONAL BANDS OF HEAVY SNOW THAT WILL SLOWLY TRAVERSE W TO
E ACRS MUCH OF THE MPX CWFA DURG THE EVE HRS...AGAIN POTENTIALLY
CREATING 1-2 IN/HR BANDS THAT MUCH OF THE CWFA WOULD EXPERIENCE.
DIFFICULT TO TIME IT BUT HAVE MAINTAIN HIGH-END POPS FOR CENTRAL-ERN
PORTIONS OF THE CWFA SINCE THE OVERALL PRECIP SHIELD WILL BE SLOW TO
EXIT THE AREA. ONCE THE TROF MOVES THRU LATE THIS EVE...THEN THE
PRECIP WILL GRADUALLY END FROM W TO E ACRS THE AREA...WITH THE VAST
MAJORITY SEEING SNOW IN VARYING INTENSITIES BY THAT POINT. IN
FACT...DUE TO THE ACCENTUATED INTENSITY SEEN EARLIER...HAVE ADDED A
FEW COUNTIES INTO THE WARNING AND SLIGHTLY NUDGED UP SNOWFALL TOTALS
IN THE WSW SEGMENTS TO ACCOUNT FOR THESE HIGH-INTENSITY SNOW BANDS.
HAVE ALSO ADJUSTED THE END TIMES OF THE ADVY/WRNG TO COINCIDE WITH
THE LOWERING OF POPS ACRS THE CWFA. TEMPS OVERALL WILL SETTLE INTO
THE LWR 20S INTO THE LWR 30S LATE TNGT WHILE WET SNOW ACCUMS WILL
GENERALLY TOP OUT IN THE 6-10 INCH RANGE IN NRN PORTIONS OF THE
CWFA...LOCALLY UPWARDS OF A FOOT NOT IMPOSSIBLE.

.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 352 PM CDT WED APR 16 2014

WHILE MOST OF THE FORECASTER ENERGY WAS SPENT ON THE SHORT TERM
WITH THE SNOW STORM...THERE ARE A COUPLE ITEMS OF NOTE IN THE LONG
TERM FORECAST. THE MAIN PRECIP EVENT IN THE EXTENDED IS A RAIN
EVENT THAT LOOKS TO LARGELY OCCUR SATURDAY OR SATURDAY NIGHT -
PERHAPS EVEN A RUMBLE OF THUNDER. THAT BEING SAID NO REALLY
SIGNIFICANT WEATHER IS ANTICIPATED THROUGH THE PERIOD...BUT A
PROGRESSIVE AND ACTIVE PATTERN IS EXPECTED. BEHIND THE CURRENT
SYSTEM...A SURFACE HIGH BUILDS IN AND TEMPS BUT TEMPS ALOFT
EITHER REMAIN STEADY OR SLOWLY MODERATE. WE`RE STILL LOOKING AT
DEPARTURES FROM NORMAL TOMORROW CLOSE TO 20 DEGREES. MORE SUNSHINE
AND WARM ADVECTION WILL ALLOW TEMPS TO REBOUND INTO THE 40S AND
LOWER 50S ON FRIDAY.

NEXT CHANCE FOR PRECIP ARRIVES ON SATURDAY WHEN WEAK ISENTROPIC
LIFT MOVES INTO MINNESOTA. MN/WI WILL BE FIGHTING DRIER AIR IN THE
WAKE OF THE HIGH...SO...AND IT LOOKS AS IF MOST OF THE MODEL
GUIDANCE HAS REDUCED THE QPF SINCE YESTERDAY`S RUNS - AT LEAST IN
SOUTHERN MN WHERE THE FORCING ISN`T AS STRONG. THE MORE ROBUST
TROUGH REMAINS NORTH AND THE RESULTING FORCING IS BETTER ACROSS
NORTHERN AND PORTIONS OF CENTRAL MN. NONETHELESS...A WEAK SHORT
WAVE AND FRONTAL BOUNDARY DROP ACROSS THE FORECAST AREA SATURDAY
NIGHT AND WITH THE HELP OF CONDITIONAL SYMMETRIC INSTABILITY OR
WEAK UPRIGHT INSTABILITY...WE COULD GENERATE SOME LIGHT SHOWERS.
DRYING IS THEN EXPECTED INTO EARLY NEXT WEEK WITH UPPER LEVEL
RIDGE BUILDING INTO THE UPPER MISSISSIPPI RIVER VALLEY.
TEMPERATURES WILL BE MILD AND ABOVE NORMAL WITH INCREASING
WARM/THETA-E ADVECTION RETURNING POPS TUESDAY NIGHT INTO
WEDNESDAY. LOOK FOR A WARMING TREND DURING THIS PERIOD...WITH
HIGHS IN THE 60S ON SUNDAY AND AND EVEN IN INTO THE LOWER 70S BY
TUESDAY. CONTINUED THE TREND OF BUMPING HIGHS SLIGHTLY ABOVE
GUIDANCE DURING THIS PERIOD WITH ALL MODELS INDICATING VERY WARM
LOW AND MID LEVEL TEMPERATURES.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 116 AM CDT THU APR 17 2014

THE PRECIPITATION HAS COME TO AN END ACROSS MOST OF MINNESOTA
(EXCEPT THE FAR EAST, INCLUDING MSP) AND THE STRATUS DECK IS ON
THE MOVE. CLEAR SKIES HAVE ALREADY REACHED AXN HAD SUBSIDENCE AND
DRY AIR ADVECTION CONTINUES IN THAT AREA. THE SNOW/RAIN INTENSITY
WILL DIMINISH OVERNIGHT AND COME TO AN END ACROSS EASTERN
MN...THEN WESTERN WI. THE TRICKY ASPECT OF THIS FORECAST
PACKAGE...IS HOW QUICKLY WE SHED THE STRATUS DECK. HI-RES GUIDANCE
INDICATES LOW LEVEL MOISTURE TO REMAIN HIGH ACROSS EASTERN MN AND
WESTERN WI THROUGH MUCH OF TODAY. NOT VERY CONFIDENT IN THIS
SOLUTION THOUGH...AS THIS GUIDANCE IS OVERDONE WITH CURRENT CLOUD
COVER. THE CLEARING LINE TO THE NORTHWEST HAS SLOWED...BUT IS
STILL PUSHING SOUTHEAST...AND MAY REACH THE WEST METRO BEFORE
HALTING AND EVEN BACK-FILLING. CURRENTLY EXCEPTING MVFR TO LINGER
AT MOST SITES (EXCEPT AXN AND RWF) WINDS WILL GENERALLY BE NW
DURING THE PERIOD AS THE SURFACE LOW PUSHES OFF ACROSS WISCONSIN.

KMSP...SNOW WILL END PRIOR TO 08Z AT MSP. HI-RES GUIDANCE
INDICATING MVFR CEILINGS INTO THE AFTERNOON TODAY...BUT CONFIDENCE
IN THIS LACKS. WILL CLOSELY MONITOR THE PROGRESSION OF THE STRATUS
DECK...AS THIS ACTUALLY COULD GO VFR MUCH QUICKER THAN CURRENTLY
ADVERTISED IN THE TAF.

/OUTLOOK FOR KMSP/
FRI...MAINLY VFR. CHC MVFR FRI NIGHT WITH -RA. WINDS NE 5-10 KTS.
SAT...MAINLY VFR. CHC MVFR WITH -RA. WINDS ESE 10-15 KTS.
SUN...VFR. WINDS NNE 5-10 KTS.


&&

.MPX WATCHES/WARNINGS/ADVISORIES...
MN...WINTER WEATHER ADVISORY UNTIL 4 AM CDT EARLY THIS MORNING FOR
     MNZ062-063.

     WINTER STORM WARNING UNTIL 4 AM CDT EARLY THIS MORNING FOR
     MNZ044-045-052-053-060-061.

WI...WINTER WEATHER ADVISORY UNTIL 4 AM CDT EARLY THIS MORNING FOR
     WIZ023.

     WINTER STORM WARNING UNTIL 4 AM CDT EARLY THIS MORNING FOR
     WIZ014.

     WINTER WEATHER ADVISORY UNTIL 7 AM CDT THIS MORNING FOR WIZ025-
     027.

     WINTER STORM WARNING UNTIL 7 AM CDT THIS MORNING FOR WIZ015-016.

&&

$$

SHORT TERM...JPC
LONG TERM...CLF
AVIATION...SPD






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