Area Forecast Discussion
Issued by NWS Twin Cities, MN

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000
FXUS63 KMPX 162348
AFDMPX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
648 PM CDT WED APR 16 2014

.UPDATE...FOR 00Z 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 00Z TAFS THROUGH 00Z THURSDAY EVENING)
ISSUED AT 648 PM CDT WED APR 16 2014

MODERATE TO HEAVY SNOW WILL PERSIST THIS EVENING ACROSS EAST
CENTRAL MN...EXPANDING INTO WEST CENTRAL MN...WITH PREVALENT LIFR
VSBYS AND IFR CIGS. A PERIOD OF RASN WILL STILL BE POSSIBLE AT
KMSP/KRNH/KEAU THIS EVE PRIOR TO THE ARRIVAL OF THE STEADIER SNOW.
SNOW WILL TAPER OFF IN MN BETWEEN 05Z AND 09Z...AND IN WEST
CENTRAL WI BETWEEN 09Z AND 12Z...BUT MVFR CIGS WILL LINGER
THURSDAY MORNING. IMPROVEMENT TO VFR CIGS WILL BE MOST NOTABLE
BETWEEN 18Z AND 21Z. GUSTY NORTHEAST WINDS BACK TO GUSTY
NORTH/NORTHWEST THIS EVE...THEN DECREASE BELOW 10KTS OVERNIGHT.

KMSP...
A BIT OF RASN TO START THE PERIOD...BUT SHOULD SEE A CHANGEOVER
TO SN BETWEEN 01Z AND 02Z WITH INCREASING RATES. 1/2SM VSBYS WILL
THEN BE POSSIBLE UNTIL 03Z...WITH -SN LINGERING UNTIL 06Z. BKN IFR
LEVEL DECK IS EXPECTED TO PREVAIL THIS EVE...WITH OVC MVFR DECK
THROUGH THURSDAY MORNING. SCATTERING TO VFR EXPECTED AROUND 18Z
THURSDAY. GUSTY NORTHEAST WINDS BACK TO NORTHWEST BY 06Z AND
REMAIN GUSTY...THEN DECREASE TO AOB 10KTS BY 12Z.

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


&&

.MPX WATCHES/WARNINGS/ADVISORIES...
MN...WINTER WEATHER ADVISORY UNTIL 10 PM CDT THIS EVENING FOR MNZ041-
     047-048-054>057-064-065-073.

     WINTER STORM WARNING UNTIL 1 AM CDT THURSDAY FOR MNZ042-043-
     049>051-058-059.

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

     WINTER WEATHER ADVISORY UNTIL 4 AM CDT THURSDAY FOR MNZ062-063.

     WINTER WEATHER ADVISORY UNTIL 1 AM CDT THURSDAY FOR MNZ066-068.

WI...WINTER STORM WARNING UNTIL 4 AM CDT THURSDAY FOR WIZ014.

     WINTER WEATHER ADVISORY UNTIL 4 AM CDT THURSDAY FOR WIZ023.

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

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

&&

$$


SHORT TERM...JPC
LONG TERM...CLF
AVIATION...LS






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