Area Forecast Discussion
Issued by NWS Twin Cities, MN

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000
FXUS63 KMPX 191759
AFDMPX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
1259 PM CDT SAT APR 19 2014

.UPDATED FOR 18Z AVIATION DISCUSSION...
ISSUED AT 1250 PM CDT SAT APR 19 2014

&&

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 340 AM CDT SAT APR 19 2014

SHORT TERM CONCERNS ARE SHOWER/THUNDER THREAT TODAY INTO TONIGHT AND
STRONG WINDS OVER THE NORTHWEST CWA EARLY THIS MORNING.

LATEST RADAR SHOWING SOME WEAK RETURNS MOVING INTO THE NORTHWEST
CORNER OF THE CWA THIS MORNING.  MOVEMENT IS EAST NORTHEAST AROUND
50 KTS. THIS DOES EXTEND BACK TO THE SOUTHWEST INTO EASTER SOUTH
DAKOTA.  PRESSURE FALLS REMAIN OVER THE NORTHWEST CORNER OF THE
STATE...AND STRONG PRESSURE GRADIENT REMAINS STRONG OVER THE AREA.
THIS WILL WILL CONTINUE THE STRONG WINDS INTO THE AREA INTO THE
MORNING HOURS. WILL ALSO LIKELY SEE SOME GUSTY WINDS ASSOCIATED WITH
ANY HEAVIER SHOWERS INTO THE EARLY MORNING AS WELL...WITH STRONG LLJ
ARCING TO THE NORTHEAST OVER THE AREA AND STEEP MID LEVEL LAPSE
RATES. ISOLD THUNDER STILL POSSIBLE ALONG THE NORTHERN CWA AS THE
TROUGH APPROACHES. WE DO EXPECT THE WIND TO GRADUALLY DIMINISH AS
THE SURFACE LOW MOVES NORTHEAST AND WEAKENS FURTHER AND THE SURFACE
FRONT MOVES INTO WESTERN MN. THE BEST FORCING REMAINS OVER THE
NORTHERN PORTION OF THE STATE THROUGH THE MORNING.  INSTABILITY IS
MEAGER WITH THE SYSTEM.  BEST LI`S ARE FAIRLY MEAGER AND THE MID
LEVEL LAPSE RATES BEGIN TO DECREASE INTO THE AFTERNOON...AS THE MAIN
UPPER TROUGH LIFTS NORTHEAST OVER THE NORTHEAST CORNER OF MN.  STILL
WILL LIKELY HAVE ENOUGH CONVERGENCE ALONG THE FRONT TO GENERATE AT
LEAST SOME SCATTERED TYPE SHOWERS.  WILL RETAIN THE ISOLD THUNDER
MENTION AS WELL...ALONG THE FRONT INTO THE EVENING. AFTERNOON
TEMPERATURES ARE EXPECTED TO RANGE CLOSE TO 70 IN THE FAR SOUTH WITH
60S COMMON IN THE SNOW FREE AREAS.

THE FRONT SAGS SOUTHEAST OVER THE AREA OVERNIGHT AND STALL OVER FAR
SOUTHERN MN.  CLOUDS SHOULD LIMIT SIGNIFICANT COOLING TO THE
SOUTH...BUT CLEARING TO THE NORTHWEST WILL YIELD TEMPERATURES BACK
INTO THE 30S OVERNIGHT.

.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 340 AM CDT SAT APR 19 2014

THE FRONT WILL REMAIN NEARLY STATIONARY ACROSS SOUTHERN MINNESOTA
SUNDAY. THIS WILL KEEP THE SHOWER/STORM CHANCES GOING ACROSS FAR
SRN MN AND PORTIONS OF WRN WI...BUT THERE ARE SOME UNCERTAINTIES
REGARDING HOW FAR NORTH THIS ACTIVITY WILL DEVELOP. NAM/GFS ARE
MUCH DRIER AND FURTHER SOUTH WHILE THE GEM AND ECMWF ARE FURTHER
NORTH AND SEEM TO PHASE A BIT WITH THE FEATURE APPROACHING FROM
THE PLAINS. DID NOT MODIFY POPS A WHOLE LOT FROM THE PREVIOUS
FORECAST TO MAINTAIN SOME CONTINUITY...BUT POPS MAY NEED TO BE
EXPANDED A BIT IF THE NAM/GFS TREND TOWARD THE GEM/ECMWF.

MEANWHILE...DRIER AIR WILL ENCOMPASS AREAS WELL NORTH OF THE
FRONT. DEW POINTS MAY END UP BEING A BIT DRIER THAN CURRENTLY
FORECAST...BUT LIGHT WINDS THROUGHOUT THE BOUNDARY LAYER MAY NOT
COMPLETELY MIX OUT THE MOISTURE AT THE SURFACE AS FORECAST
SOUNDINGS INDICATE. ABUNDANT SUNSHINE SHOULD ALLOW FOR STEEP LOW
LEVEL LAPSE RATES...EASILY TAPPING INTO THE WARM AIR ALOFT AND
MAKING FOR A RATHER MILD DAY WITH HIGHS IN THE UPPER 60S TO LOWER
70S.

WEAK LOW PRESSURE WILL TRACK FROM NORTH DAKOTA ACROSS NRN MN AND
THE NORTHERN GREAT LAKES MONDAY. THERMAL RIDGING WILL BE TAMPED
DOWN LATE WITH THE FRONT AND THE SURFACE HIGH PRESSURE BUILDING
SOUTH INTO THE PLAINS. SHOULD STILL BE ENOUGH TIME AND AVAILABLE
SUNSHINE TO BRING HIGHS BACK INTO THE 60S.

THE SURFACE HIGH PUSHING ACROSS MN WILL BECOME ELONGATED...
STRETCHING FROM THE MISSISSIPPI AND OHIO VALLEYS NORTHWEST INTO
NORTHERN CANADA NEXT WEEK. AS LOW PRESSURE BECOMES ORGANIZED OVER
THE HIGH PLAINS AND NORTHERN ROCKIES IN RESPONSE TO A DEEPENING
TROUGH DOWN THE WEST COAST...A COOL EAST/SOUTHEASTERLY BOUNDARY
LAYER FLOW WILL STRENGTHEN ACROSS THE MIDWEST. ROBUST WARM SECTOR
ACROSS THE PLAINS AND STRONG SOUTHWEST MID LEVEL WINDS WILL SPREAD
THE EML NORTHEASTWARD INTO MN/WI MIDWEEK. LOW LEVEL WAA/MOISTURE
ADVECTION ON A POTENT LOW LEVEL JET AND DECENT ISENTROPIC UPGLIDE
WILL BE SUFFICIENT TO GENERATE A BAND OF SHOWERS AND THUNDERSTORMS
NORTH OF THE WARM FRONT LATE WEDNESDAY AND WEDNESDAY NIGHT.

THE EVOLUTION OF THE SYSTEM IS LESS CERTAIN THURSDAY AND FRIDAY.
THE ECMWF BECOMES NEGATIVELY TILTED AND EVENTUALLY OCCLUDES THE
SYSTEM OVER THE CWA WITH WIDESPREAD SHOWERS CONTINUING FOR THE
REMAINDER OF THE WEEK. THE GEM IS FURTHER NORTH AND NEUTRALLY
TILTED WITH THE WARM SECTOR PUSHING NORTH INTO MN. THE GFS IS EVEN
FURTHER NORTH...BUT IS QUITE FAST WITH THE COLD FRONT AND DRY
SLOTS THE CWA THURSDAY WITH BACKSIDE SHOWERS REACHING THE AREA
FRIDAY. GIVEN ALL OF THIS...MAINTAINED CHC POPS FOR LATE IN THE
WEEK BUT MOST SIGNS POINT TO AN UNSETTLED PERIOD.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1250 PM CDT SAT APR 19 2014

VFR CONDITIONS EXPECTED. A LINE OF SHOWERS WAS DEVELOPING ALONG A
BOUNDARY THAT AS OF 1PM WAS LOCATED ALONG A LINE FROM ST CLOUD TO
ASHLAND WI. HERE THE ELEVATED INSTABILITY LINED UP WITH THE DEEP
MOISTURE CONVERGENCE. SOUTHERLY WINDS AHEAD OF THIS LINE WERE
GUSTING 20 TO 30KTS...WITH LIGHT WESTERLY WINDS BEHIND THE LINE.
OVER THE NEXT 24HRS THIS BOUNDARY WILL SAG SOUTHEAST...AND SO TO
WILL THE CHANCE FOR PRECIP.

KMSP...CURRENTLY THE BEST CHANCE FOR PRECIP WILL BE JUST NORTH OF
KMSP...BUT COULD SEE A FEW SHOWERS THIS EVENING. WINDS WILL
DECREASE AS THE FRONT APPROACHES...AND REMAIN LIGHT THROUGH THE
DAY TOMORROW.

/OUTLOOK FOR KMSP/
MON...VFR. WINDS NW 10-15 KTS.
TUE...VFR. WINDS N 5 TO 10 KTS.
WED...VFR WITH MVFR/-RA POSSIBLE. WINDS SSE AT 15G25KTS.

&&

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

$$

SHORT TERM...DWE
LONG TERM...BORGHOFF
AVIATION...JRB






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