000
FXUS63 KMPX 211756
AFDMPX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
1256 PM CDT TUE MAY 21 2013
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 1235 PM CDT TUE MAY 21 2013
LATEST WATER VAPOR IMAGERY SHOWS OUR BOTTLED UP AND STAGNANT UPPER
AIR PATTERN STILL IN PLACE... WITH THE CUTOFF LOW LINGERING IN OUR
AREA AND ANOTHER CUTOFF OFF THE NORTHWEST COAST. THINGS ARE
STARTING TO SLOWLY MOVE EASTWARD WITH THE PATTERN DE-AMPLIFYING
SOME OVER THE UPCOMING 24 HOURS OR SO. SHRA CURRENTLY ACROSS THE
AREA IS TAKING ADVANTAGE OF WHAT MEAGER INSTABILITY THERE IS ALONG
WITH LOW LEVEL FORCING ARISING FROM THE STATIONARY FRONT LACED
ACROSS THE CENTER OF THE FORECAST AREA. MORE WIDESPREAD LIGHT PCPN
CAN BE FOUND IN THE MID-LEVEL DEFORMATION AND ASSOCIATED AREA OF
FRONTOGENESIS OVER THE NORTH CENTRAL AND NORTHWEST CWFA. WITH
THINGS SLOWLY SHIFTING EAST THROUGH WEDNESDAY... THE GENERAL LOOK
OF ACTIVITY CURRENTLY OVER THE AREA WILL SHIFT ALONG WITH THE
OVERALL LARGE SCALE PATTERN... MEANING SHOWERS WILL PERSIST
THROUGH THE PERIOD... WITH SOME DIURNAL ENHANCEMENT IN THE PSEUDO-
WARM SECTOR AGAIN ON WEDNESDAY... ALTHOUGH IT WILL BE PRETTY MUCH
EAST OF US AT THAT TIME. PCPN NORTH/WEST OF THE SURFACE AND UPPER
LOW WILL REMAIN FAIRLY CONSISTENT OVER TIME... ALONG WITH THE
OVERCAST SKIES. DON/T EXPECT THINGS TO DRY OUT OR CLOUDS TO EXIT
UNTIL WE MOVE BEYOND TOMORROW/S DAYTIME HOURS.
&&
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 328 AM CDT TUE MAY 21 2013
CLOUDY...COOL...AND SCATTERED TO NUMEROUS LIGHT RAIN SHOWERS OR
SPRINKLES ARE ON TAP WEDNESDAY WITH THE LOW STILL TAKING ITS TIME
TO MOVE ACROSS THE FORECAST AREA. REALLY THINK BY TUESDAY NIGHT
THE INSTABILITY WILL BE SHOVED FAR ENOUGH TO THE WEST THAT WE
SHOULD JUST BE DEALING WITH THE LIGHT SHOWERS AND NO THUNDER. WE
ARE DRY BY EARLY THURSDAY MORNING...BUT CLOUDS SHOULD BE SLOWER TO
CLEAR. NO MAJOR FORECAST CHANGES IN THE THURSDAY-FRIDAY TIME
FRAME. WENT JUST A BIT COOLER WITH TEMPERATURES DURING THIS TIME.
THE GUIDANCE TRENDED THAT WAY...BUT SIMPLY THINK IT IS MORE TO DO
WITH SLIGHT CHANGES IN THE TIMING OF SHOWERS DURING THE DAY ON
WEDNESDAY AND CLEARING OF CLOUDS LATE THURSDAY NIGHT. THIS SHOULD
SET THE STAGE FOR A VERY COOL FRIDAY MORNING. UPPER 30S ARE
CERTAINLY WITHIN REASON ACROSS CENTRAL MN AND WEST CENTRAL WI WITH
THE CLOUDS MOVING OUT AND THAT HIGH MOVING IN.
MEDIUM TO LONG RANGE GUIDANCE CONTINUES TO FORECAST TROUGHS ALONG
BOTH WEST/EAST COASTS AND A RIDGE OVER THE CENTRAL STATES AND A
CLOSED ANTICYCLONE THROUGH THE WEEKEND INTO EARLY NEXT
WEEK. SOUTHERLY FLOW AHEAD OF THE TROUGH AND SFC LOW/WARM FRONT
DEVELOPMENT SHOULD FOCUS PRECIP OVER THE CENTRAL PLAINS LATE IN
THE WEEKEND AND INTO THE NORTHERN PLAINS/MID-UPPER MS VALLEY/GREAT
LAKES EARLY NEXT WEEK WHERE CONVECTION IS LIKELY AS INDICATED IN
THE GEFS/ECMWF ENSEMBLE MEMBERS AND GFS RUNS. THERE ARE A LOT OF
POPS IN THE EXTENDED...BUT IT IS DIFFICULT TO REMOVE THEM...EVEN
GIVEN WE HAVE FAIRLY LOW CONFIDENCE IN THE TIMING AND PLACEMENT
OF THE SHOWERS AND THUNDERSTORMS LATE THIS WEEKEND AND EARLY NEXT
WEEK. HERE`S WHY ITS DIFFICULT TO REMOVE POPS. CLIMATOLOGY IS
RIGHT AROUND 25% FOR A 24 POP FORECAST THIS TIME OF YEAR. THE
21.00Z GFS HAS A LONGWAVE TROUGH APPROACHING FROM THE WEST AND
SOUTHWEST FLOW HERE AND THE 21.00Z ECMWF IS LESS AMPLIFIED AND
EVEN QUASI ZONAL. BOTH OF THESE PATTERNS WOULD BE FAIRLY ACTIVE
AND WOULD CERTAINLY WARRANT KEEPING POPS AT LEAST AT THE
MUTED/AVERAGED VALUES OF CLIMATOLOGY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1235 PM CDT TUE MAY 21 2013
SLOWLY MOVING SURFACE AND UPPER LEVEL LOWS WILL DRIFT EAST THROUGH
THE FORECAST PERIOD... MEANING A CONTINUATION OF THE CONDITIONS
WE/VE SEEN FOR THE PAST FEW DAYS. SCATTERED SHRA CAN BE EXPECTED
OVER MUCH OF THE AREA THIS AFTERNOON INTO THIS EVENING... WITH A
DIURNAL WANING TREND LATER IN THE EVENING. HOWEVER... WITH THE LOW
SLIDING EAST WE WILL FIND MORE OF THE FORECAST AREA UNDER THE
INFLUENCE OF DEEPER MOISTURE AND PERSISTENT/WEAK FORCING LATER
TONIGHT INTO WEDNESDAY. GENERALLY OVERCAST CONDITIONS WITH MVFR
CEILINGS WILL PREVAIL... WITH A RETURN TO IFR CEILINGS AND SOME
LIFR TONIGHT. VISIBILITIES LOOK TO MAINLY BE VFR... ALTHOUGH MORE
WIDESPREAD MVFR WILL OCCUR LATER TONIGHT INTO WEDNESDAY MORNING AS
CEILINGS LOWER AND SOME PERSISTENT LIGHT RAIN OR DRIZZLE OCCURS
ACROSS MUCH OF THE AREA. WINDS WILL BE PROBLEMATIC FOR LOCATIONS
NEAR THE STATIONARY FRONT... INCLUDING KMSP... WITH SHIFTS OF
AROUND 180 DEGREES IN DIRECTION EITHER SIDE OF THE BOUNDARY...
WHICH WILL DRIFT A BIT NORTH AND SOUTH THROUGH EARLY EVENING.
WINDS WILL SHIFT AND BECOME PREDOMINANTLY NORTH/NORTHEAST LATER
THIS EVENING AS THE SURFACE LOW SHIFTS TO THE EAST.
KMSP...HAVE DECENT CONFIDENCE IN THE OVERALL TRENDS IN THE TAF...
BUT LOWER CONFIDENCE IN SOME OF THE DETAILS. CEILINGS COULD WIND
UP LOWER THAN FORECAST FROM LATE EVENING THROUGH THE OVERNIGHT
HOURS WHEN THE BOUNDARY FINALLY GETS PERMANENTLY SOUTH OF THE
AREA. WIND DIRECTION IS TRICKY THIS AFTERNOON INTO EARLY EVENING
WITH THE FRONT ESSENTIALLY STALLED OVER THE AREA. WENT CLOSE TO
SOME OF THE HIGH RESOLUTION MODEL GUIDANCE WHICH SUGGESTS THE
CURRENT NORTH WINDS WILL SHIFT BACK TO THE SOUTHWEST/WEST FOR A
TIME THIS AFTERNOON BEFORE EVENTUALLY SWINGING BACK TO THE NORTH
FOR GOOD THIS EVENING. VISIBILITIES COULD CERTAINLY BE LOWER FOR
BRIEF PERIODS OF TIME THIS AFTERNOON AND EVENING WITH SHRA... AND
THERE IS SOME POTENTIAL FOR LONGER DURATION MVFR VISIBILITIES
OVERNIGHT INTO WEDNESDAY AS LOWER CEILINGS RETURN.
/OUTLOOK FOR KMSP/
WEDNESDAY NIGHT...MVFR CEILINGS POSSIBLE EARLY... OTHERWISE VFR
CONDITIONS EXPECTED. NORTHEAST WIND 10 TO 15 KT.
THURSDAY...VFR CONDITIONS EXPECTED. NORTHEAST WIND 5 TO 15 KT.
THURSDAY NIGHT...VFR CONDITIONS EXPECTED. EAST WIND LESS THAN 10
KT BECOMING SOUTHEAST.
FRIDAY AND FRIDAY NIGHT...VFR CONDITIONS EXPECTED. SOUTHEAST WIND 5 TO
15 KT.
SATURDAY...MVFR CEILINGS AND VISIBILITIES POSSIBLE WITH A CHANCE
OF SHOWERS AND THUNDERSTORMS. SOUTHEAST WIND 10 TO 20 KT.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
SHORT TERM...
LONG TERM...CLF
AVIATION...
000
FXUS63 KMPX 211239
AFDMPX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
739 AM CDT TUE MAY 21 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 328 AM CDT TUE MAY 21 2013
THE CENTER OF THE SURFACE LOW RESPONSIBLE FOR ALL OF THE SENSIBLE
WEATHER THE PAST FEW DAYS CONTINUES TO SIT AND SPIN /NEARLY
STATIONARY/ ACROSS EASTERN SD. ALTHOUGH THERE HAS BEEN NO
SIGNIFICANT MOVEMENT WITH THE UPPER TROUGH OVER THE LAST 12
HOURS...THE SMALL 500 M HEIGHT FALLS YESTERDAY ACTUALLY HELPED
DEEPEN THE SURFACE LOW BY 2-3 MB AND PERHAPS EVEN TIGHTEN UP THE
CIRCULATION AND CORRESPONDING FRONTAL BOUNDARIES ACROSS THE AREA.
THE ATTENDANT COLD FRONT STRETCHING SOUTH ACROSS THE CENTRAL AND
SOUTHERN PLAINS WAS RESPONSIBLE FOR FOCUSING THE VIOLENT WEATHER
IN THE STATES TO OUR SOUTH. BUT EVEN THIS MORNING THE STATIONARY
BOUNDARY STRETCHED OUT FROM WEST TO EAST FROM THE SURFACE LOW
ACROSS CENTRAL MN AND NORTHERN WI IS THE FOCUS FOR WIDESPREAD
SHOWERS AND WEAK THUNDERSTORMS IN THESE SAME AREAS. THERE IS NICE
MID LEVEL DRYING STRETCHING FROM THE MN/WI BORDER ALL THE WAY
SOUTH INTO KS AND OK. THIS DRYING WILL LIKELY KEEP MUCH OF
SOUTHERN MN AND PORTIONS OF WEST CENTRAL WI DRY AT LEAST DURING
THE MORNING. CLOSER TO THE MID LEVEL CIRCULATION IN CENTRAL MN
/ESPECIALLY WEST CENTRAL/ THERE SHOULD BE LIGHT STRATIFORM TYPE
PRECIP LATE THIS MORNING AND AFTERNOON WHERE FRONTOGENETICAL
FORCING WILL BE STRONGER. HOWEVER...PROBABLY NOT A WISE MOVE TO
COMPLETELY REMOVE POPS IN THE WARM QUADRANT OF THE SYSTEM ACROSS
SOUTHERN MN...BECAUSE THERE SHOULD BE ENOUGH AFTERNOON INSTABILITY
GIVEN DECENT BL MOISTURE TO POP SOME CU AND AFTERNOON SHOWERS.
THERE IS STILL A DECENT THUNDER CHANCE WITH ANY OF THE SHOWERS IN
EASTERN AND WEST CENTRAL WI TODAY. AVAILABLE SHORT-RANGE WRF
GUIDANCE INCLUDING THE HOP-WRF /AT HOPWRF.INFO/ SUPPORT THIS.
OVERALL...THE LOW FILLS AND DRIFTS SOUTHEAST WITH TIME TONIGHT.
THERE IS STILL ENOUGH LIFT TO WARRANT POP MENTION EVEN WITH THE
WEAKENING TREND...BUT DO NOT EXPECT HEAVY PRECIP. JUST PULL UP A
RADAR MOSAIC AND LOOK AT THE RADARS TO OUR NORTH
/KABR/KFGF/KDLH...THOSE SHOWERS WILL CONTINUE TO ROTATE
CYCLONICALLY AROUND THE LOW AND WHEN THE LOW MOVES OFF TO THE
SOUTHEAST...THOSE SHOWERS WILL COME ALONG WITH IT.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 328 AM CDT TUE MAY 21 2013
CLOUDY...COOL...AND SCATTERED TO NUMEROUS LIGHT RAIN SHOWERS OR
SPRINKLES ARE ON TAP WEDNESDAY WITH THE LOW STILL TAKING ITS TIME
TO MOVE ACROSS THE FORECAST AREA. REALLY THINK BY TUESDAY NIGHT
THE INSTABILITY WILL BE SHOVED FAR ENOUGH TO THE WEST THAT WE
SHOULD JUST BE DEALING WITH THE LIGHT SHOWERS AND NO THUNDER. WE
ARE DRY BY EARLY THURSDAY MORNING...BUT CLOUDS SHOULD BE SLOWER TO
CLEAR. NO MAJOR FORECAST CHANGES IN THE THURSDAY-FRIDAY TIME
FRAME. WENT JUST A BIT COOLER WITH TEMPERATURES DURING THIS TIME.
THE GUIDANCE TRENDED THAT WAY...BUT SIMPLY THINK IT IS MORE TO DO
WITH SLIGHT CHANGES IN THE TIMING OF SHOWERS DURING THE DAY ON
WEDNESDAY AND CLEARING OF CLOUDS LATE THURSDAY NIGHT. THIS SHOULD
SET THE STAGE FOR A VERY COOL FRIDAY MORNING. UPPER 30S ARE
CERTAINLY WITHIN REASON ACROSS CENTRAL MN AND WEST CENTRAL WI WITH
THE CLOUDS MOVING OUT AND THAT HIGH MOVING IN.
MEDIUM TO LONG RANGE GUIDANCE CONTINUES TO FORECAST TROUGHS ALONG
BOTH WEST/EAST COASTS AND A RIDGE OVER THE CENTRAL STATES AND A
CLOSED ANTICYCLONE THROUGH THE WEEKEND INTO EARLY NEXT
WEEK. SOUTHERLY FLOW AHEAD OF THE TROUGH AND SFC LOW/WARM FRONT
DEVELOPMENT SHOULD FOCUS PRECIP OVER THE CENTRAL PLAINS LATE IN
THE WEEKEND AND INTO THE NORTHERN PLAINS/MID-UPPER MS VALLEY/GREAT
LAKES EARLY NEXT WEEK WHERE CONVECTION IS LIKELY AS INDICATED IN
THE GEFS/ECMWF ENSEMBLE MEMBERS AND GFS RUNS. THERE ARE A LOT OF
POPS IN THE EXTENDED...BUT IT IS DIFFICULT TO REMOVE THEM...EVEN
GIVEN WE HAVE FAIRLY LOW CONFIDENCE IN THE TIMING AND PLACEMENT
OF THE SHOWERS AND THUNDERSTORMS LATE THIS WEEKEND AND EARLY NEXT
WEEK. HERE`S WHY ITS DIFFICULT TO REMOVE POPS. CLIMATOLOGY IS
RIGHT AROUND 25% FOR A 24 POP FORECAST THIS TIME OF YEAR. THE
21.00Z GFS HAS A LONGWAVE TROUGH APPROACHING FROM THE WEST AND
SOUTHWEST FLOW HERE AND THE 21.00Z ECMWF IS LESS AMPLIFIED AND
EVEN QUASI ZONAL. BOTH OF THESE PATTERNS WOULD BE FAIRLY ACTIVE
AND WOULD CERTAINLY WARRANT KEEPING POPS AT LEAST AT THE
MUTED/AVERAGED VALUES OF CLIMATOLOGY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 655 AM CDT TUE MAY 21 2013
SEVERAL COMPLICATIONS WITH THIS TAF SET DUE TO A WOBBLING WMFNT
OVER CENTRAL MN INTO WRN WI...INCLUDING OVER NEARLY ALL TAF SITES.
THIS WILL MAKE FOR VARYING WIND DIRECTIONS...CLOUD HEIGHTS AND
TIMING FOR PRECIPITATION. AS THE FNT LIFTS N...MAINLY N THRU
KRWF-KMSP-KRNH-EAU...WINDS WILL SHIFT FROM E TO SW OVER THE NEXT
FEW HOURS...ESPECIALLY AS THE CDFNT LINGERS OVER WRN MN. N OF THE
WMFNT...KAXN-KSTC WILL LIKELY REMAIN NE THRU THE DAY. HAVE ALREADY
SEEN MOST SITES REPORTING LOW-END MVFR TO IFR. ALTHOUGH THERE WILL
GENERALLY BE A LIFTING OF THE CEILINGS TDA...CIGS WILL MAINLY
REMAIN WITHIN MVFR TO LOW-END VFR. SCALED BACK THE PRECIP DUE TO
LOWER CONFIDENCE ON COVERAGE AND THE MORE SHOWERY NATURE OF PRECIP
RATHER THAN A SOLID RAIN SHIELD. THAT SAID...THERE STILL MAY BE
SOME ISOLD POCKETS OF MOD-HVY RAIN THAT COULD IMPACT VSBY
INCLUDING TSTMS. PRECIP CHCS REMAIN GENERALLY 30-60 PERCENT THRU
THE DAY...LOWERING THIS EVENING INTO TNGT THEN LOW STRATUS LIKELY
TO DEVELOP OVERNIGHT.
KMSP...ASIDE FROM PATCHY SHWRS THIS MRNG WHICH ARE NOT XPCTD TO
DEGRADE VSBY...WILL KEEP MSP DRY THRU THE NEXT 30 HRS. STILL MAY
SEE SOME PASSING SHWRS DURING THIS TIME BUT NOTHING THAT SHOULD
DROP VSBY BELOW 6SM. WILL LOOK FOR CEILINGS TO RISE ABOVE 3 KFT
MIDDAY TDA BEFORE DROPPING BACK DOWN THIS EVENING THRU TNGT. GOOD
CHC THAT CIGS WILL DROP BELOW THE 1700 FT THRESHOLD OVERNIGHT TNGT
AND REMAIN THERE THRU THE WED MRNG PUSH AS THE LARGE UPPER LEVEL
LOW OVER WRN MN SHIFTS INTO WI. WINDS WILL BE TRICKY WITH THE
WOBBLING FRONT OVERHEAD FOLLOWED BY THE UPPER LEVEL LOW. WINDS ARE
EXPECTED TO SHIFT FROM E TO SW BY AROUND NOON...BUT THE TIMING IS
PROBLEMATIC TO PIN DOWN AND SPEEDS ARE EXPECTED TO REMAIN AOB 7 KT
SO HAVE USED VRB05 THRU THE MRNG TO GET TO THE EARLY AFTN WIND
SHIFT. WINDS DROP TO VRB AGAIN TNGT BEFORE PICKING UP TO NLY BY
DAYBREAK TMRW.
/OUTLOOK FOR KMSP/
WED...VFR/MVFR CIGS WITH -SHRA LIKELY. WINDS NE AT 5G10KTS.
THU...VFR. WINDS NNE AT 10-15KTS.
FRI...VFR. WINDS SE AT 5-15KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
SHORT TERM...CLF
LONG TERM...CLF
AVIATION...JPC
000
FXUS63 KMPX 210930
AFDMPX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
430 AM CDT TUE MAY 21 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 328 AM CDT TUE MAY 21 2013
THE CENTER OF THE SURFACE LOW RESPONSIBLE FOR ALL OF THE SENSIBLE
WEATHER THE PAST FEW DAYS CONTINUES TO SIT AND SPIN /NEARLY
STATIONARY/ ACROSS EASTERN SD. ALTHOUGH THERE HAS BEEN NO
SIGNIFICANT MOVEMENT WITH THE UPPER TROUGH OVER THE LAST 12
HOURS...THE SMALL 500 M HEIGHT FALLS YESTERDAY ACTUALLY HELPED
DEEPEN THE SURFACE LOW BY 2-3 MB AND PERHAPS EVEN TIGHTEN UP THE
CIRCULATION AND CORRESPONDING FRONTAL BOUNDARIES ACROSS THE AREA.
THE ATTENDANT COLD FRONT STRETCHING SOUTH ACROSS THE CENTRAL AND
SOUTHERN PLAINS WAS RESPONSIBLE FOR FOCUSING THE VIOLENT WEATHER
IN THE STATES TO OUR SOUTH. BUT EVEN THIS MORNING THE STATIONARY
BOUNDARY STRETCHED OUT FROM WEST TO EAST FROM THE SURFACE LOW
ACROSS CENTRAL MN AND NORTHERN WI IS THE FOCUS FOR WIDESPREAD
SHOWERS AND WEAK THUNDERSTORMS IN THESE SAME AREAS. THERE IS NICE
MID LEVEL DRYING STRETCHING FROM THE MN/WI BORDER ALL THE WAY
SOUTH INTO KS AND OK. THIS DRYING WILL LIKELY KEEP MUCH OF
SOUTHERN MN AND PORTIONS OF WEST CENTRAL WI DRY AT LEAST DURING
THE MORNING. CLOSER TO THE MID LEVEL CIRCULATION IN CENTRAL MN
/ESPECIALLY WEST CENTRAL/ THERE SHOULD BE LIGHT STRATIFORM TYPE
PRECIP LATE THIS MORNING AND AFTERNOON WHERE FRONTOGENETICAL
FORCING WILL BE STRONGER. HOWEVER...PROBABLY NOT A WISE MOVE TO
COMPLETELY REMOVE POPS IN THE WARM QUADRANT OF THE SYSTEM ACROSS
SOUTHERN MN...BECAUSE THERE SHOULD BE ENOUGH AFTERNOON INSTABILITY
GIVEN DECENT BL MOISTURE TO POP SOME CU AND AFTERNOON SHOWERS.
THERE IS STILL A DECENT THUNDER CHANCE WITH ANY OF THE SHOWERS IN
EASTERN AND WEST CENTRAL WI TODAY. AVAILABLE SHORT-RANGE WRF
GUIDANCE INCLUDING THE HOP-WRF /AT HOPWRF.INFO/ SUPPORT THIS.
OVERALL...THE LOW FILLS AND DRIFTS SOUTHEAST WITH TIME TONIGHT.
THERE IS STILL ENOUGH LIFT TO WARRANT POP MENTION EVEN WITH THE
WEAKENING TREND...BUT DO NOT EXPECT HEAVY PRECIP. JUST PULL UP A
RADAR MOSAIC AND LOOK AT THE RADARS TO OUR NORTH
/KABR/KFGF/KDLH...THOSE SHOWERS WILL CONTINUE TO ROTATE
CYCLONICALLY AROUND THE LOW AND WHEN THE LOW MOVES OFF TO THE
SOUTHEAST...THOSE SHOWERS WILL COME ALONG WITH IT.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 328 AM CDT TUE MAY 21 2013
CLOUDY...COOL...AND SCATTERED TO NUMEROUS LIGHT RAIN SHOWERS OR
SPRINKLES ARE ON TAP WEDNESDAY WITH THE LOW STILL TAKING ITS TIME
TO MOVE ACROSS THE FORECAST AREA. REALLY THINK BY TUESDAY NIGHT
THE INSTABILITY WILL BE SHOVED FAR ENOUGH TO THE WEST THAT WE
SHOULD JUST BE DEALING WITH THE LIGHT SHOWERS AND NO THUNDER. WE
ARE DRY BY EARLY THURSDAY MORNING...BUT CLOUDS SHOULD BE SLOWER TO
CLEAR. NO MAJOR FORECAST CHANGES IN THE THURSDAY-FRIDAY TIME
FRAME. WENT JUST A BIT COOLER WITH TEMPERATURES DURING THIS TIME.
THE GUIDANCE TRENDED THAT WAY...BUT SIMPLY THINK IT IS MORE TO DO
WITH SLIGHT CHANGES IN THE TIMING OF SHOWERS DURING THE DAY ON
WEDNESDAY AND CLEARING OF CLOUDS LATE THURSDAY NIGHT. THIS SHOULD
SET THE STAGE FOR A VERY COOL FRIDAY MORNING. UPPER 30S ARE
CERTAINLY WITHIN REASON ACROSS CENTRAL MN AND WEST CENTRAL WI WITH
THE CLOUDS MOVING OUT AND THAT HIGH MOVING IN.
MEDIUM TO LONG RANGE GUIDANCE CONTINUES TO FORECAST TROUGHS ALONG
BOTH WEST/EAST COASTS AND A RIDGE OVER THE CENTRAL STATES AND A
CLOSED ANTICYCLONE THROUGH THE WEEKEND INTO EARLY NEXT
WEEK. SOUTHERLY FLOW AHEAD OF THE TROUGH AND SFC LOW/WARM FRONT
DEVELOPMENT SHOULD FOCUS PRECIP OVER THE CENTRAL PLAINS LATE IN
THE WEEKEND AND INTO THE NORTHERN PLAINS/MID-UPPER MS VALLEY/GREAT
LAKES EARLY NEXT WEEK WHERE CONVECTION IS LIKELY AS INDICATED IN
THE GEFS/ECMWF ENSEMBLE MEMBERS AND GFS RUNS. THERE ARE A LOT OF
POPS IN THE EXTENDED...BUT IT IS DIFFICULT TO REMOVE THEM...EVEN
GIVEN WE HAVE FAIRLY LOW CONFIDENCE IN THE TIMING AND PLACEMENT
OF THE SHOWERS AND THUNDERSTORMS LATE THIS WEEKEND AND EARLY NEXT
WEEK. HERE`S WHY ITS DIFFICULT TO REMOVE POPS. CLIMATOLOGY IS
RIGHT AROUND 25% FOR A 24 POP FORECAST THIS TIME OF YEAR. THE
21.00Z GFS HAS A LONGWAVE TROUGH APPROACHING FROM THE WEST AND
SOUTHWEST FLOW HERE AND THE 21.00Z ECMWF IS LESS AMPLIFIED AND
EVEN QUASI ZONAL. BOTH OF THESE PATTERNS WOULD BE FAIRLY ACTIVE
AND WOULD CERTAINLY WARRANT KEEPING POPS AT LEAST AT THE
MUTED/AVERAGED VALUES OF CLIMATOLOGY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1057 PM CDT MON MAY 20 2013
WIDELY SCATTERED SHOWERS WILL BE POSSIBLE THROUGH THE OVERNIGHT
HOURS AS A LOW PRESSURE CENTER MOVES INTO THE AREA. CIGS WILL
DEGRADE TO MVFR AT MN SITES...WITH IFR CIGS AT KAXN-KSTC-KRWF IN
CLOSER PROXIMITY TO THE LOW PRESSURE CENTER. CIGS GRADUALLY
SCATTER AND IMPROVE BY 18Z TUESDAY. SCATTERED SHOWERS/TS WILL BE
POSSIBLE AGAIN ON TUESDAY. WINDS WILL BECOME SOUTHWEST/WESTERLY ON
TUESDAY AT ALL BUT KAXN/KSTC WHERE NORTHEASTERLY WINDS WILL
PERSIST.
KMSP...
AFTER THE LINE OF SHOWERS AND THUNDERSTORMS EXITS MSP /BY
08Z/...SLIGHT VSBY REDUCTIONS IN BR WILL BE POSSIBLE THROUGH
SUNRISE. CIGS EXPECTED TO LOWER TO AROUND 1800 FEET
OVERNIGHT...AND SCATTER OUT FOR AWHILE TUESDAY AFTERNOON. SOUTHEASTERLY
WINDS PREVAIL THROUGH THE OVERNIGHT HOURS...VEER TO SOUTHERLY BY
DAYBREAK...AND THEN SOUTHWEST/WESTERLY DURING THE AFTERNOON.
SPEEDS AT 5-10 KTS THROUGH THE PERIOD.
/OUTLOOK FOR KMSP/
WED...VFR/MVFR CIGS WITH -SHRA LIKELY. WINDS NE AT 05G10KTS.
THU...VFR. WINDS NNE AT 10-15KTS.
FRI...VFR. WINDS SE AT 5-15KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
SHORT TERM...CLF
LONG TERM...CLF
AVIATION...LS
000
FXUS63 KMPX 210355
AFDMPX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
1055 PM CDT MON MAY 20 2013
.UPDATE...
FOR 06Z AVIATION DISCUSSION BELOW
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED 258 PM CDT MON MAY 20 2013
EARLY AFTERNOON WATER VAPOR IMAGERY TOGETHER WITH RAP40 500MB
HEIGHTS...WINDS...OVERLAID WITH SURFACE PRESSURE SHOWED A VERTICALLY
STACKED CYCLONE OVER THE MN/DAKOTA BORDER. A WELL-DEFINED WARM FRONT
WAS ORIENTED WEST/EAST FROM THE ELBOW OF WESTERN MINNESOTA UP
THROUGH LAKE SUPERIOR...WITH A COLD FRONT EXTENDING SOUTHWEST
THROUGH CENTRAL NEBRASKA. ROTATING AROUND THE UPPER LEVEL LOW WAS A
SHORTWAVE OVER SOUTHEASTERN MINNESOTA WHICH WAS THE DRIVING FACTOR
BEHIND A FEW SCATTERED SHOWERS ALONG AND NORTH OF I94. 19Z SPC
MESOANALYSIS SHOWED 500J/KG OF SBCAPE IN THE WARM SECTOR OF THIS
CYCLONE...WITH NO CIN...THUS THE SCATTERED SHOWER ACTIVITY ONGOING
ACROSS THE REGION WILL PERSIST INTO THE EVENING HOURS. COULD SEE A
STRAY THUNDERSTORM AS WELL...BUT THE BEST DEEP LAYER SHEAR WILL BE
CONFINED ACROSS THE SOUTHEAST OF THE CWA. THEREFORE NOT ANTICIPATING
MUCH OF A THREAT FOR SEVERE WEATHER...ESPECIALLY CONSIDERING THE
CONTROLLED RELEASE OF CAPE EVIDENT ACROSS THE REGION VIA THE
CELLULAR CONVECTION.
TONIGHT THE SHOWERS SHOULD DECREASE IN COVERAGE ACROSS THE SOUTH...
WITH REDEVELOPMENT EXPECTED AGAIN ON TUESDAY AFTERNOON. THE SURFACE
LOW WILL GRADUALLY FILL AS IT SLOWLY MEANDERS EASTWARD. BUFR
FORECAST SOUNDINGS VIA BOTH THE NAM AND GFS SHOW MUCH SHALLOWER CAPE
PROFILE TUESDAY AFTERNOON WHEN COMPARED TO TODAY...SO HAVE REMOVED
THUNDER ACROSS THE WEST AND HAVE LOWERED TEMPS OVER THE ENTIRE
REGION. IN SHORT TUESDAY WILL BE A CLOUDY AND COOL DAY WITH LIGHT
RAIN SHOWERS EXPECTED ONCE AGAIN.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 247 PM CDT MON MAY 20 2013
WE WILL STILL BE DEALING WITH THE EFFECTS OF THE SLOWLY DEPARTING
UPPER LOW TUESDAY NIGHT INTO WEDNESDAY... WITH A CONTINUATION OF
SHOWER CHANCES OVER THE AREA... ENHANCED WITH THE DIURNAL CYCLE
AND PASSAGE OF INDIVIDUAL VORTICITY LOBES ACROSS THE AREA.
HOWEVER... THE TREND OF INSTABILITY AND SHEAR BEING DISPLACED EAST
WILL CONTINUE... SO CHANCES FOR SEVERE WEATHER WILL ALSO BE ON THE
DOWNWARD TREND THROUGH THE PERIOD AND BE FOCUSED EAST OF OUR AREA.
WE FINALLY LOOK TO GET ON THE BACKSIDE OF THE UPPER TROUGH
WEDNESDAY NIGHT... WITH SURFACE RIDGING NOSING IN FROM THE NORTH
BY THURSDAY. THE GFS... NAM... AND ECMWF ARE ALL IN DECENT
AGREEMENT ON THE TIMING OF THINGS... SO HAVE GOOD CONFIDENCE THAT
WE/LL FINALLY SEE A COMPLETELY DRY DAY BY THURSDAY. THE SURFACE
RIDGE WILL SLIDE EAST BY FRIDAY... WITH WARM ADVECTION STARTING TO
SETUP ACROSS THE AREA. AT THIS POINT... THE GFS AND ECMWF START TO
DIVERGE SOME... BUT MAINLY WITH THE DEGREE TO FORCING AND
INSTABILITY ALONG THE ELEVATED WARM FRONT... WITH THE ECMWF
ACTUALLY GENERATING PCPN SOONER AND FARTHER EAST THAN THE GFS. AT
THIS POINT... AM INCLINED TO GO WITH THE SLOWER SOLUTION AND KEEP
THINGS DRY THROUGH FRIDAY. HOWEVER... BY SATURDAY AND THEN THROUGH
THE REMAINDER OF THE FORECAST IT LOOKS LIKE WE/LL HAVE CHANCES FOR
SHRA/TSRA ACROSS THE AREA ONCE AGAIN AS LOW PRESSURE SITS OVER THE
CENTRAL PLAINS AND WE SEE A PROLONGED PERIOD OF WARM ADVECTION AND
ELEVATED INSTABILITY ACROSS THE AREA WITH THE PRIMARY SURFACE WARM
FRONTAL BOUNDARY SLOWLY LIFTING NORTH TOWARD THE REGION.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1057 PM CDT MON MAY 20 2013
WIDELY SCATTERED SHOWERS WILL BE POSSIBLE THROUGH THE OVERNIGHT
HOURS AS A LOW PRESSURE CENTER MOVES INTO THE AREA. CIGS WILL
DEGRADE TO MVFR AT MN SITES...WITH IFR CIGS AT KAXN-KSTC-KRWF IN
CLOSER PROXIMITY TO THE LOW PRESSURE CENTER. CIGS GRADUALLY
SCATTER AND IMPROVE BY 18Z TUESDAY. SCATTERED SHOWERS/TS WILL BE
POSSIBLE AGAIN ON TUESDAY. WINDS WILL BECOME SOUTHWEST/WESTERLY ON
TUESDAY AT ALL BUT KAXN/KSTC WHERE NORTHEASTERLY WINDS WILL
PERSIST.
KMSP...
AFTER THE LINE OF SHOWERS AND THUNDERSTORMS EXITS MSP /BY
08Z/...SLIGHT VSBY REDUCTIONS IN BR WILL BE POSSIBLE THROUGH
SUNRISE. CIGS EXPECTED TO LOWER TO AROUND 1800 FEET
OVERNIGHT...AND SCATTER OUT FOR AWHILE TUESDAY AFTERNOON. SOUTHEASTERLY
WINDS PREVAIL THROUGH THE OVERNIGHT HOURS...VEER TO SOUTHERLY BY
DAYBREAK...AND THEN SOUTHWEST/WESTERLY DURING THE AFTERNOON.
SPEEDS AT 5-10 KTS THROUGH THE PERIOD.
/OUTLOOK FOR KMSP/
WED...VFR/MVFR CIGS WITH -SHRA LIKELY. WINDS NE AT 05G10KTS.
THU...VFR. WINDS NNE AT 10-15KTS.
FRI...VFR. WINDS SE AT 5-15KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
SHORT TERM...JRB
LONG TERM...TRH
AVIATION...LS
000
FXUS63 KMPX 202356
AFDMPX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
656 PM CDT MON MAY 20 2013
.UPDATE...
FOR 00Z AVIATION DISCUSSION BELOW
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED 258 PM CDT MON MAY 20 2013
EARLY AFTERNOON WATER VAPOR IMAGERY TOGETHER WITH RAP40 500MB
HEIGHTS...WINDS...OVERLAID WITH SURFACE PRESSURE SHOWED A VERTICALLY
STACKED CYCLONE OVER THE MN/DAKOTA BORDER. A WELL-DEFINED WARM FRONT
WAS ORIENTED WEST/EAST FROM THE ELBOW OF WESTERN MINNESOTA UP
THROUGH LAKE SUPERIOR...WITH A COLD FRONT EXTENDING SOUTHWEST
THROUGH CENTRAL NEBRASKA. ROTATING AROUND THE UPPER LEVEL LOW WAS A
SHORTWAVE OVER SOUTHEASTERN MINNESOTA WHICH WAS THE DRIVING FACTOR
BEHIND A FEW SCATTERED SHOWERS ALONG AND NORTH OF I94. 19Z SPC
MESOANALYSIS SHOWED 500J/KG OF SBCAPE IN THE WARM SECTOR OF THIS
CYCLONE...WITH NO CIN...THUS THE SCATTERED SHOWER ACTIVITY ONGOING
ACROSS THE REGION WILL PERSIST INTO THE EVENING HOURS. COULD SEE A
STRAY THUNDERSTORM AS WELL...BUT THE BEST DEEP LAYER SHEAR WILL BE
CONFINED ACROSS THE SOUTHEAST OF THE CWA. THEREFORE NOT ANTICIPATING
MUCH OF A THREAT FOR SEVERE WEATHER...ESPECIALLY CONSIDERING THE
CONTROLLED RELEASE OF CAPE EVIDENT ACROSS THE REGION VIA THE
CELLULAR CONVECTION.
TONIGHT THE SHOWERS SHOULD DECREASE IN COVERAGE ACROSS THE SOUTH...
WITH REDEVELOPMENT EXPECTED AGAIN ON TUESDAY AFTERNOON. THE SURFACE
LOW WILL GRADUALLY FILL AS IT SLOWLY MEANDERS EASTWARD. BUFR
FORECAST SOUNDINGS VIA BOTH THE NAM AND GFS SHOW MUCH SHALLOWER CAPE
PROFILE TUESDAY AFTERNOON WHEN COMPARED TO TODAY...SO HAVE REMOVED
THUNDER ACROSS THE WEST AND HAVE LOWERED TEMPS OVER THE ENTIRE
REGION. IN SHORT TUESDAY WILL BE A CLOUDY AND COOL DAY WITH LIGHT
RAIN SHOWERS EXPECTED ONCE AGAIN.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 247 PM CDT MON MAY 20 2013
WE WILL STILL BE DEALING WITH THE EFFECTS OF THE SLOWLY DEPARTING
UPPER LOW TUESDAY NIGHT INTO WEDNESDAY... WITH A CONTINUATION OF
SHOWER CHANCES OVER THE AREA... ENHANCED WITH THE DIURNAL CYCLE
AND PASSAGE OF INDIVIDUAL VORTICITY LOBES ACROSS THE AREA.
HOWEVER... THE TREND OF INSTABILITY AND SHEAR BEING DISPLACED EAST
WILL CONTINUE... SO CHANCES FOR SEVERE WEATHER WILL ALSO BE ON THE
DOWNWARD TREND THROUGH THE PERIOD AND BE FOCUSED EAST OF OUR AREA.
WE FINALLY LOOK TO GET ON THE BACKSIDE OF THE UPPER TROUGH
WEDNESDAY NIGHT... WITH SURFACE RIDGING NOSING IN FROM THE NORTH
BY THURSDAY. THE GFS... NAM... AND ECMWF ARE ALL IN DECENT
AGREEMENT ON THE TIMING OF THINGS... SO HAVE GOOD CONFIDENCE THAT
WE/LL FINALLY SEE A COMPLETELY DRY DAY BY THURSDAY. THE SURFACE
RIDGE WILL SLIDE EAST BY FRIDAY... WITH WARM ADVECTION STARTING TO
SETUP ACROSS THE AREA. AT THIS POINT... THE GFS AND ECMWF START TO
DIVERGE SOME... BUT MAINLY WITH THE DEGREE TO FORCING AND
INSTABILITY ALONG THE ELEVATED WARM FRONT... WITH THE ECMWF
ACTUALLY GENERATING PCPN SOONER AND FARTHER EAST THAN THE GFS. AT
THIS POINT... AM INCLINED TO GO WITH THE SLOWER SOLUTION AND KEEP
THINGS DRY THROUGH FRIDAY. HOWEVER... BY SATURDAY AND THEN THROUGH
THE REMAINDER OF THE FORECAST IT LOOKS LIKE WE/LL HAVE CHANCES FOR
SHRA/TSRA ACROSS THE AREA ONCE AGAIN AS LOW PRESSURE SITS OVER THE
CENTRAL PLAINS AND WE SEE A PROLONGED PERIOD OF WARM ADVECTION AND
ELEVATED INSTABILITY ACROSS THE AREA WITH THE PRIMARY SURFACE WARM
FRONTAL BOUNDARY SLOWLY LIFTING NORTH TOWARD THE REGION.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 656 PM CDT MON MAY 20 2013
WIDELY SCATTERED SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE THIS
EVENING AS A LOW PRESSURE CENTER MOVES INTO THE AREA. ANTICIPATED
COVERAGE ONLY WARRANTS A VICINITY MENTION HOWEVER...OUTSIDE OF THE
00Z-04Z TIMEFRAME WHEN INSTABILITY IS HIGHER AND A TEMPO SHRA/TS
WITH MVFR CIGS/VSBYS APPEARS REASONABLE AT MOST SITES. CIGS WILL
DEGRADE TO MVFR AT MN SITES AFTER SUNSET...WITH IFR CIGS AT KAXN-
KSTC-KRWF IN CLOSER PROXIMITY TO THE LOW PRESSURE CENTER. CIGS
GRADUALLY SCATTER AND IMPROVE BY 18Z TUESDAY. COULD SEE SCATTERED
SHOWERS/TS AGAIN ON TUESDAY...BUT CONFIDENCE ON TIMING/COVERAGE IS
TOO LOW AT THIS POINT TO INCLUDE IN THE TAF. SOUTH-SOUTHWEST WINDS
WILL BACK TO EAST/SOUTHEASTERLY AND LOSE THE GUSTINESS BY 02Z...AND
THEN BECOME SOUTHWEST/WESTERLY ON TUESDAY AT ALL BUT KAXN/KSTC
WHERE NORTHEASTERLY WINDS WILL PERSIST.
KMSP...
THE MOST PROBABLE TIME FRAME FOR THUNDERSTORMS IS BETWEEN 01Z AND
03Z. AFTER THAT...COULD SEE WIDELY SCATTERED SHOWERS THROUGH
08Z...WITH SLIGHT VSBY REDUCTIONS IN BR THROUGH SUNRISE. CIGS
EXPECTED TO LOWER TO AROUND 1800 FEET OVERNIGHT...AND SCATTER OUT
TUESDAY AFTERNOON. WINDS WILL BECOME SOUTHEASTERLY /110-130
DEGREES/ BY 03Z THROUGH THE OVERNIGHT HOURS...VEER TO SOUTHERLY BY
DAYBREAK...AND THEN SOUTHWEST/WESTERLY DURING THE AFTERNOON.
SPEEDS AT 5-10 KTS THROUGH THE PERIOD.
/OUTLOOK FOR KMSP/
WED...VFR/MVFR CIGS WITH -SHRA LIKELY. WINDS NE AT 05G10KTS.
THU...VFR. WINDS NNE AT 10-15KTS.
FRI...VFR. WINDS SE AT 5-15KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
SHORT TERM...JRB
LONG TERM...TRH
AVIATION...LS
000
FXUS63 KMPX 201958
AFDMPX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
258 PM CDT MON MAY 20 2013
.SHORT TERM...(TODAY AND TONIGHT)
EARLY AFTERNOON WATER VAPOR IMAGERY TOGETHER WITH RAP40 500MB
HEIGHTS...WINDS...OVERLAID WITH SURFACE PRESSURE SHOWED A VERTICALLY
STACKED CYCLONE OVER THE MN/DAKOTA BORDER. A WELL-DEFINED WARM FRONT
WAS ORIENTED WEST/EAST FROM THE ELBOW OF WESTERN MINNESOTA UP
THROUGH LAKE SUPERIOR...WITH A COLD FRONT EXTENDING SOUTHWEST
THROUGH CENTRAL NEBRASKA. ROTATING AROUND THE UPPER LEVEL LOW WAS A
SHORTWAVE OVER SOUTHEASTERN MINNESOTA WHICH WAS THE DRIVING FACTOR
BEHIND A FEW SCATTERED SHOWERS ALONG AND NORTH OF I94. 19Z SPC
MESOANALYSIS SHOWED 500J/KG OF SBCAPE IN THE WARM SECTOR OF THIS
CYCLONE...WITH NO CIN...THUS THE SCATTERED SHOWER ACTIVITY ONGOING
ACROSS THE REGION WILL PERSIST INTO THE EVENING HOURS. COULD SEE A
STRAY THUNDERSTORM AS WELL...BUT THE BEST DEEP LAYER SHEAR WILL BE
CONFINED ACROSS THE SOUTHEAST OF THE CWA. THEREFORE NOT ANTICIPATING
MUCH OF A THREAT FOR SEVERE WEATHER...ESPECIALLY CONSIDERING THE
CONTROLLED RELEASE OF CAPE EVIDENT ACROSS THE REGION VIA THE
CELLULAR CONVECTION.
TONIGHT THE SHOWERS SHOULD DECREASE IN COVERAGE ACROSS THE SOUTH...
WITH REDEVELOPMENT EXPECTED AGAIN ON TUESDAY AFTERNOON. THE SURFACE
LOW WILL GRADUALLY FILL AS IT SLOWLY MEANDERS EASTWARD. BUFR
FORECAST SOUNDINGS VIA BOTH THE NAM AND GFS SHOW MUCH SHALLOWER CAPE
PROFILE TUESDAY AFTERNOON WHEN COMPARED TO TODAY...SO HAVE REMOVED
THUNDER ACROSS THE WEST AND HAVE LOWERED TEMPS OVER THE ENTIRE
REGION. IN SHORT TUESDAY WILL BE A CLOUDY AND COOL DAY WITH LIGHT
RAIN SHOWERS EXPECTED ONCE AGAIN.
&&
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 247 PM CDT MON MAY 20 2013
WE WILL STILL BE DEALING WITH THE EFFECTS OF THE SLOWLY DEPARTING
UPPER LOW TUESDAY NIGHT INTO WEDNESDAY... WITH A CONTINUATION OF
SHOWER CHANCES OVER THE AREA... ENHANCED WITH THE DIURNAL CYCLE
AND PASSAGE OF INDIVIDUAL VORTICITY LOBES ACROSS THE AREA.
HOWEVER... THE TREND OF INSTABILITY AND SHEAR BEING DISPLACED EAST
WILL CONTINUE... SO CHANCES FOR SEVERE WEATHER WILL ALSO BE ON THE
DOWNWARD TREND THROUGH THE PERIOD AND BE FOCUSED EAST OF OUR AREA.
WE FINALLY LOOK TO GET ON THE BACKSIDE OF THE UPPER TROUGH
WEDNESDAY NIGHT... WITH SURFACE RIDGING NOSING IN FROM THE NORTH
BY THURSDAY. THE GFS... NAM... AND ECMWF ARE ALL IN DECENT
AGREEMENT ON THE TIMING OF THINGS... SO HAVE GOOD CONFIDENCE THAT
WE/LL FINALLY SEE A COMPLETELY DRY DAY BY THURSDAY. THE SURFACE
RIDGE WILL SLIDE EAST BY FRIDAY... WITH WARM ADVECTION STARTING TO
SETUP ACROSS THE AREA. AT THIS POINT... THE GFS AND ECMWF START TO
DIVERGE SOME... BUT MAINLY WITH THE DEGREE TO FORCING AND
INSTABILITY ALONG THE ELEVATED WARM FRONT... WITH THE ECMWF
ACTUALLY GENERATING PCPN SOONER AND FARTHER EAST THAN THE GFS. AT
THIS POINT... AM INCLINED TO GO WITH THE SLOWER SOLUTION AND KEEP
THINGS DRY THROUGH FRIDAY. HOWEVER... BY SATURDAY AND THEN THROUGH
THE REMAINDER OF THE FORECAST IT LOOKS LIKE WE/LL HAVE CHANCES FOR
SHRA/TSRA ACROSS THE AREA ONCE AGAIN AS LOW PRESSURE SITS OVER THE
CENTRAL PLAINS AND WE SEE A PROLONGED PERIOD OF WARM ADVECTION AND
ELEVATED INSTABILITY ACROSS THE AREA WITH THE PRIMARY SURFACE WARM
FRONTAL BOUNDARY SLOWLY LIFTING NORTH TOWARD THE REGION.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1250 PM CDT MON MAY 20 2013
SHOWERS WILL CONTINUE TO INCREASE IN COVERAGE THIS
AFTERNOON...WITH A FEW ISOLATED THUNDERSTORMS POSSIBLE AS WELL.
COULD SEE VISBYS BRIEFLY DROP BENEATH THE HEAVIER SHOWERS...BUT
MAINLY EXPECTING VFR/MVFR. TONIGHT FORECAST GUIDANCE SHOWS CIGS
DROPPING AGAIN...WITH IFR/LIFR CONDITIONS ACROSS THE NORTH AT KAXN
AND KSTC.
KMSP...
SHOWERS WILL CONTINUE TO MOVE ACROSS THE METRO AREA TODAY...WITH
AN OUTSIDE CHANCE OF THUNDER AS WELL. HOWEVER THE COVERAGE FOR
THUNDER WILL BE SCARE SO REMOVED IT FROM THE AFTERNOON TIMING AND
HAVE JUST A SHORT VCTS THIS EVENING AS INDICATED BY THE SHORT TERM
HRRR AND HOPWRF MODELS. SHOWERS WILL DECREASE IN COVERAGE LATER
TONIGHT.
/OUTLOOK FOR KMSP/
WED...VFR/MVFR CIGS WITH -SHRA LIKELY. WINDS NE AT 05G10KTS.
THU...VFR. WINDS NE AT 10KTS.
FRI...VFR. WINDS SE AT 10G15KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
SHORT TERM...JRB
LONG TERM...
AVIATION...JRB
000
FXUS63 KMPX 201801
AFDMPX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
101 PM CDT MON MAY 20 2013
.UPDATED FOR 18Z AVIATION DISCUSSION...
ISSUED AT 1250 PM CDT MON MAY 20 2013
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 400 AM CDT MON MAY 20 2013
TODAY-TONIGHT...BROAD UPPER LEVEL CENTRAL CONUS TROUGH WILL SLOWLY
MEANDER TWD THE E...WITH ITS CUTOFF LOW WOBBLING OVER WRN MN AND THE
ERN DAKOTAS. SEVERAL SHORTWAVE SPOKES WILL ROTATE ARND THIS UPPER
LOW...SWINGING THRU THE MPX CWFA TDA INTO TNGT. THE MAIN ISSUES ARE
AROUND TIMING OF PRECIP AND POTENTIAL FOR SEVERE WX IN FAR ERN MN
INTO WRN WI. SCATTERED SHWRS THIS MRNG WILL CONTINUE TO DEVELOP AND
DISSIPATE AS MODELS INDICATE DRY SLOTTING TO SHIFT NE INTO THE
REGION THIS MRNG...LASTING THRU AT LEAST MID AFTN. THIS WOULD HALT
ANY WIDESPREAD PRECIP BUT ISOLD TO SCATTERED SHWRS/TSTMS CERTAINLY
CANNOT BE RULED OUT. ONCE THIS DRY SLOTTING SHIFTS WELL INTO NRN MN
AND NW WI BY THIS EVE...ANOTHER SWATH OF MOISTURE WILL BR DRAGGED
INTO THE REGION WHICH WILL BE ABLY TAPPED TO PRODUCE ADDITIONAL
BANDS OF PRECIP...IF NOT A LARGE PRECIP SHIELD. ONE DETERMINING
FACTOR WILL BE THE PLACEMENT OF THE SFC LOW UNDER THE UPPER LOW. THE
SFC LOW LOOKS TO REMAIN PRIMARILY NEAR THE ND/SD/MN TRIPLE POINT...
AND THIS POSITION WOULD KEEP THE BULK OF THE PRECIP ALONG AND N OF
ITS LATITUDE. AS FOR SEVERE WX POTENTIAL...THE EWD SHIFT OF THE
UPPER TROUGH PUTS THE BEST JETTING AND EXIT REGION OVER FAR ERN MN
AND WRN WI. IN ADDITION...THE BREAK IN THE PRECIP MAY ALLOW FOR A
FEW BREAKS IN THE OVERCAST...ALLOWING FOR ADDITIONAL
INSTABILITY...ESP IN WRN WI WHERE PRECIP HAS NOW VIRTUALLY SHUT DOWN
EVERYWHERE. THIS WILL ALLOW A RELOADING OF THE ATMOS TO GENERATE
MLCAPE IN THE 2000-2500 J/KG RANGE WITH LITTLE CAPPING...WHILE
CENTRAL-WRN MN WILL BE DEALING WITH LESS IMPRESSIVE LAPSE RATES AND
INSTABILITY PARAMETERS. STILL HAVE A SLGT RISK IN PLACE PER SPC IN
THEIR SWODY1 FOR ALL OF FAR ERN MN THRU WI WHICH IS VERY REASONABLE.
AS FOR TEMPERATURES AND DEWPOINTS...WITH THE WMFNT CONTINUING TO
LUMBER NWD THRU THE CWFA AND ITS TRAILING CDFNT STILL IN THE
DAKOTAS...ANOTHER WARM/HUMID DAY CAN BE EXPECTED. WILL LOOK FOR
HIGHS FROM ARND 70 IN WRN MN TO THE LOWER 80S IN WRN WI... WITH LOWS
TNGT AGAIN MILD IN THE MID 50S TO LWR 60S. DEWPOINTS WILL AGAIN
REACH THE LWR 60S...KEEPING AN UNSEASONABLY HUMID AIRMASS IN PLACE.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 400 AM CDT MON MAY 20 2013
IT ISN`T UNTIL TUESDAY NIGHT/WEDNESDAY MORNING THAT WE FINALLY
SEE SOME SLOW EASTWARD PROGRESS WITH THE TROUGH OVER THE CENTRAL
CONUS. DURING THIS TIME THE SURFACE LOW SLOWLY FILLS AND MOVES
FROM MN TO WI. HOWEVER...BEFORE THEN...DURING THE DAY ON
TUESDAY...WE EXPECT SCATTERED SHOWERS ACROSS PRIMARILY CENTRAL MN
AND NORTHERN WI. JUST LIKE THIS MORNING...WHERE WE SEE GOOD DRYING
SHOWING UP IN THE WATER VAPOR IMAGERY ACROSS EASTERN NE AND
WESTERN IA...TUESDAY SHOULD SEE A DRY SLOT ACROSS THE SOUTHERN
HALF OF THE FORECAST AREA. BETTER Q-VECTOR CONVERGENCE AND
SLIGHTLY BETTER FGEN IS LOCATED ACROSS THE NORTHERN FORECAST AREA
JUST NORTH OF THE DRY WEDGE SHIFTING NORTHEAST DURING THE DAY. AS
A RESULT...KEPT HIGH CHANCE POPS OR LIKELY POPS IN THE FORECAST
FOR THE NORTHERN CWA...BUT LOWERED POPS OR WENT NO WEATHER IN THE
SOUTHERN CWA TUE/TUE NIGHT. LINGERING INSTABILITY IN EASTERN MN
AND WESTERN WI WARRANTS THUNDERSTORMS FOR THE WEATHER TYPE ON
TUESDAY...BUT EVEN BEFORE TUESDAY NIGHT THE MUCAPE SLIDES FARTHER
EASY AND DIMINISHES. THEREFORE...KEPT THE THUNDER OUT OF THE
FORECAST IN MOST LOCATIONS TUESDAY NIGHT AND WEDNESDAY. WE ALSO
COOLED TEMPERATURES A BIT ON WEDNESDAY...ESPECIALLY ACROSS CENTRAL
MN...WHERE LIGHT SHOWERS MAY BE MORE WIDESPREAD AND HANG AROUND
LONGER. ALSO...WITH EAST-SOUTHEAST SHIFT TO THE SYSTEM ON
WEDNESDAY...THE BETTER LARGE-SCALE FORCING SHOULD GET PULLED
ACROSS THE AREA. SO WEDNESDAY`S POPS ARE ACTUALLY HIGHER THAN
TUESDAY`S AND ARE COMPARABLE TO THE PROBABILITIES FORECASTED
TODAY. HOWEVER...THE QPF IS LOW.
LOOKS LIKE WE`LL GET A BRIEF REPRIEVE FROM THE WET WEATHER THURSDAY
AND FRIDAY WITH A SURFACE HIGH BUILDING IN TROUGH...RIDGE...TROUGH
PATTERN SETTING UP ACROSS THE CONUS. THE WEATHER PREDICTION CENTER
PREFERS A GFS/GEFS/EC/EC-MEAN BLEND IN THE EXTENDED AND TO THAT
SEEMS REASONABLE GIVEN THE RELATIVELY SMALL SPREAD IN THE LONG
WAVE PATTERN...EVEN WITH AN ANOMALOUSLY DEEP TROUGH ALONG THE WEST
COAST. BY THE WEEKEND...A WARM FRONT IS FORECAST TO MOVE EAST
ACROSS SD/NE AND APPROACH WESTERN MN. MOST OF THE FORECAST AREA
TAKES SOME TIME TO MOISTEN IN LIGHT OF THE DRIER E-SE FLOW UNDER
THE RIDGE. NONETHELESS...WITH AT LEAST SOME MOISTURE PLACE...THE WARM
ADVECTION COULD KICK OFF SOME SHOWERS BY SATURDAY...ESPECIALLY IN
WESTERN MN.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1250 PM CDT MON MAY 20 2013
SHOWERS WILL CONTINUE TO INCREASE IN COVERAGE THIS
AFTERNOON...WITH A FEW ISOLATED THUNDERSTORMS POSSIBLE AS WELL.
COULD SEE VISBYS BRIEFLY DROP BENEATH THE HEAVIER SHOWERS...BUT
MAINLY EXPECTING VFR/MVFR. TONIGHT FORECAST GUIDANCE SHOWS CIGS
DROPPING AGAIN...WITH IFR/LIFR CONDITIONS ACROSS THE NORTH AT KAXN
AND KSTC.
KMSP...
SHOWERS WILL CONTINUE TO MOVE ACROSS THE METRO AREA TODAY...WITH
AN OUTSIDE CHANCE OF THUNDER AS WELL. HOWEVER THE COVERAGE FOR
THUNDER WILL BE SCARE SO REMOVED IT FROM THE AFTERNOON TIMING AND
HAVE JUST A SHORT VCTS THIS EVENING AS INDICATED BY THE SHORT TERM
HRRR AND HOPWRF MODELS. SHOWERS WILL DECREASE IN COVERAGE LATER
TONIGHT.
/OUTLOOK FOR KMSP/
WED...VFR/MVFR CIGS WITH -SHRA LIKELY. WINDS NE AT 05G10KTS.
THU...VFR. WINDS NE AT 10KTS.
FRI...VFR. WINDS SE AT 10G15KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
SHORT TERM...JPC
LONG TERM...CLF
AVIATION...JRB
000
FXUS63 KMPX 201241
AFDMPX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
741 AM CDT MON MAY 20 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 400 AM CDT MON MAY 20 2013
TODAY-TONIGHT...BROAD UPPER LEVEL CENTRAL CONUS TROUGH WILL SLOWLY
MEANDER TWD THE E...WITH ITS CUTOFF LOW WOBBLING OVER WRN MN AND THE
ERN DAKOTAS. SEVERAL SHORTWAVE SPOKES WILL ROTATE ARND THIS UPPER
LOW...SWINGING THRU THE MPX CWFA TDA INTO TNGT. THE MAIN ISSUES ARE
AROUND TIMING OF PRECIP AND POTENTIAL FOR SEVERE WX IN FAR ERN MN
INTO WRN WI. SCATTERED SHWRS THIS MRNG WILL CONTINUE TO DEVELOP AND
DISSIPATE AS MODELS INDICATE DRY SLOTTING TO SHIFT NE INTO THE
REGION THIS MRNG...LASTING THRU AT LEAST MID AFTN. THIS WOULD HALT
ANY WIDESPREAD PRECIP BUT ISOLD TO SCATTERED SHWRS/TSTMS CERTAINLY
CANNOT BE RULED OUT. ONCE THIS DRY SLOTTING SHIFTS WELL INTO NRN MN
AND NW WI BY THIS EVE...ANOTHER SWATH OF MOISTURE WILL BR DRAGGED
INTO THE REGION WHICH WILL BE ABLY TAPPED TO PRODUCE ADDITIONAL
BANDS OF PRECIP...IF NOT A LARGE PRECIP SHIELD. ONE DETERMINING
FACTOR WILL BE THE PLACEMENT OF THE SFC LOW UNDER THE UPPER LOW. THE
SFC LOW LOOKS TO REMAIN PRIMARILY NEAR THE ND/SD/MN TRIPLE POINT...
AND THIS POSITION WOULD KEEP THE BULK OF THE PRECIP ALONG AND N OF
ITS LATITUDE. AS FOR SEVERE WX POTENTIAL...THE EWD SHIFT OF THE
UPPER TROUGH PUTS THE BEST JETTING AND EXIT REGION OVER FAR ERN MN
AND WRN WI. IN ADDITION...THE BREAK IN THE PRECIP MAY ALLOW FOR A
FEW BREAKS IN THE OVERCAST...ALLOWING FOR ADDITIONAL
INSTABILITY...ESP IN WRN WI WHERE PRECIP HAS NOW VIRTUALLY SHUT DOWN
EVERYWHERE. THIS WILL ALLOW A RELOADING OF THE ATMOS TO GENERATE
MLCAPE IN THE 2000-2500 J/KG RANGE WITH LITTLE CAPPING...WHILE
CENTRAL-WRN MN WILL BE DEALING WITH LESS IMPRESSIVE LAPSE RATES AND
INSTABILITY PARAMETERS. STILL HAVE A SLGT RISK IN PLACE PER SPC IN
THEIR SWODY1 FOR ALL OF FAR ERN MN THRU WI WHICH IS VERY REASONABLE.
AS FOR TEMPERATURES AND DEWPOINTS...WITH THE WMFNT CONTINUING TO
LUMBER NWD THRU THE CWFA AND ITS TRAILING CDFNT STILL IN THE
DAKOTAS...ANOTHER WARM/HUMID DAY CAN BE EXPECTED. WILL LOOK FOR
HIGHS FROM ARND 70 IN WRN MN TO THE LOWER 80S IN WRN WI... WITH LOWS
TNGT AGAIN MILD IN THE MID 50S TO LWR 60S. DEWPOINTS WILL AGAIN
REACH THE LWR 60S...KEEPING AN UNSEASONABLY HUMID AIRMASS IN PLACE.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 400 AM CDT MON MAY 20 2013
IT ISN`T UNTIL TUESDAY NIGHT/WEDNESDAY MORNING THAT WE FINALLY
SEE SOME SLOW EASTWARD PROGRESS WITH THE TROUGH OVER THE CENTRAL
CONUS. DURING THIS TIME THE SURFACE LOW SLOWLY FILLS AND MOVES
FROM MN TO WI. HOWEVER...BEFORE THEN...DURING THE DAY ON
TUESDAY...WE EXPECT SCATTERED SHOWERS ACROSS PRIMARILY CENTRAL MN
AND NORTHERN WI. JUST LIKE THIS MORNING...WHERE WE SEE GOOD DRYING
SHOWING UP IN THE WATER VAPOR IMAGERY ACROSS EASTERN NE AND
WESTERN IA...TUESDAY SHOULD SEE A DRY SLOT ACROSS THE SOUTHERN
HALF OF THE FORECAST AREA. BETTER Q-VECTOR CONVERGENCE AND
SLIGHTLY BETTER FGEN IS LOCATED ACROSS THE NORTHERN FORECAST AREA
JUST NORTH OF THE DRY WEDGE SHIFTING NORTHEAST DURING THE DAY. AS
A RESULT...KEPT HIGH CHANCE POPS OR LIKELY POPS IN THE FORECAST
FOR THE NORTHERN CWA...BUT LOWERED POPS OR WENT NO WEATHER IN THE
SOUTHERN CWA TUE/TUE NIGHT. LINGERING INSTABILITY IN EASTERN MN
AND WESTERN WI WARRANTS THUNDERSTORMS FOR THE WEATHER TYPE ON
TUESDAY...BUT EVEN BEFORE TUESDAY NIGHT THE MUCAPE SLIDES FARTHER
EASY AND DIMINISHES. THEREFORE...KEPT THE THUNDER OUT OF THE
FORECAST IN MOST LOCATIONS TUESDAY NIGHT AND WEDNESDAY. WE ALSO
COOLED TEMPERATURES A BIT ON WEDNESDAY...ESPECIALLY ACROSS CENTRAL
MN...WHERE LIGHT SHOWERS MAY BE MORE WIDESPREAD AND HANG AROUND
LONGER. ALSO...WITH EAST-SOUTHEAST SHIFT TO THE SYSTEM ON
WEDNESDAY...THE BETTER LARGE-SCALE FORCING SHOULD GET PULLED
ACROSS THE AREA. SO WEDNESDAY`S POPS ARE ACTUALLY HIGHER THAN
TUESDAY`S AND ARE COMPARABLE TO THE PROBABILITIES FORECASTED
TODAY. HOWEVER...THE QPF IS LOW.
LOOKS LIKE WE`LL GET A BRIEF REPRIEVE FROM THE WET WEATHER THURSDAY
AND FRIDAY WITH A SURFACE HIGH BUILDING IN TROUGH...RIDGE...TROUGH
PATTERN SETTING UP ACROSS THE CONUS. THE WEATHER PREDICTION CENTER
PREFERS A GFS/GEFS/EC/EC-MEAN BLEND IN THE EXTENDED AND TO THAT
SEEMS REASONABLE GIVEN THE RELATIVELY SMALL SPREAD IN THE LONG
WAVE PATTERN...EVEN WITH AN ANOMALOUSLY DEEP TROUGH ALONG THE WEST
COAST. BY THE WEEKEND...A WARM FRONT IS FORECAST TO MOVE EAST
ACROSS SD/NE AND APPROACH WESTERN MN. MOST OF THE FORECAST AREA
TAKES SOME TIME TO MOISTEN IN LIGHT OF THE DRIER E-SE FLOW UNDER
THE RIDGE. NONETHELESS...WITH AT LEAST SOME MOISTURE PLACE...THE WARM
ADVECTION COULD KICK OFF SOME SHOWERS BY SATURDAY...ESPECIALLY IN
WESTERN MN.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 711 AM CDT MON MAY 20 2013
ANOTHER DAY OF RADAR MONITORING AND FAIRLY FREQUENT AMENDMENTS.
LITTLE BIT OF A TRICKY START WITH IFR/LIFR CIGS OVER MUCH OF THE
AREA AND DETERMINING ANY IMPROVEMENT AND WHEN. MAIN CULPRIT IS THE
STILL-ROTATING EXPANSIVE LOW PRESSURE SYSTEM CENTERED OVER THE ERN
DAKOTAS INTO WRN MN. THIS SYSTEM WILL SLOWLY DRIFT E TDA WHILE ITS
ASSOCIATED WMFNT LIFTS N AND THE CDFNT LINGERS NEAR THE WRMN MN
STATE LINE. LOW CLOUDS WILL GRADUALLY LIFT INTO MVFR RANGE WITH
PRECIPITATION SLOWLY COMING TO AN END...ESP FOR ERN MN INTO WRN
WI. BY THIS AFTN...ENOUGH DAYTIME HEATING WILL ALLOW CONVECTION TO
DEVELOP ACRS THE ENTIRE REGION. HAVE HELD OFF TIMING TO MAINLY
ARND 20Z AND AFTERWARDS. IF/WHEN ANY TSTMS MOVE ACRS A TERMINAL...
CONDS CAN EASILY BE WORSE THAN WHAT IS ADVERTISED BUT DID NOT WANT
TO GO TOO HARD ATTM. MORE SHOWERY PRECIP IS THEN EXPECTED
OVERNIGHT WITH CONDS AGAIN DEGRADING TO AT LEAST MVFR TNGT.
KMSP...TRICKY START AS CONDS HAVE BOUNCED BETWEEN LOWER-END
MVFR... INCLUDING BELOW 1700 FT...AND VFR AT INITIALIZATION. HAVE
COVERED THIS USING A TEMPO GROUP AT THE START AND WILL MONITOR
TRENDS TO SEE IF ADDITIONAL TWEAKS ARE NEEDED. MVFR CONDS LIKELY
TO HOLD FROM MIDDAY ONWARD...WITH PRECIPITATION RE-DEVELOPING ARND
MSP LATER THIS AFTN. FEW TSTMS AT THE START THEN MORE PERSISTENT
RAINS EXPECTED AFTER 00Z. STILL SOME TIMING/DURATION COMPLICATIONS
SO SOME CHANGES TO THE LATTER HALF OF THE TAF WOULD NOT BE
UNEXPECTED. WINDS START OUT SE...BECOME S...THEN BECOME SE AGAIN
DURG THE EARLY MRNG HOURS...AND SPEEDS WILL BE GUSTY THIS AFTN.
/OUTLOOK FOR KMSP/
TUE...VFR/MVFR CIGS. SHRA/TSRA LIKELY. S-SW WIND 5 KTS.
WED...VFR/MVFR CIGS. SHRA LIKELY. NE WIND 5-10 KTS.
THU...VFR. NE WINDS 10 KTS.
&&
.HYDROLOGY...
ISSUED AT 249 AM CDT MON MAY 20 2013
HAVE MAINTAINED FLASH FLOOD WATCH AS-IS THRU THIS FCST
PKG BUT CONFIDENCE IS WANING THAT ACTUAL FLASH FLOODING MAY BE
ACHIEVED DUE TO DRY SLOTTING MOVING INTO THE REGION THIS MRNG. THIS
HAS CUT INTO ADDITIONAL QPF EXPECTED. THAT SAID...MUCH OF THE AREA
HAS RECEIVED 2-4 INCHES OF RAIN WITH LOCALLY HIGHER AMOUNTS THE PAST
COUPLE OF DAYS...SO SOILS ARE CERTAINLY CLOSE TO IF NOT COMPLETELY
SATURATED. THERE MAY NOT BE THE QUINTESSENTIAL FLASH FLOODING THAT
DEVELOPS...BUT QUICK RISES IN RIVERS AND STREAMS ALONG WITH URBAN
FLOODING DUE TO RUNOFF CERTAINLY CANNOT BE RULED OUT AS ANOTHER ONE
HALF TO ONE INCH IS EXPECTED TDA IN MUCH OF THE AREA COVERED BY THE
WATCH...ESP IN CENTRAL MN.
EVEN THOUGH THE FORECAST IS LOADED WITH SHOWERS THROUGH WEDNESDAY.
TODAY APPEARS LIKE THE LAST REMAINING CHANCE TO GET ANY KIND OF
QUICK RESPONSE TO LOCAL RIVERS AND STREAMS. WE LOSE THE
ENVIRONMENT FOR VIGOROUS DEEP CONVECTION TUESDAY AND WEDNESDAY AND
SHOULD JUST GET SCATTERED LIGHT SHOWERS WITH LOWER QPF TOTALS ON
BOTH OF THOSE DAYS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...FLASH FLOOD WATCH UNTIL 7 PM CDT THIS EVENING FOR MNZ041>045-
047>053-057>063-066>070-075>078-084-085-093.
WI...FLASH FLOOD WATCH UNTIL 7 PM CDT THIS EVENING FOR WIZ014>016-
023>028.
&&
$$
SHORT TERM...JPC
LONG TERM...CLF
AVIATION...JPC
HYDROLOGY...CLF
000
FXUS63 KMPX 200907
AFDMPX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
407 AM CDT MON MAY 20 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 400 AM CDT MON MAY 20 2013
TODAY-TONIGHT...BROAD UPPER LEVEL CENTRAL CONUS TROUGH WILL SLOWLY
MEANDER TWD THE E...WITH ITS CUTOFF LOW WOBBLING OVER WRN MN AND THE
ERN DAKOTAS. SEVERAL SHORTWAVE SPOKES WILL ROTATE ARND THIS UPPER
LOW...SWINGING THRU THE MPX CWFA TDA INTO TNGT. THE MAIN ISSUES ARE
AROUND TIMING OF PRECIP AND POTENTIAL FOR SEVERE WX IN FAR ERN MN
INTO WRN WI. SCATTERED SHWRS THIS MRNG WILL CONTINUE TO DEVELOP AND
DISSIPATE AS MODELS INDICATE DRY SLOTTING TO SHIFT NE INTO THE
REGION THIS MRNG...LASTING THRU AT LEAST MID AFTN. THIS WOULD HALT
ANY WIDESPREAD PRECIP BUT ISOLD TO SCATTERED SHWRS/TSTMS CERTAINLY
CANNOT BE RULED OUT. ONCE THIS DRY SLOTTING SHIFTS WELL INTO NRN MN
AND NW WI BY THIS EVE...ANOTHER SWATH OF MOISTURE WILL BR DRAGGED
INTO THE REGION WHICH WILL BE ABLY TAPPED TO PRODUCE ADDITIONAL
BANDS OF PRECIP...IF NOT A LARGE PRECIP SHIELD. ONE DETERMINING
FACTOR WILL BE THE PLACEMENT OF THE SFC LOW UNDER THE UPPER LOW. THE
SFC LOW LOOKS TO REMAIN PRIMARILY NEAR THE ND/SD/MN TRIPLE POINT...
AND THIS POSITION WOULD KEEP THE BULK OF THE PRECIP ALONG AND N OF
ITS LATITUDE. AS FOR SEVERE WX POTENTIAL...THE EWD SHIFT OF THE
UPPER TROUGH PUTS THE BEST JETTING AND EXIT REGION OVER FAR ERN MN
AND WRN WI. IN ADDITION...THE BREAK IN THE PRECIP MAY ALLOW FOR A
FEW BREAKS IN THE OVERCAST...ALLOWING FOR ADDITIONAL
INSTABILITY...ESP IN WRN WI WHERE PRECIP HAS NOW VIRTUALLY SHUT DOWN
EVERYWHERE. THIS WILL ALLOW A RELOADING OF THE ATMOS TO GENERATE
MLCAPE IN THE 2000-2500 J/KG RANGE WITH LITTLE CAPPING...WHILE
CENTRAL-WRN MN WILL BE DEALING WITH LESS IMPRESSIVE LAPSE RATES AND
INSTABILITY PARAMETERS. STILL HAVE A SLGT RISK IN PLACE PER SPC IN
THEIR SWODY1 FOR ALL OF FAR ERN MN THRU WI WHICH IS VERY REASONABLE.
AS FOR TEMPERATURES AND DEWPOINTS...WITH THE WMFNT CONTINUING TO
LUMBER NWD THRU THE CWFA AND ITS TRAILING CDFNT STILL IN THE
DAKOTAS...ANOTHER WARM/HUMID DAY CAN BE EXPECTED. WILL LOOK FOR
HIGHS FROM ARND 70 IN WRN MN TO THE LOWER 80S IN WRN WI... WITH LOWS
TNGT AGAIN MILD IN THE MID 50S TO LWR 60S. DEWPOINTS WILL AGAIN
REACH THE LWR 60S...KEEPING AN UNSEASONABLY HUMID AIRMASS IN PLACE.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 400 AM CDT MON MAY 20 2013
IT ISN`T UNTIL TUESDAY NIGHT/WEDNESDAY MORNING THAT WE FINALLY
SEE SOME SLOW EASTWARD PROGRESS WITH THE TROUGH OVER THE CENTRAL
CONUS. DURING THIS TIME THE SURFACE LOW SLOWLY FILLS AND MOVES
FROM MN TO WI. HOWEVER...BEFORE THEN...DURING THE DAY ON
TUESDAY...WE EXPECT SCATTERED SHOWERS ACROSS PRIMARILY CENTRAL MN
AND NORTHERN WI. JUST LIKE THIS MORNING...WHERE WE SEE GOOD DRYING
SHOWING UP IN THE WATER VAPOR IMAGERY ACROSS EASTERN NE AND
WESTERN IA...TUESDAY SHOULD SEE A DRY SLOT ACROSS THE SOUTHERN
HALF OF THE FORECAST AREA. BETTER Q-VECTOR CONVERGENCE AND
SLIGHTLY BETTER FGEN IS LOCATED ACROSS THE NORTHERN FORECAST AREA
JUST NORTH OF THE DRY WEDGE SHIFTING NORTHEAST DURING THE DAY. AS
A RESULT...KEPT HIGH CHANCE POPS OR LIKELY POPS IN THE FORECAST
FOR THE NORTHERN CWA...BUT LOWERED POPS OR WENT NO WEATHER IN THE
SOUTHERN CWA TUE/TUE NIGHT. LINGERING INSTABILITY IN EASTERN MN
AND WESTERN WI WARRANTS THUNDERSTORMS FOR THE WEATHER TYPE ON
TUESDAY...BUT EVEN BEFORE TUESDAY NIGHT THE MUCAPE SLIDES FARTHER
EASY AND DIMINISHES. THEREFORE...KEPT THE THUNDER OUT OF THE
FORECAST IN MOST LOCATIONS TUESDAY NIGHT AND WEDNESDAY. WE ALSO
COOLED TEMPERATURES A BIT ON WEDNESDAY...ESPECIALLY ACROSS CENTRAL
MN...WHERE LIGHT SHOWERS MAY BE MORE WIDESPREAD AND HANG AROUND
LONGER. ALSO...WITH EAST-SOUTHEAST SHIFT TO THE SYSTEM ON
WEDNESDAY...THE BETTER LARGE-SCALE FORCING SHOULD GET PULLED
ACROSS THE AREA. SO WEDNESDAY`S POPS ARE ACTUALLY HIGHER THAN
TUESDAY`S AND ARE COMPARABLE TO THE PROBABILITIES FORECASTED
TODAY. HOWEVER...THE QPF IS LOW.
LOOKS LIKE WE`LL GET A BRIEF REPRIEVE FROM THE WET WEATHER THURSDAY
AND FRIDAY WITH A SURFACE HIGH BUILDING IN TROUGH...RIDGE...TROUGH
PATTERN SETTING UP ACROSS THE CONUS. THE WEATHER PREDICTION CENTER
PREFERS A GFS/GEFS/EC/EC-MEAN BLEND IN THE EXTENDED AND TO THAT
SEEMS REASONABLE GIVEN THE RELATIVELY SMALL SPREAD IN THE LONG
WAVE PATTERN...EVEN WITH AN ANOMALOUSLY DEEP TROUGH ALONG THE WEST
COAST. BY THE WEEKEND...A WARM FRONT IS FORECAST TO MOVE EAST
ACROSS SD/NE AND APPROACH WESTERN MN. MOST OF THE FORECAST AREA
TAKES SOME TIME TO MOISTEN IN LIGHT OF THE DRIER E-SE FLOW UNDER
THE RIDGE. NONETHELESS...WITH AT LEAST SOME MOISTURE PLACE...THE WARM
ADVECTION COULD KICK OFF SOME SHOWERS BY SATURDAY...ESPECIALLY IN
WESTERN MN.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1042 PM CDT SUN MAY 19 2013
THE AREA OF SHOWERS AND THUNDERSTORMS OVER SOUTHEASTERN MN AND
WEST CENTRAL WI WILL GRADUALLY FILL BACK IN TO THE NORTH AND WEST
ACROSS CENTRAL MN OVERNIGHT...WHICH IS ILLUSTRATED BY THE HRRR
MODEL. MVFR CIGS/VSBYS IN THE SHRA ARE EXPECTED...ALONG WITH IFR
CIGS FROM KSTC-KAXN. AFTER 15Z MONDAY...EXPECT A LULL IN
CONVECTION UNTIL DAYTIME HEATING CAUSES THE NEXT ROUND OF
POTENTIALLY STRONG TO SEVERE THUNDERSTORMS TO DEVELOP. WINDS WILL
BE SOUTHEASTERLY AOB 10 KTS OVERNIGHT...THEN BECOME GUSTY BY LATE
MORNING MONDAY AND VEER SLIGHTLY TO MORE SOUTH/SOUTHWESTERLY IN
DIRECTION.
KMSP...
EXPECT THE SHOWERS OVER SOUTHEASTERN MN TO GRADUALLY EXPAND BACK
WEST/NORTHWEST AT THE START OF THE PERIOD...THEN TAPER OFF BY 14Z
MONDAY WHEN WINDS BECOME GUSTY. CIGS MAY DIP TO 1500 FT OVERNIGHT
WITH THE SHOWER ACTIVITY...BUT THE PREVALENT CIG SHOULD BE
2500-3500FT. SOUTHEAST WINDS AROUND 150 DEGREES BEGIN GUSTING TO
25 KTS BY 15Z...THEN VEER TO AROUND 200 DEGREES BY 18Z WITH GUSTS
CONTINUING.
/OUTLOOK FOR KMSP/
TUE...VFR/MVFR CIGS. SHRA/TSRA LIKELY. S-SW WIND 5 KTS.
WED...VFR/MVFR CIGS. SHRA LIKELY. NE WIND 5-10 KTS.
THU...VFR. NE WINDS 10 KTS.
&&
.HYDROLOGY...
ISSUED AT 249 AM CDT MON MAY 20 2013
HAVE MAINTAINED FLASH FLOOD WATCH AS-IS THRU THIS FCST
PKG BUT CONFIDENCE IS WANING THAT ACTUAL FLASH FLOODING MAY BE
ACHIEVED DUE TO DRY SLOTTING MOVING INTO THE REGION THIS MRNG. THIS
HAS CUT INTO ADDITIONAL QPF EXPECTED. THAT SAID...MUCH OF THE AREA
HAS RECEIVED 2-4 INCHES OF RAIN WITH LOCALLY HIGHER AMOUNTS THE PAST
COUPLE OF DAYS...SO SOILS ARE CERTAINLY CLOSE TO IF NOT COMPLETELY
SATURATED. THERE MAY NOT BE THE QUINTESSENTIAL FLASH FLOODING THAT
DEVELOPS...BUT QUICK RISES IN RIVERS AND STREAMS ALONG WITH URBAN
FLOODING DUE TO RUNOFF CERTAINLY CANNOT BE RULED OUT AS ANOTHER ONE
HALF TO ONE INCH IS EXPECTED TDA IN MUCH OF THE AREA COVERED BY THE
WATCH...ESP IN CENTRAL MN.
EVEN THOUGH THE FORECAST IS LOADED WITH SHOWERS THROUGH WEDNESDAY.
TODAY APPEARS LIKE THE LAST REMAINING CHANCE TO GET ANY KIND OF
QUICK RESPONSE TO LOCAL RIVERS AND STREAMS. WE LOSE THE
ENVIRONMENT FOR VIGOROUS DEEP CONVECTION TUESDAY AND WEDNESDAY AND
SHOULD JUST GET SCATTERED LIGHT SHOWERS WITH LOWER QPF TOTALS ON
BOTH OF THOSE DAYS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...FLASH FLOOD WATCH THROUGH THIS EVENING FOR MNZ041>045-047>053-
057>063-066>070-075>078-084-085-093.
WI...FLASH FLOOD WATCH THROUGH THIS EVENING FOR WIZ014>016-023>028.
&&
$$
SHORT TERM...JPC
LONG TERM...CLF
AVIATION...LS
HYDROLOGY...CLF
000
FXUS63 KMPX 200341
AFDMPX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
1041 PM CDT SUN MAY 19 2013
.UPDATE...
FOR 06Z AVIATION DISCUSSION BELOW
&&
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 345 PM CDT SUN MAY 19 2013
NARROW AREA OF MODERATE TO STRONG THUNDERSTORMS NOTED ON RADAR
FROM TWIN CITIES SOUTH INTO EASTERN FREEBORN COUNTY. HRRR HANDLED
INTIATION OF THIS ACTIVITY OVER FAR NORTHERN IOWA AND FAR SOUTH
CENTRAL MN VERY WELL EARLIER THIS AFTERNOON...SO USED SAME TO
HELP PROJECT CONVECTION INTO TONIGHT ACROSS MUCH OF THE CWA.
USED GFS40 THETA E ADVECTION TO SORT OUT TIMING AND INTENSITY
OF PCPN INTO MONDAY AFTERNOON. THROTTLED BACK SOMEWHAT ON
QPF VALUES OVER PORTION OF THE FA DUE TO SLACKENING POP CHANCES
LATER TONIGHT AND AGAIN ON MONDAY. LOCAL WRF MODEL STILL INDICATING
VERY IMPRESSIVE 850MB TRANSPORT VECTOR CONVERGENCE OVER MUCH OF
THE FA LATE THIS AFTN INTO THIS EVENING...WITH SLACKENING VALUES
NOTED OVER SW PORTION OF CWA BY 06Z. WITH THAT SAID ANTICIPATE
BEST CHANCES FOR ANY FLOOD POTENTIAL FOR REMAINDER OF FLASH
FLOOD WATCH REGION WILL BE EAST OF A LINE...FROM ST CLOUD TO
HUTCHINSON...TO WINNEBAGO. 50H LOW OVER WESTERN DAKOTAS WILL
BECOME VERTICALLY STACKED WITH SFC CYCLONE BY MON/12Z TIME FRAME
ABOVE SE SODAK. SYSTEM WILL RETROGRADE INTO SE NODAK BY EARLY
MONDAY EVENING. BEST CHANCES FOR POPS CLEARLY INDICATED OVER
NORTHERN HALF OF FA MONDAY AFTN...IN ASSOCIATION WITH BEST
THETA E ADVECTION COUPLED WITH POSITION OF RIGHT REAR QUAD RELATED
TO 130KT JET CORE ABOVE NORTHERN ONTARIO.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 355 PM CDT SUN MAY 19 2013
BRIEF DISCUSSION DUE TO ONGOING STORMS. STUBBORN LOW PRESSURE SYSTEM
IN SOUTH DAKOTA LOOKS LIKE IT WILL DRIFT EAST...STILL OVER MN ON
WEDNESDAY. TROUGH AXIS SWINGS BY TO THE SOUTH EARLY WEDNESDAY...AND
HAVE THUS ENDED MENTION OF STORMS TUESDAY NIGHT. WILL KEEP MENTION
OF SHOWERS WEDNESDAY AND WED NIGHT. MOSTLY CLOUDY AND COOL WEATHER
EXPECTED AND HAVE LOWERED MAX TEMPS. UPPER LOW STILL CLOSE ENOUGH TO
MERIT KEEPING A CHANCE OF SHOWERS INTO THURSDAY IN THE EAST. THEN
UPPER RIDGE APPROACHES. CANADIAN SURFACE HIGH MAKES A GLANCING BLOW
AND WINDS MAY BE LIGHT ENOUGH THURSDAY NIGHT TO ALLOW TEMPS TO DROP
INTO THE UPPER 30S FROM MILLE LACS LAKE TO RICE LAKE AND LADYSMITH.
SOME VARIATION IN MODELS AS TO HOW LONG THE UPPER RIDGE WILL REMAIN
OVER THE AREA LATE THIS WEEK. SOME GUIDANCE SUGGESTS IT MOVING EAST
QUICKLY ENOUGH TO BRING IN ANOTHER CHANCE OF STORMS SATURDAY AND
SUNDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1042 PM CDT SUN MAY 19 2013
THE AREA OF SHOWERS AND THUNDERSTORMS OVER SOUTHEASTERN MN AND
WEST CENTRAL WI WILL GRADUALLY FILL BACK IN TO THE NORTH AND WEST
ACROSS CENTRAL MN OVERNIGHT...WHICH IS ILLUSTRATED BY THE HRRR
MODEL. MVFR CIGS/VSBYS IN THE SHRA ARE EXPECTED...ALONG WITH IFR
CIGS FROM KSTC-KAXN. AFTER 15Z MONDAY...EXPECT A LULL IN
CONVECTION UNTIL DAYTIME HEATING CAUSES THE NEXT ROUND OF
POTENTIALLY STRONG TO SEVERE THUNDERSTORMS TO DEVELOP. WINDS WILL
BE SOUTHEASTERLY AOB 10 KTS OVERNIGHT...THEN BECOME GUSTY BY LATE
MORNING MONDAY AND VEER SLIGHTLY TO MORE SOUTH/SOUTHWESTERLY IN
DIRECTION.
KMSP...
EXPECT THE SHOWERS OVER SOUTHEASTERN MN TO GRADUALLY EXPAND BACK
WEST/NORTHWEST AT THE START OF THE PERIOD...THEN TAPER OFF BY 14Z
MONDAY WHEN WINDS BECOME GUSTY. CIGS MAY DIP TO 1500 FT OVERNIGHT
WITH THE SHOWER ACTIVITY...BUT THE PREVALENT CIG SHOULD BE
2500-3500FT. SOUTHEAST WINDS AROUND 150 DEGREES BEGIN GUSTING TO
25 KTS BY 15Z...THEN VEER TO AROUND 200 DEGREES BY 18Z WITH GUSTS
CONTINUING.
/OUTLOOK FOR KMSP/
TUE...VFR/MVFR CIGS. SHRA/TSRA LIKELY. S-SW WIND 5 KTS.
WED...VFR/MVFR CIGS. SHRA LIKELY. NE WIND 5-10 KTS.
THU...VFR. NE WINDS 10 KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...FLASH FLOOD WATCH THROUGH MONDAY EVENING FOR MNZ041>045-047>053-
057>063-066>070-075>078-084-085-093.
WI...FLASH FLOOD WATCH THROUGH MONDAY EVENING FOR WIZ014>016-023>028.
&&
$$
SHORT TERM...AJZ
LONG TERM...TDK
AVIATION...LS
000
FXUS63 KMPX 192354
AFDMPX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
654 PM CDT SUN MAY 19 2013
.UPDATE...
FOR 00Z AVIATION DISCUSSION BELOW
&&
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 345 PM CDT SUN MAY 19 2013
NARROW AREA OF MODERATE TO STRONG THUNDERSTORMS NOTED ON RADAR
FROM TWIN CITIES SOUTH INTO EASTERN FREEBORN COUNTY. HRRR HANDLED
INTIATION OF THIS ACTIVITY OVER FAR NORTHERN IOWA AND FAR SOUTH
CENTRAL MN VERY WELL EARLIER THIS AFTERNOON...SO USED SAME TO
HELP PROJECT CONVECTION INTO TONIGHT ACROSS MUCH OF THE CWA.
USED GFS40 THETA E ADVECTION TO SORT OUT TIMING AND INTENSITY
OF PCPN INTO MONDAY AFTERNOON. THROTTLED BACK SOMEWHAT ON
QPF VALUES OVER PORTION OF THE FA DUE TO SLACKENING POP CHANCES
LATER TONIGHT AND AGAIN ON MONDAY. LOCAL WRF MODEL STILL INDICATING
VERY IMPRESSIVE 850MB TRANSPORT VECTOR CONVERGENCE OVER MUCH OF
THE FA LATE THIS AFTN INTO THIS EVENING...WITH SLACKENING VALUES
NOTED OVER SW PORTION OF CWA BY 06Z. WITH THAT SAID ANTICIPATE
BEST CHANCES FOR ANY FLOOD POTENTIAL FOR REMAINDER OF FLASH
FLOOD WATCH REGION WILL BE EAST OF A LINE...FROM ST CLOUD TO
HUTCHINSON...TO WINNEBAGO. 50H LOW OVER WESTERN DAKOTAS WILL
BECOME VERTICALLY STACKED WITH SFC CYCLONE BY MON/12Z TIME FRAME
ABOVE SE SODAK. SYSTEM WILL RETROGRADE INTO SE NODAK BY EARLY
MONDAY EVENING. BEST CHANCES FOR POPS CLEARLY INDICATED OVER
NORTHERN HALF OF FA MONDAY AFTN...IN ASSOCIATION WITH BEST
THETA E ADVECTION COUPLED WITH POSITION OF RIGHT REAR QUAD RELATED
TO 130KT JET CORE ABOVE NORTHERN ONTARIO.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 355 PM CDT SUN MAY 19 2013
BRIEF DISCUSSION DUE TO ONGOING STORMS. STUBBORN LOW PRESSURE SYSTEM
IN SOUTH DAKOTA LOOKS LIKE IT WILL DRIFT EAST...STILL OVER MN ON
WEDNESDAY. TROUGH AXIS SWINGS BY TO THE SOUTH EARLY WEDNESDAY...AND
HAVE THUS ENDED MENTION OF STORMS TUESDAY NIGHT. WILL KEEP MENTION
OF SHOWERS WEDNESDAY AND WED NIGHT. MOSTLY CLOUDY AND COOL WEATHER
EXPECTED AND HAVE LOWERED MAX TEMPS. UPPER LOW STILL CLOSE ENOUGH TO
MERIT KEEPING A CHANCE OF SHOWERS INTO THURSDAY IN THE EAST. THEN
UPPER RIDGE APPROACHES. CANADIAN SURFACE HIGH MAKES A GLANCING BLOW
AND WINDS MAY BE LIGHT ENOUGH THURSDAY NIGHT TO ALLOW TEMPS TO DROP
INTO THE UPPER 30S FROM MILLE LACS LAKE TO RICE LAKE AND LADYSMITH.
SOME VARIATION IN MODELS AS TO HOW LONG THE UPPER RIDGE WILL REMAIN
OVER THE AREA LATE THIS WEEK. SOME GUIDANCE SUGGESTS IT MOVING EAST
QUICKLY ENOUGH TO BRING IN ANOTHER CHANCE OF STORMS SATURDAY AND
SUNDAY.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING)
ISSUED AT 653 PM CDT SUN MAY 19 2013
CONVECTIVE COMPLEX OF SHOWERS AND THUNDERSTORMS WILL MAINLY AFFECT
NORTHERN/EASTERN TAF SITES THIS EVENING /KAXN-KSTC-KEAU/...WITH
COVERAGE BECOMING MORE WORTHY ONLY OF A VICINITY MENTION AFTER
02Z. COULD BE SCATTERED SHOWERS AND THUNDERSTORMS AROUND THROUGH
TONIGHT AS THE UPPER LOW ROTATES INTO THE AREA. AFTER SUNSET THIS
EVENING HOWEVER...THE STRONG STORMS SHOULD HOLD OFF UNTIL DIURNAL
DESTABILIZATION OCCURS AFTER 17Z MONDAY. LOOKING LIKE ANOTHER
AFTERNOON WITH A DECENT RISK OF SEVERE THUNDERSTORMS. WINDS WILL
PRIMARILY BE SOUTHEASTERLY THROUGH MONDAY MORNING...WITH GUSTS TO
BETWEEN 20 AND 25 KTS DEVELOPING BY 17Z MONDAY. THE DIRECTIONAL
COMPONENT WILL BECOME MORE SOUTH-SOUTHWESTERLY MONDAY AFTERNOON
AS THE SURFACE LOW APPROACHES.
KMSP...
THERE WILL BE A SHORT BREAK IN THE SHOWER/THUNDERSTORM ACTIVITY
THROUGH SUNSET...AND THEN WIDELY SCATTERED SHOWERS AND
THUNDERSTORMS WILL BE POSSIBLE FROM AROUND 02Z THROUGH 09Z. AFTER
THE NOCTURNAL ACTIVITY...THERE SHOULD BE A BREAK UNTIL DIURNAL
HEATING AIDS IN THUNDERSTORM DEVELOPMENT ON MONDAY AFTERNOON. CIGS
SHOULD BE MOSTLY VFR WITH THE EXCEPTION OF MVFR IN SHRA.
/OUTLOOK FOR KMSP/
MON...VFR/MVFR CIGS. SHRA/TSRA LIKELY. S-SSE WIND 10-15 G 25 KTS.
TUE...VFR/MVFR CIGS. SHRA/TSRA LIKELY. S-SW WIND 5 KTS.
WED...VFR/MVFR CIGS. SHRA LIKELY. NE WIND 5-10 KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...FLASH FLOOD WATCH THROUGH MONDAY EVENING FOR MNZ041>045-047>053-
057>063-066>070-075>078-084-085-093.
WI...FLASH FLOOD WATCH THROUGH MONDAY EVENING FOR WIZ014>016-023>028.
&&
$$
SHORT TERM...AJZ
LONG TERM...TDK
AVIATION...LS
000
FXUS63 KMPX 192123
AFDMPX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
359 PM CDT SUN MAY 19 2013
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 345 PM CDT SUN MAY 19 2013
NARROW AREA OF MODERATE TO STRONG THUNDERSTORMS NOTED ON RADAR
FROM TWIN CITIES SOUTH INTO EASTERN FREEBORN COUNTY. HRRR HANDLED
INTIATION OF THIS ACTIVITY OVER FAR NORTHERN IOWA AND FAR SOUTH
CENTRAL MN VERY WELL EARLIER THIS AFTERNOON...SO USED SAME TO
HELP PROJECT CONVECTION INTO TONIGHT ACROSS MUCH OF THE CWA.
USED GFS40 THETA E ADVECTION TO SORT OUT TIMING AND INTENSITY
OF PCPN INTO MONDAY AFTERNOON. THROTTLED BACK SOMEWHAT ON
QPF VALUES OVER PORTION OF THE FA DUE TO SLACKENING POP CHANCES
LATER TONIGHT AND AGAIN ON MONDAY. LOCAL WRF MODEL STILL INDICATING
VERY IMPRESSIVE 850MB TRANSPORT VECTOR CONVERGENCE OVER MUCH OF
THE FA LATE THIS AFTN INTO THIS EVENING...WITH SLACKENING VALUES
NOTED OVER SW PORTION OF CWA BY 06Z. WITH THAT SAID ANTICIPATE
BEST CHANCES FOR ANY FLOOD POTENTIAL FOR REMAINDER OF FLASH
FLOOD WATCH REGION WILL BE EAST OF A LINE...FROM ST CLOUD TO
HUTCHINSON...TO WINNEBAGO. 50H LOW OVER WESTERN DAKOTAS WILL
BECOME VERTICALLY STACKED WITH SFC CYCLONE BY MON/12Z TIME FRAME
ABOVE SE SODAK. SYSTEM WILL RETROGRADE INTO SE NODAK BY EARLY
MONDAY EVENING. BEST CHANCES FOR POPS CLEARLY INDICATED OVER
NORTHERN HALF OF FA MONDAY AFTN...IN ASSOCIATION WITH BEST
THETA E ADVECTION COUPLED WITH POSITION OF RIGHT REAR QUAD RELATED
TO 130KT JET CORE ABOVE NORTHERN ONTARIO.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 355 PM CDT SUN MAY 19 2013
BRIEF DISCUSSION DUE TO ONGOING STORMS. STUBBORN LOW PRESSURE SYSTEM
IN SOUTH DAKOTA LOOKS LIKE IT WILL DRIFT EAST...STILL OVER MN ON
WEDNESDAY. TROUGH AXIS SWINGS BY TO THE SOUTH EARLY WEDNESDAY...AND
HAVE THUS ENDED MENTION OF STORMS TUESDAY NIGHT. WILL KEEP MENTION
OF SHOWERS WEDNESDAY AND WED NIGHT. MOSTLY CLOUDY AND COOL WEATHER
EXPECTED AND HAVE LOWERED MAX TEMPS. UPPER LOW STILL CLOSE ENOUGH TO
MERIT KEEPING A CHANCE OF SHOWERS INTO THURSDAY IN THE EAST. THEN
UPPER RIDGE APPROACHES. CANADIAN SURFACE HIGH MAKES A GLANCING BLOW
AND WINDS MAY BE LIGHT ENOUGH THURSDAY NIGHT TO ALLOW TEMPS TO DROP
INTO THE UPPER 30S FROM MILLE LACS LAKE TO RICE LAKE AND LADYSMITH.
SOME VARIATION IN MODELS AS TO HOW LONG THE UPPER RIDGE WILL REMAIN
OVER THE AREA LATE THIS WEEK. SOME GUIDANCE SUGGESTS IT MOVING EAST
QUICKLY ENOUGH TO BRING IN ANOTHER CHANCE OF STORMS SATURDAY AND
SUNDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY MORNING)
ISSUED AT 1250 PM CDT SUN MAY 19 2013
WARM FRONTAL BOUNDARY WHICH WAS CATALYST FOR EARLY MORNING
MODERATE TO HEAVY RAIN ACTIVITY CURRENTLY TREKKING INTO NORTHERN
MN. ANOTHER SHORT WAVE INITIATING ADDITIONAL CONVECTIVE ACTIVITY
OVER SW MN AND WESTERN IOWA. PRETTY STEEP LAPSE RATES NOTED
THIS AFTN ACROSS THE REGION. 12Z MSP UPPER AIR SOUNDING CONFIRMING
THIS FORECAST. USED HRRR MODEL WITH NEEDED TWEAKING TO ADVECT
SECOND ROUND OF CONVECTION INTO TAF REGION MAINLY LATE THIS
AFTN-INTO THE EARLY EVENING HOURS. BEST CHANCE FOR THUNDER
WILL REMAIN SOUTH OF A LINE FROM CANBY TO LAKEVILLE TO EAU CLAIRE.
STILL MOST OF ACTIVITY WILL BE OF SHOWERY TYPE VARIETY. LOOK
FOR MVFR CIGS AND VSBYS WITH MUCH OF THIS ACTIVITY. ANOTHER
ROUND OF MAINLY SHOWERS SHOULD REAPPEAR OVER THE TAF REGION
AFTER ABOUT 08Z...AND CONTINUE UP UNTIL ABOUT 14Z. COULD
EASILY BE SEVERAL HOURS OF LOW END MVFR CIGS AT MOST LOCATIONS
WITH THIS ACTIVITY...WITH KAXN VFR. LOOK FOR A THIRD ROUND
OF CONVECTIVE ACTIVITY AFTER 19-20Z TIME FRAME ON MONDAY.
MODERATE SE FLOW WILL RELAX TO LIGHT SE FLOW OVERNIGHT...WITH
A MORE MDT SOUTHERLY TO EVEN SSW BENT ANTICIPATED BY 20/17Z
AND THEN LASTING THROUGH END OF PERIOD.
KMSP...ATMOSPHERE IS BEING PRIMED WITH HEATING FOR ADDITIONAL
CONVECTIVE ACTIVITY TO MARCH THROUGH BY LATE THIS AFTERNOON.
LOOK FOR OCNL MVFR CIGS/VSBYS WITH ISOLATED TO SCT THUNDERSTORMS.
SECOND ROUND OF CONVECTIVE ACTIVITY WILL INITIATE AROUND 08Z
TIME FRAME...WITH SLACKENING LAPSE RATES POINTING TO MAINLY
SHOWERS. MDT SE FLOW WILL DECOUPLE TO BELOW 10KTS BY 03Z...AND
RETURN TO MDT SE FLOW BY 14Z. BEST CHANCE FOR A MORE SCT SHOWER
SITUATION WILL BE SEEN ON MONDAY BETWEEN 19Z AND 23Z TIME FRAME
...WITH ONCE AGAIN OCNL MVFR CIGS/VSBYS.
/OUTLOOK FOR KMSP/
MON...VFR/MVFR CIGS. SHRA/TSRA LIKELY. S-SSE WIND 10-15 KTS.
TUE...VFR/MVFR CIGS. SHRA/TSRA LIKELY. E-NE WIND 5 KTS.
WED...VFR/MVFR CIGS. SHRA LIKELY. NE WIND 5-10 KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...FLASH FLOOD WATCH THROUGH MONDAY EVENING FOR MNZ041>045-047>053-
057>063-066>070-075>078-084-085-093.
WI...FLASH FLOOD WATCH THROUGH MONDAY EVENING FOR WIZ014>016-023>028.
&&
$$
SHORT TERM...AJZ
LONG TERM...TDK
AVIATION...AJZ
000
FXUS63 KMPX 192054
AFDMPX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
354 PM CDT SUN MAY 19 2013
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 345 PM CDT SUN MAY 19 2013
NARROW AREA OF MODERATE TO STRONG THUNDERSTORMS NOTED ON RADAR
FROM TWIN CITIES SOUTH INTO EASTERN FREEBORN COUNTY. HRRR HANDLED
INTIATION OF THIS ACTIVITY OVER FAR NORTHERN IOWA AND FAR SOUTH
CENTRAL MN VERY WELL EARLIER THIS AFTERNOON...SO USED SAME TO
HELP PROJECT CONVECTION INTO TONIGHT ACROSS MUCH OF THE CWA.
USED GFS40 THETA E ADVECTION TO SORT OUT TIMING AND INTENSITY
OF PCPN INTO MONDAY AFTERNOON. THROTTLED BACK SOMEWHAT ON
QPF VALUES OVER PORTION OF THE FA DUE TO SLACKENING POP CHANCES
LATER TONIGHT AND AGAIN ON MONDAY. LOCAL WRF MODEL STILL INDICATING
VERY IMPRESSIVE 850MB TRANSPORT VECTOR CONVERGENCE OVER MUCH OF
THE FA LATE THIS AFTN INTO THIS EVENING...WITH SLACKENING VALUES
NOTED OVER SW PORTION OF CWA BY 06Z. WITH THAT SAID ANTICIPATE
BEST CHANCES FOR ANY FLOOD POTENTIAL FOR REMAINDER OF FLASH
FLOOD WATCH REGION WILL BE EAST OF A LINE...FROM ST CLOUD TO
HUTCHINSON...TO WINNEBAGO. 50H LOW OVER WESTERN DAKOTAS WILL
BECOME VERTICALLY STACKED WITH SFC CYCLONE BY MON/12Z TIME FRAME
ABOVE SE SODAK. SYSTEM WILL RETROGRADE INTO SE NODAK BY EARLY
MONDAY EVENING. BEST CHANCES FOR POPS CLEARLY INDICATED OVER
NORTHERN HALF OF FA MONDAY AFTN...IN ASSOCIATION WITH BEST
THETA E ADVECTION COUPLED WITH POSITION OF RIGHT REAR QUAD RELATED
TO 130KT JET CORE ABOVE NORTHERN ONTARIO.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 345 PM CDT SUN MAY 19 2013
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY MORNING)
ISSUED AT 1250 PM CDT SUN MAY 19 2013
WARM FRONTAL BOUNDARY WHICH WAS CATALYST FOR EARLY MORNING
MODERATE TO HEAVY RAIN ACTIVITY CURRENTLY TREKKING INTO NORTHERN
MN. ANOTHER SHORT WAVE INITIATING ADDITIONAL CONVECTIVE ACTIVITY
OVER SW MN AND WESTERN IOWA. PRETTY STEEP LAPSE RATES NOTED
THIS AFTN ACROSS THE REGION. 12Z MSP UPPER AIR SOUNDING CONFIRMING
THIS FORECAST. USED HRRR MODEL WITH NEEDED TWEAKING TO ADVECT
SECOND ROUND OF CONVECTION INTO TAF REGION MAINLY LATE THIS
AFTN-INTO THE EARLY EVENING HOURS. BEST CHANCE FOR THUNDER
WILL REMAIN SOUTH OF A LINE FROM CANBY TO LAKEVILLE TO EAU CLAIRE.
STILL MOST OF ACTIVITY WILL BE OF SHOWERY TYPE VARIETY. LOOK
FOR MVFR CIGS AND VSBYS WITH MUCH OF THIS ACTIVITY. ANOTHER
ROUND OF MAINLY SHOWERS SHOULD REAPPEAR OVER THE TAF REGION
AFTER ABOUT 08Z...AND CONTINUE UP UNTIL ABOUT 14Z. COULD
EASILY BE SEVERAL HOURS OF LOW END MVFR CIGS AT MOST LOCATIONS
WITH THIS ACTIVITY...WITH KAXN VFR. LOOK FOR A THIRD ROUND
OF CONVECTIVE ACTIVITY AFTER 19-20Z TIME FRAME ON MONDAY.
MODERATE SE FLOW WILL RELAX TO LIGHT SE FLOW OVERNIGHT...WITH
A MORE MDT SOUTHERLY TO EVEN SSW BENT ANTICIPATED BY 20/17Z
AND THEN LASTING THROUGH END OF PERIOD.
KMSP...ATMOSPHERE IS BEING PRIMED WITH HEATING FOR ADDITIONAL
CONVECTIVE ACTIVITY TO MARCH THROUGH BY LATE THIS AFTERNOON.
LOOK FOR OCNL MVFR CIGS/VSBYS WITH ISOLATED TO SCT THUNDERSTORMS.
SECOND ROUND OF CONVECTIVE ACTIVITY WILL INITIATE AROUND 08Z
TIME FRAME...WITH SLACKENING LAPSE RATES POINTING TO MAINLY
SHOWERS. MDT SE FLOW WILL DECOUPLE TO BELOW 10KTS BY 03Z...AND
RETURN TO MDT SE FLOW BY 14Z. BEST CHANCE FOR A MORE SCT SHOWER
SITUATION WILL BE SEEN ON MONDAY BETWEEN 19Z AND 23Z TIME FRAME
...WITH ONCE AGAIN OCNL MVFR CIGS/VSBYS.
/OUTLOOK FOR KMSP/
MON...VFR/MVFR CIGS. SHRA/TSRA LIKELY. S-SSE WIND 10-15 KTS.
TUE...VFR/MVFR CIGS. SHRA/TSRA LIKELY. E-NE WIND 5 KTS.
WED...VFR/MVFR CIGS. SHRA LIKELY. NE WIND 5-10 KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...FLASH FLOOD WATCH THROUGH MONDAY EVENING FOR MNZ041>045-047>053-
057>063-066>070-075>078-084-085-093.
WI...FLASH FLOOD WATCH THROUGH MONDAY EVENING FOR WIZ014>016-023>028.
&&
$$
SHORT TERM...AJZ
LONG TERM...TDK
AVIATION...AJZ
000
FXUS63 KMPX 191802
AFDMPX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
1250 PM CDT SUN MAY 19 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 314 AM CDT SUN MAY 19 2013
TODAY-TONIGHT...UPPER LEVEL RIDGE AXIS HAS SHIFTED INTO NRN
MN...EXTENDING SE THRU CENTRAL WI...AND WILL CONTINUE TO PUSH OFF TO
THE EAST WHILE A LARGE TROUGH DIGS DEEPER AND EXPANDS OVER THE
PLAINS STATES. AT THE SFC...A LOW PRES CENTER OVER CENTRAL SD UNDER
THE UPPER LOW WILL WOBBLE OVER CENTRAL-ERN SD...WITH A WMFNT
EXTENDING OVER SRN MN SLOWLY NUDGING N. WARM AIR AND ADDITIONAL
MOISTURE CONTINUE TO SURGE NWD INTO THE REGION WITHIN MERIDIONAL
FLOW BETWEEN THE EXITING RIDGE AND STRENGTHENING TROF...EVIDENCED BY
DEWPOINTS STILL IN THE 60S AND PWATS OVER 1.25 INCHES. ALTHOUGH THE
MORE FORMIDABLE SETUP OF THE DEEPENING SFC LOW UNDER THE ROTATING
UPPER LOW IN ERN SD WILL NOT SET UP UNTIL TNGT...A FEW BANDS OF
RAIN/TSTMS WILL PUSH THRU THE REGION DURG THE DAY TDA. SOME OF THE
RAIN MAY BE HEAVY AT TIMES...AND THERE IS STILL THE SLGT RISK OF
SEVERE TSTMS. ENHANCED UPPER LEVEL JETTING COMBINED WITH SURGING
MOISTURE /HENCE GREATER INSTABILITY/ AND STEEP LAPSE RATES WILL
CONTRIBUTE TO AN OVERALL ENVIRONMENT CAPABLE OF PRODUCING LARGE HAIL
AND DAMAGING WINDS...ESPECIALLY THIS AFTN AND EVENING OVER SRN
PORTIONS OF THE MPX CWFA. RADAR WILL NEED TO BE CONTINUALLY
MONITORED FOR NOT ONLY THE DEVELOPMENT OF STRONG/SEVERE TSTMS BUT
ALSO FOR THE POTENTIAL OF TRAINING TSTMS WHICH WOULD LEAD TO HEAVY
PERSISTENT RAIN AND POSSIBLY FLOODING /SEE HYDROLOGY SECTION/. THE
RAIN SHIELD WILL BE MORE PROMINENT LATE THIS AFTN THRU TNGT AS THE
UPPER LOW DEVELOPS SEVERAL SHORTWAVE SPOKES AROUND IT THAT WILL
ROTATE THRU THE AREA WHILE LOW LEVEL CONVERGENCE IS ENHANCED ARND A
SFC TROUGH BEING DRAGGED INTO THE AREA ARND THE SD SFC LOW. THE NET
EFFECT WILL BE MORE WIDESPREAD RAIN OVERNIGHT TNGT...SOME OF WHICH
MAY BE HEAVY AT TIMES.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 314 AM CDT SUN MAY 19 2013
EXPECT WEAKENING CONVECTION TO BE ONGOING ACROSS MOST OF THE AREA
MONDAY MORNING OUT AHEAD OF THE DAKOTAS SURFACE LOW AND
FRONT...ACROSS THE WARM SECTOR. SHOULD SEE DESTABILIZATION AHEAD
OF SURFACE LOW AND FRONT DURING THE DAY. THE NEARLY STATIONARY
BOUNDARY TO THE NORTH WILL EVENTUALLY GIVE WAY TO LARGE SCALE LIFT
WITH THE APPROACH OF THE UPPER TROUGH...AND SURFACE SYSTEM
OCCLUDES. CAPE SHOULD BE SUFFICIENT ALONG WITH SHEAR AS THE DAY
PROGRESSES...WITH THE GREATEST THREAT OF SEVERE MAINLY ACROSS THE
EASTERN CWA...NEAR FRONTAL/SFC LOW PRESSURE INTERSECTION. PER DAY2
OUTLOOK FROM SPC...MAIN THREAT WILL BE LARGE HAIL...STRONG
WINDS...AND HEAVY RAIN AS THE SYSTEM IS SLOW TO MAKE EASTWARD
PROGRESS. TEMPERATURES WILL DEPEND ON HOW MUCH SUNSHINE...IF ANY
OCCURS DURING THE DAY. WILL HAVE SIGNIFICANT CLOUD DEBRIS...WITH
BEST CHANCE OF SEEING SUN IN THE FAR SOUTH MONDAY AFTERNOON.
THE UPPER LOW WILL GRADUALLY SHIFT EAST AND WEAKEN AS ANOTHER
STRONG TROUGH MOVES ACROSS THE WESTERN CONUS. THIS SHOULD IMPROVE
THE WEATHER ACROSS THE MIDSECTION OF THE COUNTRY...THURSDAY AND
FRIDAY...AS RIDGING ALOFT TAKES OVER. MUCH COOLER TEMPERATURES
WILL DIVE IN BEHIND THE DEPARTING SYSTEM...MAKING FOR A COOL END
OF THE WEEK. THE 00Z DETERMINISTIC ECMWF BRINGS IN ANOTHER CHANCE
OF RAIN INTO THE AREA LATER IN THE WEEKEND...AS THE WESTERN TROUGH
MOVES SLOWLY EAST. THE GFS IS A BIT SLOWER WITH OVERALL
PROGRESSION OF THE LOW AND BREAK DOWN OF THE RIDGE. WILL START TO
BRING IN SMALL CHANCE POPS INTO MAINLY THE WESTERN CWA SATURDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY MORNING)
ISSUED AT 1250 PM CDT SUN MAY 19 2013
WARM FRONTAL BOUNDARY WHICH WAS CATALYST FOR EARLY MORNING
MODERATE TO HEAVY RAIN ACTIVITY CURRENTLY TREKKING INTO NORTHERN
MN. ANOTHER SHORT WAVE INITIATING ADDITIONAL CONVECTIVE ACTIVITY
OVER SW MN AND WESTERN IOWA. PRETTY STEEP LAPSE RATES NOTED
THIS AFTN ACROSS THE REGION. 12Z MSP UPPER AIR SOUNDING CONFIRMING
THIS FORECAST. USED HRRR MODEL WITH NEEDED TWEAKING TO ADVECT
SECOND ROUND OF CONVECTION INTO TAF REGION MAINLY LATE THIS
AFTN-INTO THE EARLY EVENING HOURS. BEST CHANCE FOR THUNDER
WILL REMAIN SOUTH OF A LINE FROM CANBY TO LAKEVILLE TO EAU CLAIRE.
STILL MOST OF ACTIVITY WILL BE OF SHOWERY TYPE VARIETY. LOOK
FOR MVFR CIGS AND VSBYS WITH MUCH OF THIS ACTIVITY. ANOTHER
ROUND OF MAINLY SHOWERS SHOULD REAPPEAR OVER THE TAF REGION
AFTER ABOUT 08Z...AND CONTINUE UP UNTIL ABOUT 14Z. COULD
EASILY BE SEVERAL HOURS OF LOW END MVFR CIGS AT MOST LOCATIONS
WITH THIS ACTIVITY...WITH KAXN VFR. LOOK FOR A THIRD ROUND
OF CONVECTIVE ACTIVITY AFTER 19-20Z TIME FRAME ON MONDAY.
MODERATE SE FLOW WILL RELAX TO LIGHT SE FLOW OVERNIGHT...WITH
A MORE MDT SOUTHERLY TO EVEN SSW BENT ANTICIPATED BY 20/17Z
AND THEN LASTING THROUGH END OF PERIOD.
KMSP...ATMOSPHERE IS BEING PRIMED WITH HEATING FOR ADDITIONAL
CONVECTIVE ACTIVITY TO MARCH THROUGH BY LATE THIS AFTERNOON.
LOOK FOR OCNL MVFR CIGS/VSBYS WITH ISOLATED TO SCT THUNDERSTORMS.
SECOND ROUND OF CONVECTIVE ACTIVITY WILL INITIATE AROUND 08Z
TIME FRAME...WITH SLACKENING LAPSE RATES POINTING TO MAINLY
SHOWERS. MDT SE FLOW WILL DECOUPLE TO BELOW 10KTS BY 03Z...AND
RETURN TO MDT SE FLOW BY 14Z. BEST CHANCE FOR A MORE SCT SHOWER
SITUATION WILL BE SEEN ON MONDAY BETWEEN 19Z AND 23Z TIME FRAME
...WITH ONCE AGAIN OCNL MVFR CIGS/VSBYS.
/OUTLOOK FOR KMSP/
MON...VFR/MVFR CIGS. SHRA/TSRA LIKELY. S-SSE WIND 10-15 KTS.
TUE...VFR/MVFR CIGS. SHRA/TSRA LIKELY. E-NE WIND 5 KTS.
WED...VFR/MVFR CIGS. SHRA LIKELY. NE WIND 5-10 KTS.
&&
.HYDROLOGY...
ISSUED AT 314 AM CDT SUN MAY 19 2013
MODEL GUIDANCE AND WPC QPF INDICATE WIDESPREAD 2-3 INCHES OF
ADDITIONAL RAINFALL THRU SUNDAY EVE ACRS THE ENTIRE CWFA. IN
ADDITION...CENTRAL AND ERN PORTIONS OF THE MPX CWFA RECEIVED 1-2
INCHES OF RAINFALL YESTERDAY. CONSIDERING THE RAPID INCRS IN SOIL
MOISTURE OVER CENTRAL AND NRN PORTIONS OF THE CWFA...PLUS WHAT IS
EXPECTED OVER THE NEXT 24-36 HRS...HAVE OPTED TO EXPAND AND EXTEND
THE FLASH FLOOD WATCH OVER MUCH OF THE MPX CWFA. MODEL RAINFALL
AMOUNTS ACTUALLY PIN THE LOWEST ADDITIONAL RAINFALL OVER SERN MN.
HOWEVER...IT IS THAT SAME REGION THAT ONLY 3 WEEKS AGO DEALT WITH
12-15 INCHES OF WET HEAVY SNOW...WHICH GREATLY ADDED TO SOIL
MOISTURE CAPACITY. CONFIDENCE IS NOT ALL THAT GREAT IN TRYING TO
HIGHLIGHT WHICH AREAS WOULD BE MORE SUSCEPTIBLE THAN OTHERS IN
SEEING FLASH FLOODING...BUT CONSIDERING THAT ANY TSTMS COULD
RAPIDLY PRODUCE HEAVY RAIN...AND THAT MORE WIDESPREAD RAINFALL IS
COMING LATE TNGT THRU MON EVE...FELT IT MOST PRUDENT TO EXPAND THE
AREA OF THE FLASH FLOOD WATCH TO PUT THE NOTICE OUT THAT HEAVY
RAIN COULD OCCUR AT ANY TIME AND QUICKLY EXACERBATE THE MOST MINOR
FLOODING CONCERNS INTO POTENTIAL FLASH FLOODING.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...FLASH FLOOD WATCH THROUGH MONDAY EVENING FOR MNZ041>045-047>053-
057>063-066>070-075>078-084-085-093.
WI...FLASH FLOOD WATCH THROUGH MONDAY EVENING FOR WIZ014>016-023>028.
&&
$$
SHORT TERM...JPC
LONG TERM...DWE
AVIATION...JPC
HYDROLOGY...JPC
000
FXUS63 KMPX 191311
AFDMPX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
811 AM CDT SUN MAY 19 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 314 AM CDT SUN MAY 19 2013
TODAY-TONIGHT...UPPER LEVEL RIDGE AXIS HAS SHIFTED INTO NRN
MN...EXTENDING SE THRU CENTRAL WI...AND WILL CONTINUE TO PUSH OFF TO
THE EAST WHILE A LARGE TROUGH DIGS DEEPER AND EXPANDS OVER THE
PLAINS STATES. AT THE SFC...A LOW PRES CENTER OVER CENTRAL SD UNDER
THE UPPER LOW WILL WOBBLE OVER CENTRAL-ERN SD...WITH A WMFNT
EXTENDING OVER SRN MN SLOWLY NUDGING N. WARM AIR AND ADDITIONAL
MOISTURE CONTINUE TO SURGE NWD INTO THE REGION WITHIN MERIDIONAL
FLOW BETWEEN THE EXITING RIDGE AND STRENGTHENING TROF...EVIDENCED BY
DEWPOINTS STILL IN THE 60S AND PWATS OVER 1.25 INCHES. ALTHOUGH THE
MORE FORMIDABLE SETUP OF THE DEEPENING SFC LOW UNDER THE ROTATING
UPPER LOW IN ERN SD WILL NOT SET UP UNTIL TNGT...A FEW BANDS OF
RAIN/TSTMS WILL PUSH THRU THE REGION DURG THE DAY TDA. SOME OF THE
RAIN MAY BE HEAVY AT TIMES...AND THERE IS STILL THE SLGT RISK OF
SEVERE TSTMS. ENHANCED UPPER LEVEL JETTING COMBINED WITH SURGING
MOISTURE /HENCE GREATER INSTABILITY/ AND STEEP LAPSE RATES WILL
CONTRIBUTE TO AN OVERALL ENVIRONMENT CAPABLE OF PRODUCING LARGE HAIL
AND DAMAGING WINDS...ESPECIALLY THIS AFTN AND EVENING OVER SRN
PORTIONS OF THE MPX CWFA. RADAR WILL NEED TO BE CONTINUALLY
MONITORED FOR NOT ONLY THE DEVELOPMENT OF STRONG/SEVERE TSTMS BUT
ALSO FOR THE POTENTIAL OF TRAINING TSTMS WHICH WOULD LEAD TO HEAVY
PERSISTENT RAIN AND POSSIBLY FLOODING /SEE HYDROLOGY SECTION/. THE
RAIN SHIELD WILL BE MORE PROMINENT LATE THIS AFTN THRU TNGT AS THE
UPPER LOW DEVELOPS SEVERAL SHORTWAVE SPOKES AROUND IT THAT WILL
ROTATE THRU THE AREA WHILE LOW LEVEL CONVERGENCE IS ENHANCED ARND A
SFC TROUGH BEING DRAGGED INTO THE AREA ARND THE SD SFC LOW. THE NET
EFFECT WILL BE MORE WIDESPREAD RAIN OVERNIGHT TNGT...SOME OF WHICH
MAY BE HEAVY AT TIMES.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 314 AM CDT SUN MAY 19 2013
EXPECT WEAKENING CONVECTION TO BE ONGOING ACROSS MOST OF THE AREA
MONDAY MORNING OUT AHEAD OF THE DAKOTAS SURFACE LOW AND
FRONT...ACROSS THE WARM SECTOR. SHOULD SEE DESTABILIZATION AHEAD
OF SURFACE LOW AND FRONT DURING THE DAY. THE NEARLY STATIONARY
BOUNDARY TO THE NORTH WILL EVENTUALLY GIVE WAY TO LARGE SCALE LIFT
WITH THE APPROACH OF THE UPPER TROUGH...AND SURFACE SYSTEM
OCCLUDES. CAPE SHOULD BE SUFFICIENT ALONG WITH SHEAR AS THE DAY
PROGRESSES...WITH THE GREATEST THREAT OF SEVERE MAINLY ACROSS THE
EASTERN CWA...NEAR FRONTAL/SFC LOW PRESSURE INTERSECTION. PER DAY2
OUTLOOK FROM SPC...MAIN THREAT WILL BE LARGE HAIL...STRONG
WINDS...AND HEAVY RAIN AS THE SYSTEM IS SLOW TO MAKE EASTWARD
PROGRESS. TEMPERATURES WILL DEPEND ON HOW MUCH SUNSHINE...IF ANY
OCCURS DURING THE DAY. WILL HAVE SIGNIFICANT CLOUD DEBRIS...WITH
BEST CHANCE OF SEEING SUN IN THE FAR SOUTH MONDAY AFTERNOON.
THE UPPER LOW WILL GRADUALLY SHIFT EAST AND WEAKEN AS ANOTHER
STRONG TROUGH MOVES ACROSS THE WESTERN CONUS. THIS SHOULD IMPROVE
THE WEATHER ACROSS THE MIDSECTION OF THE COUNTRY...THURSDAY AND
FRIDAY...AS RIDGING ALOFT TAKES OVER. MUCH COOLER TEMPERATURES
WILL DIVE IN BEHIND THE DEPARTING SYSTEM...MAKING FOR A COOL END
OF THE WEEK. THE 00Z DETERMINISTIC ECMWF BRINGS IN ANOTHER CHANCE
OF RAIN INTO THE AREA LATER IN THE WEEKEND...AS THE WESTERN TROUGH
MOVES SLOWLY EAST. THE GFS IS A BIT SLOWER WITH OVERALL
PROGRESSION OF THE LOW AND BREAK DOWN OF THE RIDGE. WILL START TO
BRING IN SMALL CHANCE POPS INTO MAINLY THE WESTERN CWA SATURDAY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 752 AM CDT SUN MAY 19 2013
ANOTHER WET TAF PERIOD. WMFNT MEANDERING FROM W-CENTRAL MN THROUGH
SE MN INTO FAR SW WI. BAND OF RA/TSRA THRUST THRU BETWEEN 11Z-13Z
THIS MRNG WITH -SHRA IN ITS WAKE. PRECIP GENERALLY WILL LAST UNTIL
15Z-16Z...THEN THERE LOOKS TO BE A DEFINITIVE BREAK IN THE PRECIP
WHILE THE WMFNT LIFTS N OF ALL THE TAF SITES. ADDITIONAL RA/TSRA
WILL RE-DEVELOP FROM THE W OVERNIGHT. TRICKY AS FAR AS TIMING OF
TSTMS SO THE THINKING WAS THAT CLOSE TO THE ONSET OF THIS NEXT
ROUND OF PRECIP WOULD BE TSTMS THEN AS THE PRECIP CONINUED...IT
WOULD BE PRIMARILY RA. WILL LOOK FOR CEILINGS TO DROP INTO MVFR
RANGE...NOT LIKELY TO GET TO IFR. VSBYS MAY WELL GET TO IFR DUE TO
RAINFALL INTENSITIES.
KMSP...MOD-HVY RAIN WITH EMBEDDED TSTMS PUSHING THRU ARND 12Z WITH
CONDITIONS QUICKLY IMPROVING BY 14Z. WILL HAVE A BREAK FROM PRECIP
THRU LATE AFTN...THEN CONVECTION EXPECTED TO RETURN BY THE EARLY
EVE HRS. TIMED IN THE PRECIP ARND 00Z WHICH LINES UP WELL WITH
SHORT-TERM MODEL GUIDANCE. PRECIP WILL THEN TRANSITION TO A MORE
STRATIFORM NATURE ONCE THE INITIAL TSTMS MOVE THRU...WITH
CONDITIONS HANGING IN THE MVFR AREA DUE TO LOWERED CEILINGS.
/OUTLOOK FOR KMSP/
MON...VFR/MVFR CIGS. SHRA/TSRA LIKELY. S WIND 10-15 KTS.
TUE...VFR/MVFR CIGS. SHRA/TSRA LIKELY. E-NE WIND 5 KTS.
WED...VFR/MVFR CIGS. SHRA LIKELY. NE WIND 5-10 KTS.
&&
.HYDROLOGY...
ISSUED AT 314 AM CDT SUN MAY 19 2013
MODEL GUIDANCE AND WPC QPF INDICATE WIDESPREAD 2-3 INCHES OF
ADDITIONAL RAINFALL THRU SUNDAY EVE ACRS THE ENTIRE CWFA. IN
ADDITION...CENTRAL AND ERN PORTIONS OF THE MPX CWFA RECEIVED 1-2
INCHES OF RAINFALL YESTERDAY. CONSIDERING THE RAPID INCRS IN SOIL
MOISTURE OVER CENTRAL AND NRN PORTIONS OF THE CWFA...PLUS WHAT IS
EXPECTED OVER THE NEXT 24-36 HRS...HAVE OPTED TO EXPAND AND EXTEND
THE FLASH FLOOD WATCH OVER MUCH OF THE MPX CWFA. MODEL RAINFALL
AMOUNTS ACTUALLY PIN THE LOWEST ADDITIONAL RAINFALL OVER SERN MN.
HOWEVER...IT IS THAT SAME REGION THAT ONLY 3 WEEKS AGO DEALT WITH
12-15 INCHES OF WET HEAVY SNOW...WHICH GREATLY ADDED TO SOIL
MOISTURE CAPACITY. CONFIDENCE IS NOT ALL THAT GREAT IN TRYING TO
HIGHLIGHT WHICH AREAS WOULD BE MORE SUSCEPTIBLE THAN OTHERS IN
SEEING FLASH FLOODING...BUT CONSIDERING THAT ANY TSTMS COULD
RAPIDLY PRODUCE HEAVY RAIN...AND THAT MORE WIDESPREAD RAINFALL IS
COMING LATE TNGT THRU MON EVE...FELT IT MOST PRUDENT TO EXPAND THE
AREA OF THE FLASH FLOOD WATCH TO PUT THE NOTICE OUT THAT HEAVY
RAIN COULD OCCUR AT ANY TIME AND QUICKLY EXACERBATE THE MOST MINOR
FLOODING CONCERNS INTO POTENTIAL FLASH FLOODING.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...FLASH FLOOD WATCH THROUGH MONDAY EVENING FOR MNZ041>045-047>053-
057>063-066>070-075>078-084-085-093.
WI...FLASH FLOOD WATCH THROUGH MONDAY EVENING FOR WIZ014>016-023>028.
&&
$$
SHORT TERM...JPC
LONG TERM...DWE
AVIATION...JPC
HYDROLOGY...JPC
000
FXUS63 KMPX 190847
AFDMPX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
347 AM CDT SUN MAY 19 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 314 AM CDT SUN MAY 19 2013
TODAY-TONIGHT...UPPER LEVEL RIDGE AXIS HAS SHIFTED INTO NRN
MN...EXTENDING SE THRU CENTRAL WI...AND WILL CONTINUE TO PUSH OFF TO
THE EAST WHILE A LARGE TROUGH DIGS DEEPER AND EXPANDS OVER THE
PLAINS STATES. AT THE SFC...A LOW PRES CENTER OVER CENTRAL SD UNDER
THE UPPER LOW WILL WOBBLE OVER CENTRAL-ERN SD...WITH A WMFNT
EXTENDING OVER SRN MN SLOWLY NUDGING N. WARM AIR AND ADDITIONAL
MOISTURE CONTINUE TO SURGE NWD INTO THE REGION WITHIN MERIDIONAL
FLOW BETWEEN THE EXITING RIDGE AND STRENGTHENING TROF...EVIDENCED BY
DEWPOINTS STILL IN THE 60S AND PWATS OVER 1.25 INCHES. ALTHOUGH THE
MORE FORMIDABLE SETUP OF THE DEEPENING SFC LOW UNDER THE ROTATING
UPPER LOW IN ERN SD WILL NOT SET UP UNTIL TNGT...A FEW BANDS OF
RAIN/TSTMS WILL PUSH THRU THE REGION DURG THE DAY TDA. SOME OF THE
RAIN MAY BE HEAVY AT TIMES...AND THERE IS STILL THE SLGT RISK OF
SEVERE TSTMS. ENHANCED UPPER LEVEL JETTING COMBINED WITH SURGING
MOISTURE /HENCE GREATER INSTABILITY/ AND STEEP LAPSE RATES WILL
CONTRIBUTE TO AN OVERALL ENVIRONMENT CAPABLE OF PRODUCING LARGE HAIL
AND DAMAGING WINDS...ESPECIALLY THIS AFTN AND EVENING OVER SRN
PORTIONS OF THE MPX CWFA. RADAR WILL NEED TO BE CONTINUALLY
MONITORED FOR NOT ONLY THE DEVELOPMENT OF STRONG/SEVERE TSTMS BUT
ALSO FOR THE POTENTIAL OF TRAINING TSTMS WHICH WOULD LEAD TO HEAVY
PERSISTENT RAIN AND POSSIBLY FLOODING /SEE HYDROLOGY SECTION/. THE
RAIN SHIELD WILL BE MORE PROMINENT LATE THIS AFTN THRU TNGT AS THE
UPPER LOW DEVELOPS SEVERAL SHORTWAVE SPOKES AROUND IT THAT WILL
ROTATE THRU THE AREA WHILE LOW LEVEL CONVERGENCE IS ENHANCED ARND A
SFC TROUGH BEING DRAGGED INTO THE AREA ARND THE SD SFC LOW. THE NET
EFFECT WILL BE MORE WIDESPREAD RAIN OVERNIGHT TNGT...SOME OF WHICH
MAY BE HEAVY AT TIMES.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 314 AM CDT SUN MAY 19 2013
EXPECT WEAKENING CONVECTION TO BE ONGOING ACROSS MOST OF THE AREA
MONDAY MORNING OUT AHEAD OF THE DAKOTAS SURFACE LOW AND
FRONT...ACROSS THE WARM SECTOR. SHOULD SEE DESTABILIZATION AHEAD
OF SURFACE LOW AND FRONT DURING THE DAY. THE NEARLY STATIONARY
BOUNDARY TO THE NORTH WILL EVENTUALLY GIVE WAY TO LARGE SCALE LIFT
WITH THE APPROACH OF THE UPPER TROUGH...AND SURFACE SYSTEM
OCCLUDES. CAPE SHOULD BE SUFFICIENT ALONG WITH SHEAR AS THE DAY
PROGRESSES...WITH THE GREATEST THREAT OF SEVERE MAINLY ACROSS THE
EASTERN CWA...NEAR FRONTAL/SFC LOW PRESSURE INTERSECTION. PER DAY2
OUTLOOK FROM SPC...MAIN THREAT WILL BE LARGE HAIL...STRONG
WINDS...AND HEAVY RAIN AS THE SYSTEM IS SLOW TO MAKE EASTWARD
PROGRESS. TEMPERATURES WILL DEPEND ON HOW MUCH SUNSHINE...IF ANY
OCCURS DURING THE DAY. WILL HAVE SIGNIFICANT CLOUD DEBRIS...WITH
BEST CHANCE OF SEEING SUN IN THE FAR SOUTH MONDAY AFTERNOON.
THE UPPER LOW WILL GRADUALLY SHIFT EAST AND WEAKEN AS ANOTHER
STRONG TROUGH MOVES ACROSS THE WESTERN CONUS. THIS SHOULD IMPROVE
THE WEATHER ACROSS THE MIDSECTION OF THE COUNTRY...THURSDAY AND
FRIDAY...AS RIDGING ALOFT TAKES OVER. MUCH COOLER TEMPERATURES
WILL DIVE IN BEHIND THE DEPARTING SYSTEM...MAKING FOR A COOL END
OF THE WEEK. THE 00Z DETERMINISTIC ECMWF BRINGS IN ANOTHER CHANCE
OF RAIN INTO THE AREA LATER IN THE WEEKEND...AS THE WESTERN TROUGH
MOVES SLOWLY EAST. THE GFS IS A BIT SLOWER WITH OVERALL
PROGRESSION OF THE LOW AND BREAK DOWN OF THE RIDGE. WILL START TO
BRING IN SMALL CHANCE POPS INTO MAINLY THE WESTERN CWA SATURDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1130 PM CDT SAT MAY 18 2013
A LULL IN SHOWER/THUNDERSTORM ACTIVITY WILL OCCUR AT THE TAF SITES UNTIL
NOCTURNAL CONVECTION OVER THE DAKOTAS SPILLS EASTWARD INTO THE
AREA. THE MODEL PREFERENCE THIS ISSUANCE WAS THE HRRR...WHICH
SEEMS TO HAVE A DECENT HANDLE ON THE CURRENT RADAR IMAGERY.
THEREFORE EXPECT SHOWER AND THUNDERSTORM ACTIVITY TO OVERSPREAD THE
AREA AFTER 07Z...REACHING CENTRAL AND EAST CENTRAL MN BY
DAYBREAK...AND WI SHORTLY THEREAFTER. AS THE PRECIP SETS IN...MVFR
CIGS WILL BE EXPECTED. CONFIDENCE ON TIMING OF THE SHOWER AND
THUNDERSTORM CHNACES IS LOW. AFTER THE NOCTURNAL ACTIVITY WANES IN
THE MORNING...ADDITIONAL DEVELOPMENT IS EXPECTED IN THE
AFTERNOON...ALTHOUGH SPATIAL/TEMPORAL UNCERTAINTY WITH THAT IS
EVEN LOWER. SOUTHEAST WINDS WILL PREVAIL THROUGH THE PERIOD...WITH
GUSTS INTO THE LOWER 20S /KNOTS/.
KMSP...
A BRIEF RESPITE FROM THE ACTVITY WILL OCCUR AT MSP THROUGH MUCH OF
THE NIGHT. SHOULD START TO SEE SOME ACIVITY NEAR DAYBREAK...WHEN
AN ATTENDANT MVFR CIG /2500 FT/ IS POSSIBLE. AFTER THE EARLY
MORNING ACTIVITY WANES...SHOULD SEE SOME ADDITIONAL DEVELOPMENT
DURING THE AFTERNOON HOURS AS DESTABILIZATION OCCURS.
/OUTLOOK FOR KMSP/
MON...VFR/MVFR CIGS. SHRA/TSRA LIKELY. S WIND 10-15 KTS.
TUE...VFR/MVFR CIGS. SHRA/TSRA LIKELY. E-NE WIND 5 KTS.
WED...VFR/MVFR CIGS. SHRA LIKELY. NE WIND 5-10 KTS.
&&
.HYDROLOGY...
ISSUED AT 314 AM CDT SUN MAY 19 2013
MODEL GUIDANCE AND WPC QPF INDICATE WIDESPREAD 2-3 INCHES OF
ADDITIONAL RAINFALL THRU SUNDAY EVE ACRS THE ENTIRE CWFA. IN
ADDITION...CENTRAL AND ERN PORTIONS OF THE MPX CWFA RECEIVED 1-2
INCHES OF RAINFALL YESTERDAY. CONSIDERING THE RAPID INCRS IN SOIL
MOISTURE OVER CENTRAL AND NRN PORTIONS OF THE CWFA...PLUS WHAT IS
EXPECTED OVER THE NEXT 24-36 HRS...HAVE OPTED TO EXPAND AND EXTEND
THE FLASH FLOOD WATCH OVER MUCH OF THE MPX CWFA. MODEL RAINFALL
AMOUNTS ACTUALLY PIN THE LOWEST ADDITIONAL RAINFALL OVER SERN MN.
HOWEVER...IT IS THAT SAME REGION THAT ONLY 3 WEEKS AGO DEALT WITH
12-15 INCHES OF WET HEAVY SNOW...WHICH GREATLY ADDED TO SOIL
MOISTURE CAPACITY. CONFIDENCE IS NOT ALL THAT GREAT IN TRYING TO
HIGHLIGHT WHICH AREAS WOULD BE MORE SUSCEPTIBLE THAN OTHERS IN
SEEING FLASH FLOODING...BUT CONSIDERING THAT ANY TSTMS COULD
RAPIDLY PRODUCE HEAVY RAIN...AND THAT MORE WIDESPREAD RAINFALL IS
COMING LATE TNGT THRU MON EVE...FELT IT MOST PRUDENT TO EXPAND THE
AREA OF THE FLASH FLOOD WATCH TO PUT THE NOTICE OUT THAT HEAVY
RAIN COULD OCCUR AT ANY TIME AND QUICKLY EXACERBATE THE MOST MINOR
FLOODING CONCERNS INTO POTENTIAL FLASH FLOODING.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...FLASH FLOOD WATCH THROUGH MONDAY EVENING FOR MNZ041>045-048>053-
057>063-066>070-075>078-084-085-093.
WI...FLASH FLOOD WATCH THROUGH MONDAY EVENING FOR WIZ014>016-023>028.
&&
$$
SHORT TERM...JPC
LONG TERM...DWE
AVIATION...LS
HYDROLOGY...JPC
000
FXUS63 KMPX 190426
AFDMPX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
1126 PM CDT SAT MAY 18 2013
.UPDATE...
FOR 06Z AVIATION DISCUSSION BELOW
&&
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 312 PM CDT SAT MAY 18 2013
THE HYDROLOGIC ISSUES FOR TONIGHT AND SUNDAY ARE DISCUSSED IN A
SEPARATE SECTION BELOW. CONVECTION IS EXPECTED TO DEVELOP LATE
THIS AFTERNOON ACROSS WEST CENTRAL MN AND PROPAGATE SLOWLY ENE
THROUGH THE EVENING. MORE CONVECTION IS FORECAST TO EXPLODE OVER
NE/KS AND RACE NE...PERHAPS REACHING SW MN AFTER MIDNIGHT AND INTO
CENTRAL...EAST CENTRAL AND SOUTHEAST MN DURING THE LATE NIGHT
HOURS. DEEP LAYER SHEAR IS BEST TONIGHT ACROSS WEST CENTRAL INTO
CENTRAL MN ALONG WITH ML CAPE NEAR 1500 J/KG. DOWNDRAFT CAPE IS
ALREADY NEAR A 1000 J/KG NEAR OUR WESTERN BORDER ATTM. HENCE...A
FEW SEVERE STORMS WITH HAIL AND WIND ARE POSSIBLE.
SUNDAY SHOULD BEGIN WITH CONVECTION ACROSS CENTRAL AND EASTERN MN
WHICH WILL WEAKEN/DISSIPATE WHILE MOVING NE THROUGH THE LATE
MORNING HOURS. THERE MAY BE A FEW HOURS DURING THE LATE MORNING
AND EARLY AFTERNOON WITH SOME SUNSHINE AND LITTLE CONVECTION
OCCURRING. THAT IS LIKELY TO CHANGE DURING THE MID TO LATE
AFTERNOON HOURS WITH CLUSTERS OF STRONG TO SEVERE STORMS
DEVELOPING ACROSS CENTRAL AND SOUTHERN MN AND BY EVENING ACROSS
WEST CENTRAL WI. MODEL CONSENSUS IS FOR 1500-2000 J/KG OF CAPE
WITH NEARLY 500 J/KG BEING HAIL CAPE. DEEP LAYER SHEAR IS BEST
(30-40 KNOTS) ACROSS SOUTHERN MN INTO WEST CENTRAL WI DURING THE
LATE AFTERNOON AND EVENING. HOWEVER...0-1KM SHEAR INCREASES TO
NEAR 25 KNOTS ACROSS CENTRAL MN WITH SFC-3KM CAPE OVER 150 J/KG
ALONG AND SOUTH OF THE AFOREMENTIONED BOUNDARY. THIS WILL NEED TO
BE WATCHED FOR POSSIBLE TORNADIC DEVELOPMENT.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 312 PM CDT SAT MAY 18 2013
THE LONG TERM FORECAST REMAINS QUITE WET INTO THURSDAY AS A
VERTICALLY STACKED LOW PRESSURE SYSTEM OVER THE NORTHERN AND
CENTRAL PLAINS BEGINS A SLOW EASTWARD DRIFT. THUNDERSTORMS WILL
WANE SUNDAY NIGHT WHILE MOVING NE. HOWEVER...MONDAY REMAINS A DAY
OF INTEREST FOR MORE SEVERE WEATHER OVER OUR EASTERN FA. AN
OCCLUDED FRONT WILL LIFT NORTHEAST ACROSS EASTERN MN AND WEST
CENTRAL WI DURING THE DAY. CAPE AND SHEAR VALUES ARE RESPECTABLE
BY AFTERNOON FROM THE TWIN CITIES ON EAST AND SOUTH AND A FEW MORE
SEVERE STORMS ARE POSSIBLE. THERE REMAINS A SMALL CHANCE FOR
THUNDER TUESDAY AND WEDNESDAY...DEPENDING ON HOW FAST THE
VERTICALLY STACKED LOW PRESSURE SYSTEM MOVES. RIGHT NOW...THERE
CONTINUES TO BE A SLOWING TREND. HENCE...WE WILL BE DEALING WITH
RATHER HIGH POPS THROUGH MID WEEK.
THE GFS AND EC SHOW THIS LOW PRESSURE SYSTEM BREAKING DOWN ACROSS
THE REGION ON THURSDAY WITH HIGH PRESSURE FOR FRIDAY AND PERHAPS
SATURDAY BEFORE YET ANOTHER LARGE UPPER TROUGH MOVES INTO THE
WESTERN THIRD OF THE NATION...SPREADING MORE SHOWERS BACK. THE
WARMEST DAY IN THE EXTENDED RANGE IS ON MONDAY WITH HIGHS IN THE
50S AND 60S FOR TUESDAY AND WEDNESDAY WITH 60S TO LOWER 70S FOR
FRIDAY AND SATURDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1130 PM CDT SAT MAY 18 2013
A LULL IN SHOWER/THUNDERSTORM ACTIVITY WILL OCCUR AT THE TAF SITES UNTIL
NOCTURNAL CONVECTION OVER THE DAKOTAS SPILLS EASTWARD INTO THE
AREA. THE MODEL PREFERENCE THIS ISSUANCE WAS THE HRRR...WHICH
SEEMS TO HAVE A DECENT HANDLE ON THE CURRENT RADAR IMAGERY.
THEREFORE EXPECT SHOWER AND THUNDERSTORM ACTIVITY TO OVERSPREAD THE
AREA AFTER 07Z...REACHING CENTRAL AND EAST CENTRAL MN BY
DAYBREAK...AND WI SHORTLY THEREAFTER. AS THE PRECIP SETS IN...MVFR
CIGS WILL BE EXPECTED. CONFIDENCE ON TIMING OF THE SHOWER AND
THUNDERSTORM CHNACES IS LOW. AFTER THE NOCTURNAL ACTIVITY WANES IN
THE MORNING...ADDITIONAL DEVELOPMENT IS EXPECTED IN THE
AFTERNOON...ALTHOUGH SPATIAL/TEMPORAL UNCERTAINTY WITH THAT IS
EVEN LOWER. SOUTHEAST WINDS WILL PREVAIL THROUGH THE PERIOD...WITH
GUSTS INTO THE LOWER 20S /KNOTS/.
KMSP...
A BRIEF RESPITE FROM THE ACTVITY WILL OCCUR AT MSP THROUGH MUCH OF
THE NIGHT. SHOULD START TO SEE SOME ACIVITY NEAR DAYBREAK...WHEN
AN ATTENDANT MVFR CIG /2500 FT/ IS POSSIBLE. AFTER THE EARLY
MORNING ACTIVITY WANES...SHOULD SEE SOME ADDITIONAL DEVELOPMENT
DURING THE AFTERNOON HOURS AS DESTABILIZATION OCCURS.
/OUTLOOK FOR KMSP/
MON...VFR/MVFR CIGS. SHRA/TSRA LIKELY. S WIND 10-15 KTS.
TUE...VFR/MVFR CIGS. SHRA/TSRA LIKELY. E-NE WIND 5 KTS.
WED...VFR/MVFR CIGS. SHRA LIKELY. NE WIND 5-10 KTS.
&&
.HYDROLOGY...
ISSUED AT 312 PM CDT SAT MAY 18 2013
A SIGNIFICANT RAINFALL EVENT IS POSSIBLE TONIGHT AND SUNDAY
MORNING ACROSS CENTRAL MN. PW VALUES ARE PROJECTED TO INCREASE TO
OVER 1.50 INCHES TONIGHT ACROSS THE MN FA IN CONCERT WITH A
DEVELOPING LOW LEVEL JET. THE PW VALUES FORECAST ARE BETTER THAN
2 STANDARD DEVIATIONS ABOVE NORMAL AND ARE NEAR RECORD VALUES FOR
THE MONTH OF MAY (1.67). A SPECIAL 16Z KMPX RAOB THIS MORNING ALREADY
HAD PW VALUES AT 1.38 INCHES. WITH THE INCREASE IN MOISTURE
TONIGHT... THERE IS STRONG (925-850MB) FRONTOGENESIS THAT DEVELOPS
ACROSS CENTRAL MN AND REMAINS IN PLACE THROUGH MIDDAY SUNDAY. IN
ADDITION...AN INVERTED SURFACE TROUGH ACROSS CENTRAL SD AND
EASTERN ND IS FORECAST TO DROP SE INTO CENTRAL AND NORTHERN MN
BY SUNDAY MORNING WITH PRETTY STRONG LOW LEVEL CONVERGENCE SHOWN.
VARIOUS WRF MODELS SHOW CONVECTION SPREADING/DEVELOPING ACROSS
CENTRAL MN THIS EVENING WITH TRAINING NOTED. ANOTHER ROUND OF
CONVECTION MAY MOVE IN LATE IN THE NIGHT FROM EASTERN SD AND SW
MN. THE STORMS COULD EASILY PRODUCE 1 TO 2 INCHES OF RAIN PER HOUR
AS THEY MOVE THROUGH...MUCH LIKE THE STORMS LAST NIGHT AND THIS
MORNING OVER PARTS OF THE MN FA. IN FACT...WIDESPREAD 1 TO 3 INCH
RAINS FELL ACROSS CENTRAL MN EARLY THIS MORNING...WHICH HAS
CERTAINLY SOAKED THE GROUND. HENCE...IN COLLABORATION WITH
KDLH...WE ISSUED A FLASH FLOOD WATCH FROM 9 PM THIS EVENING UNTIL
1 PM ON SUNDAY FOR AREAS ALONG AND NORTH OF A LINE FROM MORRIS
THROUGH ST. CLOUD TO CAMBRIDGE.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...FLASH FLOOD WATCH THROUGH SUNDAY AFTERNOON FOR MNZ041>045-
047>052.
WI...NONE.
&&
$$
SHORT TERM...RAH
LONG TERM...RAH
AVIATION...LS
HYDROLOGY...RAH
000
FXUS63 KMPX 190200
AFDMPX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
900 PM CDT SAT MAY 18 2013
.UPDATE...
00Z AVIATION DISCUSSION ADDED BELOW.
&&
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 312 PM CDT SAT MAY 18 2013
THE HYDROLOGIC ISSUES FOR TONIGHT AND SUNDAY ARE DISCUSSED IN A
SEPARATE SECTION BELOW. CONVECTION IS EXPECTED TO DEVELOP LATE
THIS AFTERNOON ACROSS WEST CENTRAL MN AND PROPAGATE SLOWLY ENE
THROUGH THE EVENING. MORE CONVECTION IS FORECAST TO EXPLODE OVER
NE/KS AND RACE NE...PERHAPS REACHING SW MN AFTER MIDNIGHT AND INTO
CENTRAL...EAST CENTRAL AND SOUTHEAST MN DURING THE LATE NIGHT
HOURS. DEEP LAYER SHEAR IS BEST TONIGHT ACROSS WEST CENTRAL INTO
CENTRAL MN ALONG WITH ML CAPE NEAR 1500 J/KG. DOWNDRAFT CAPE IS
ALREADY NEAR A 1000 J/KG NEAR OUR WESTERN BORDER ATTM. HENCE...A
FEW SEVERE STORMS WITH HAIL AND WIND ARE POSSIBLE.
SUNDAY SHOULD BEGIN WITH CONVECTION ACROSS CENTRAL AND EASTERN MN
WHICH WILL WEAKEN/DISSIPATE WHILE MOVING NE THROUGH THE LATE
MORNING HOURS. THERE MAY BE A FEW HOURS DURING THE LATE MORNING
AND EARLY AFTERNOON WITH SOME SUNSHINE AND LITTLE CONVECTION
OCCURRING. THAT IS LIKELY TO CHANGE DURING THE MID TO LATE
AFTERNOON HOURS WITH CLUSTERS OF STRONG TO SEVERE STORMS
DEVELOPING ACROSS CENTRAL AND SOUTHERN MN AND BY EVENING ACROSS
WEST CENTRAL WI. MODEL CONSENSUS IS FOR 1500-2000 J/KG OF CAPE
WITH NEARLY 500 J/KG BEING HAIL CAPE. DEEP LAYER SHEAR IS BEST
(30-40 KNOTS) ACROSS SOUTHERN MN INTO WEST CENTRAL WI DURING THE
LATE AFTERNOON AND EVENING. HOWEVER...0-1KM SHEAR INCREASES TO
NEAR 25 KNOTS ACROSS CENTRAL MN WITH SFC-3KM CAPE OVER 150 J/KG
ALONG AND SOUTH OF THE AFOREMENTIONED BOUNDARY. THIS WILL NEED TO
BE WATCHED FOR POSSIBLE TORNADIC DEVELOPMENT.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 312 PM CDT SAT MAY 18 2013
THE LONG TERM FORECAST REMAINS QUITE WET INTO THURSDAY AS A
VERTICALLY STACKED LOW PRESSURE SYSTEM OVER THE NORTHERN AND
CENTRAL PLAINS BEGINS A SLOW EASTWARD DRIFT. THUNDERSTORMS WILL
WANE SUNDAY NIGHT WHILE MOVING NE. HOWEVER...MONDAY REMAINS A DAY
OF INTEREST FOR MORE SEVERE WEATHER OVER OUR EASTERN FA. AN
OCCLUDED FRONT WILL LIFT NORTHEAST ACROSS EASTERN MN AND WEST
CENTRAL WI DURING THE DAY. CAPE AND SHEAR VALUES ARE RESPECTABLE
BY AFTERNOON FROM THE TWIN CITIES ON EAST AND SOUTH AND A FEW MORE
SEVERE STORMS ARE POSSIBLE. THERE REMAINS A SMALL CHANCE FOR
THUNDER TUESDAY AND WEDNESDAY...DEPENDING ON HOW FAST THE
VERTICALLY STACKED LOW PRESSURE SYSTEM MOVES. RIGHT NOW...THERE
CONTINUES TO BE A SLOWING TREND. HENCE...WE WILL BE DEALING WITH
RATHER HIGH POPS THROUGH MID WEEK.
THE GFS AND EC SHOW THIS LOW PRESSURE SYSTEM BREAKING DOWN ACROSS
THE REGION ON THURSDAY WITH HIGH PRESSURE FOR FRIDAY AND PERHAPS
SATURDAY BEFORE YET ANOTHER LARGE UPPER TROUGH MOVES INTO THE
WESTERN THIRD OF THE NATION...SPREADING MORE SHOWERS BACK. THE
WARMEST DAY IN THE EXTENDED RANGE IS ON MONDAY WITH HIGHS IN THE
50S AND 60S FOR TUESDAY AND WEDNESDAY WITH 60S TO LOWER 70S FOR
FRIDAY AND SATURDAY.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SUNDAY EVENING)
ISSUED AT 859 CDT SAT MAY 18 2013
UNCERTAINTY RULES THE DAY IN THESE TAFS AS A FEW ROUNDS OF SHOWERS
AND THUNDERSTORMS WILL BE POSSIBLE. THIS EVENING...STORMS HAVE
INITIATED IN WRN MN ALONG A STATIONARY FRONT THAT STRETCHES EAST
ACROSS CENTRAL MN INTO NW WI. BASED ON MEMBERS 1 AND 3 OF THE
HOPWRF...EXPECT THESE CELLS TO REMAIN CONFINED TO NEAR THEIR
CURRENT LOCATION DUE TO WEAK STEERING FLOW AND SLOWLY DISSIPATE
AFTER SUNSET. ATTENTION THEN TURNS TO LINE OF BKN STORMS FROM
SODAK ALL THE WAY DOWN TO KS AS IT PUSHES EAST OVERNIGHT. TIMED
THIS NEXT BATCH OF SHRA/TSRA IN OFF THE HRRR...THOUGH IT IS
RUNNING A FEW HOURS FASTER THAN THE HOPWRF. NOTICED THE 22Z
VERSION OF THE HRRR SLOWED THE LINE DOWN SOME AS WELL...SO THE
RETURN OF SHRA/TSRA LATE TONIGHT INTO SUN MORNING MAY NEED TO BE
SLOWED DOWN. SUNDAY MORNING MAY VERY WELL BE SIMILAR TO WHAT WAS
SEEN THIS MORNING WITH CONVECTION THAT MOVED ACROSS THE AREA.
EXPECT MAINLY VFR CIGS THROUGH THE NIGHT...THOUGH WITH RECENT RAIN
AND HIGH DEWPS...MVFR VSBYS IN BR/HZ WILL LIKELY DEVELOP. EXPECT
ANOTHER LULL IN ACTIVITY IN THE LATE MORNING/EARLY AFTERNOON
SUNDAY...BEFORE MORE STORMS DEVELOP MAINLY AFTER 20Z ON SUNDAY.
SOUNDINGS AT ALL TERMINALS ARE MOIST/UNSTABLE AND WEAKLY CAPPED...
SO WILL NOT TAKE MUCH FORCING TO KICK OFF STORMS. GIVEN HIGH
CONFIDENCE IN THUNDERSTORMS OCCURRING TOMORROW...BUT LOW
CONFIDENCE IN TIMING/LOCATION THIS FAR OUT...WENT WITH PROB30
GROUPS FOR TSRA AT ALL TERMINALS SUNDAY AFTERNOON.
KMSP...EXPECT ANY TSRA ACTIVITY THIS EVENING TO REMAIN NEAR OR
NORTH OF THE BOUNDARY SITUATED ACROSS CENTRAL MN. CONFIDENCE IS
HIGH IN ANOTHER ROUND OF MORNING STORMS FOR MSP...THOUGH THERE ARE
TIMING ISSUES WITH IT. 21Z RUN OF THE HRRR HAS STORMS APPROACHING
THE FIELD AT 11Z...WHILE ALL MEMBERS OF THE HOPWRF HAVE THE LINE
WELL WEST OF THE FIELD AT 12Z SUNDAY. HAVE A SOMEWHAT LARGE 10Z TO
16Z WINDOW FOR CONVECTION...BUT DOES LOOK LIKE FOR 2 OR 3 OF THOSE
HOURS...THERE WILL BE TSRA ACTIVITY. FOR SUNDAY AFTERNOON/EVENING...
GIVEN UNSTABLE AND WEAKLY CAPPED ENVIRONMENT...EXPECT WIDESPREAD
TSRA TO DEVELOP AGAIN IN THE AFTERNOON AND LAST INTO SUNDAY
EVENING. STILL PLENTY OF UNCERTAINTY WITH TIMING/PLACEMENT OF
STORMS SUNDAY AFTERNOON...SO HAVE A PROB30 GROUP FOR MOST LIKELY
WINDOW FOR SEEING STORMS AT THIS POINT.
/OUTLOOK FOR KMSP/
MON...VFR/MVFR CIGS. SHRA/TSRA LIKELY. S WIND 10-15 KTS.
TUE...VFR/MVFR CIGS. SHRA/TSRA LIKELY. E-NE WIND 5 KTS.
WED...VFR/MVFR CIGS. SHRA LIKELY. NE WIND 5-10 KTS.
&&
.HYDROLOGY...
ISSUED AT 312 PM CDT SAT MAY 18 2013
A SIGNIFICANT RAINFALL EVENT IS POSSIBLE TONIGHT AND SUNDAY
MORNING ACROSS CENTRAL MN. PW VALUES ARE PROJECTED TO INCREASE TO
OVER 1.50 INCHES TONIGHT ACROSS THE MN FA IN CONCERT WITH A
DEVELOPING LOW LEVEL JET. THE PW VALUES FORECAST ARE BETTER THAN
2 STANDARD DEVIATIONS ABOVE NORMAL AND ARE NEAR RECORD VALUES FOR
THE MONTH OF MAY (1.67). A SPECIAL 16Z KMPX RAOB THIS MORNING ALREADY
HAD PW VALUES AT 1.38 INCHES. WITH THE INCREASE IN MOISTURE
TONIGHT... THERE IS STRONG (925-850MB) FRONTOGENESIS THAT DEVELOPS
ACROSS CENTRAL MN AND REMAINS IN PLACE THROUGH MIDDAY SUNDAY. IN
ADDITION...AN INVERTED SURFACE TROUGH ACROSS CENTRAL SD AND
EASTERN ND IS FORECAST TO DROP SE INTO CENTRAL AND NORTHERN MN
BY SUNDAY MORNING WITH PRETTY STRONG LOW LEVEL CONVERGENCE SHOWN.
VARIOUS WRF MODELS SHOW CONVECTION SPREADING/DEVELOPING ACROSS
CENTRAL MN THIS EVENING WITH TRAINING NOTED. ANOTHER ROUND OF
CONVECTION MAY MOVE IN LATE IN THE NIGHT FROM EASTERN SD AND SW
MN. THE STORMS COULD EASILY PRODUCE 1 TO 2 INCHES OF RAIN PER HOUR
AS THEY MOVE THROUGH...MUCH LIKE THE STORMS LAST NIGHT AND THIS
MORNING OVER PARTS OF THE MN FA. IN FACT...WIDESPREAD 1 TO 3 INCH
RAINS FELL ACROSS CENTRAL MN EARLY THIS MORNING...WHICH HAS
CERTAINLY SOAKED THE GROUND. HENCE...IN COLLABORATION WITH
KDLH...WE ISSUED A FLASH FLOOD WATCH FROM 9 PM THIS EVENING UNTIL
1 PM ON SUNDAY FOR AREAS ALONG AND NORTH OF A LINE FROM MORRIS
THROUGH ST. CLOUD TO CAMBRIDGE.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...FLASH FLOOD WATCH THROUGH SUNDAY AFTERNOON FOR MNZ041>045-
047>052.
WI...NONE.
&&
$$
SHORT TERM...RAH
LONG TERM...RAH
AVIATION...MPG
HYDROLOGY...RAH
000
FXUS63 KMPX 182012
AFDMPX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
312 PM CDT SAT MAY 18 2013
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 312 PM CDT SAT MAY 18 2013
THE HYDROLOGIC ISSUES FOR TONIGHT AND SUNDAY ARE DISCUSSED IN A
SEPARATE SECTION BELOW. CONVECTION IS EXPECTED TO DEVELOP LATE
THIS AFTERNOON ACROSS WEST CENTRAL MN AND PROPAGATE SLOWLY ENE
THROUGH THE EVENING. MORE CONVECTION IS FORECAST TO EXPLODE OVER
NE/KS AND RACE NE...PERHAPS REACHING SW MN AFTER MIDNIGHT AND INTO
CENTRAL...EAST CENTRAL AND SOUTHEAST MN DURING THE LATE NIGHT
HOURS. DEEP LAYER SHEAR IS BEST TONIGHT ACROSS WEST CENTRAL INTO
CENTRAL MN ALONG WITH ML CAPE NEAR 1500 J/KG. DOWNDRAFT CAPE IS
ALREADY NEAR A 1000 J/KG NEAR OUR WESTERN BORDER ATTM. HENCE...A
FEW SEVERE STORMS WITH HAIL AND WIND ARE POSSIBLE.
SUNDAY SHOULD BEGIN WITH CONVECTION ACROSS CENTRAL AND EASTERN MN
WHICH WILL WEAKEN/DISSIPATE WHILE MOVING NE THROUGH THE LATE
MORNING HOURS. THERE MAY BE A FEW HOURS DURING THE LATE MORNING
AND EARLY AFTERNOON WITH SOME SUNSHINE AND LITTLE CONVECTION
OCCURRING. THAT IS LIKELY TO CHANGE DURING THE MID TO LATE
AFTERNOON HOURS WITH CLUSTERS OF STRONG TO SEVERE STORMS
DEVELOPING ACROSS CENTRAL AND SOUTHERN MN AND BY EVENING ACROSS
WEST CENTRAL WI. MODEL CONSENSUS IS FOR 1500-2000 J/KG OF CAPE
WITH NEARLY 500 J/KG BEING HAIL CAPE. DEEP LAYER SHEAR IS BEST
(30-40 KNOTS) ACROSS SOUTHERN MN INTO WEST CENTRAL WI DURING THE
LATE AFTERNOON AND EVENING. HOWEVER...0-1KM SHEAR INCREASES TO
NEAR 25 KNOTS ACROSS CENTRAL MN WITH SFC-3KM CAPE OVER 150 J/KG
ALONG AND SOUTH OF THE AFOREMENTIONED BOUNDARY. THIS WILL NEED TO
BE WATCHED FOR POSSIBLE TORNADIC DEVELOPMENT.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 312 PM CDT SAT MAY 18 2013
THE LONG TERM FORECAST REMAINS QUITE WET INTO THURSDAY AS A
VERTICALLY STACKED LOW PRESSURE SYSTEM OVER THE NORTHERN AND
CENTRAL PLAINS BEGINS A SLOW EASTWARD DRIFT. THUNDERSTORMS WILL
WANE SUNDAY NIGHT WHILE MOVING NE. HOWEVER...MONDAY REMAINS A DAY
OF INTEREST FOR MORE SEVERE WEATHER OVER OUR EASTERN FA. AN
OCCLUDED FRONT WILL LIFT NORTHEAST ACROSS EASTERN MN AND WEST
CENTRAL WI DURING THE DAY. CAPE AND SHEAR VALUES ARE RESPECTABLE
BY AFTERNOON FROM THE TWIN CITIES ON EAST AND SOUTH AND A FEW MORE
SEVERE STORMS ARE POSSIBLE. THERE REMAINS A SMALL CHANCE FOR
THUNDER TUESDAY AND WEDNESDAY...DEPENDING ON HOW FAST THE
VERTICALLY STACKED LOW PRESSURE SYSTEM MOVES. RIGHT NOW...THERE
CONTINUES TO BE A SLOWING TREND. HENCE...WE WILL BE DEALING WITH
RATHER HIGH POPS THROUGH MID WEEK.
THE GFS AND EC SHOW THIS LOW PRESSURE SYSTEM BREAKING DOWN ACROSS
THE REGION ON THURSDAY WITH HIGH PRESSURE FOR FRIDAY AND PERHAPS
SATURDAY BEFORE YET ANOTHER LARGE UPPER TROUGH MOVES INTO THE
WESTERN THIRD OF THE NATION...SPREADING MORE SHOWERS BACK. THE
WARMEST DAY IN THE EXTENDED RANGE IS ON MONDAY WITH HIGHS IN THE
50S AND 60S FOR TUESDAY AND WEDNESDAY WITH 60S TO LOWER 70S FOR
FRIDAY AND SATURDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 107 PM CDT SAT MAY 18 2013
MORNING STORMS LEFT BEHIND AN AREA OF MVFR CIGS AND EVEN SOME IFR
VSBYS IN SPOTS FROM WEST CENTRAL MN INTO WISC. THIS WILL HANG ON
FOR ANOTHER HOUR OR TWO AT PLACES LIKE AXN/STC/RNH...WHICH ARE
FARTHER NORTH OF THE WARM FRONT CURRENTLY IN SOUTHERN MN. ANOTHER
ISSUE IS POTENTIAL FOR MVFR FOG TONIGHT IN EASTERN MN AND WISC
WITH RESIDUAL MOISTURE AND SOUTHEAST WINDS. THIRD ISSUE IS
DEVELOPMENT OF STORMS THIS EVENING IN WEST CENTRAL MN PER HOPWRF
AND OTHER SHORT TERM MODELS. NORTHEAST MOVEMENT TO INDIVIDUAL
STORMS BUT OVERALL AREA GRADUALLY TRANSLATES EASTWARD...REACHING
EASTERN MN AND WESTERN WISC 08Z-12Z.
KMSP...DRY WEATHER IN WAKE OF MORNING STORMS. NAM SUGGESTS
REDEVELOPING STORMS IN WESTERN MN REACHING KMSP SHORTLY AFTER 00Z
THIS EVENING BUT MOST SHORT TERM MODELS HOLD OFF UNTIL LATE
TONIGHT. THUS HAVE PRECIP AT KMSP NOT UNTIL 10Z. COULD WELL BE TWO
OR THREE HOURS OF THUNDER BUT HAVE NOT ADDED THAT WITH UNCERTAIN
TIMING. SOME GUSTS POSSIBLE AROUND 20 KTS THIS AFTERNOON PER KMPX
SOUNDING.
/OUTLOOK FOR KMSP/
SUN NIGHT...MVFR CIGS/VSBY. LIKELY SHRA/TSRA WITH CHC IFR. S-SE WINDS 8-12
KTS.
MON...VFR/MVFR CIGS. CHC SHRA/TSRA. S WIND 10-15 KTS.
TUE...VFR/MVFR CIGS. CHC SHRA/TSRA. E-NE WIND 5 KTS.
&&
.HYDROLOGY...
ISSUED AT 312 PM CDT SAT MAY 18 2013
A SIGNIFICANT RAINFALL EVENT IS POSSIBLE TONIGHT AND SUNDAY
MORNING ACROSS CENTRAL MN. PW VALUES ARE PROJECTED TO INCREASE TO
OVER 1.50 INCHES TONIGHT ACROSS THE MN FA IN CONCERT WITH A
DEVELOPING LOW LEVEL JET. THE PW VALUES FORECAST ARE BETTER THAN
2 STANDARD DEVIATIONS ABOVE NORMAL AND ARE NEAR RECORD VALUES FOR
THE MONTH OF MAY (1.67). A SPECIAL 16Z KMPX RAOB THIS MORNING ALREADY
HAD PW VALUES AT 1.38 INCHES. WITH THE INCREASE IN MOISTURE
TONIGHT... THERE IS STRONG (925-850MB) FRONTOGENESIS THAT DEVELOPS
ACROSS CENTRAL MN AND REMAINS IN PLACE THROUGH MIDDAY SUNDAY. IN
ADDITION...AN INVERTED SURFACE TROUGH ACROSS CENTRAL SD AND
EASTERN ND IS FORECAST TO DROP SE INTO CENTRAL AND NORTHERN MN
BY SUNDAY MORNING WITH PRETTY STRONG LOW LEVEL CONVERGENCE SHOWN.
VARIOUS WRF MODELS SHOW CONVECTION SPREADING/DEVELOPING ACROSS
CENTRAL MN THIS EVENING WITH TRAINING NOTED. ANOTHER ROUND OF
CONVECTION MAY MOVE IN LATE IN THE NIGHT FROM EASTERN SD AND SW
MN. THE STORMS COULD EASILY PRODUCE 1 TO 2 INCHES OF RAIN PER HOUR
AS THEY MOVE THROUGH...MUCH LIKE THE STORMS LAST NIGHT AND THIS
MORNING OVER PARTS OF THE MN FA. IN FACT...WIDESPREAD 1 TO 3 INCH
RAINS FELL ACROSS CENTRAL MN EARLY THIS MORNING...WHICH HAS
CERTAINLY SOAKED THE GROUND. HENCE...IN COLLABORATION WITH
KDLH...WE ISSUED A FLASH FLOOD WATCH FROM 9 PM THIS EVENING UNTIL
1 PM ON SUNDAY FOR AREAS ALONG AND NORTH OF A LINE FROM MORRIS
THROUGH ST. CLOUD TO CAMBRIDGE.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...FLASH FLOOD WATCH FROM 9 PM CDT THIS EVENING THROUGH SUNDAY
AFTERNOON FOR MNZ041>045-047>052.
WI...NONE.
&&
$$
SHORT TERM...RAH
LONG TERM...RAH
AVIATION...TDK
HYDROLOGY...RAH
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