000
FXUS63 KMPX 162045
AFDMPX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
345 PM CDT THU MAY 16 2013

.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 207 PM CDT THU MAY 16 2013

TWO WEATHER CONCERNS FOR LATE TONIGHT...AND THRU FRIDAY AS
INITIAL VERY DRY ATMOSPHERE WILL SUPPRESS CONVECTIVE TO THE
SW THIS AFTN/EARLY EVENING. HOWEVER..A VERY POTENT DISTURBANCE
NOTED ON SATELLITE MOVING ACROSS NEBRASKA WILL EVENTUALLY MOISTEN
UP THE ATMOSPHERE...AND BASED ON THE AMOUNT OF ENERGY ASSOCIATED
WITH THE COMPLEX OF TSRA/SHRA ACROSS NEBRASKA...PRECIPITATION WILL
SPREAD ACROSS SW/SC MN BY MIDNIGHT. HOWEVER...DEPENDING UPON THE
LOW LEVEL JET ORIENTATION TONIGHT...AND THE INTERACTION OF THE
DISTURBANCE/PLUS HOW FAST THE ATMOSPHERE MOISTENS UP...WILL DEPEND
ON HOW FAR N/NW THIS AREA OF PRECIPITATION SPREADS ACROSS OUR FA.
BEST SCENARIO IS TO CONTINUE WITH HIGH POPS ALONG THE IA/MN
BORDER...NORTHWARD TO MSP/WC WI WHERE THE BEST MOISTURE ADVECTION
AND ENERGY WILL OCCUR. ELSEWHERE...PRECIPITATION WILL LIKELY OCCUR
BUT RAINFALL AMTS WILL BE SUPPRESS AND LIKELY MUCH LOWER THAN
EXPECTED. THIS AREA OF PRECIPITATION WILL LIKELY SPREAD NE OF THE
FA BY LATE FRIDAY AFTN...WITH MAINLY AFTN ISOLD CONVECTION
POSSIBLE IN SOUTHERN/CENTRAL MN DUE TO THE INCREASED INSTABILITY.

.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 344 PM CDT THU MAY 16 2013

THE LONG TERM PORTION OF THE FORECAST IS A DAMP ONE. A LARGE UPPER
TROUGH OVER THE INTER-MOUNTAIN REGION OF THE WEST AT THE START OF
THE PERIOD WILL BECOME NEGATIVE TILT THROUGH THE WEEKEND... AND
THEN TRANSITION INTO A CLOSED UPPER LOW OVER THE NORTHERN PLAINS
BY MONDAY. THE SLOW PROGRESSION OF THIS FEATURE IS TIED TO AN
OMEGA BLOCK THAT DEVELOPS OVER THE NORTH ATLANTIC. AS TIME
PROGRESSES NEXT WEEK...WE ACTUALLY HAVE A SMALL REX BLOCK OVER THE
NORTHERN PLAINS AND CENTRAL CANADA. TIMING BETWEEN THE MODELS
WITH THE UPPER LOW IS RATHER EXCEPTIONAL.

AT THE SURFACE...A WARM FRONT ACROSS FAR SOUTHERN MN AND WI FRIDAY
EVENING WILL LIFT SLOWLY NORTHWARD INTO CENTRAL MN AND WEST
CENTRAL WI BY SATURDAY EVENING AND INTO THE NORTHERN PORTIONS OF MN
AND WI BY SUNDAY MORNING. SHOWER AND THUNDERSTORM CHANCES WILL BE
BEST ALONG AND NORTH OF THE ADVANCING FRONT WITH HIGH CHANCE TO
LIKELY POPS IN PLACE. ONE CONCERN IS THAT A MID LEVEL CAP WILL DEVELOP
IN THE WAKE OF THE WARM FRONT...WITH LITTLE OR NO POPS ACROSS MUCH
OF THE AREA SATURDAY NIGHT AND EARLY SUNDAY. LATER SHIFTS MAY NEED
TO DRIVE DRY WEATHER FARTHER NORTH AND WEST THAN CURRENTLY
FORECAST. THE THREAT FOR SEVERE STORMS STILL HAS MERIT OVER WEST
CENTRAL MN AS THE NOSE OF THE LOW LEVEL JET PUSHES IN FROM
EASTERN SD DURING THE EVENING ALONG WITH MODEST SHEAR AND CAPE.

SUNDAY IS MORE PROBLEMATIC AS LITTLE WAVES RIDE NORTHWARD IN THE
UPPER FLOW ACROSS THE FA. LIKELY POPS IN PLACE FOR THE AFTERNOON.
SEVERE CHANCES ARE HIGHEST ACROSS SOUTHERN MN WHERE THE BEST CAPE
AND SHEAR ALIGN DURING THE AFTERNOON AND EVENING. EVENTUALLY A
COLD FRONT WILL PASS ACROSS THE FA FROM MONDAY INTO TUESDAY WITH
THE SURFACE LOW CAPTURED BY THE UPPER LOW IN THE EASTERN DAKOTAS.
THE VERTICALLY STACKED LOW WILL THEN MOVE SLOWLY EASTWARD ACROSS
THE FA THROUGH THURSDAY WITH DRY WEATHER NOT RETURNING UNTIL
PERHAPS FRIDAY. HIGH TEMPERATURES WILL BEGIN WELL ABOVE NORMAL FOR
THE WEEKEND BUT THEN TRANSITION TO AT OR BELOW SEASONAL VALUES
FROM TUESDAY ONWARD.

MODEL QPF FOR THE ENTIRE FORECAST PERIOD (SHORT AND LONG) IS WHERE
THE BIGGEST DISCREPANCIES EXISTS. THE TREND TODAY IS FOR THE
HEAVIER TOTAL AMOUNTS OF RAIN TO BE PROJECTED ACROSS OUR FAR
WESTERN AND NORTHERN FA AS WELL AS POINTS TO THE WEST AND NORTH
(EASTERN DAKOTAS/NORTHERN MN). SEVERAL INCHES OF RAIN ARE
POSSIBLE FROM TONIGHT THROUGH THE WEEKEND. FORTUNATELY...IT SHOULD
COME IN PIECES AND WE HAVE HAD A RECENT DRY SPELL. HOWEVER... QPF
AMOUNTS STILL BARE WATCHING.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1231 PM CDT THU MAY 16 2013

NO AVIATION CONCERNS THRU 00Z AS DRY EAST/EAST-SOUTHEASTERLY FLOW
CONTINUES. COMPLEX OF TSRA/SHRA ACROSS THE DAKOTAS WILL BEGIN TO
AFFECT THE WESTERN MPX TAF FORECAST AREA AFT 00-03Z WITH VSBYS
INITIALLY DECREASE IN HEAVIER PRECIPITATION. EVENTUALLY CIGS WILL
LOWER...WITH MVFR CIGS LIKELY BY MORNING. SFC WINDS WILL REMAIN FROM
THE EAST-EAST-SOUTHEAST TODAY WITH SOME GUSTS AT AXN/STC/RNH
BEFORE 00Z. GUSTY WINDS WILL ALSO ACCOMPANY ANY TSRA OVERNIGHT.
THE BEST TIME FRAME FOR TSRA/SHRA WILL OCCUR AT AXN BETWEEN 4-10Z.
AT STC BETWEEN 8-14Z...AT RWF BETWEEN 4 AND 10Z. RNH/EAU WILL
LIKELY BE DRY UNTIL AFT 9Z.

KMSP...

VFR CONDS ALONG WITH EASTERLY WINDS WILL CONTINUE THRU 6Z WITH
CIGS SLOWLY LOWERING TO LOW END VFR AFT 6Z AS SHRA BECOME TO
DEVELOP ACROSS EASTERN MN. TSRA WILL BE POSSIBLE AFT 9Z...WITH A
PERIOD OF MODERATE TO HEAVY RAINFALL DURING THE 10-14Z TIME FRAME.
VSBYS WILL BE THE MAIN CONCERN WITH THE HEAVIER
PRECIPITATION...EVENTUALLY CIGS WILL LOWER TO HIGH END MVFR AFT
12Z. THERE WILL LIKELY BE A BRIEF IN THE PRECIPITATION BY MID/LATE
MORNING...WITH MORE PRECIPITATION LIKELY ON SATURDAY. GUSTY E/SE
WINDS WILL LIKELY DEVELOP AFT MIDNIGHT AS THE BOUNDARY LAYER WINDS
INCREASE TO OVER 20 KTS.

/OUTLOOK FOR KMSP/

FRI NIGHT...VFR/MVFR CIGS. CHC IFR IN HEAVIER TSRA. E-SE WIND 10 KTS.
SAT...VFR/MVFR CIGS. CHC IFR IN HEAVIER TSRA. SE-S WINDS 5-10 KTS.
SUN...VFR/MVFR CIGS. CHC IFR IN HEAVIER TSRA. S-SE WINDS 8-12 KTS.


&&

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

$$

SHORT TERM...JLT
LONG TERM...RAH
AVIATION...JLT