000
FXUS63 KMPX 220356
AFDMPX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
1056 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 NIGHT THROUGH TUESDAY)
ISSUED AT 355 PM CDT TUE MAY 21 2013

OMEGA BLOCK REMAINS IN PLACE OVER MUCH OF CONTIGUOUS US FOR
WEDNESDAY NIGHT INTO THURSDAY. DP/DT INDICATED SLOWER EXIT
OF 50H LOW PRESSURE AREA INTO NORTHERN OHIO VALLEY LATE
WED NIGHT INTO THURSDAY. THUS HAVE SLOWED DECREASE OF POPS
OVER EASTERN THIRD OF FA WEDNESDAY EVENING...VERY EARLY THU
MORNING TO ACCOUNT FOR SAME. NICE SURGE OF CANADIAN POLAR
AIR OVER FA...BEHIND EXITING CUT OFF LOW ANTICIPATED FOR
LATE WEDNESDAY NIGHT INTO FRIDAY MORNING. ANOTHER WARM FRONTAL
BOUNDARY EXPECTED TO IMPACT WESTERN FA BY FRIDAY MORNING. BROAD
AREA OF SFC LOW PRESSURE ASSOCIATED WITH SAME WILL BE SEEN ABOVE
NORTHEASTERN WYOMING BY SAT/12Z...AS 50H CUT OFF LOW NOTED UPSTREAM
OVER WASHINGTON AND OREGON. BOTH GFS40 AND EUROPEAN BRINGING IN
DECENT SWATH OF MOISTURE OVER REGION FOR MUCH OF SATURDAY WITH
BEST FORCING NOTED OVER SW THIRD OF FA. BY SUN/12Z BROAD AREA
OF SURFACE LOW PRESSURE FINALLY TREKS INTO WESTERN SODAK...AND
WESTERN NE BY SUNDAY/12Z TIME PERIOD.

PROXIMITY OF WARM FRONTAL BOUNDARY TO OR OVER PORTIONS OF CWA
SUNDAY-MONDAY WILL DETERMINE TIMING AND EXTENT OF CONVECTIVE
ACTIVITY FOR THIS TIME PERIOD. GFS40 MUCH MORE AGGRESSIVE WITH
INSTABILITY AND PCPN CHANCES SUNDAY INTO MONDAY MORNING AS
OPPOSED TO EUROPEAN. WITH THAT SAID JUST TWEAKED POPS FOR
SUN-TUESDAY PERIOD...WITH HIGHEST POP PROBABILITIES PAINTED OVER
SW AND WEST CENTRAL CWA. SLOW MOVING COLD FRONTAL BOUNDARY
STILL PROGGED OVER FAR WESTERN MN INTO SE SODAK ON WED
AFTN...AND SHOULD PUSH THROUGH MUCH OF FA NEXT WED NIGHT
...AND THEN STALL OVER SOUTHERN WI INTO FAR NORTHERN IA.
ANOTHER MUCH STRONGER SFC CYCLONE FORMS ON THE WESTERN
PORTION OF THIS BOUNDARY LATE THURSDAY...INSURING PROBABLE
CHANCES FOR MOISTURE ENDING THE MONTH OF MAY.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1056 PM CDT TUE MAY 21 2013

OCCLUDED SYSTEM WILL BE SLOW TO MOVE OUT OF THE AREA. APPEARS THE
NORTHEAST PORTION OF THE AREA WILL REMAIN DRIEST...WITH NORTHEAST
FLOW TRYING TO DRAW IN SOMEWHAT DRIER AIR. STILL LOOKS GOOD IFR
CONDITIONS CONTINUING THROUGH THE NIGHT MOST AREAS. KAXN WILL BE
ON THE EDGE TO THE NORTHWEST AND KRNH AND KEAU TO THE EAST. LIGHT
RAIN AND DRIZZLE APPEARS MOST LIKELY AS THE SYSTEM MOVES THROUGH.
AS THE UPPER LOW DROPS SOUTHEAST...COULD SEE MORE STEADY RAIN
DEVELOP TO THE SOUTHEAST INTO THE AFTERNOON. CIGS SHOULD GRADUALLY
IMPROVE TO MVFR LATE IN THE MORNING NORTHWEST AND THEN CLEAR OUT
DURING THE EVENING AS THE SURFACE RIDGE BEGINS TO MOVE IN. THIS
CLEARING TREND EXPECTED TO CONTINUE TO KMSP AFTER 05Z//THU. NORTH
NORTHEAST WINDS DURING THE PERIOD...BECOMING GUSTY IN THE MORNING
OUT WEST.

KMSP...LIGHT RAIN/DRIZZLE REMAINS ON THE EDGE ACROSS THE FILED.
THIS MAY CONTINUE INTO EARLY MORNING BEFORE MAIN UPPER CIRCULATION
DROPS SOUTHEAST INTO THE REGION...MAINLY AFTER 10Z. WILL CONTINUE
THE IFR CIGS AS WELL...GRADUALLY IMPROVING LATE MORNING/EARLY
AFTERNOON...AS MAIN LIGHT RAIN AREA DROPS TO THE SOUTHEAST.
CLEARING TREND INTO THE EVENING...WITH SKC DEVELOPING AFTER
06Z/WED. NORTHEAST TO NORTH WINDS DURING THE PERIOD...MAY BECOME A
BIT GUSTY IN THE AFTERNOON. SHOULD DIMINISH OVERNIGHT AS THE
SURFACE RIDGE BUILDS SOUTHEAST.


/OUTLOOK FOR KMSP/

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.

&&

$$

SHORT TERM...TH
LONG TERM...AZ
AVIATION...DWE