Expires:No;;507145 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