Forget the date at the bottom, it's displayed on mouse roll-over, the little circle on the graph is correct.

Total Accumulated Precip - 24 hours

Total Accumulated Precip - 36 hours

Total Accumulated Precip - 48 hours

Total Accumulated Precip - 60 hours

GFS

NAM 4km

FRONT SHOULD BE ENTERING NORTHEAST NEBRASKA BY LATE MORNING OR EARLY AFTERNOON...THEN PROGRESS SOUTHEAST LATER TODAY AND THIS EVENING. NORTHERN PORTION OF THIS FRONT WILL CONTINUE EAST WITH UPPER SUPPORT ACROSS THE NORTHERN PLAINS... WHILE SOUTHERN SECTION STALLS ACROSS SOUTHEAST NEBRASKA AND SOUTHWEST IOWA TONIGHT. 

ALONG/AHEAD OF THE FRONT THIS AFTERNOON... SURFACE DEW POINTS IN THE LOWER 70S COMBINED WITH TEMPERATURES SURGING INTO THE LOWER 90S WILL YIELD GREATER THAN 2000 J/KG OF SURFACE-BASED CAPES OVER A GOOD PORTION OF OUR AREA. DECENT FLOW WILL ALSO BE IN PLACE WITH MODELS SUGGESTING 0-6KM BULK SHEAR NEAR 35KT. WITH A BETTER COMBINATION OF SHEAR/INSTABILITY NORTHEAST OF OUR AREA THIS AFTERNOON... EXPECT CONVECTION TO BEGIN THERE AND EVENTUALLY DEVELOP SOUTHWEST ALONG FRONT LATE IN THE DAY. 

SOME POTENTIAL FOR HAIL/WINDS GIVEN INSTABILITY/SHEAR... ESPECIALLY WITH INITIAL DEVELOPMENT WHEN SHEAR VECTORS ARE MORE PERPENDICULAR TO FRONTAL ZONE SUPPORTING INDIVIDUAL CELLS. A PROGRESSION TO A MORE LINEAR CONFIGURATION TO THE CONVECTION SHOULD OCCUR AS FRONT BECOMES MORE EAST-WEST AND PARALLELS UPPER FLOW. PROPAGATION VECTORS AT THIS TIME GET SMALL WITH PRECIPITABLE WATER VALUES NEAR OR ABOVE 2 INCHES. THIS WILL SUPPORT TRAINING OF SLOW-MOVING STORMS...WITH BEST COMBINATION OF THESE FACTORS OVER SOUTHWEST INTO CENTRAL IOWA. WILL GO AHEAD AND ISSUE A FLASH FLOOD WATCH FOR THOSE AREAS FOR TONIGHT WHERE RAIN TOTALS WELL OVER 2 INCHES COULD OCCUR.


CONVECTION SHOULD BE WANING MONDAY MORNING AS UPPER SUPPORT LIFTS TO THE NORTHEAST. HOWEVER MAIN MID LEVEL FLOW PATTERN WILL BEGIN A TRANSITION TO A BROAD TROUGH FROM UPPER LOW IN SOUTHERN CANADA INTO THE PLAINS. TROUGH AXIS WILL BE APPROACHING THE HIGH PLAINS IN THE AFTERNOON... INDUCING SOUTHERLY FLOW AND MOISTURE RETURN IN THE PLAINS. FRONTAL BOUNDARY ALONG THE KANSAS BORDER INTO NORTHERN MISSOURI WILL LIKELY LIFT A BIT NORTH...WITH DECENT ISENTROPIC UPGLIDE OVER THE FRONT INTO MUCH OF EASTERN NEBRASKA AND SOUTHWEST IOWA. INSTABILITY AND SHEAR WILL AGAIN INCREASE MONDAY AFTERNOON WITH SOUPY PRECIPITABLE WATER VALUES REMAINING NEAR 2 INCHES. THUS ANOTHER ROUND OF HEAVY RAIN IS LIKELY ACROSS SOME OF THE SAME AREAS THAT WILL SEE HEAVY RAIN TONIGHT. ANOTHER FLOOD OR FLASH FLOOD WATCH WILL LIKELY BE NEEDED AT THAT TIME. THEN A GENERAL DECREASE IN ACTIVITY IS EXPECTED DURING THE AFTERNOON TUESDAY AS TROUGH AXIS BEGINS TO SHIFT THROUGH EASTERN NEBRASKA. COOLER TEMPS WILL FOLLOW AS HIGHS LIKELY REMAIN IN THE 70S IN OUR NORTH TUESDAY AFTERNOON.

WILL LIKELY SEE A DECREASE IN ACTIVITY SUNDAY MORNING AS LOW LEVEL JET SUBSIDES FOR A TIME. THEN BY LATER SUNDAY MORNING...COLD FRONT BEING DRIVEN EAST AND SOUTHEAST BY NORTHERN PLAINS TROUGH WILL ENTER NORTHEAST NEBRASKA. QUALITY OF ATMOSPHERE AHEAD OF THIS FRONT IS STILL IN QUESTION GIVEN POTENTIAL FOR MORNING CLOUDS/CONVECTION. 

HOWEVER MODEL FORECASTS ARE HONING IN ON A RIBBON OF SIGNIFICANT INSTABILITY ON THE ORDER OF 2000 J/KG OR GREATER JUST AHEAD OF WIND SHIFT SUNDAY AFTERNOON. 0-6KM BULK SHEAR OF 35KT IS FORECAST AS WELL...STARTING OUT NEARLY PERPENDICULAR TO LINE OF CONVECTION SUGGESTING SUPERCELL STORMS ARE POSSIBLE DURING EARLY STORM DEVELOPMENT PHASE. SHEAR VECTORS BECOME MORE PARALLEL TO FRONT/CONVECTION WITH TIME DURING THE EVENING...LEADING TO MORE LINEAR STORM STRUCTURES AND A POTENTIAL FOR TRAINING OF STORMS AS FRONT BEGINS TO STALL OUT IN SOUTHEAST NEBRASKA AND SOUTHWEST IOWA. 

SIGNIFICANT QPF IS NOTED FROM GFS IN 00Z-06Z MONDAY TIMEFRAME WHEN 2 TO 4 INCHES OF RAIN IS PAINTED ACROSS SOUTHWEST IOWA. FRONT IS EXPECTED TO ONLY SLOWLY DRIFT SOUTH LATER SUNDAY NIGHT INTO MONDAY MORNING...BASICALLY STALLING OUT NEAR THE KANSAS BORDER. 

SHOULD SEE GENERAL DECREASE IN STORMS TOWARD MONDAY MORNING WITH UPPER SUPPORT WANING AND LOW LEVEL JET DECREASING. HOWEVER WILL SEE AN INCREASE IN ACTIVITY THROUGH THE DAY WHEN MID LEVEL SHORTWAVE/JET ROTATE THROUGH BROAD TROUGH IN THE PLAINS...LEADING TO STRONG ISENTROPIC UPGLIDE OVER FRONT MONDAY AFTERNOON. 

IN FACT...GFS SHOWS MORE INSTABILITY MONDAY AFTERNOON THAN SUNDAY DESPITE NORTHERLY SURFACE WINDS. WE COULD AGAIN SEE SIGNIFICANT RAINFALL IN PARTS OF EASTERN NEBRASKA AND SOUTHWEST IOWA WITH TRAINING OF STORMS.

.LONG TERM...(MONDAY NIGHT THROUGH FRIDAY)
ISSUED AT 352 AM CDT SAT SEP 5 2015 

MUCH COOLER WEATHER IS FORECAST THROUGH THE BALANCE OF THE WEEK AS A BROAD TROUGH REMAINS OVER THE MIDDLE OF THE COUNTRY. A COUPLE OF SHORTWAVES MOVING THROUGH THE MAIN FLOW WILL BRING A CHANCE FOR SHOWERS AND THUNDERSTORMS TUESDAY AND THEN AGAIN THURSDAY. RELATIVELY STABLE BOUNDARY LEVEL AIR SUGGESTS SEVERE POTENTIAL IS LOW DURING THIS TIME. AND A STRONG COLD FRONT ACCOMPANYING THURSDAY WAVE WILL LEAD TO EVEN COOLER TEMPERATURES ON FRIDAY. LOOK FOR HIGHS CLOSE TO 80 TUESDAY AND WEDNESDAY BEFORE COOLING INTO THE 70S THURSDAY...AND PERHAPS 60S FOR FRIDAY.