000
FXUS63 KFGF 101928
AFDFGF
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND FORKS ND
228 PM CDT FRI OCT 10 2008
.SHORT TERM...
INTENSE BAND OF RAIN FROM SE ND THRU NRN MN ASSOC WITH STRONG
ISENTROPIC LIFT AT 300-295K AND STRONG 850 MB WARM/MOIST ADVECTION
WILL GRADUALLY SHIFT EAST OUT OF SE ND LATE THIS AFT/EARLY EVE AND
OUT OF WCNTRL MN (DTL-BJI-PKD) BY 06Z. FOR THE
OVERNIGHT...ISENTROPIC LIFT IN THE 750-850 MB LAYER GREATLY
DECREASES AND THUS THREAT FOR PCPN IS QUITE A BIT LESS OVER THE
FCST AREA INTO EARLY SATURDAY.
THE NEXT SURGE IN 850 MB WARM ADV/ISENTROPIC LIFT WILL ARRIVE LATE
MORNING AND AFTN ON SATURDAY WITH THE FOCUS JUST A BIT FARTHER
NORTH THAN ON FRIDAY...WITH THE MODELS INDICATE THE MAIN AXIS OF
PCPN 0.50 TO 1 INCH SAT AFTN/EVE NR A JMS-MAYVILLE-TVF-BDE LINE
NORTH OF A NORTHWARD MOVING 850 MB WARM FRONT WHICH BY SATURDAY
EVENING WILL BE VERY NEAR OUT SOUTHEASTERN FCST AREA.
SATURDAY NIGHT INTO SUNDAY WILL SEE STRONG 500 MB LOW MOVE INTO
ERN MT WITH SFC LOW MOVING NORTH NORTHEAST FROM KS/NEBRASKA INTO
SCNTRL ND BY 18Z SUN. PREFERENCE HERE IS FOR THE FARTHER WEST SFC
LOW WITH TRACK NR A BIS-DVL LINE ON SUNDAY VERSUS NAM WHICH IS
MORE ABR-GFK LINE. NAM REMAINS A BIT SLOWER (ABOUT 6 HRS) THAN
GFS. ATTM GFS REMAINS A BIT PREFERRED...BUT NOTE THAT THE 12Z GFS
IS A BIT SLOWER THAN ITS PREV RUNS. NET RESULT IS MAX ISENTROPIC
LIFT NORTH OF 850 MB WARM FROM FROM CNTRL INTO NE ND/FAR NW MN
LATE SATURDAY NIGHT INTO SUNDAY MIDDAY WITH 1-2 INCH RAINS VERY PSBL.
FOR SE ND/WCNTRL MN AREA GETS INTO MORE A WARM SECTOR (AT LEAST AT
850 MB) AND THUS COVERAGE OF RAIN LESS. WITH FOCUS OF NEXT HEAVY
RAIN EVENT SAT NIGHT-SUN NORTH OF FRIDAYS HVY RAIN WILL NOT ISSUE
ANY FLOOD WATCHES. RAINFALL RATES SO FAR EVEN IN TODAYS RAIN SLOW
ENOUGH TO CAUSE MINIMAL TROUBLES IN TERMS OF FLASH
FLOODING....MORE OF A STANDING WATER IN DITCHES/FIELDS
SCENERIO/WET BASEMENTS SCENERIO.
ENTIRE SYSTEM SHIFTS NORTH SUN NIGHT INTO MONDAY WITH COLDER AIR
COMING IN. SOME WRAPAROUND SHOWERS PSBL. KEPT MOSTLY LIQUID EXCEPT
IN DVL BASIN CLOSER TO 850 COLD POOL.
.LONG TERM... /TUE THROUGH FRI/
AFTER AN UPPER LOW PULLS OUT NEAR THE END OF THE SHORT TERM...MUCH
COLDER AIR WILL MOVE IN MONDAY. MODELS ARE IN SOME DISAGREEMENT
BEYOND SUNDAY....WITH CONSENSUS ECMWF SHOWING A DRY AND SEASONABLY
COOL PERIOD FOR TUE-THU...WITH MAINLY ZONAL FLOW ALOFT. GFS DOES
SHOW SOME PRECIP ACROSS THE SOUTH...BUT AGAIN WILL GO WITH CONSENSUS
ECMWF IN THE LONG TERM.
&&
.AVIATION FAR AND BJI SHOULD SEE RAIN FOR REMAINDER OF
AFTERNOON...WITH CIGS TAKING DIPS INTO THE MVFR RANGE THROUGHOUT
THE DAY. RAIN WILL SPREAD NORTHWARD TO GFK...TVF...AND DVL BY
EVENING. COULD SEE A BREAK IN RAINFALL EARLY TOMORROW MORNING
BEFORE A SECOND WAVE BRINGS PRECIP BACK INTO THE TAF AREAS BY NOON
SATURDAY. EXPECT BJI TO DROP TO NEAR IFR CONDS BY EARLY AM
&&
.HYDRO...
RIVER FLOODING MAY WELL GET GOING IN THE SOUTHERN BASIN NEXT FEW
DAYS AS WATER RUNOFF INTO THE STREAMS. SOILS IN SRN VALLEY AND DVL
BASIN ARE SATURATED. RAINFALL RATES APPEAR NOT ENOUGH TO CAUSE
REAL FLASH FLOODING...BUT SOILS SUCH TO KEEP WATER FROM SEEPING IN
FAST.
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
RIDDLE/SPEICHER
