FXUS63 KOAX 222020
AFDOAX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE OMAHA/VALLEY NE
320 PM CDT FRI OCT 22 2010
.SHORT TERM...TONIGHT THROUGH MONDAY.
WEEKEND CONTINUES TO LOOK ACTIVE AS UPPER LOW MOVES NORTHEAST OUT OF
COLORADO...OPENS UP AND MOVES OVER ERN NEB BY LATER IN THE WEEKEND.
LLVL MOIST ADVECTION IS UNDERWAY ACROSS MUCH OF THE CWA WITH SFC
DEWPOINTS SLIDING FROM THE LOWER 40S THIS MORNING INTO THE LOWER TO
MID 50S BY EARLY THIS AFTERNOON ACROSS SOUTHEAST NEBRASKA. OBVIOUS
LOW CIRCULATION CAN BE SEEN SPIRALING ON LATEST SATELLITE IMAGERY
WITH CLOUD BLANKET CONTINUING TO MOVE NWD THRU THE CWA. AIDED BY
ISENTROPIC LIFT AND STRENGTHENING NOCTURNAL LLVL JET...SHOWERS AND
ISOLATED TSTMS SHOULD CONTINUE TO SPREAD NWD ACROSS THE CWA
THIS EVENING AND CONTINUE INTO THE OVERNIGHT HOURS.
PRECIPITATION SHOULD BECOME MORE SPOTTY DURING THE DAY SATURDAY AS
UPPER LOW APPROACHES AND SFC LOW BEGINS TO MOVE INTO ERN NEB. DRY
SLOT IS PROGGED TO PUNCH INTO SERN NEB WHICH SHOULD HELP WARM TEMPS
INTO THE MID TO UPPER 70S IN THE SOUTH WITH MAJOR BUST POTENTIAL
ACROSS ALL OF THE CWA DEPENDING ON CLOUD COVER AND SHOWER ACTIVITY.
AS DRY PUNCH SPREADS IN NEAR PEAK HEATING...SCATTERED STRONG
CONVECTION FROM ERN NEB INTO SWRN IA IS CERTAINLY
POSSIBLE...ESPECIALLY ACROSS SERN NEB AND SWRN IA WHERE MUCAPE IS
FORECAST NEAR 2500 J/KG. AS THE SFC LOW PUSHES INTO NERN
NEB...LLVL FLOW WL BECOME SLIGHTLY BACKED WHILE 0-6KM BULK SHEAR
VALUES WL BE IN THE 30 TO 40KT RANGE. AS MID LEVEL LAPSE RATES
INCREASE AHEAD OF UPPER LOW...STRONG STORMS CERTAINLY POSSIBLE SAT
AFTERNOON ACROSS MUCH OF SOUTHEAST NEBRASKA AND SOUTHWEST IOWA.
SYSTEM PULLS OUT LATE SAT/EARLY SUN MORNING BUT WL LEAVE A SMALL
CHANCE IN FOR THE NORTHEASTERN COUNTIES FOR ANY ACTIVITY THAT WRAPS
AROUND BACKSIDE OF THE SYSTEM.
MUCH OF SUNDAY INTO THE EARLY PART OF MONDAY LOOKS DRY WITH RETURN
FLOW AND WAA QUICKLY SETTING UP AHEAD OF NEXT STRONG UPPER TROF.
THIS TROF IS FORECAST TO MOVE EWD ACROSS THE DAKOTAS AND PUSH A
FAIRLY STRONG COLD FRONT INTO THE CWA LATE MONDAY. WL CONTINUE LOW
POPS FOR OUR NWRN COUNTIES IN THE AFTERNOON WITH MUCH OF THE PCPN
COMING MONDAY NIGHT INTO TUESDAY.
.LONG TERM...MONDAY NIGHT THROUGH FRIDAY.
AT THE START OF THE EXTENDED...A COLD FRONT WILL MOVE THRU THE FCST
AREA. THERE ARE TIMING DIFFERENCES BETWEEN THE MODELS...WITH THE
GFS FASTER THEN THE ECMWF/GEM. WILL TREND MORE WITH THE ECMWF TIMING
WITH PRECIP IN THE EVENING AND MOVING OUT AFT 06Z WITH MAINLY DRY WX
AFT 12Z. TUESDAY...THERE WILL BE CYCLONIC FLOW AROUND THE MID LEVEL
CLOSED LOW NORTH OF DULUTH. EVENTUALLY...COOLING AROUND THE LOW
MOVES SOUTH FM THE NRN PLAINS WED...WHILE THE CLOSED MID LEVEL LOW
REMAINS ANCHORED NORTH OF DULUTH. THE GFS IS MUCH STRONGER WITH THE
COOL AIR...WHILE THE ECWMF/GEM SHOW MORE OF A GLANCING
BLOW...MEANWHILE REMOP SHOWS DECREASING PREDICTABILITY DURING THIS
PD. TRENDED WITH BELOW NORMAL TEMPS WED AND THU...MODERATING FRIDAY
AS THE RIDGE BUILDS IN. INCLUDED LIKELY POPS MONDAY EVENING...WITH
PRECIP MOVING OUT AFT 06Z. TUE THRU FRI REMAINS MOSTLY DRY...HOWEVER
DEPENDING ON WRAP-AROUND RH...MAY SEE SOME LIGHT PRECIP IN THE
NORTHEAST WED NIGHT. PRECIP TYPE COULD BE RAIN OR SNOW DEPENDING ON
THE DEGREE OF COLD AIR.
&&
.AVIATION...
TAF SITES KOFK/KOMA/KLNK
18Z TAFS
PATTERN WILL BE MUCH MORE ACTIVE THAN IT HAS BEEN THE LAST FEW WEEKS
WITH POTENTIAL FOR MVFR AND IFR CONDITIONS MOVING IN TONIGHT. TSTMS
MAY OCCUR ALSO...BUT HANDLED WITH -SHRA AND CB CLOUD GROUPS FOR NOW.
UPPER LEVEL ENERGY WILL SPREAD INTO THE AREA FROM THE SOUTH AND
SOUTHWEST...AND LOW LEVEL MOISTURE WILL INCREASE AT THE SAME TIME.
MVFR CEILINGS SEEM POSSIBLE MAINLY AFTER 03Z...AND WE COULD SEE IFR
CONDITIONS AFTER 08Z. COULD HAVE SOME VSBYS BELOW A MILE...BUT DID
NOT GO THAT LOW WITH 18Z TAFS. WILL HAVE TO AMEND AS NEEDED.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
KERN/ZAPOTOCNY/MILLER