047 
FXUS63 KOAX 271813
AFDOAX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE OMAHA/VALLEY NE
113 PM CDT SAT APR 27 2013

.AVIATION...
18Z TAFS FOR KOMA...KLNK AND KOFK.

EXPECT CONTINUED EROSION OF STRATUS AND FOG AT KOMA AND
POINTS SOUTH THROUGH 21Z WITH VFR CONDITIONS AT ALL THREE SITES
FOR THE REMAINDER OF THE PERIOD. SOME MVFR VSBY POSSIBLE AT
KLNK AFTER 09Z AS WINDS BECOME LIGHT. 

&&

.PREV DISCUSSION... /ISSUED 545 AM CDT SAT APR 27 2013/

UPDATE...
UPDATED TO EXPAND AREAL COVERAGE OF DENSE FOG ADVISORY.

DISCUSSION...
DENSE FOG WAS EXPANDING NORTH TOWARD NORFOLK...HARLAN AND NORTH OF
ALBION AS OF 1040Z AND ADVISORY WAS EXPANDED TO INCLUDE THOSE
LOCATIONS. PATCHY FOG AND INCREASED MORNING SKY GRIDS WERE ALSO
INCLUDED A LITTLE FARTHER NORTH THIS MORNING AS WELL. NO OTHER
CHANGES.

CHERMOK

PREV DISCUSSION... /ISSUED 318 AM CDT SAT APR 27 2013/ 

DISCUSSION...

ALTHOUGH TEMPERATURES ARE THE PRIMARY FOCUS IN SHORTER TERM...FOG
ISSUES IN THE VERY SHORT TERM AND SMALL PRECIP CHANCES WITH
GLANCING/WEAKENING FRONT SUNDAY NIGHT INTO TUESDAY ARE ALSO
ISSUES. AFTER THAT WEATHER PROBABLY RETURNS TO WHAT MUCH OF THIS
SPRING HAS BEEN THUS FAR...COLD AND WET.

TODAY INTO SUNDAY.  WIND SHIFT WHICH PUSHED INTO NRN ZONES FRIDAY
AND DRIED OUT SURFACE DWPTS WAS BEING REPLACED BY LOW LEVEL
MOISTURE RETURN ON WEAK SE FLOW. THIS WAS CAUSING AREAS OF FOG TO
DEVELOP SINCE MIDNIGHT...IN SOME CASES DENSE. AS OF 08Z DENSEST
WAS RESERVED TO NW FRINGE OF STRATUS JUST TO OUR W...BUT THIS
COULD EXPAND NE THROUGH COLUMBUS...TEKAMAH AND WCNTRL IA ACCORDING
TO LATEST RAP/HRRR. WILL ISSUE A DENSE FOG ADVISORY TO ACCOUNT FOR
THE EXPECTED AREA OF WIDESPREAD DENSEST FOG...WHICH MAY NEED SOME
FINE TUNING AS CONDITIONS BECOME MORE APPARENT THROUGH SUNRISE.
OTHERWISE...LOW CLOUDS COULD BE SOMEWHAT SLOW TO DEPART SERN ZONES
WHICH WILL LIMIT WARMUP TODAY...AND BORDER CENTRAL COUNTIES MAY
ALSO FEEL SOME OF THESE EFFECTS AS WELL. NW ZONES APPEAR TO
ESCAPE BULK OF EFFECTS..SPCLY BY AFTN...AND BOOSTED SOME HIGHS TO
UPPER 70S. SUNDAY APPEARS WARMER MOST AREAS...ESPECIALLY IN H85
THERMAL RIDGE/COMPRESSIONAL HEATING AREA AHEAD OF WIND SHIFT/WEAK
FRONT WHERE SOME READINGS COULD MAKE A RUN TOWARD MID 80S.
FORECAST SOUNDINGS NOT TOO FAVORABLE FOR CONVECTION SUNDAY SO LEFT
THAT PERIOD DRY FOR NOW.

SUNDAY NIGHT INTO TUESDAY...SOME MODEST POPS STILL APPEAR
WARRANTED SUNDAY NIGHT...SPCLY NERN ZONES...AS WEAK MID LVL
SHORTWV TROUGH/COOLING POSSIBLY GENERATES A SMALL POST-FRONTAL
AREA OF SHOWERS/TSTMS. FRONT WASHES MONDAY OUT AS STRONGER UPPER
TROUGH APPROACHES AND CONVECTIVE TRENDS BECOME MORE UNCERTAIN
MONDAY/MONDAY NIGHT. FELT SOME ACTIVITY COULD LINGER MONDAY
MORNING BUT DEVELOPMENT APPEARED UNLIKELY ENOUGH IN THE AFTERNOON
TO DROP POPS. LEFT THEM IN SERN ZONES MONDAY NIGHT AS INCREASING
LOW LEVEL JET COULD ACT ON FRONTAL REMNANTS AND ON TUESDAY IN CASE
NEXT COLD FRONT ARRIVES TOWARD MAX HEATING. APPEARS H85 COOLING
BEHIND WEAKENING FRONT MONDAY WILL BE MINIMAL...BUT RESIDUAL
CLOUDS ARE A WILD CARD. DECIDED TO MAKE LITTLE/NO CHANGES TO
PREVIOUS FORECAST WARM TEMPS WHICH WERE SUPPORTED BY 00Z MEX. ALSO
NO CHANGES TO A PREV FORECAST/MODEL BLEND FOR TUESDAY DUE TO
FRONTAL TIMING QUESTIONS...BUT COULD SEE NEED FOR INCREASING INTO
80S ANYWHERE AHEAD OF FRONT.

FOR THE PERIOD WEDNESDAY THROUGH FRIDAY. CONDITIONS LOOK TO
REVERT TO THE WEATHER MUCH OF THE AREA HAS EXPERIENCED THUS FAR
THIS SPRING...COLD AND WET. 00Z ECMWF IS ESPECIALLY DISHEARTENING
TO SUNSHINE/WARMTH LOVERS AS NEARLY CONTINUAL RAIN FORECAST FOR
PARTS OF THE AREA WITH MUCH BELOW NORMAL TEMPERATURES. BOOSTED
POPS UP INTO LIKELY CATEGORY MUCH OF THE SE 1/2 ON WED BASED ON
00Z GFS/ECMWF AND LOWERED A FEW MAX TEMPS THURSDAY BECAUSE OF
ECMWF. GFS NOT QUITE AS WET/COOL...BUT STILL REPRESENTS QUITE A
CHANGE FROM THE WEATHER THAT WILL BE EXPERIENCED NEXT FEW DAYS.
IF GFS COMES AROUND TOWARD ECMWF POPS WILL NEED RAISING THU AND
FRIDAY AND TEMPS LOWERED.

CHERMOK

&&

.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&

$$

FOBERT