FXUS63 KOAX 102021
AFDOAX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE OMAHA/VALLEY NE
321 PM CDT SUN APR 10 2011
.DISCUSSION...
MAIN FORECAST CONCERNS ARE IN REGARDS TO PRECIPITATION CHANCES FROM
TUESDAY NIGHT THROUGH FRIDAY NIGHT. PRECIPITATION TYPE IS ALSO AN
ISSUE FRIDAY/FRIDAY NIGHT.
COLD FRONT EXTENDED FROM LOW PRESSURE OVER WESTERN WISCONSIN AT 20Z
DOWN INTO KANSAS. COOLER AIR WILL MOVE INTO THE LOCAL AREA
OVERNIGHT. A FEW SHOWERS POSSIBLE BEFORE MIDNIGHT...MAINLY ACROSS
PARTS OF NORTHEAST NEBRASKA.
SHORTWAVE RIDGE AT 500 MB SHOULD BUILD ACROSS THE AREA MONDAY. A
FAIRLY TIGHT PRESSURE GRADIENT AT THE SURFACE SHOULD RESULT IN
BREEZY CONDITIONS MUCH OF THE DAY...BUT AN AREA OF HIGH PRESSURE
WILL BUILD IN BY EVENING. EXPECT HIGHS FROM 60 TO 65. AS THE HIGH
PRESSURE SYSTEM SHIFTS EAST...RETURN FLOW DEVELOPS. SOUTHERLY
WINDS WILL STRENGTHEN TUESDAY AND WARMER AIR WILL START TO MOVE IN
FROM THE SOUTHWEST. THIS SHOULD ALLOW HIGHS TO REACH THE LOWER
70S. BY EARLY TUESDAY EVENING A COLD FRONT WILL STRETCH FROM
NORTHERN MINNESOTA INTO SOUTHWEST NEBRASKA. SHOWERS APPEAR LIKELY
ALONG AND BEHIND THE FRONT WITH INCREASING MOISTURE AND DECENT
LARGE SCALE LIFT. THE FRONT SHOULD CONTINUE TO SAG SOUTHEAST
ACROSS THE AREA TUESDAY NIGHT AND WEDNESDAY. BOTH THE 12Z NAM AND
12Z GFS BRING THE FRONT INTO THE FAR SOUTHEAST CORNER OF NEBRASKA
BY 00Z THURSDAY. 850 MB DEWPOINTS INCREASE TO BETWEEN 4 AND 8
DEGREES CELSIUS ON WEDNESDAY WITH SOME ELEVATED INSTABILITY MOVING
INTO SOUTHEAST NEBRASKA AND SOUTHWEST IOWA...SO THUNDERSTORMS
APPEAR POSSIBLE. AT THIS TIME...POTENTIAL FOR ORGANIZED SEVERE
STORMS SEEMS LOW.
VERY STRONG MID TROPOSPHERIC FLOW ACROSS THE EASTERN PACIFIC AND
INTO THE WEST COAST OF THE UNITED STATES WEDNESDAY SPREADS EAST
THURSDAY...WHILE A NEGATIVELY TILTED TROUGH TAKES SHAPE FROM BRITISH
COLUMBIA INTO THE CENTRAL PLAINS. BOTH THE ECMWF AND GFS INDICATE
THAT A CLOSED LOW SHOULD DEVELOP SOMEWHERE IN THE NEBRASKA/IOWA/
KANSAS/MISSOURI REGION THURSDAY NIGHT THEN TRACK EASTWARD THROUGH
FRIDAY NIGHT.
DETAILS FOR LATER IN THE WEEK APPEARED TO BE BEST HANDLED BY A BLEND
OF THE 00Z ECMWF AND 12Z GFS. FORECAST SOUNDINGS...ESPECIALLY THOSE
FROM THE 12Z GFS...INDICATE THE COLUMN SHOULD BE COLD ENOUGH FOR
AT LEAST A RAIN/SNOW MIX. LEFT THE PRECIPITATION AS JUST RAIN FOR
NOW ON FRIDAY...BUT DID MENTION POTENTIAL FOR A MIX FRIDAY NIGHT.
AFWA ENSEMBLE PROBABILITIES SHOW 10-30 PERCENT CHANCE OF RECEIVING
OVER ONE INCH OF SNOW IN SIX HOURS BETWEEN 00Z FRIDAY AND 00Z
SATURDAY ACROSS THE NORTHERN PART OF OUR FORECAST AREA.
SYSTEM IS EXPECTED TO PUSH OFF TO THE EAST SATURDAY NIGHT AND
SUNDAY...WITH HIGH PRESSURE BUILDING OVER OUR AREA AT THE SURFACE.
THERE IS SOME POTENTIAL FOR RAIN AGAIN BY SUNDAY...BUT LEFT THINGS
DRY FOR NOW.
&&
.AVIATION...
TAF SITES KOFK/KOMA/KLNK
18Z TAFS
SURFACE COLD FRONT HAD PUSHED EAST OF ALL THREE TAF SITES AT 18Z
WITH BROAD AREA OF MVFR CIGS IN THE COOLER AIR BEHIND THE FRONT.
KLNK AND KOMA AT INTERFACE BETWEEN DRY LINE AND COLD FRONT WITH
QUASI-STATIONARY LEADING EDGE OF LOWER CLOUDS ALONG A KOMA KLNK LINE
WHERE SCT-BKN LAYER REPORTED. MVFR CIGS SHOULD EVENTUALLY BECOME
PREVALENT AT BOTH SITES AS THE COOLER AIR WORKS INTO THE AREA THIS
AFTERNOON. UPPER TROUGH PASSES EAST OF THE AREA BY MORNING AND WITH
DRIER AIR COMING IN AT THE SURFACE VFR CONDITIONS EXPECTED AFTER 12Z.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
DISCUSSION....MILLER
AVIATION...FOBERT