FXUS63 KOAX 100955
AFDOAX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE OMAHA/VALLEY NE
355 AM CST THU MAR 10 2011
.DISCUSSION...
...MAIN FORECAST PROBLEM IS TEMPERATURES...
09Z SURFACE ANALYSIS HAD CENTER OF HIGH PRESSURE OVER ORD NEBRASKA
WITH SURFACE RIDGE AXIS FROM TEXAS PANHANDLE THROUGH NORTHEAST
NEBRASKA AND INTO NORTHEAST SOUTH DAKOTA. THE SURFACE RIDGE AXIS
WAS A GOOD APPROXIMATION OF WHERE FOG AND STRATUS WAS DEVELOPING
EARLY THIS MORNING...ALSO IN LINE WITH AREA OF SNOW COVER. IN
ADDITION...PERSISTENT STRATUS DECK CONTINUED TO BE ANCHORED JUST
EAST OF THE MISSOURI RIVER AT 0915Z.
CONSIDERING THE NAM FORECAST SOUNDING FOR NELIGH...THIS DEVELOPING
AREA OF FOG AND STRATUS OVER NORTHEAST AND NORTH CENTRAL NEBRASKA
WILL LIKELY CONTINUE TO SPREAD THROUGHOUT THE EARLY MORNING
HOURS...AT LEAST WHERE SNOW COVER REMAINS. THE VERTICAL CHANGE IN
SPECIFIC HUMIDITY WITH HEIGHT FAVORS FOG...AS DOES THE COLD GROUND
TEMPERATURES IN THAT AREA...AROUND 10F...ESPECIALLY GIVEN THAT
SURFACE DEWPOINT TEMPERATURES WERE IN THE LOWER 20S YESTERDAY AT
23Z. WILL THEREFORE PLAN ON THIS FOG CONTINUING TO SPREAD AND WILL
NEED TO MENTION IN MORNING FORECAST. THIS MAY ALSO HAVE A
SIGNIFICANT IMPACT ON HIGHS TODAY.
THE GENERAL UPPER PATTERN CONSISTS OF A BROAD RIDGE OVER THE WESTERN
HALF OF THE US WITH WIDESPREAD HEIGHT RISES OVER THE PLAINS. THE
RIDGE AXIS IS PROGGED BY MOST MODELS TO DRIFT OVER THE FORECAST AREA
AROUND 06Z TONIGHT...WITH A MUCH MILDER AIRMASS MOVING IN. MODELS
WERE IN GOOD AGREEMENT WITH 850 MB TEMPERATURES...AND RESULTING
HIGHS FOR TODAY AND FRIDAY SEVERAL DEGREES WARMER THAN THE PAST FEW
DAYS. HOWEVER THE ABOVE MENTIONED FOG AND SNOW COVER WILL
POTENTIALLY KEEP HIGHS DOWN MAINLY TO THE NORTH AND WEST OF NORFOLK
TODAY.
BEYOND FRIDAY...FAST MOVING SHORTWAVE MOVES THROUGH THE ROCKIES
FRIDAY AND CUTS OFF TO A CLOSED LOW OVER SOUTH DAKOTA FRIDAY NIGHT.
ALTHOUGH THIS SYSTEM WILL HAVE LITTLE MOISTURE TO WORK WITH...THE
STRENGTH OF THE FRONT MAY BE ENOUGH TO SQUEEZE OUT A FEW LIGHT
SHOWERS. KEPT THE SLIGHT CHANCE POPS IN THE NORTHERN COUNTIES FOR
FRIDAY AFTERNOON INTO FRIDAY EVENING. STILL LOOKS TO BE QUITE
WINDY BEHIND THE FRONT AS WELL...WITH THE NAM AND GFS SHOWING 60
KNOTS AT 850 MB AT 06Z SATURDAY.
NEXT WAVE FOR SUNDAY IS STILL ON TRACK...SO MADE FEW CHANGES TO THE
DAYS 4-7FORECAST.
&&
.AVIATION...
TAF SITES KOFK/KOMA/KLNK
06Z TAFS
A BAND OF LOW CLOUDS BASICALLY ALONG AND EAST OF MISSOURI RIVER WILL
THREATEN OR OCCASIONALLY PREVAIL AT KOMA TAF SITE THIS
MORNING...GENERALLY EARLY...BUT SHOULD ERODE OR SHIFT FARTHER EAST
AS LOW LVL WINDS BACK AROUND TO MORE WRLY. CIGS HAVE GENERALLY BEEN
MVFR WITHIN THIS BAND AT KOMA...BUT WERE LOWER JUST TO THE N AND
NE. IN ADDITION...FOG WAS DEVELOPING WEST OF STRATUS DECK AT KONL
AND KODX. ALTHOUGH NOT INCLUDED WITH 06Z TAFS...LIFR VSBYS/CIGS
COULD EXPAND INTO KOFK VCNTY AND CONDITIONS WILL BE MONITORED.
OTHERWISE...VFR CONDITIONS ARE EXPECTED LATER THIS MORNING AS
SURFACE HIGH PRESSURE BUILDS EWD ACROSS MISSOURI RIVER TDA.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
NIETFELD/CHERMOK